Anexo 2 ASYTRAIN. Antenna Training Kit Lab. Antenna design, development and test

Transcription

1 Anexo 2 ASYTRAIN Antenna Training Kit Lab Antenna design, development and test

2 1 SCOPE The following document is an outline of Radiation Group s latest training product ASYTRAIN. The package is a collection of four antenna lab courses comprised of four courses which will be described in detail in conjunction with details of each antenna used in the course. 2 SUMMARY The ASYTRAIN Antenna Training Kit Lab has been designed to facilitate the understanding of electromagnetic radiation in the context of communication antennas. All the antennas and the teaching material included in the kit have been designed and developed by professors of the RF Group of the Technical University of Madrid in Spain. The overall experience of this professor group amounts to over 80 years. The courses are structured in two levels. Basic level which is targeted at first level students (high schools) and junior technical staff of defence organizations. Advanced level is aimed at University students who would be expected to design and construct antennas with components provided in the kit. Each level (basic and advanced) has two main options: 1. Linear Antenna Option at L/S-band: Basic: Dipoles (single and folded), Monopole, Log Periodic dipole, 3 elements Yagi- Uda, one LHC and two RHC Helixes, Advanced: Basic antennas plus a six element Yagi kit, two additional monopole antennas to build a three monopole array (broadside, end fire, etc.), antennas and two S-band patch antennas (Linear, LHC and RHC polarization). 2. Aperture Antenna Option at X-band: Basic: Conical and Pyramidal Horns, Ring Focus Reflector + splash and feeder, one LHC and two RHC Helixes. Advanced: Single offset reflector with two adjustable corrugated feeders (several circular plates with support, to visualize the blockage effect), pyramidal horns building kits, corrugated lens, rod dielectric antenna, etc. Furthermore the advanced level (linear and aperture antennas) are complemented with a set of optional modules which will allow the students to analyse and understand the complex operation of more sophisticated antenna types, as Reflect arrays, Rotman Lens, Planar Phase Array, Resonant and no Resonant Slot WG Arrays, Cavity Antennas, etc. Furthermore, there are two more options: 2 1. Related design and measurement of Radomes, 2. Related to RCS measurement Each option can be purchased to suit individual needs. The measurement system used in these courses is made up of the following components: - The ASYTRAIN CONTROLLER provides an integrated azimuth stepper positioner with position commands to allow the measurement of gain, VSWR and antenna patterns. It contains two frequency synthesizers (for TX and RX LO) which covers both measurement bands (L/S and X). The use of these synthesizers (with the IF receiver narrow band filter) allows simultaneous measurement at different frequencies, without interference, inside the same laboratory room.

3 - Spirit levels, laser and mirror, for alignment of the positioners (if desired), this is usually performed in the professional anechoic chamber. - The ASYTRAIN SOFTWARE (PenDrive) consists of the following functions: Antenna design, Acquisition, and Analysis and Representation modules. Following these sequential functions, for advanced courses, the student can create their antenna design. They can build it by using the included components kits, and finally, measure their designed antenna performance. 3 ACKNOWLEDGEMENT The laboratory teaching courses (ASYTRAIN) offered by Radiation Group are the result of the experience of over 40 years of Professor Jose Luis Besada as well as the experience of over 20 years of his colleagues Dr Leandro de Haro and Dr Belén Galocha, in the Radiation Group of the Universidad Politécnica de Madrid (UPM). They all teach subjects such as Electromagnetic Fields and Antennas and Propagation. These courses are mainly the result of their huge experience in R&D in many types of microwave antennas. These were developed to be deployed on satellites (HISPASAT),Man-pack and SATCOM terminals (INDRA Space), feeders for ground station and radio-telescopes (ESA and CAY), and Radar antennas (INDRA Systems). Professor Besada also has a huge experience in antenna mechanical design, due to the engineering direction of a large amount of turnkey projects, and in the design and implementation of all kind of antenna measurement systems (FF, NF, CATR, etc.) His huge experience has been used to design and machine the large assembly of antennas that ASYTRAIN courses and their corresponding options utilise; this also applies to the construction of a roll (manual) over azimuth (motorized) positioner system, to perform most of the usual antenna measurements in a professional anechoic chamber. It is also important to highlight the developed components for radomes and RCS measurement, which can be used in any professional anechoic chamber. Finally, it is worth taking note of the quality the quality of the theoretical and practical documentation, both for the basic courses aimed to high school students and junior staff of defence organizations, and the advanced courses aimed to University students presenting and reinforcing antenna design principles. 4 DETAILED ASYTRAIN PRESENTATION The ASYTRAIN courses have been designed to make it easy to understand the concepts related to radiation in the context of communication antennas. As mentioned previously the courses have been structured in two levels: Basic and Advanced The Basic level has been designed for high school students and junior staff of defence organizations with a flavour of training related with wireless communications. The advanced course, which supplement the previous basic course is aimed at university students. To teach and learn about the antennas used in these advanced courses, a new methodology is used, based on the following project development steps: A short theoretical presentation of each antenna type, the experiments that the students can carry out with it, and the available simulation software in ASYTRAIN SOFT. The student should extend the theoretical lecture based on the recommended bibliography. 3

