What is a YIG Filter?

Transcription

1 YIG Filter Products

2 YIG Filters Introduction Yttrium Iron Garnet (YIG) filters have been used in military systems and commercial test equipment for over 30 years. The extremely high unloaded Qu of the YIG sphere (approximately,000) makes it an ideal choice as the frequency-determining element for these electronically tunable filters. Their excellent linearity, low insertion loss, and broadband tuning characteristics are ideal for applications in the GHz frequency range. Bandpass filter applications include preselectors for radar warning and ELINT (Electronic Intelligence) receivers in the EW (Electronic Warfare) arena and spectrum analyzers in the microwave and commercial test equipment industry. Band-reject filter applications include notching out a particular signal for ESM and ECM systems, and rejecting signals in commercial test equipment measurement set-ups. YIG is a ferrite material that resonates at a precise frequency when placed in a magnetic field. The frequency of resonance is directly proportional to the strength of the applied magnetic field. The high reliability of YIG devices is excellent for military applications. Their low loss, wideband tuning, and excellent linearity characteristics make them ideal for commercial test equipment applications such as sweepers, synthesizers and spectrum analyzers. YIG Filters with low loss, wideband tuning, and excellent linearity characteristics make them ideal for commercial test equipment applications What is a YIG Filter? A YIG Filter is an electronically tuned filter whose center frequency can be varied by changing the magnetic bias applied to a resonator. Often, filter resonators are realized using YIG material, although YIG doped with other substances such as Gallium or crystals of Lithium-Ferrite or Nickel-Zinc are also widely used to satisfy various requirements. Equipped with integrated drivers (voltage-to-current or digital word-to-current converters), these filters combine many sophisticated technologies, including crystal physics, magnetics, and analog and digital design.

3 Providing Customer Solutions Using the highest level of technology and manufacturing expertise is not enough. We support our customers from preliminary design through installation. Teledyne Microwave provides solutions to customer requirements in three key areas: Technical Support Technical Notes with detailed discussions of various aspects of YIG filter perfor- mance, including tuning errors, driver stability, and tuning speed. Discussion prior to proposal ensures that we offer a solution that will work in the system and is producible at the rates required. Our engineering personnel are available to answer customer questions as they arise. Technical Proposals detail our solution so that all system options are clear. Customer Service Feedback on delivery and technical progress during the design and manufacturing periods after order placement. Stringent Quality Assurance All Teledyne components and subsystems are designed, built and screened with the highest quality standards available in the industry. Teledyne Microwave is certified to ISO-9001 & ISO Technology Features In addition to the three key areas mentioned above, Teledyne Products believes our level of technology distinguishes us from other YIG vendors. Some of the key technology features of Teledyne s YIG filter products include: Proprietary Coupling Loop Technology Both band-reject and bandpass filters are designed using Teledyne s proprietary coupling loop technology. This CAD technique entails extensive modeling and characterization of the filter circuit at the onset of the design phase. Using modified filter modeling software, coupling coefficients are generated that precisely define coupling loop properties and relationships in the filter itself. These coefficients are set by Teledyne Products technicians who align the filters using vector network analyzers to make minute adjustments to match the computer designed coupling bandwidths. The net result is a final set of coupling coefficients that precisely match the characteristics of the filter to the customers requirements. As figure 1 shows, the coupling in a bandpass filter varies with tuned frequency, even if the structures and resonators are perfectly realized. The external bandwidth is continuously varying with frequency. Coupling bandwidth changes with frequency cause filter bandwidth growth and poor VSWR as the tuned frequency increases. This results in degraded rejection at key frequencies, such as the LO and image frequencies of a superheterodyne receiver, and increased mismatch loss and ripple in the filter passband. Teledyne proprietary loop technology reduces coupling bandwidth changes thus minimizing bandwidth growth, and optimizing input match. This means better control of spurious responses, improved sensitivity, flatter group delay, and enhanced control of noise bandwidth in receiver applications. Among the benefits of using this technology in designing YIG filters: The RF behavior of the filter can be precisely controlled via its coupling loop characteristics. In particular, bandwidth growth, input and output VSWR, and bandwidth can be precisely set to meet system requirements. Spurious responses are controlled and minimized using these techniques. Filter performance, from unit to unit, is replicated on a consistent basis. Large quantities of filters can be produced to support customer production requirements since Teledyne s technology lends itself to efficient manufacturing and results in YIG filters that are inherently manufacturable. This is in contrast to the empirical method that the majority of YIG manufacturers use today, in which a filter is simply built up and tweaked until the desired performance is achieved. Wide Instantaneous Bandwidths Variations in group delay in the frontend of modern communications systems, with their complex modulations and dense channel spacing, cause degradation measured as increased bit error rates and higher noise power ratios. The complexity of the modulation alone requires even wider instantaneous bandwidths. Teledyne s improved designs reduce mismatch effects and reduce delay distortion due to crossing modes in the resonators, and offer the widest bandwidths available for communications applications. In addition, Teledyne s 6-stage, or more, produc-

4 Technology Features Interstage Coupling Coefficients K12, K23, K34 Input / Output Coupling Coefficients BWe K23 Standard Coupling Techniques New Teledyne Coupling Techniques Input K23 K23 Output F Low Frequency F High BWe BWe Figure 1. Teledyne loop technology reduces coupling coefficient variations tion filters hold the line on selectivity without forcing a change in architecture to higher intermediate frequencies or to new conversion schemes. Wide bandwidth filter specifications may be found on pages 122. Balanced Magnet Structure Tuning a ferrimagnetic resonator over a large frequency range in the microwave region requires high magnetic fields. Over 6,400 Gauss are required to bias a YIG sphere to 18 GHz. This field must be uniform in the region of the sphere. In the absence of magnet saturation, a linear current in the coils of the electromagnet produces a linear field in the magnet gap. However, as Figure 2 shows, leakage flux (flux that does not bias the sphere) will cause tuning non-linearity. This leakage flux is considerably more pronounced with single ended magnets than with the Teledyne balanced structure. Teledyne s balanced magnet need not be increased in size to compensate for the leakage flux. Thus, for the same magnet volume, Ferretec can offer more linear tuning than devices employing single-ended magnets. Temperature Compensated Magnet By compensating the magnetic field zero frequency drift is possible. Ferrimagnetic spherical resonators, properly positioned in the magnetic field, are extremely well behaved over a wide temperature range. Positioned on a particular axis, and temperature controlled by small heater elements, most materials experience almost no drift. Stabilizing the magnetic structure, however, represents a much greater challenge. Gap changes as small as 3 millionths of an inch (.076 microns) at 18 GHz cause a 1 MHz shift in filter frequency. Uncompensated, a filter in a nickeliron electromagnet will drift +11 MHz as the temperature is varied from -55 to +85 C, the MIL-E- 5400, Class 11 temperature range. Ferretec magnets are temperaturecompensated using uniquely shaped rings of a different metal both to compensate for the air gap changes in the magnet and to track the several resonators across the tuning range. Moisture-sealed magnet structures for MIL environments without using paint or epoxy. Since Teledyne filters contain no exposed active semi-conductors, they are basically passive components which need not be hermetically sealed. However, for most defense electronics applications, it is obviously necessary to prevent moisture, dust, and salt atmosphere from entering the magnet and eventually causing corrosion which would lead to premature failure. Many manufacturers have resorted to epoxy and/or RTV potting and epoxy paints UNBALANCED BALANCED Figure 2. Reduced leakage flux in balanced magnets improve leakage

5 Technology Features to accomplish this sealing. However, these methods do not stand up under the constant temperature cycling and vibration experienced over an extended period of time. Teledyne magnets are sealed without paint or epoxy. As Figure 3 shows, fluorosilicon O-rings are used to seal the unique three-piece magnet. These devices are guaranteed to maintain the seal for the lifetime of the filter. This gives the reliability engineer the confidence that a unit will not only pass the qualification O-Ring Seals Connector Assembly O-Ring Seals Magnet Cup to within.01% at a level of 900 ma. A driver, or voltage-to-current converter, must therefore have the capability to translate a specific voltage input to the required current, with high accuracy, over the life of the system. Changes in the values of resistors, integrated circuits, and potentiometers over time degrade filter tuning accuracy. Teledyne has analyzed these aging effects in YIG filter drivers and has developed a highly stable circuit which minimizes aging. This requires the use of high-quality devices such as stable IC voltage references and low-drift operational amplifiers. In addition, this necessitates the use O-Ring Seals YIG Access Hole Figure 3. Teledyne Magnet structure is moisture sealed with lifetime guarantee O-rings Ultra-stable driver Stabilized driver circuits with the best available components for enhanced tuning accuracy over the life of the unit. Given that typical filter bandwidths are often less than 0.1% suggests that setting them properly on frequency requires superior control of the magnet coil current. For example, if the tuning sensitivity of the magnet is 20 MHz/mA, setting the frequency to within 2 MHz at 18 GHz requires that the current be accurately set of a minimum adjustment range on the slope and offset potentiometers, and, in some cases, no potentiometers at all. For MIL applications, all parts are selected from established reliability components or screened to equivalent requirements. More information on tuning errors in YIG filters is available in a comprehensive technical note (see page 38). Driver specifications can be found on page 24. Closed-Loop YIG Filters Closed-loop filters contain a patented locking circuit insuring unmatched tuning accuracy and repeatability in the harshest environments. Regardless of the care taken in the design and manufacture of YIG filters, they are subject to tuning errors that cannot be predicted or controlled with open-loop correction schemes. Closed-loop filters receive a sample of RF power and use it to sense tuning errors, locking the filter to the RF sample. For example, a closed-loop preselector can be locked to a receiver local oscillator and offset by the IF frequency, insuring tracking under all conditions. A closed-loop filter can track a sweep oscillator or synthesizer to remove unwanted spurious and harmonic signals. A notch can be accurately positioned on an interfering signal to prevent it from blocking an EW receiver. For more information on closed-loop filters, see pages Filter Capabilities Tuning Range YIG devices offer tremendous flexibility in the choice of tuning range. Since the coupling coefficients in these inductivelycoupled filters vary with frequency, the factors limiting tuning range are based on trade-offs involving input match, bandwidth growth, spurious responses, insertion loss, etc. Bandpass filters can be made to tune ranges as broad as 20:1 with few compromises in performance and even larger ratios with trade-offs depending on actual frequency. Band-reject filters have a more narrow notch tuning range due to the inherent property of transmission line-type characteristics from only a few hundred MHz to over a 5:1 range. The passbands of these filters, however, can be made much broader, covering ranges similar to that of bandpass filters.

