ELEC RADAR FRONT-END SUMMARY

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1 ELEC Radar Front-End is designed for FMCW (including CW) radar application. The output frequency of each RX provides range, speed, and amplitude information to DSP. It will detect target azimuth angle when use multi RX CH design. The front-end is not a final radar product. It works with radar DSP unit, display unit or radar data interface/format as a complete radar product. To use ELEC radar front-end only, customer should have the background knowledge of FMCW radar, mono-pulse radar, and/or beaming forming radar. Front-End Family 1. Basic Front-End Information 1. Front-End (FE) is composed by TX, at least 1 RX, and multi antennas (at least 2) 2. TX is controlled by embedded processor. The available waveforms are: CW (for Doppler radar to detect speed) Saw-tooth (FMCW radar to detect range for slow speed target) Triangle (FMCW radar to get both range and speed) There are 2 pins at interface for DSP select desired TX waveform. 3. Each RX has 55dB RF to IF gain. RF band is typical from 15KHz to 2.5MHz. 4. Single 5V to run front-end, current dependent on RF frequency and RX CH. 2. Front-End Code System (or Ordering No.) ELEC Radar Front-End Code System includes TX, RX and antenna specification TX frequency, sweep band, and modulation frequency (sweep period) Number of RX, each RX has one CH output, or 2 CH output (IQ mixer) Antenna patch number in azimuth-dir of TX and RX (beam coverage) Patch rows in Elevation-dir of antenna Page 1 of 11

2 ELEC Radar has standard Front-End designs. 3. Basic Front-End Structure Fig 1 is the basic structure of Front-End (FE) of ELEC Radar. There are triple patch array antennas. One with 4X8 patches is connected to TX output. Two 2X8 patches are connected to input of RX. RX and TX are called as transceiver. They are typical assembled on 2 side of a support plate. Transceiver is on the backside of planar antenna. Fig 1: Basic Radar Front-End Structure of ELEC Radar Page 2 of 11

3 Typical interface between front-end and DSP are: 5V and G (Ground) pins RX output (to DSP) pins R1 and R2 (R3, R4,.Rn for different FE design) TX waveform select pins D3 and D4 for DSP Fr (either for external FMCW refer in, or send internal waveform out) 4. Available FMCW Waveform and TX Model All TX of ELEC Radar are RF synthesizer which refer-frequency is generated by internal waveform generator (IWG). Waveform is programmed by embedded CPU. DSP engineer can select waveform by pin D4 and D3. And get refer-signal thru Fr pin. It is option to get external refer-signal thru Fr pin. 4-1) Available TX Waveforms: Waveform Radar application Key parameter CW (when B=0) Doppler radar for target speed Fo Up ramp saw tooth FMCW radar for target range Fo, B, Fm Down ramp saw-tooth FMCW radar for target range Fo, B, Fm Triangle wave (default) FMCW radar for target speed and range Fo, B, Fm 4-2) Standard TX Model: Standard TX model is IWG provide triangle wave refer-signal to RF synthesizer. The default specifications are: Frequency band Center frequency Sweep band Modulation freq Fo (GHz) B (MHz) Fm (KHz) 24GHz GHz GHz GHz At this model, D4, and D3 pin don t work. Fr pin send Fr to DSP for synchronous process. Optional for standard model are adjust Fo, B and Fm, including waveform option (saw-tooth) without charge when option value is no more than 50%. Customer should be check application frequency and band if there is frequency license requirement. 4-3) DSP Select Waveform: Waveform is selected by DSP engineer thru D4 and D3 pin. The control logic of D4, D3 are: waveform D4 D3 CW 0 0 Up ramp saw-tooth 0 1 Down ramp saw-tooth 1 0 Triangle wave Page 3 of 11