4 The design and simulation of the antennas under study, using the ASYTRAIN design module. These modules are streamlined for students use. The actual construction of the antennas using ASYTRAIN ANTENNA KITS (modular kits). The measurement of the built antennas with ASYTRAIN CONTROLLER in the students labs or classrooms. As explained above, for each level there are two alternatives: 1. Linear antennas at L/S-bands such as: dipoles, monopoles, Yagi antennas, log periodical dipoles, helixes, patches, etc. 2. Aperture antennas at X band such as conical and pyramidal horns, lens, and centred and offset reflectors. These courses are customizable with a set of more advanced options to analyse and understand the operation of more sophisticated antennas for professional use. The options are available separately for easy acquisition. All the courses have in common the following key elements: 1. The ASYTRAIN CONTROLLER with the azimuth stepper motor and the RF Tx/Rx system. 2. Two manual roll positioners for rotating, in phi, the antennas under the test, and antenna source. 3. A laser, a mirror and two spirit levels to align the positioner system. 4. The ASYTRAIN SOFTWARE. 5. RF and control cables. 4.1 COMMON ELEMENTS TO ALL COURSES The common elements for all the courses to perform the different experiments are: the ASYTRAIN controller, the ASYTRAIN software and the auxiliary hardware to make measurements. 4.2 ASYTRAIN controller This equipment has a stepper motor that works as azimuth positioner and executes the programmed movements to measure the radiation patterns. The motor is controlled by a Microchip PIC from the ASYTRAIN-SOFT via USB. This PIC also sends the measured frequency data to the RF synthesizers (Tx and Rx LO). The RF synthesizers cover directly the L/S band measurements ( MHz) with a resolution of 1 MHz. Two RF multipliers (x3) are used to obtain the X-band frequencies (6-12 GHz). The band selection is made by ASYTRAIN-SOFT, automatically according to the frequency selected. For both bands, the received IF signal (40 MHz) is sent to a logarithmic detector, with a dynamic range of 60 db, to be read by a 10 bit A/D converter controlled within the PIC. 4.3 ASYTRAIN SOFTWARE The ASYTRAIN SOFTWARE, which will be delivered on a memory stick, is developed using the JAVA programming language (no license required). The file with the software results, for measurement and design, have an ASCII format so the user can export them to any other software. The main software functions are the ones shown in the figure: 4

5 Figure 1. Main ASYTRAIN SOFTWARE window 1. Design programs (only included within advanced course) These programs allow the design and measurement of a variety of antennas. The design SW packages are as follows: SABOR: To analyse the sectorial, pyramidal, conical horns (smoothed and corrugated) and single and double reflectors (in centred and offset configurations). MOMENTOS: To analyse simple dipoles and antennas with parallel dipoles such as Yaghi s, panels of dipoles 4NEC2: To analyse any type of linear antennas (based on the popular NEC). ARRAY: To analyse and synthesize linear and reticular planar arrays. PATCH: To design single rectangular micro strip patch antennas. LENS: To design lens for horn aperture phase compensation. REFLECTARRAY: To design basic reflectarray antennas (courtesy of professor Encinar, Universidad Politécnica de Madrid ). SPLASH: To analyse a Gregorian ring focus reflector antenna. In addition other antennas such as RADOME, MFRA, SLOTS, ROTMAN can be analysed (see section 7). The ASYTRAIN SOFTWARE is delivered as open source so the teaching staff can include their own software routines. 5

6 2. New measurement: To define and execute antenna measurements, according to the following open window: Figure 2. Measurement data window 3. Representation: to process the data and to graphically represent the radiation patterns, gain and return losses. Figure 3. Representation example 6