6 Filter Capabilities MAX - ULTRA - WIDE BANDWIDTH 3dB BANDWIDTH (MHz) MAX - OCTAVE TUNING MAX - MULTI +/- OCTAVE TUNING MIN FREQUENCY - AT LOW END OF TUNING RANGE (GHz) Figure 4. Range of 3dB bandwidths available in Teledyne bandpass YIG Filters Instantaneous Bandwidth Figure 4 shows the wide range of bandwidths Ferretec provides in bandpass filters. Both minimum and maximum achievable bandwidths are shown as a function of the minimum operating frequency of the filter. Changes in the coupling coefficients occur with frequency, and result in the growth of the bandwidth near the high end of the tuning range. Ferretec s precisely designed structures and proprietary loop configurations minimize this growth while maintaining the best possible VSWR.

7 Filter Capabilities Selectivity Filter selectivity depends on the number of YIG resonators (stages) in the filter and Ratio of Bandwidth to 3dB Bandwidth STAGE is nominally 6 db per stage per octave bandwidth. Thus, for a four-stage filter, the rejection increases by 24 db each time the band-width doubles (see Figure 5). The number of stages that can be built in a single filter is limited by the space under the magnet pole tips and the need to position the spheres for optimum coupling. Making the pole tips larger increases tuning coil inductance and slows magnet tuning speed. Bandpass filters are usually 2 to 7 stages and band-reject filters can be as many as 16 stages. The ultimate isolation of a particular filter also depends on the number of stages. Spurious Responses Spurious responses originate from magnetostatic modes wherein the precession of the electron spins in the ferrimagnetic material varies across the sphere, instead of being uniform as desired. These result in secondary resonances which may or may not be fixed in position with respect to the main resonance. They will appear either as ripples in the passband, or as isolated bumps in the off-resonance 4-STAGE region of the filter. Spurious responses which hold their relative position with respect to the desired filter response are termed tracking modes Those which tune at a different rate than the desired response, and therefore, at some frequencies cross through the filter response, are termed crossing modes Part of the art of the YIG filter construction consists of limiting the size of these spurious responses, and in controlling their position so as to keep them from appearing, for example, in bandpass preselectors just where local oscillator or image rejection is desired. The tracking spurious response most often seen in band-pass filters is known as the 2 mode. It is greatly suppressed by Teledyne s proprietary coupling loop technology but, in most cases, is somewhat less than the full off-resonance rejection of the filter. The location of this mode with respect to the passband depends mainly on the saturation magnetization of the ferrimagnetic resonator. For pure YIG (used in filters operating over 4 GHz), the 2 mode is 600 to 700 MHz below the filter response. For example, Gallium-doped YIG, used in filters with start frequencies of 2 GHz, have a 2 mode approximately 3 to 335 MHz below the filter response. In addition to the 2 mode, band-reject filters also demonstrate the 540 and 220 modes. These are tracking spurious modes which cause narrow notches in the filter passband, typically 4 db deep. These are located above the main filter notch response by 75 to 350 MHz, depending on the ferrimagnetic material used for the resonators. 6-STAGE 7-STAGE Attenuation (db) Figure 5. Filter Selectivity Screening Levels The following defines the component quality, inspection, and screening levels available with Teledyne filters or filters with drivers. Teledyne Microwave s quality system is registered to ISO-9001:2004. Commercial ( C ) 1. Temperature cycling of filters from -55 C to +95 C, non-operating, five cycles. 2. 0% Electrical Test at + C: Tuning Range, Linearity, Bandwidth, Insertion Loss, Spurious & Ripple, VSWR, ORI & ORS RF, Limiting Hysteresis, Tuning Sensitivity, Heater Current, Bias Current (for Filter with Driver) 3. 0% External Visual Inspection 4. Operating temperature: 0 C to +60 C Military ( M ) 1. Temperature cycling of filters from -55 C to +95 C, non-operating, five cycles per MIL-STD-202, Method 7D, condition A, except high temp. shall be +95 C. 2. 0% Electrical Test at + C: Tuning Range, Linearity, Bandwidth, Insertion Loss, Spurious & Ripple, VSWR, ORI & ORS RF, Limiting Hysteresis, Tuning Sensitivity, Heater Current, Bias Current (for Filter with Driver) 3. 0% External Visual Inspection 4. Operating temperature: -54 C to +85 C 5. Filters are O-ring sealed 6. Printed circuit board assemblies are conformally coated to MIL-I C.

8 Closed-Loop Bandpass Filters to the RF reference, and a frequency tuning repeatability of ±0.5 MHz. Teledyne s closed-loop YIG filter technology has the advantages of precise frequency tuning, exact frequency repeatability and is self-contained, requiring no external system correction hardware or software. The closed-loop filter corrects all YIG filter tuning errors, regardless of their origin, and does so in a self-contained package requiring only a coarse tuning signal and an RF reference. Introduction YIG filters have many inherent advantages such as wideband tuning, excellent linearity and low insertion loss. However, they also have static and dynamic tuning errors that can adversely affect their microwave system and measurement performance. These errors include hysteresis, non-linearity, frequency drift over temperature, and aging of the components in the YIG driver circuitry. Regardless of the specific source, these tuning errors all produce the same net result: A decrease in the filters tuning accuracy and frequency repeatability. While YIG filters have extremely good frequency linearity characteristics (less than ±20 MHz non-linearity over a 2 to 26.5 GHz tuning range, typically), when adding up other tuning errors such as hysteresis ( to 20 MHz) and temperature drift ( to 20 MHz), the total frequency error can become significant. For certain applications these tuning errors can be tolerated. In others, the tuning errors are corrected via software algorithms or computer-controlled correction schemes. However, the system complexity and increased processor demands of these additional correction schemes can make them a less desirable solution. In contrast, the closed-loop filter corrects all YIG filter tuning errors, regardless of their origin, and does so in a self-contained package requiring only a coarse tuning signal and an RF reference. The closed-loop filter effectively consists of a YIG-tuned filter, a frequency discriminator and a driver circuit to tune the filter s center frequency. The output of the discriminator is an error signal that is fed back to the tuning coil driver, to provide the required correction of the filter s center frequency. The net result is a YIGtuned filter with a guaranteed frequency accuracy on the order of ±1 MHz relative Closed-Loop Filter Product Line For the past 20 years, Ferretec has provided a closed-loop solution in the form of the analog-tuned Ferretrac filter. This unit has found wide-spread usage in both commercial and military systems, as part of a closed-loop subsystem, or on a standalone basis. On a single military program alone, over 1800 Ferretrac filters were delivered and installed in the ALQ-172 ECM system. Recently, Teledyne completed a technology advancement program which resulted in the development of a digital closedloop filter product line. This unit enjoys the enhanced performance of closed-loop technology in a smaller, lighter package that is digitally tuned. Together, the Ferretrac and the digital closed-loop filter are the key components of Teledyne s closed-loop product line.

