Radar Altimeter Simulator Based On FPGA

Recently, radar altimeter has been grately improved on ranging, measurementaccuracy, sensitivity and other aspects of fuction. The requirements for emulationaltechnology of radar altimeter are very high. Because general simulation equipments can’treach the purpose that realistically simulate the echo signal. Radar altimeter simulatoremerged in this background. The issue was to design a radar altimeter simulator to analogradar altimeter echo, radar altimeter measurements and sensitivity. The main contents asfollows:First of all, we presented the radar altimeter simulator design and discussed the basicarchitecture of altimeter system based on the theory of radar altimeter. Then we discussedthe composition of the simulator systerm in detail. It included a microwave link unit, abaseband signal processing unit, a test of beat signal unit, a computer display and controlunit and the delay unit. And we explained how to achieve the function of each unit.Secondly, we designed the key point of the baseband signal processing unit, thecontrol of microwave, the beat signal board. The baseband signal processing unit was toanalyze the key logic modules, such as a digital quadrature frequency below, an integermultiple of the interpolation filtering, decimation, digital delay, IQ modulation and so on.Microwave link unit was to control the communication among up conversion link, downconversion link, and frequency synthesizer based microwave control board Xilinx FPGASpartan-6on.We can also control the module internal attenuator, filter and so on. Inaddition, we designed the beat signal board schematics, PCB. Through controlling, we canproduce sine, sawtooth and triangular wave signal.At last, the paper illustrated the timing and function simulation and verification of thededign using Modelsim and Chipscope, to ensure that the design was correct andreasonable. We build the environment of test and we used an oscilloscope, signal sources,spectrum analyzer to observe the result of the test. The verification result can be proved bythe simulator was feasible combined with radar altimeter.The altimeter simulator can meetthe function inicators and reach the simulation purpose.