7 4.4 Auxiliary hardware of the measurement system The measurement system also includes the following elements: 1. A linear slide (next figure) to move the AUT and centre it on the azimuth axis. This slide is also used to check the 1/r 2 law of the far field radiated power density of the antennas. Figure 4. Lineal slide over azimuth positioner 2. Two dielectric support cylinders, one of them with adjustable height in order to align the roll a polarization positioners. 3. Two manual roll positioners to rotate the AUT and the auxiliary source antenna to record the CP and XP patterns. Figure 5. Manual Roll positioner 7

8 4. Levels (over roll positioners) for vertical adjustment of the two dielectric supports and a laser and target mirror to align, if desired, the roll axis of AUT and the polarization axis of the source antenna. Figure 6. Alignment laser and mirror 5. Two RF cables, a USB cable and several SMA-N transitions in order to connect the different components of the system. 5 DESCRIPTION OF COURSES The following sections describe the objectives of each course, their elements and the practices that can be performed. 5.1 ASYTRAIN L/S-bands / Basic course 1. Objectives The objective of this course is to introduce students to the properties of the antenna radiated field, analysing the attenuation as a function of the distance, the Tx/Rx coupling for different polarizations, the variation of the input impedance with the frequency, the concepts of gain and directivity, and the definition of the other radiation parameters, such as beam width, side low levels, etc. This course is targeted towards first level students (high schools) and junior technical staff of defence organizations. The antennas (L/S-band) in this course are shown in the following figure, except 3 helix antennas (1 LHC and 2 RHC). 2. Antennas included in the package In this course the antennas are the following: Coaxial fed dipole Balun fed dipole (single and blended) Monopole 3-element Yagi antenna 8

9 Three Helix (1 LHC, 2 RHC) Log-periodic dipole antenna Other included components: 20 cm diameter planar disc (for monopole), and a 40x25 cm rectangular plate (for reflection surface). Some of these antennas are show in the following figure: Figure 7. Some of the basic course linear antennas Lecture Notes System alignment, 1/R2 Law, Interference from reflections, Measurements setup guidelines Friis formula, Polarization losses (cases: linear-linear, linear-circular, circular-circular), Co-Cross polarization definitions, Tx/Rx mismatch losses (AUT return losses), Gain measurement. Radiation pattern, Near/Far-field measurement, Beam width (3 db), Side-lobes level, Directivity. Study of the different included antennas and measurement of its patterns, return losses, directivity, gain, etc. ASYTRAIN X-band / Basic course 1. Objectives This course includes the same experiments as the previous one, but using the X-band aperture antennas. It allows the visualization of the radiation patterns of the antennas similar to those employed for satellite communications. 2. Antennas Included In this course the antennas are the following: Pyramidal horn Turrin conical horn Cylindrical waveguide feeder (with a choke and splash) Two axes Gregorian reflector antenna One LHC and two RHC Helix Other included components: Two SMA to WR-90 waveguide transitions, one WR-90 rectangular to cylindrical waveguide transition, and a 60x40 cm rectangular plate (for reflection surface). The antennas (X band) in this course are shown in the following figure (except two screws RHC/LHC polarizers). 9

10 Figure 8. Some of the basic course aperture antennas 3. Lectures Notes The basic experiments (Friis formula, polarization, etc.) that can be performed in this course are the same to those of the S/L-band basic course, but the antenna description is based on the aperture theory (Huyghens principle) and the radiation characteristic of these antennas are in general more precise and interesting. 5.2 ASYTRAIN L/S-bands / Advanced course 1. Objectives The objective of this course is to expand the student s knowledge regarding linear antennas. This is achieved by utilising the design software tools (MOMENTOS, 4NEC2 and ARRAY) and the antenna building kits included. 2. Antennas Included This course contains the whole elements of the ASYTRAIN L/S-band basic course plus the following building antenna kits: 2 elements Yagi with adjustable dipoles 6 elements Yagi kit 2 additional monopole antennas for building a three monopole array (broadside, endfire, etc.) 2 S-band patch antennas (Linear, LHC and RHC polarization) Other included components: 9 RF cables for the 3 antenna arrays setup, three ways L-band power divider, 4 SMA attenuators (two of 3 db and two of 6 db, to implement triangular excitation in order to reduce the secondary lobes), a 60x15 cm plate with holes for monopole arraying. In addition, a 300 Ohm bifilar line fed through a coaxial split balun (1:4 impedance ratio) and a probe loop for stationary wave measurement is included. 10