9 Closed-Loop Bandpass Filters Filter Technology Eliminates System Compromise When considering open-loop YIG tuned filters, the designer must often compromise system performance due to tradeoffs in filter performance. Tuning errors inherent in the YIG device often require that the filter bandwidth be increased in an attempt to keep a minimum acceptable bandwidth on frequency, under all conditions. This necessitates compromises in system performance parameters, such as selectivity, image rejection, and passband ripple. Aging of the components may also require the end user to employ frequent and expensive field alignments, or to develop special calibration algorithms to maintain these filters on frequency. Teledyne s closed-loop filters contain a unique reference loop circuit that allows a tunable filter to be locked to an RF reference signal (i.e., a tracking filter) or offset from the reference signal (i.e., an offset filter). All tuning errors are corrected by the loop gain. As a result, the designer can concentrate on specifying the optimum RF performance required for his design. System Solutions Closed-loop filters offer the system designer a complete solution to the electronically-tunable filter requirement. The microwave filter, driver circuit (voltage-to-current converter) for main filter tuning, and the closed-loop circuits are all contained in one compact assembly. A closed-loop filter needs only to be installed and supplied with an RF reference signal and a tuning signal in order to immediately work to specification. No need to tweak drivers, program PROMs, or make readjustments in the field due to component aging. Teledyne manufactures companion test equipment products utilizing closed-loop YIG filter technology. The C01 Controller provides all operating controls and power supplies for the closed-loop Ferretrac filter. Closed-loop filters are always on frequency. No specifications are necessary for hysteresis, tuning non-linearity, temperature drift, or post-tuning drift. They also lock onto the reference signal in a fraction of the time it takes open-loop filters to settle into the desired band-width. A lock indicator signal provides ongoing feedback that the filter is locked to the reference signal. Teledyne has designed and specified closed-loop filters to address system and component requirements. The RF specifications use classical filter parameters such as those traditionally used for fixed-tuned filters but defined for tunable system use. For example, RF bandwidth is specified relative to the desired center frequency and rejection is specified at the image frequency and other pertinent spurious susceptible frequencies. Applications Closed-loop filter applications include active and passive countermeasures systems, radar and communications systems, and automatic test instrumentation for bench and field testing. Some of these applications are detailed in this catalog. More extensive closed-loop applications information can be found in the following papers available from Ferretec: 1. Application Note FT3, Improving Microwave Measurements with Ferretrac Filters

10 2. Application Note YIG Preselectors in Multi-Channel Phase Tracked Receivers 3. Application Note Reference Stabilized YIG-Tuned Receiver Front-Ends 4. Application Note Ferretrac Operation 5. Application Note Set-on Techniques for YIG-Tuned Band-Reject Filters 6. Technical Paper Digital ASIC Advances Microwave Filter Technology Courtesy of USAF Closed-loop filter applications include active and passive countermeasures systems, radar and communications systems, and automatic test instrumentation MIL Specification Devices Teledyne offers closed-loop filters for both commercial and military applications. For MIL-SPEC units, Teledyne has carefully selected all passive components from available established reliability devices. All semiconductor devices are JANTX or MIL-STD-883 screened. To ensure the specified filter performance for MIL environments over the lifetime of the device, Teledyne has carefully prepared an error budget using the guaranteed specifications of these MIL parts. Closed-Loop Filter Operation The key to closed-loop filter operation is an additional YIG sphere located in the same magnetic structure as the filter. Thus, any variations in the magnetic field, which tend to tune the filter to other than the desired frequency are also sensed by this additional reference sphere. The reference sphere is surrounded by a small air coil which can be biased to establish any desired fixed offset, up to ±300 MHz, between the reference sphere and the filter. Together with the elements of the loop circuits, the reference sphere and air coil form a unique microwave discriminator. The output of this discriminator is a voltage proportional to the error between the quiescent tuned frequency of the YIG filter and the RF reference frequency (+ or - any deliberate offset). This error is fed back to the main electromagnet driver to force the filter onto the reference frequency and keep it there under all static and dynamic conditions (e.g., temperature, vibration, driver component aging, etc.). Figure 6 shows the block diagram of the basic Ferretrac device. Note that the closed-loop circuits are independent of the filter, allowing complete flexibility for design and optimization of the filter. A high loop gain insures a reduction of all open-loop errors by approximately 200:1. The discriminator band-width is varied to initially provide a capture range of ±0 MHz and then reduced to provide better than 1 MHz resolution. Once within the capture range of the loop, the filter settles very rapidly to the specified reference frequency. A lock indicator, TTL signal compatible, provides an indication to the system that the loop has acquired the referenced signal. In certain applications, particularly those involving Doppler signal processing or synthesizer filtering, it may be necessary

11 Closed-Loop Bandpass Filters to disable the closed-loop to eliminate a small amount of incidental modulation that is coupled to the main filter from the reference-sphere air coil. This incidental tuning typically produces amplitude modulation of 0.5 db and phase modulation of 2 degrees at a fixed rate of about 350 KHz for the Ferretrac filter. This modulation can be entirely eliminated by employing a sample-and-hold circuit contained in all closed-loop filters. After receiving a lock signal indication that the filter is on frequency, activation of the hold input stores the corrected tuning voltage during the user s measurement or signal receiving period. During this time, for at least one minute (one second for MIL units at +85 C), the RF bandwidth remains on frequency. Filter tuning can be periodically updated by returning to the sample mode for approximately two milliseconds. RF Input Hold Control Common Magnet YIG Filter RF Reference Circuits Loop Circuit Error Signal Driver Circuit Filter Coarse Tune RF Output Reference Input Lock Indicator Figure 6. Ferretrac Functional Block Diagram Summary of Key Ferretrac Closed-Loop Filters The specifications presented in this catalog use super-heterodyne receiver terminology since a majority of applications are for preselectors or tracking filters. The closed-loop filter is locked to a local oscillator or other reference source frequency, or offset by an intermediate frequency (IF) from the source frequency. Care should be taken to avoid confusion with RF specifications for open-loop tunable filters. FT (Tuned Frequency) The desired center frequency of the passband. FT is equal to F0, the reference source frequency + or - the IF offset frequency. FO (Reference Frequency) The reference source (or local oscillator) frequency. For zero offset (tracking filter) FO=FT. FI (Image Frequency) The image frequency in a receiver located on the opposite side of the local oscillator, FO, and spaced from FO by the IF offset. BW (3 db Bandwidth) The minimum frequency band centered on the desired tuned frequency, FT, over which the total filter loss will not exceed IL + IR. IL (Insertion Loss) The insertion loss at a point in the bandwidth BW that exhibits the minimum value. IR (Passband Ripple) The maximum ripple, including magnetostatic modes occurring in the bandwidth BW.

12 VSWR Measured at the best point in the bandwidth BW. IF (Intermediate Frequency) The offset frequency (+ or -) at which the bandwidth BW is centered from the reference frequency FO. RI (IMAGE REJECTION) The minimum rejection in a band BW wide centered at a frequency FI on the opposite side of FO from the passband (usually called the image band ). In the case of zero offset (filter tracks on reference frequency) RI is defined as the minimum rejection ±200 MHz from FT. RH (HARMONIC REJECTION) The minimum rejection at harmonics and subharmonics of the frequency FT within the specified tuning range. RF (Half IF Rejection) The minimum rejection, in a band BW/2 wide centered at one-half of the IF frequency from the tuned frequency FT and located between FT and FO. This half IF rejection is needed to determine rejection of a spurious intermodulation product in the receiver systems caused by 2L0, 2SIG combinations. RC (LO REJECTION) The minimum rejection at the reference frequency, FO. This is needed to determine the amount of LO suppression provided by the filter in receiver applications. 0 db IR IL RF RH RI RC BW IF/2 IF IF FT/N FI FO FT N x FT Figure 7. Closed-loop bandpass filter specification definitions

13 Ferretrac Model Number System Always 1 for Catalog Model 1 FT 1 X X X M OFFSET 2 NO. STAGES & COARSE TUNE VOLTAGE TUNING RANGE COMPONENT SCREENING LEVEL X MHz X Stages Tuning Voltage X GHz C M to.0 V to 2.0 COMMERCIAL MIL to.0 V to V/GHz to V/GHz to V/GHz to V/GHz to V/GHz to V/GHz to Specials are assigned model numbers which are of the form FT2XXX. The last three digits are assigned sequentially. Any offset between ±300 MHz are available on special order. 2-STAGE 4-STAGE PARAMETER FT11 FT14 FT46 FT1111 FT1435 FT56 FT1117 Tuning Range (GHz) 0.5 to to to to to to to 40.0 Offset (MHz) BW (MHz, min) IL (db, max) IR (db, max) RF (Half IF) (db, min) RC (Reference) (db, min) RI (Image) (db, min) RH (db, min) Course Tune Voltage 0 to V 1.0 V/GHz 0.5 V/GHz 0 to V 1.0 V/GHz 0.5 V/GHz 0 to V Tracking (Zero Offset) Filters * 2-STAGE 4-STAGE PARAMETER FT1741 FT00 1 FT1749 FT1767 FT1751 FT 1 FT1759 FT1777 Tuning Range (GHz) 0.5 to to to to to to to to 40.0 BW (MHz, min) IL (db, max) RH (db, min) Course Tune Voltage 0.5 V/GHz 0.5 V/GHz 0.5 V/GHz 0. V/GHz 0.5 V/GHz 0.5 V/GHz 0.5 V/GHz 0. V/GHz * Fully compatible with C01 Controller 1 Special Numbers Assigned Consult factory for availability of other tuning ranges and tuning voltages. All Specifications shown are for operating temperatures of 0 to 60 C for commercial units and -55 to +85 C for MIL-SPEC units.

14 Ferretrac Bandpass Filter Specifications Offset Filters - 2-Stages 2-Stages FT1X01 FT1X02 Fri X03 FT1X04 FT1X05 FT1X06 FT1X07 Tuning Range (GHz) 0.5 to to to to to to to 40 BW (MHz min) IL (db max) IR (db max) Rejection (db min) 60 MHz Offset (X = 2 or 3) RF RC RI MHz Offset (X= 0 or 1) RF RC RI MHz Offset (X = 4 or 5) RF RC RI All Offsets RH Offset Filters - 4-Stages 4-Stages FT1X11 FT1X12 FT1X13 FT1X14 FT1X FT1X16 FT1X17 Tuning Range (GHz) 0.5 to to to to to to to 40. BW (MHz min) IL (db max) IR (db max) Rejection (db min) 60 MHz Offset (X= 2 or 3) RF RC RI MHz Offset (X = 0 or 1) RF RC RI MHz Offset (X = 4 or 5) RF RC RI All Offsets RH The above units have 0 to volts coarse tuning; for other coarse tuning voltages available see Model Number System. All specifications shown are for operating temperatures of 0 to 60 C for commercial units and -55 to +85 C for MIL-SPEC units.

