Study And Design On RF Front For S-Band Through-Wall Radar

Since the unique penetration detection capability for obstacles such as walls,boards and cardboard boxes,through-wall radar(TWR)has widely applications in indoor positioning,military counter-terrorism,post-disaster search,rescue,and medical treatment.A miniaturised RF front circuits for S-band FM continuous wave(FMCW)through-wall is designed in this thesis.This thesis first introduces the basic principle of distance and speed measurement of TWR and the basic transceiver architecture of TWR.According to the transceiver architecture,the transmitter link directly filters and amplifies the FMCW generated by the phase-locked loop chip and sends it to the transmitting antenna;the receiver link adopts a zero IF structure,consisting of an RF switch,a low-noise amplifier(LNA),a mixer and a variable gain amplifier(VGA),which filters and amplifies the received signal containing spurious waves,and then mixes it with the FMCW generated by the phase-locked loop chip after power division to obtain a signal containing the distance information.Finally,the IF signal is amplified by the VGA to a suitable power value.This paper presents a complete RF circuit design of TWR,and gives the circuit schematic and PCB layout in detail.Finally,the measurement of the RF front has been carried out,and the results agree well with the expectations,which provides a solution for the design of the RF front of TWR.