11 Figure 9. Some of the building linear antenna kits 3. Lecture Notes The basic experiments (Friis formula, polarization, etc.) that can be performed in this course are the same to those of basic one plus any experiment proposed by the teaching staff using the included kits. For example, Yagi design with different number of elements (up to six directors), 3 elements arrays with different distance and phases to test the scanning, grating lobes, secondary lobes control, etc. With the probe loop, the students can visualize the current distribution along the bifilar line with different load conditions (open, short and match), and the current distribution of the dipoles. 5.3 ASYTRAIN X-band / Advanced course 1. Objectives The objective of this course is to expand the student s knowledge about aperture antennas. This is achieved with the design software tools (SABOR and LENS) and the included antenna building kits. 2. Antennas Included: This course contains all components of the ASYTRAIN X-band basic course plus the following building antenna kits: Single offset reflector with a feeder with two adjustable corrugations 2 Pyramidal horns building kits (2 WR-90 short waveguides with flange as basement of the sectorial or pyramidal horn building) High phase error conical horn and corrugated lens to compensate the phase error. Rod dielectric antenna 11

12 Other included components: Adjustable screw polarizer, 3 circular plates (different diameters) with support to visualize its blockage effect over the aperture of the reflector, supports for lateral feed movement, aluminium sheets (0.2 and 0.4 mm thick, scissors, cutter and guillotine to cut and blend the wall of the pyramidal horns. Some of the additional antennas and components included in this course are shown in the following figure. Figure 10. Some advanced option aperture antennas 3. Lecture Notes The basic experiments (Friis formula, polarization, etc.) that can be performed in this course are the same to those of the X-band basic one plus any experiment proposed by the teaching staff using the included kits. For example, sectorial and pyramidal horns with different gain, different aperture phase errors, different or equal main planes 3db beam width, etc. With the offset antenna reflector the following antenna analysis and measurements can be performed: 1. Single offset reflector (SOR) fed from the focus and lateral positions by the feeder. 2. Analysis and measurement of the level of SOR intrinsic cross polar radiation in the antisymmetric reflector plane. 3. To check the SOR squint effect in the antisymmetric plane when illuminated with circular polarizations. 4. Visualize the induced central blockage effects (with circular plates). With the high phase error horn and the lens, the compensation of the phase error on the radiation pattern can be visualised. 6 DOCUMENTATION The content of the course documents is organized as follow: 1. Basic courses For the basic courses, there is a detailed introduction to plane and spherical wave theory, and its propagation through a transmission line. In addition, the definition of the main parameters of antennas 12

13 ( IEEE Standard) and the Friis formula, are presented. With this background, the students are capable of following all the basic courses of both linear and aperture antennas lectures at S/L and X- bands. 2. Before starting any of the basic laboratory lectures, the students should make use of a questionnaire in order to assess their knowledge of the subject. Advanced courses For the advanced courses, there is a brief introduction about the principles of the antenna under analysis, and the each lecture objectives are described. This introduction includes a selected bibliography aimed to enhance the student s background concerning the lecture notes.. Besides, a laboratory guide to complete the antenna design, build and take measurements is included. 7 ASYTRAIN OPTIONS OPTION 1: REFLECTARRAY Included Components : Prototype under construction Reflectarray printed prototype. Turrin horn feeder. Documentation: Introduction to Reflectarrays. REFLECTARRAY design software. Figure 11. Reflect array prototype The reflect array documentation and software have been developed by Prof. José A. Encinar (IEEE Fellow). One of the most important international researchers on this topic. OPTION 2: MULTIBEAM ROTMAN LENS Included Components : 10 beam dielectric Rotman lens. Documentation: Principles of Rotman lens. ROTMAN analysis software. Figure beam Rotman lens 13

14 OPTION 3: 4X4 PATCH PLANAR PHASED ARRAY Included Components: Under mechanical design 4X4 printed patch array. Power divider and 4 bits digital phase shifters (controlled by manual digital micro switches). Documentation: Linear and reticular planar arrays. ARRAY software. Figure 13. 4x4 patch elements planar phased array prototype OPTION 4: RESONANT AND NON RESONANT SLOT WG ARRAYS Included Components: 32 cm Waveguide section with upper wall open, finished with load (for no resonant designs). 27 cm Waveguide section with upper wall open, finished with short (for resonant designs). One plate with slots (nr design)*. One plate with slots (r design)*. *In both cases for 25dB Chebyschev array design. Documentation: Description of resonant and non-resonant slot antennas. Figure 14. Resonant and non-resonant slot array antennas SLOTS Software: Chebyschev synthesis and slot displacements for resonant and no resonant array designs. 14