15 Teledyne has introduced a line of digitally tuned closed-loop bandpass filters based on Ferretrac technology. Similar RF performance to the Ferretrac is available in a smaller and lighter package. Loop and control circuits are realized digitally, allowing for a zero droop sample-andhold, and the elimination of all potentiometers. Programmable logic arrays allow for frequency calibration and provide for system design flexibility Features: 12 Bit Digital (TTL) Tuning Control Zero Droop Sample-and-Hold Reduced Size and Weight No Potentiometers Typical RF Specifications 2-Stage Closed-Loop Bandpass Filters with +160 MHz Offsets [1] 2-Stages FTD11 FTD12 FTD13 FTD14 FTD Tuning Range (GHz) 0.5 to to to to to 18.0 BW (MHz min) IL (db max) IR (db max) RH (Harmonic Rej. db min) Rejection with +160 MHz Offset (db min) RF (Half IF) RC (Reference) RI (Image) Bit Digital Tuning Word Input: Low-end frequency corresponds to all zeros, high-end frequency corresponds to all ones. 2. Consult factory for availability of other tuning ranges. 3. All specifications shown are guaranteed for operating temperatures of 0 to 60 C for commercial units and -55 to +85 C for MIL-SPEC units 4-Stage Closed-Loop Bandpass Filters with +160 MHz Offsets [1] 4-Stages FTD1111 FTD1112 FTD1113 FTD1114 FTD11 Tuning Range (GHz) 0.5 to to to to to 18.0 BW (MHz min) IL (db max) IR (db max) RH (Harmonic Rej. db min) Rejection with +160 MHz Offset (db min) RF (Half IF) RC (Reference) RI (Image) Bit Digital Tuning Word Input: Low-end frequency corresponds to all zeros, high-end frequency corresponds to all ones. 2. Consult factory for availability of other tuning ranges. 3. All specifications shown are guaranteed for operating temperatures of 0 to 60 C for commercial units and -55 to +85 C for MIL-SPEC units [1] Other offsets between ±300 MHz are also available.

16 Digital Closed-Loop Bandpass Filter Specifications Tracking Closed-Loop Bandpass Filters (Zero Offset) Tuning Range (GHz) BW (MHz min) IL (db max) RH (db min) 2-Stages 4-Stages FTD1741 FTD00 FTD1751 FTD 0.5 to to to to Bit Digital Tuning Word Input: Low-end frequency corresponds to all zeros, high-end frequency corresponds to all ones. 2. Consult factory for availability of other tuning ranges. 3. All specifications shown are guaranteed for operating temperatures of 0 to 60 C for commercial units and -55 to +85 C for MIL-SPEC units Filter Repeatability: ±0.5 MHz Max The major contributors to short-term repeatability errors in conventional YIG devices are Magnetic Relaxation Uncertainty (MRU) and Post Tuning Drift (PTD). MRU is related to what is commonly referred to as hysteresis in the magnet. It is an unstable magnet bias condition that changes dramatically as a function of tuning step size, vibration, and shock. The result is a fixed-frequency uncertainty with a potential spread equal to the magnet hysteresis PTD is caused by the thermal gradient set up in the magnet shell due to the uneven internal heating by the tuning coil. The dissipation typically varies from 50 mw +20 to 5 Watts from 2 to + 18 GHz. + Both MRU and PTD are present, even at a fixed ambient temperature. In Ferretrac filters both errors are reduced by the loop gain, providing a dramatic improvement in repeatability as illustrated in Figure 8. REPEATABILITY (MHz) +5 FT Accuracy: Filter center frequency accuracy is ±1 MHz of reference signal typically. VSWR: 2.0:1 (Best Point) Tuning Speed: Tuning speed is the time from the initiation of a tuning step to the presence of the desired bandwidth (BW) centered at the desired frequency (FT). Step Size (GHz) Tuning Time (msec max) OPEN LOOP TUNING STEP (GHz) YIG filter tuning speed curves show a long time constant tail as shown in FERRETRAC +/- 0.5 MHz Figure 8 Repeatability as a function of Tuning Step (GHz) shows the effects of Magnetic Relaxation Uncertainty (MRU) and Post Tuning Drift (PTD). Figure 9. Ferretrac filters overcome this effect since, after acquisition by the loop, the filter tuning error AF is reduced to zero with a loop time constant of approximately 0 microseconds. ΔF (MHz) FT OPEN LOOP CLOSED LOOP 16GHz STEP 8GHz STEP 1GHz STEP Time ms Figure 9 Tuning speed enhanced by closed-loop circuit

17 Digital Closed-Loop Bandpass Filter Specifications Filter Input Signal (unless otherwise specified) Start Frequencies: Below 1 GHz Above 1 GHz 1 db Compression (min) 0 dbm + dbm No Damage (max) Frequency Reference RF Power Input No Damage (max) Source VSWR Required Reference Accuracy 1 Watt CW - dbm min/-5 dbm max 1 Watt CW 1.5:1 max The frequency of the signal fed to the reference port must be within ±50 MHz of the frequency indicated by the tuning voltage. (Typical accuracy is ±1 MHz relative to reference frequency.) Reference Offset: up to ±300 MHz Lock Indicator Standard TTL output, 2 loads Digital ±.4 VDC Digital ± 1.5 VDC Logic 0 indicates in capture range Logic 1 indicates outside capture range, 3.5 ± 1.5 VDC Sample and Hold: Standard TTL Input Logic Digital ± 0.4 VDC Digital ± 1.5 VDC 0 Commands Hold 1 Commands Closed Loop Ferretrac Tuning Input: Input Voltage to Tune Full Band: 0 to VDC, 1 V/GHz, 0.5 V/GHz and 0. V/GHz are available. For offset filters, reference tracking is also available (coarse-tune voltage tracks reference frequency rather than filter frequency). Input Impedance: minimum K ohms Digital Closed-Loop Tuning Input: 12-Bit digital tuning word. Low-end frequency corresponds to all zeros, high-end frequency corresponds to all ones. Power Requirements 28 ± 4 VDC (heaters) Heater Current 2-Stage 4-Stage Surge (max) 0.75 A 1.2 A + C Steady State 75 ma 1 ma -55 C Steady State 0 ma 0 ma Ferretrac : + VDC ±% at 1 ma per MHz of offset plus 0 ma for zero or negative offset, or, plus 200 ma for positive offset. - VDC ±% at 60 ma, plus typically 50 ma times max frequency in GHz. Outline Drawings: See Ferretrac Outline Drawing Rev. 6 on page 35. See Digital Closed-Loop Outline Drawing Rev. 1 on page 35.

18 Closed-Loop Bandpass Filter Applications RF INPUT HOLD CONTROL Receiver Preselection Teledyne closed-loop filters are ideal for receiver preselector applications where suppression of spurious responses is the key to system performance. Figure shows the block diagram of a receiver front end using a closed-loop preselector. A sample of the local oscillator signal is coupled to the closed-loop reference input and the filter locks onto the local oscillator, offset precisely by the IF frequency. This ensures that the minimum loss bandwidth of the filter is always centered on the desired frequency. The filter response can then be optimized for in band and skirt response characteristics without any compromises due to poor oscillator tracking, non-linearities, temperature drift, or other open-loop errors. FILTER COARSE TUNE CLOSED-LOOP FILTER TUNING INPUT RF OUTPUT REF INPUT LOCK INDICATOR OSC TUNE RECEIVER MIXER IF OUTPUT COUPLER LOCAL OSCILLATOR Figure - Closed-Loop Filter in a receiver preselector application Source Clean Up Sweet oscillators and frequency synthesizers output harmonics and subharmonics that are unacceptable to the user for many applications. Scalar network analyzers, for example, cannot distinguish between fundamental and harmonic signal content, causing sizable measurement errors unless adequate filtering of the signal source output is provided. Also, automatic test systems, operating over wide dynamic ranges, are easily confused in the presence of multiple, simultaneous outputs. Figure 11 shows a closed-loop filter used to clean-up a sweep oscillator or synthesizer. The voltage reference output of the sweeper (normally 1.0 or 0.5 V/GHz) is used to coarsely tune the filter, while a sample of the signal RF output provides an RF reference for the loop circuits. The filter is then automatically centered on the signal reducing harmonics and other spurious outputs of the source to the required level. In this application, the filter bandwidth can be kept narrow since the tracking is automatic, and the output power can be kept well leveled even while sweeping, since there is no peaking needed to keep the signal at the minimum loss point of the passband. Best of all, there are no adjustments needed when changing the end limits of the frequency sweep, alternately switching between different frequency end limits, or randomly programming with a computer. In automatic test equipment, no separate computer controls are required. The closed-loop filter is automatically IEEE- 488 Bus compatible since it faithfully tracks any programmed signal from the source. RF INPUT HOLD CONTROL 1 OR 1/2 GHz/VOLT OUTPUT SWEEPER OR SYNTHESIZER RF COUPLER CLOSED-LOOP FILTER FILTER COARSE TUNE REF INPUT LOCK INDICATOR RF OUTPUT Figure 11 - Closed-Loop Filter in a source clean-up application Other Applications Other applications of Teledyne closedloop filters can be found in the Teledyne Application Note FT3 Improving Microwave Measurements with Ferretrac Filters available on request.