4 Which 0~0.7V is digit 0, and 3.5~5V is digit 1. Fr pin still sends internal refer-signal to DSP 4-4) External Refer-Signal for TX Synthesizer: Typical, embedded CPU in TX set up FMCW radar key parameters, such as Fo, B and Fm and waveform by either standard spec, or follow customer specification. After burn machine code to embedded CPU, above parameters are not adjustable. The only different is waveform is option selected by either IWG, or by DSP thru D4 and D3 pins. In both applications, Fr is output port. DSP engineer does not have ability to adjust Fo, B and Fm. The last option to operate TX is extern refer-signal are used as RF synthesizer refers. So Fo, B and Fm are adjustable by DSP engineer. To get this option, the detail interface specification will open to customer after sign NDA document. 5. Why Multi Coherent RX CH Used The RX is coherent with TX which mixer pumping power is coupling from TX. R4 filter and IF amplifier is used after RF LNA and homodyne balanced mixer. This design is better to improve dynamic range. All RX CH will use the same design. Multi RX CH model is used to detect angle. Radar only detects target range, and speed parameters. Antenna will provide angle parameters. There are 2 beam directions in space, azimuth (AZ) and elevation (EL). ELEC Radar only provides azimuth angle detecting. Typical 2 key parameters will be considered for angle detecting: angle coverage and angle resolution. Angle coverage is antenna 3dB beam width. It is also the angle resolution when just use single antenna (without mechanical scan). Then the problem is conflict between wider coverage and narrow beam resolution. Traditional mechanical scan antenna has narrow 3dB beam (2 deg or less) because get wide (up to 360 degree) coverage by scan. But most FMCW radar application don t accept mechanical scan. Electronic phase scan array is the best technology but it is too expensive to be used in commercial application. Anyway, most FMCW radar AZ beam coverage is limited in 30 degree with 1 or 2 degree resolution. 2CH RX of mono-pulse radar works when maximum detect range is 200m, and target size is 2~5 m. 4 CH RX will made beam-forming radar (just in RX, not including TX) which is better for the case that 2 targets at the same range with different angle. ELEC Radar standard products are 1, 2 and 4 RX CH. Each CH has standard antenna, and option for customer design antenna. in simple, multi CH RX (with antenna) are used for angle detecting. 6. Antenna Beam, Pattern, and Size etc ELEC radar front-end provides standard FMCW radar TX and multi-ch RXs. We have some standard design antennas. In other words, we only provides limited standard front-end. Most front-end is customer design because antenna beam specifications are wider different with special application. Since ELEC radar mainly use patch array antenna and transceiver will be integrated on the backside of antennas, it is impossible to get any beam antenna. Even for limited beam angle antenna, it is hard for ELEC radar to pre product all possible front-end. Page 4 of 11

5 We will use GHz radar as example. Attached draw list patch number is 4, 6, 8, and 10 in azimuth-direction, and patch number is 6, 8, 10, 12, and 14 in elevation-direction. There are total 20 different antennas. Azimuth beam are 25.2(4patch), 17.6, 13.2, and 10.6 degree Elevation beam are 17.8(6 patch), 13.4, 10.6, 8.8, and 7.4 degree Antenna gain is from 15.5dB (4X6) to 22.1dB (10X14) One antenna size is from 1.08 X1.71 (27.5mmX43.4mm) for 4X8 patches to 2.86 X4.09 (72.6mmX104mm) for 10X14 patches Antenna spec outside our standard hardware is customer design. We only charge limit customer design cost for prototype. Another important fact is front-end size. For example, 4X8 patch array antenna has AZ beam 25.2 degree, EL beam 13.4 degree with 16.4dB gain. Antenna size is 1.08 X2.31. (27.5mmX 58.7mm) The front-end cross section size is different depend on design approaches. Most company design TX and RX share one antenna. Size maybe 1.3X 2.6 (need little larger than antenna size1.08 x2.31 ). This radar has no ability to detect AZ beam. And sensitivity is lower because leakage from TX to RX. ELEC Radar will use 2 antennas; no AZ beams detect ability, to improve sensitivity. But front-end size is increase to 2.4X2.6 ELEC Radar mono-pulse front-end need 3 antennas, size is increase to 3.5 X2.6. this front end has AZ beam detect ability (1 degree resolution from >22 degree coverage) If use 5 antennas to get 4-CH RX beam-forming front-end antenna, the size is increase to 5.7 X2.6. This front-end can detect multi targets even some of them in the same range. It is clear that even for 20 antennas listed in our attached table, there are 1, 2, 3, and 5 antennas for different function transceiver. Total is 80 selections. Since antenna is directly connected to backside TX or RX point, transceiver card design should change with antenna design. Page 5 of 11

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