15 OPTION 5: HORN CLUSTER FOR CONTOUR BEAM ANTENNAS Included Components:: Under mechanical design. 6 cylindrical horns cluster*. X-band 8-way power splitter/combiner. 6 cylindrical to rectangular waveguide to SMA transitions. 6 SMA RF cables. Documentation: Introduction to contour beam antennas MFRA software: Multi Feed Reflector Analysis software for contour beam antennas design. *As reflector, the antenna uses the 40 cm off-set reflector included in X-band advanced course. Figure 14. Horn cluster prototype OPTION 6: SUPERTURSTYLE ANTENNA 15

16 Included Components Cylinder boom, 4 wing sheets and 8 coupling cylinders. 2 mm wire to construct the wired version. 4 Way power splitter. Set of 4 RF-SMA cables. Documentation: Instructions for design and ensemble*. * The wired version can be analysed with 4NEC2 software. Figure 15. Superturs antenna prototype OPTION 7: RADOME MEASUREMENT SETUP Included Components : Rotating support setup. 30x30 cm thin Raydel test specimen. 30x30 cm thick fibre glass test specimen. X-band B sandwich radome test specimen. 30x30 cm half wavelength PVC window. RADOME software: Design of single layer and B sandwich radomes. Figure16. Setup and two radome probes 16

17 OPTION 8: SETUP AND CALIBRATING ELEMENTS FOR RCS MEASUREMENTS Included Components : Dual Roll positioners for TX and RX antennas. Calibrating Elements Two rectangular planar plates. One cylinder. One dihedral. One trihedral. Radar blank>>???? One Raptor (1:144). One Commercial Plane (1:144). ASYTRAIN RCS Software (Special software for RCS measurements). Figure 17. Cylinder and Trihedral Calibration RCS target OPTION 9: MOBILE CABINET 17

18 Figure18. 3D view of the Mobile cabinet Included Components: This option allows organization of all the antennas and measurement components to be arranged in trays. With this option the ASYTRAIN-CONTROLLER is integrated in the cabinet upon with the azimuth axis emerging through its top. The cabinet has wheels for movement and a front door with key for security. 8 SPECIFICATIONS Frequency range: Type Rx Dynamic Range Controller Interface Power supply Axes Antenna Parameters Manuals Software modules 1-2GHz (L-band) 8-10GHz (X-band) Synthesized with 1 MHz increment 60dB USB 110/220V 50/60Hz Motorised Azimuth (Stepper motor) Roll Manual Axis Source Polarisation Manual Axis VSWR, Gain, Axial Ratio, Principal Plane Pattern Student and Instructor Manuals (basic) Student and Lecturer Manual (advanced) SABOR (horn and reflector analysis) 18

19 MOMENTOS (dipoles and Yagi, Dipole panels) 4NEC2 (linear antennas) SPLASH (Gregorian double axes reflectors) ARRAY (Linear and planar grid arrays) SLOTS (Resonant and non-resonant slot WG array) LENS (Dielectric lens design) PATCH(Single rectangular microstreep patch antennas) MFRA (Multi feed reflector antennas) RADOME (radome analysis) ROTMAN (Multibeam dielectric Rotman Lens) LPDA (Log Periodic dipole Antennas) 19

20 9 PRICING TRAINING COURSES: (Includes ASYTRAIN CONTROLLER, ASYTRAIN SW) ASYTRAIN BASIC L Band ASYTRAIN BASIC X Band ASYTRAIN BASIC L + X Band ASYTRAIN L Band ADVANCED ASYTRAIN X Band ADVANCED ASYTRAIN L + X Bands ADVANCED OPTIONS: OPTION 1: RADOME MEASUREMENTS OPTION 2: RCS MEASUREMENTS OPTION 3: SIX HORNS CLUSTER CONTOUR BEAM ANT OPTION 4: MULTIBEAM ROTMAN ANTENA OPTION 5: PLANAR PHASED ARRAY ANTENA OPTION 6: RESON. AND NON RESON. SLOT WG ARRAYS OPTION 7: SUPERTURNSTYLE ANTENNAS OPTION 8: ROD ANTENNAS OPTION 9: L-Band CAVITY ANTENNAS OPTION 10: MOBILE CABINET For Sales please contact your local distributor which can be found on Radiation Group website: 20