| Radar is an equipment that uses electromagnetic waves to detect targets.In the war era,information superiority is an indispensable condition to win the battle.By using reconnaissance radar to detect the ground and low altitude moving targets,determine their positions and classify the targets,we can soon master the battlefield status comprehensively,and then take countermeasures and make tactical adjustments.In peacetime,reconnaissance radar also plays a vital role in protecting border areas,preventing smuggling and terrorists,so the research on reconnaissance radar cannot be stopped.The progress of The Times request radar not only to achieve the function of target detection,and toward a high precision,all-weather,light quality,small volume,low power consumption direction,and the millimeter wave radar beam narrow,small size,light weight,resistance to electromagnetic interference ability,ability to penetrate smoke,rain,fog,therefore very suitable for single-soldier reconnaissance.The antenna at the front end of the radar has a great influence on the performance of the whole radar system,so it needs to be researched and designed.Therefore,this paper focuses on the front end of 3mm band soldier radar.In this paper,the type of radar transmitting antenna and receiving antenna is Cassegrain antenna.Due to the existence of the sub-reflective surface,the Cassegrain antenna extends the focal length of the antenna and has a short radial distance,which is in line with the design background of small volume of individual soldier radar.Considering the important influence of the feed on the performance of the reflector antenna,the tapered horn antenna and the tapered dielectric rod antenna are simulated and designed.The gain,sidelobe level and irradiation Angle of the two antennas meet the requirements of feeding the reflector antenna.The designed Cassegrain antenna has a gain of 40 dB,a lobe width of 0.7°,and a side lobe level of-23 dB,all of which meet the design requirements.In the design,an aluminum plate is added between the transceiver antennas to isolate the propagation of space waves,which improves the isolation degree between antennas and achieves good results.This article expounds the frequency modulated continuous wave radar range and velocity measuring principle,research branch of radar transceiver and designed a W band filter of the hardware and the structure of waveguide to microstrip transition,on the basis of radar performance picked out in such aspects as working frequency,gain,noise figure meet the requirements of the chip,shows the main function and the performance parameters of the chip.Through octave frequency and power amplifier,the local oscillator signal with the required frequency and power value is obtained.Design,intermediate frequency signal to frequency converter to rf signal through the two levels of power amplifier power amplifier,when the intermediate frequency signal of power input around-10 dBm,launch branch of the output signal power conservative can reach 20 dBm,choose the form of a superheterodyne receiver,receiver to receive the echo signal of under frequency conversion to the intermediate frequency signal for the first time,Then the signal is converted down for the second time to realize the demodulation of the echo signal.The noise coefficient of the receiving branch is 5.29 dB,and the gain is up to 40 dB.Finally,based on the principle of radar ranging,the radar equation is derived,and the maximum detection range of radar target is estimated by combining the parameters in the design. |
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