C-band Pseudo-code Phase Modulation Detector Front-end Key Technologies

This dissertation introduces the key techniques of the front-end system in a C wave band detector. The main contents are as follows:(1) Design and make a four-patch microstrip antenna array. Because the finite ground plane is circular and also very small, we press the antenna array a little narrow, and use a SMA joint to make a probe-feed; when simulating the antenna array model in IE3D, we do a non-uniform meshing of the circular ground plane by hand. In this way, we can reduce the unknowns and the design cycle as far as possible, while it is also very accurate. The test results (the resonant frequency: 5.81 GHz, the bandwidth (VSWR<2): 140 MHz) prove good enough to meet the needs of the system.(2) Do some research on the microstrip antenna of C wave band from three aspects.(3) Design and make a PLL frequency synthesis as the local oscillation source. The test results (the locked frequency: 5.8 GHz, the phase noise: -93.51 dBc/Hz@10KHz) prove good enough to meet the needs of the system.(4) Design modulation and demodulation circuits; Design a power-split to split the signal of the PLL frequency synthesis.