19 Open-Loop Bandpass Filters Teledyne YIG Filters have been designed to meet the multi-octave, wide dynamic range requirements of today s EW systems and instruments. The electrical length of the interstage coupling elements is kept to a minimum so that multi-octave performance is achieved with no degradation over previous octave designs. Lowloss, gold plated cavities allow Teledyne to achieve the superior selectivity and off-resonance rejection of a 6-stage bandpass filter with the lower insertion loss of 4-stage filters. For military units, rugged construction in a temperature compensated, moisture sealed magnet maintains specified performance over the temperature, humidity, and salt-spray environments of MIL-E-5400 Class II. Bandpass Filter Specification Definitions Selectivity Filter selectivity depends on the number of YIG resonators (stages) and is nominally 6 db per stage per octave bandwidth. Thus for a six-stage filter, the rejection increases by 36 db each time the bandwidth doubles (see Figure 5, page 8). Limiting Level The input power at which the input/output transfer characteristic exhibits a 1 db compression. Linearity The maximum deviation of the tuned center frequency versus coil current from a best fit straight line over the specified operating frequency range. Hysteresis The maximum value of the differential tuned frequency, at the same coil current, when the coil is tuned slowly throughout the operation range in both directions. Since this hysteresis is caused by an unstable magnetization, it represents a tuning uncertainty as shown in Figure 12. For a given coil current, the tuned frequency will fall within the shaded area depending on tuning step size and speed, and also environment factors. The line A-B represents a stable magnetic condition. This can be best realized by step tuning each frequency from the low end of the tuning range. Temperature Drift The change in resonant frequency (at a fixed coil current) corresponding to a change in ambient operating temperature. Teledyne filter designs are mechanically compensated to reduce this temperature drift. Tuning Speed There are several factors affecting tuning speed including tuning coil and magnet design, method of tuning, driver design, etc. The nominal full-band switching speed is milliseconds to approach within 0.5% of the final frequency (see page 16). For data on tuning speed for a particular application, consult Teledyne directly. Repeatability Error (MHz) A F Low Hysteresis F High Stable Tuning Line Figure 12 Magnetic Relaxation Uncertainty Maximum frequency repeatability error at any fixed coil current due to unknown hysteresis bias of the magnet as a result of tuning speed, magnitude of step and/or direction, vibration, and mechanical and/or thermal shock. Maximum error is equal to hysteresis. Teledyne YIG Bandpass filters must function in a dense electromagnetic signal environment where preselection is required to separate signals from spurious, to reject co-located high-level interference, and maximize receiver sensitivity. B

20 Open-Loop Bandpass Filter Specifications Model Number System FXXXX C - AD Basic Model Number C - Commercial M - MIL No Suffix - Filter Only AD - Analog Driver DD - Digital Driver Bandpass Filters Specification Definitions RF Parameters (See Figure 13) 0 db IR IL 3dB IL (Insertion Loss): The loss at the point in the passband exhibiting the minimum loss value. BW (3 db Bandwidth): The bandwidth measured where the insertion loss is 3 db greater than the mini-mum loss value, IL. ORS ORI BW (Passband Ripple): The sum of amplitude ripple and spurious responses which cross through the filter passband. The filter ripple changes with tuning due to interstage coupling variations and frequency pulling of the YIG resonators. Spurious responses are due to magnetostatic modes that are excited in the YIG spheres. Some track the main filter response at a relatively fixed frequency offset while others tune at a different rate than the passband and appear to walk through the passband as it is tuned. Additional losses due to the spurious modes that track at a different rate than the filter passband are included in IR. Figure 13 - RF specification definitions for bandpass filters F T Return Loss (VSWR): Measured at the best point in the bandwidth, BW. ORI (Off-Resonance Isolation): The rejection, referenced to IL, measured at any frequency outside of the filter passband skirts within the specified tuning range. It is usually measured by turning the filter off and observing the residual signal leakage level. ORS (Off-Resonance Spurious): The amount of suppression referenced to IL of magnetostatic spurious modes that track at a nearly fixed offset from the main filter response. Since their frequency spacing can be controlled in the design by the choice of YIG material used, the system designer should specify any offset frequency range that is required to be free of spurious modes (i.e., the image frequency, local oscillator frequency, harmonics, etc.). These modes are typically only a few MHz wide.

21 Specifications - 2 Stage Filters Parameter F51 F52 F53 F54 F55 F56 Tuning Range (GHz) 0.5 to to to to to to 26.5 BW (MHz, min) IL (db, max) IR (db, max) ORI (db, min) ORS (db, min) Linearity (MHz, max) Hysteresis (MHz, max) ±3 4 ±6 ± ±12 ± 20 ±20 Temp. Drift (MHz, max) 0 to 60 C -55 to +85 C Tuning Sensitivity (MHz/mA, nominal) Coil Resistance (Ω, nominal) Coil Inductance (mh, nominal) Outline Filter With analog driver With digital driver 1 2 [1] 1 2 [1] 1 2 [1] 1 2 [1] 1 2 [1] 1 2 [1] Specifications - 4 Stage Filters Parameter F71 F72 F73 F75 F76 F77 F2000 Tuning Range (GHz) 0.5 to to to to to to to 50.0 BW (MHz, min) IL (db, max) IR (db, max) ORI (db, min) ORS (db, min) Linearity (MHz, max) Hysteresis (MHz, max) ±3 4 ±6 ± ± 20 ±20 ±30 60 ±35 70 Temp. Drift (MHz, max) 0 to 60 C -55 to +85 C Tuning Sensitivity (MHz/mA, nominal) Coil Resistance (Ω, nominal) Coil Inductance (mh, nominal) Outline Filter With analog driver With digital driver [1] Consult Factory [1] [1] 4 [1] [1]

22 Open-Loop Bandpass Filter Specifications Specifications - 7 Stage Filters Parameter F80 F81 F82 F83 F84 Tuning Range (GHz) 0.5 to to to to to 18.0 BW (MHz, min) IL (db, max) IR (db, max) ORI (db, min) ORS (db, min) Linearity (MHz, max) Hysteresis (MHz, max) Temp. Drift (MHz, max) 0 to 60 C -55 to +85 C Tuning Sensitivity (MHz/mA, nominal 60 ± ± ±20 60 ± ± Coil Resistance (Ω, nominal) Coil Inductance (mh, nominal) Outline Filter With analog driver [1] With digital driver [1]

23 Wide Bandwidth Bandpass Filters Introduction Wide Instantaneous Bandwidth Filters Today s surveillance receivers, EW countermeasure systems, and EMI measurement instruments require wider instantaneous bandwidths than the or 20 MHz normally available. The signals they must process are increasingly more complex with wider information bandwidth. They also must function in a dense electromagnetic signal environment where preselection is required to separate signals from spurious, to reject co-located high level interference, and maximize receiver sensitivity. Teledyne has developed a series of very wide instantaneous bandwidth bandpass filters which offer an ideal solution. Advanced computer aided design has enabled the incorporation of new coupling techniques to pro-vide the needed bandwidths while demonstrating low insertion loss, low passband ripple, and superior pass-band VSWR. These techniques also minimize variation in group delay, a parameter which is becoming even more important with the increase in complexity and bandwidth of the signal environment. The units specified in this catalog show Teledyne s capability to produce widebandwidth bandpass filters with limiting levels in the range 0 dbm to over + dbm (rather than the -23 dbm maximum linear input levels of filters operating in coincidence limiting). The wideband filters in this catalog are divided into two groups: Increased BW filters with bandwidths from 30 to 80 MHz for multi-octave tuning ranges, and wide-band filters with up to 500 MHz bandwidth in the 6 to 18 GHz range. Design Tradeoffs For 500MHz Filters To achieve extremely wide bandwidths, on the order of 500 MHz, high saturation magnetization Teledyne materials, such as Nickel Zinc Ferrite or Lithium Ferrite are required. However, the limiting level of Nickel Zinc decreases rapidly as the filter is tuned below 11 GHz. This results in a 500 MHz BW filter that is not only limited to a tuning range of approximately GHz, but also has a decreased input limiting level (typically +3 dbm). A third consideration in designing a system with a 500 MHz wide YIG filter involves the location of the 2 spurious mode. Its location can affect the image rejection specification under certain conditions, such as in systems with an IF frequency of 1 GHz and a low side LO. For these extremely wideband filters, the 2 spurious mode frequency is fixed at approximately 2 GHz below the filter passband, which is also the tuner s image frequency for a 1 GHz IF Thus, the 2 mode can cause a decrease in the system image rejection performance. This situation can be avoided at the system design level via selection of the IF frequency. For instance, an IF of 750 MHz has an IF image frequency of 00 MHz which is offset from the 2 spurious mode by 500 MHz, typically. However, for wideband tuners requiring a 1 GHz IF and an image rejection specification of greater than 70 db, the task of building these wideband filters becomes extremely difficult. Teledyne has developed a wideband filter that addresses this problem. 7-Stage Wideband Filter Solution The image rejection is improved in a 1 GHz IF system by the increased ORS suppression of the 6-stage filter design. However, achieving a specification of >60 db ORS suppression at FT-2 GHz while maintaining a 500 MHz minimum bandwidth has proven extremely difficult to accomplish on a production basis, even for a 6-stage design. To provide a filter that not only meets the wide bandwidth and increased ORS requirement, and can also be built on a repeatable basis, Teledyne has developed an advanced technology 7-stage wide-band filter design. This second generation wideband filter technology has achieved the three primary design goals of: 1) Increased minimum bandwidth specification margin (550 to 600 MHz, versus 500 MHz), 2) Increased ORS suppression of 70 db, for the worst-case system requirements of high IF image suppression and 1 GHz IF, and 3) Achieving these specifications on a consistent and repeatable basis, to support large production quantities. This wide bandwidth filter is ideal for wideband ELINT receivers. They are primarily used in the GHz band, but are also suited for usage over the extended GHz frequency range, with only minor performance tradeoffs. In addition to increasing margin for key filter specifications such as minimum BW, off-resonance spurious, and off-resonance isolation, Teledyne s advanced technology maintains excellent input and output VSWR while minimizing passband spurious and ripple. These wideband filters can be built and aligned in an efficient, cost-effective manner, resulting in a filter which can be shipped in large quantities, with consistent repeatable performance. The filters are packaged in a 1.7 cube, and can be supplied with drivers (digital or analog), if required. For increased spurious suppression and selectivity requirements, additional stages can be accommodated with the current technology.

