A multi-channel S-band FMCW radar front-end

This paper describes the design and performance of a low-cost synthesized FMCW radar module, operating in S band. The bi-layer PCB contains a frequency-agile low phase-noise synthesizer and three identical coherent receive-channels. The transmit channel has an automatic power control system that reduces the output power when a large reflection causes the receiver input level to exceed the linear input range. Standard surface-mount components from commercial WLAN applications have been used to create a versatile programmable radar module. The DDS-based PLL synthesizer achieves a SSB phase-noise level of -101 dBc/H @ 10 kHz offset from a 2.4 GHz carrier. A basic serial PC interface enables control of the FMCW radar parameters that can be stored in the on-board non-volatile memory. The complete front-end operates from a single 3.6 - 5.5 Volts supply, drawing 220 mA and measures only 55 times 100 mm.