24 Wide Bandwidth Bandpass Filter Specifications Specifications - 4-Stage Increased Bandwidth Bandpass Filters Parameter F91 F92 F93 F94 F95 F96 Tuning Range (GHz) 0.5 to to to to to to 26.5 BW (MHz, min) IL (db, max) IR (db, max) ORI (db, min) ORS (db, min) Limiting Level (db, min) Linearity (MHz, max) ±3 ±4 ±4 ±6 ± ± Hysteresis (MHz, max) Temp. Drift (MHz, max) 0 to 60 C -55 to +85 C Tuning Sensitivity (MHz/ma, nominal) Coil Resistance (Ω, nominal) Coil Inductance (mh, nominal) Outline Filter With analog driver With digital driver Specifications - Ultra-Wide Bandwidth Bandpass Filters Parameter 4-Stage 7-Stage F97 F98 F99 F1201 F1200 Tuning Range (GHz) 6.0 to to to to to 18.0 BW (MHz, min) IL (db, max) IR (db, max) ORI (db, min) ORS (db, min) Limiting Level 0 [1] + +3 [1] 0 [1] +3 [1] Linearity (MHz, max) ±80 ±40 ±40 ±80 ±40 Hysteresis (MHz, max) Temp. Drift (MHz, max) O to 60 C -55 to +85 C Tuning Sensitivity (MHz, nominal) Coil Resistance (Ω, nominal) Coil Inductance (mh, nominal) Outline Filter With analog driver With digital driver [2] [2] 5 [2] [2] [1] Limiting level increases to greater than + dbm above 11 GHz. [2] Consult factory for further details.

25 Open-Loop Bandpass Filter and Driver Specifications General Specifications The following specifications are common to all filters unless otherwise specified in the model specification tables. Passband VSWR: 2.0:1 (Best Point) Input Limiting Level (1 db compression): (except for wide-bandwidth filters) Start Frequency Below 1 GHz Above 1 GHz 0 dbm + dbm Maximum RF Power Without Damage: 1 Watt CW Heaters: To minimize fluctuations in tuned frequency with changes in ambient temperature the YIG spheres are stabilized by internal, self-regulating heaters. The current drawn by these heaters varies with the number of stages and the temperature. Note that there is an initial current surge when power is first applied to the heaters which rapidly decays to a steady state. Heater Current Surge (max) +28 VDC Nominal 2-Stage 4-Stage 6-Stage & Greater At Turn-on 0.6 A 1.2 A 1.8 A C Steady State 75 ma 0 ma 200 ma RF Connectors: Type SMA-Female Tuning & Heater Terminals: Solder Pins or Multi-pin Connector (see outline drawings) Operating Temperature: Commercial Units: 0 C to +60 C MIL Units: -55 C to +85 C Screening Levels: See page 8 Open-Loop Filters with Drivers The filters described in this catalog can be provided with integral drivers (voltageto-current converters); both analog and digital drivers are available. The analog drivers are tuned by a customer-supplied 0- Volt ramp. Other voltage ranges are available if needed. The digital drivers are tuned by a digital tuning word of up to 12 bits. The input is TTL-compatible, and is available either latched or non-latched. Teledyne drivers are especially designed to reduce the effects of aging. Aging, the slow change in component values (especially resistors) with time, causes the voltage-to-frequency transfer characteristic of the filter / driver to change. Trim potentiometers, used to adjust the driver to set the filter endpoints, are especially susceptible to aging. Teledyne matches every driver to its specific filter using computer-chosen, select-attest resistors. This enables the use of potentiometers with much smaller range, and therefore minimizes the effect their aging has on the transfer characteristic. Teledyne MIL drivers contain all MILspecified parts and are temperature compensated for operation over the -55 to +85 C range. The resulting static frequency drift with temperature of the filter / driver combination is minimized. Conformal coating of the printed circuit boards insures survival in the MIL-E Class II airborne environment. Typical Specifications Analog Driver: Tuning Voltage: 0 to +V (OV = Low-end frequency, +V = High-end frequency) Tuning Impedance: KΩ, min. Power Supply: +V±% at 50 ma -V±% at 50 ma plus tuning coil current requirements (see individual filter specification). For example, an F73 filter will draw an additional 900 ma when tuned to 18 GHz. +28V: See appropriate filter specification. Connector: See appropriate outline drawing. Digital Driver: Tuning Input: 12-Bit TTL (All 0 s = Low-end frequency, All 1 s = High-end frequency) Latch (Optional): Level Triggered (0 = Transparent, 1 = Latched). Tuning Load: 1 TTL Load Power Supply: +V±% at 50 ma -V±% at 50 ma plus tuning coil current requirements (see individual filter specification). For example, an F73 filter will draw an additional 900 ma when tuned to 18 GHz. +5V at 30 ma +28V: See appropriate filter specification. Connector: See appropriate outline drawing Note that various driver options are available for Teledyne filters. Options include ±12V bias, positive or negative drivers (coil current drawn from the positive or negative supply), and various outline configurations. Please consult factory for details.

26 Band-Reject Filters Introduction Teledyne band-reject filters are designed for high performance, producibility, and maximum reliability in military or commercial systems. Using recent breakthroughs in BRF technology, the overall notch depth and rejection BW is increased while maintaining a minimum 3 db bandwidth. With a nominal filter skirt selectivity of up to 96 db/octave, a 16- stage band-reject filter allows the system designer to notch out an undesired signal while sacrificing the smallest possible system operational bandwidth. Standard designs with -, 12-, and 16-stages are available in 1.4-inch and 1.7-inch packages. Depending on customer requirements, Teledyne band-reject filters are available as a stand-alone filter, filter with analog or digitally tuned, 12-bit driver. Closed-loop band-reject filters are also available for signal suppression applications. Technical Discussion YIG-tuned band-reject filter bandwidths are inherently frequency dependent, since the equivalent circuit can be modeled as a set of parallel resonant circuits separated by quarter-wavelength impedance inverters. As such, the filter design can only be optimized for a single frequency, typically at the mid-point of the tuning range. In addition, the individual YIG sphere coupling bandwidths are proportional to tuned frequency. The net effect of both factors is that, unlike the bandpass filter, whose bandwidth is essentially constant with frequency, a YIG-tuned notch filter will have a bandwidth which is approximately proportional to frequency. As a result, to produce a notch filter with the ideal characteristics of maximum rejection BW and notch depth, and minimum values of 3 db BW, VSWR, insertion loss, and spurious, Teledyne filter designs are fully characterized via analysis and computer modeling, and then properly implemented. The result is a band-reject filter that exhibits high performance and reliability, and is inherently producible. For notch filters with drivers, each Teledyne driver is individually matched to its specific filter using computer-selected resistors to minimize the effects of driver drift over time. Together with MILspecified components, the Teledyne driver has been optimized to insure long-term reliability and operation with a band-reject filter, in any environment, military or commercial. Teledyne band-reject filters are available as a stand-alone filter, filter with analog or digitally tuned, 12-bit driver. Closed-loop band-reject filters are also available for signal suppression applications.

27 Advanced Band-Reject Filter Technology Teledyne has developed an Advanced Technology line of band-reject filters that breaks through conventional size, specification, and reliability barriers. These band-reject filters (BRF s) are smaller, lighter, more reliable, and can meet extremely deep and wide notch bandwidth specifications while maintaining a narrow 3 db bandwidth. While enjoying the deeper notch and wider notch bandwidth benefits of -, 12-, and 16-stage designs, spurious levels are reduced to levels far below those of typical 4- to 8-stage designs. As a result, greater selectivity is achieved with significantly reduced spurious levels, on the order of 2 db (versus conventional spurious levels of 4 to 5 db). This reduction in spurious and increase in selectivity, notch depth, and notch bandwidth was accomplished with an overall decrease in the filter magnetic shell size, to a 1.4-inch cube. These breakthroughs in BRF technology have resulted in the first production design of a wideband notch filter that tunes the entire 4-18 GHz range, in a single unit. General characteristics of this advanced BRF technology include: Reduced size: 1.4 filter for -stage units; 1.7 for 16-stage and certain 7 & -stage units. Increased skirt selectivity: 60 to 96 db/octave nominal skirt rolloff. Increased notch depth: 50 to 0 db. Increased notch BW: db for a narrowband 12-stage unit. Decreased 3 db BW: 0 MHz, max, for a 60 MHz notch at the 70 db point. Decreased spurious: 2-4 db, typical for a 12-stage filter. Enhanced producibility: High production rates. Increased tuning range: 4-18 GHz in a single filter. More stages: - and 12-stage standard units. 16-stage for 4-18 GHz units. Increased reliability: MTBF increases. These band-reject filters are available with 12-bit digital or analog drivers, or as stand-alone units. These units are also available in closed-loop versions, both the standard analog version Ferretrac units and the latest digital closed-loop version. Closed-Loop Band-Reject Filters In addition to the traditional open-loop band-reject filter, Teledyne has pioneered closed-loop band-reject filter technology. There are three primary advantages of a closed-loop solution for band-reject filter applications: 1. The closed-loop circuit decreases the time it takes to set on the notch filters. Set-on time is typically decreased by a factor of five, versus that of the same filter in an open loop configuration. For a 5- GHz closed-loop Ferretrac filter, the tuning speed for a full band 5 GHz step is on the order of 3 milliseconds, to be within ±2 MHz of the final frequency. This compares to approximately milliseconds for an open-loop version of the same filter. 2. The filter is set to precisely the frequency required by the system, to within ±1 MHz. Furthermore, the frequency repeatability of the filter is such that, regardless of conditions (sweep speed, step size, temperature variations, etc.), the filter will repeat to within ±500 KHz of the initial frequency. 3. Since precise frequency set-on is achieved within the closed-loop circuitry itself, once the system processor has specified the frequency tune word, the processor can proceed to other system tasks while the filter tunes itself to precisely the correct frequency. With the closed-loop filter, the system becomes a tune and forget.

28 Band-Reject Filter Parameters / Closed Loop BRF s Teledyne closed-loop tunable band-reject filters allow a narrow notch to be positioned precisely over an interfering, or receiver limiting, signal. This function is particularly useful in integrated defense electronics systems where interference from adjacent emitters such as radars and jammers (both hostile and friendly) can deny use of large segments of receiver bands needed to identify hostile threats. As with bandpass applications, closedloop technology insures that the notch is where it belongs all the time, every time. Low passband insertion loss allows cascading of band-reject filters to simultaneously notch out multiple signals without seriously degrading system performance. Since applications of this device are so varied, consult Teledyne on your special requirements. The specifications below are examples of our capabilities. Closed-Loop Band-Reject Filters Ferretrac Band-Reject Filters Model FT1802 FT1806 FT1807 Frequency Range [1] BR (MHz, min) RB (db, min) BW (MHz, max) IL (db, max) ORS (db, max) [1] Passband extends from DC to maximum tuned frequency. Enhanced BRF Set-On Performance Positioning a relatively narrowband notch on the desired frequency is often a challenge to the system designer. Typically, a step tuned system approach is employed, but this often lengthens processing time and requires additional software capability. A faster, more accurate approach is to use the Ferretrac closedloop notch filter. Set-on time is decreased (typically by a factor of 5), the center of the notch can be locked precisely to the desired signal, and the filter itself can tune to within ±500 KHz of any desired frequency, regardless of the environmental conditions or threat environment. The frequency reference signal can be taken from existing system sources, and can be operated at tuning offset of up to ±300 MHz. Teledyne has just completed the design of a second-generation, closed-loop filter that offers enhanced performance, a smaller package, and is ideal for band-reject filter applications. Use of a closed-loop band-reject filter offers a system-level solution to the designer s requirements.

29 Band-Reject Filter RF Parameters See Figure 14 0 db ORS IL IL (Insertion Loss): The maximum loss in the passband measured with the filter turned off or tuned out of the passband. BW 3dB BW (3 db Bandwidth): The bandwidth measured 3 db below the insertion loss value. RB VSWR: Measured in the passband with the filter turned off or tuned out of the passband frequency range. BR ORS (Off Resonance Spurious): The passband attenuation caused by magnetostatic modes at frequencies offset from the desired response. FT FREQ BR (Rejection Bandwidth): The minimum bandwidth required over which the rejection must be at least rejection level, RB. Figure 14 RF specification definitions for band-reject filters RB (Rejection Level): The amount of attenuation, referenced to the insertion loss, of signals within the rejection bandwidth, BR. Low-Frequency Band-Reject Filters (7- and 16-Stage) Model F1300 F13 F1311 F1312 F16 F1302 Frequency Stages BR (MHz, min) RB (db, min) db BW (MHz, max) IL (db, max) ORS (db, max) Linearity (MHz, max) ±3 ±6 ±8 ± ±3 ±3 Hysteresis (MHz, max) Temperature Drift (MHz, max) 0 to 60 C to +85 C Tuning Sensitivity (MHz/mA nominal) Coil Resistance (Ω, nominal) Coil Inductance (mh, nominal) Outline Filter with analog driver with digital driver

30 High-Frequency Band-Reject Filters (- and 16-Stage) Model F1323 F1322 F1321 F1333 F1332 F1331 F1330 Frequency [1] Stages BR (MHz, min) RB (db, min) db BW (MHz, max) IL (db, max) ORS (db, max) Linearity (MHz, max) ± ±20 ±20 ± ±20 ±20 ±20 Hysteresis (MHz, max) Temperature Drift (MHz, max) 0 to 60 C -55 to +85 C Tuning Sensitivity (MHz/mA nominal) Coil Resistance (Ohms, nominal) Coil Inductance (mh, nominal) Outline Filter with analog driver with digital driver 8 [2] [2] 8 [2] [2] 8 [2] [2] 9 [2] 9 [2] 9 [2] 9 [2] 1 Passband extends from DC to maximum tuned frequency 2 Consult factory 20 30

31 Additional Teledyne YIG Products INSTRUMENTATION. Teledyne manufactures companion test equipment products utilizing closed-loop YIG filter technology. The C01 Controller provides all operating controls and power supplies for the closedloop Ferretrac filter. Please contact the factory for details on this product. New YIG Technology From Teledyne Although YIG devices have been in use for over 30 years, Teledyne continues to advance the technology. Recent Teledyne developments include advanced broadband tunable notch filters, multi-function single-magnet filters, the use of permanent magnets to enhance YIG component performance, advanced closed-loop filter design, vibration stabilization techniques, and YIG-based instrumentation products. Teledyne s capabilities are increasing rapidly, and some of the latest technology may not be included in our catalogs, so please contact the factory or our local representative for unique solutions to your most challenging systems problems. Examples of advanced YIG technology include: 16-stage Band-Reject Filter 2-18 GHz frequency coverage - in a single filter Increased notch depth Industry s smallest package size Multi-function Filters (Single Magnet Designs) Dual 2-stage and Dual 4-stage bandpass filters 8-stage band-reject filter with 2-stage bandpass filter -stage band-reject filter with 4-stage bandpass filter Dual 8-stage band-reject filter Permanent Magnet Bias (Oscillators and Filters) Smaller size Reduced power consumption Faster tuning speeds Low phase noise oscillators Vibration Stabilized Designs Reduced residual FM under vibration in oscillators Reduced additive noise in filter 7-Stage Bandpass Filter Design 500 MHz instantaneous bandwidth Increased selectivity and isolation Smaller size Digitally tuned Advanced Closed-Loop Filter Instrumentation Products Scalar Network Analyzer enhancements

32 Outline Drawings 1.4" BANDPASS FILTER, 2/4-STAGE OUTLINE #1,( REV B) NOTES: (UNLESS OTHERWISE SPECIFIED) 1. DC CONNECTION: SOLDER PINS EI-E4 2. El, E4 LABELED AT THE FACTORY, LOCATIONS MAY BE REVERSED [35.56].70 [17.78]. [3.81] MAX CONN PIN NO. FUNCTION J1 SMA RF INPUT J2 SMA RF OUTPUT DC E l COIL + DC E2 HEATER DC E3 HEATER DC E4 COIL - J [35.56].70 [17.78] J2.38 [9.53] TYP TOLERANCE. XX *.03 [.76].XXX *.005 [.127] INCHES [MILLIMETERS] 1.4" BANDPASS FILTER W/ANALOG DRIVER OUTLINE #2 ( REV B) LABEL AREA.12 MAX [3.0] NOTES: (UNLESS OTHERWISE SPECIFIED) 1. DC CONNECTOR: ITT CANNON DE-9P (MATING CONN. DE-9S OR EQUVALENT).70 2 PL [17.8].90 2 PL [22.9].13 [3.3] 2. [54.6] [66.55].46 MAX [11.7] 1.62 [41.1] 1.02 [.9] #6-32 UNC-2B X.30 [7.6] DP. 4 PLACES (HELICOIL INSERT) CONN - PIN NO. FUNCTION J l SMA RF IN J2 SMA RF OUT DC 1 +V DC 2 COMMON 3 -l5v DC 4 V TUNE 5 N/C 6 N/C 7 HEATER +2BV DC 8 HEATER RETURN DC 9 N/C. [3.8] 1.0 [27.94] 1.40 [35.6] TOLERANCE. XX *.03 [.76].XXX *.005 [.127] INCHES [MILLIMETERS] 2.90 [73.66]

33 Outline Drawings 1.7" BANDPASS FILTER, 2/4-STAGE OUTLINE #3, (02000-REV B). [3.8] 1.70 [43.2].85 [22] LABEL AREA 1.70 [43.2] 1.70 [43.2] J1 J1 E1 E2 E3 E4.85 [22] J2.38 [9.5] TYP 2.0" BANDPASS FILTER, 4-STAGE OUTLINE #4, ( REV A) CONN PIN NO. FUNCTION J1 SMA RF INPUT J2 SMA RF OUTPUT DC E1 MAIN COIL DC E2 HEATER DC E3 HEATER DC E4 MAIN COIL TELEDYNE MICROWAVE 1.7" BANDPASS FILTER, 7-STAGE OUTLINE #5, ( REV A) NOTES: (UNLESS OTHERWISE SPECIFIED) 1. DC CONNECTION: SOLDER PINS, El-E4. J1 E1 E2 E3 E4 2. El,E4 LABELED AT THE FACTORY, LOCATIONS MAY BE REVERSED [43.2].85 [21.6] CONN PIN NO. FUNCTION J1 SMA RF INPUT J2 SMA RF OUTPUT DC E1 COIL + DC E2 HEATER DC E3 HEATER DC E4 COIL - [13.7] 1.70 [43.2] 1.70 [43.2] TOLERANCE. XX *.03 [.76].XXX *.005 [.127] INCHES [MILLIMETERS]

34 Outline Drawings 1.7" BANDPASS FILTER W/ANALOG DRIVER OUTLINE #6, ( REV 1) CHAMFER.12 X 45 2 PLCS J2 (RF OUTPUT) LABEL AREA R.22, 2 PLCS NOTES: (UNLESS OTHERWISE SPECIFIED) 1. DC CONNECTOR: POSITRONIC SMPL9MOTOLB (MATING CONN. SGMC9FOT0000 OR EQUIVALENT).24 [6.1] 1.95 [49.5] J1 (RF INPUT).85 2 PL [22] 2 PL 1. 2 PL [27.9] 2 PL J1 J3 "A" PIN 1.07 [27.2] CONN-PIN-FUNCTION J1- SMA- RF INPUT J2- SMA- RF OUTPUT + V B COMMON C - V D HTR + E HTR - F N/C H N/C J V TUNE + J3- K V TUNE - J3- A 2.95 [74.9].80 [20] #6-32 UNC-2B X.20 DP. HELICOIL INSERT 6 PLACES 2.00 [50.8] [38.].44 [11] [38.] [58.93] 1.7" BANDPASS FILTERW/DIGITAL DRIVER OUTLINE #7, ( REV. [6.3] CHAMFER.12 X 45 2 PLCS J2 (RF OUTPUT) LABEL AREA R.22, 2 PLCS NOTES: (UNLESS OTHERWISE SPECIFIED) 1, DC CONNECTOR: POSITRONIC SMPL26MOTOLB (MATING CONN. MC26FOT0000 OR EQUIVALENT).19 [4.83] J1 (RF INPUT) CONN PIN NO.- FUNCTION J1 SMA RF INPUT J2 SMA RF OUTPUT J3 A B C D E F H J K LATCH BIT 11 BIT 12 (LSB) N/C BIT 9 BIT N/C BIT 7 BIT 8 L M N P R S T U V W X Y Z a b +V BIT 5 BIT 6 COMMON BIT 3 BIT 4 -V BIT 1 (MSB) BIT 2 N/C N/C +5V N/C N/C N/C c +28V J3 d -28V RTN 1.95 [49.5].85 2 PL [22] 2 PL 1. 2 PL [27.9] 2 PL 2.00 [50.8].44 [11] J [52.7] 3.35 [85.1] [38.] [70.] J3 MALE PIN "A" PIN 2.00 [50.8].57 [] #6-32 UNC-2B X.20 DP. HELICOIL INSERT, 6 PLACES [38.]. [6.3]

35 Outline Drawings 1.4" BAND-REJECT FILTER OUTLINE #8, ( REV A) 1.40 [35.6]. [3.8].57 [4.3] CONN PIN NO. FUNCTION J1 SMA RF INPUT J2 SMA RF OUTPUT DC E l COIL + DC E2 HEATER DC E3 HEATER DC E4 COIL -.38 [9.6] 1.40 [35.6].39 [9.9].63 [16.0].17 TYP [4.3] LABEL AREA 4X.12 [3] X 45 CHAMFER TOLERANCE. XX *.03 [.76]. XXX *.005 [.127] INCHES [MILLIMETERS] J1 J2 E1 E2 E3 E [35.6].70 [17.8] 1.7" BAND-REJECT FILTER OUTLINE #9, ( REV 1) CONN PIN NO. FUNCTION J1 SMA RF INPUT J2 SMA RF OUTPUT DC E l COIL + DC E2 HEATER DC E3 HEATER DC E4 COIL -.38 [9.6] 1.70 [43.2].54 [13.7] 1.70 [43.2].63 [16.0]. [3.8].57 [4.3].17 TYP [4.3] LABEL AREA 4X.12 [3] X 45 CHAMFER TOLERANCE. XX *.03 [.76]. XXX *.005 [.127] INCHES [MILLIMETERS] 1.70 [43.2] J1 J2.85 [21.6] E1E2 E3 E4 1.7" BAND-REJECT FILTER W/DIGITAL DRIVER OUTLINE #, (02001-REV 1) 1.95 [49.5] CHAMFER.12 X 45 2 PLCS.23 TYP. [5.7].54 TYP. [14] 1. TYP. [27.9] J1 J [52.7] TELEDYNE MICROWAVE.63 TYP. [16] P1 MODEL # FDXXXX S/N: XXXX D/C: YYWW FEMALE PIN "A" PIN R.22, 2 PLCS IDENT LABEL.19 [4.83].57 [] 2.00 [50.8] NOTES: (UNLESS OTHERWISE SPECIFIED) DC CONNECTOR: POSITRONIC SMPL26MOTOLB (MATING CONN. CONN PIN NO.- FUNCTION OR EQUIVALENT) J1 SMA RF INPUT J2 SMA RF OUTPUT J3 A B C D E F H J K LATCH BIT 11 BIT 12 (LSB) N/C BIT 9 BIT N/C BIT 7 BIT 8 L M N P R S T U V W X Y Z a b +V BIT 5 BIT 6 COMMON BIT 3 BIT 4 -V BIT 1 (MSB) BIT 2 N/C N/C +5V N/C N/C N/C c +28V J3 d -28V RTN TOLERANCE. XX *.03 [.76]. XXX *.005 [.127] INCHES [MILLIMETERS]

36 Outline Drawings 1.7" BAND-REJECT FILTER W/ANALOG DRIVER OUTLINE #11,( REV 1) CONN-PIN-FUNCTION J1- SMA- RF INPUT J2- SMA- RF OUTPUT + V B COMMON C - V D HTR + E HTR - F N/C H N/C J V TUNE + J3- K V TUNE - J3- A CHAMFER.12 X 45 2 PLCS.23 [5.7] LABEL AREA R.22, 2 PLCS.24 [6.1].54 [13.7].62 [.7].80 [20] J1 J2 P1 "A" PIN 1.95 [49.5] 1. [27.9] 1.07 [27.2] FERRETRAC (CLOSED-LOOP) FILTER OUTLINE #12, ( REV 2.95 [74.9] #6-32 UNC-2B X.20 DP HELICOIL INSERT, 6 PLACES 2.00 [50.8] [38.].12 [3.2] [47.63].12 [3.2] 4 MOUNTING HOLES.6 [3.9] DIA THRU [38.]. [6.3].44 [11] [58.93] [82.5] [69.9] MAX [76.20] [113.7].62 [.7].88 [22.3] 3.75 MAX [95.2] NOTES: (UNLESS OTHERWISE SPECIFIED) 1, DC CONNECTOR: ITT CANNON DE-9P (MATING CONN. DE-9S OR EQUIVALENT) CONN PIN NO.- FUNCTION J1 SMA RF INPUT J2 SMA RF OUTPUT J3 SMA REF IN +V DC GND -V DC V TUNE SAMPLE & HOLD LOCK INDICATOR HEATER +28V HEATER RETURN J3 9 (FACTORY TST PT.).88 [22].62 [.7] J2 J1 J3.78 [20] 2.18 [55.3]. [6.4] 3.05 MAX. [77.5] TELEDYNE MICROWAVE MODEL # S/N: D/C: MADE IN USA 2.18 [55.3] 1.06 [26.8] 2.13 [54.0] DC CONNECTOR TYPE DE-9P ITT CANNON OR EQUIVALENT FERRETEC PRODUCT LABEL

37 Prices subject to change without notice.