79 GHz Short Range FMICW Radar

Abstract

Short range FMICW radar chip was proposed. This chip integrates a single pole double throw (SPDT) antenna switch, power amplifier (PA), low-noise amplifier (LNA), voltage control oscillator (VCO), mixer and divider chain. An single pole double throw (SPDT) an-tenna switch integrated with a CMOS power amplifier (PA) and a low-noise amplifier (LNA) by using a 3-piece transmission line transformer (TLT) for a frequency-modulated interrupted continuous-wave (FMICW) radar front-end is proposed. The 3-piece transmis-sion line transformer consists of a power amplifier output transmission line (TL), a low noise amplifier input TL, and a TL connected to antenna. Parallel switches and $\lambda/4$ effective im-pedance transformers are used to provide high isolation. Due to the effective integration, the chip size and overall insertion loss are reduced significantly. For measuring the short dis-tance by using the chip, the synchronization method (synchronizing with PLL clock, ADC clock, and switch clock) is proposed. The measured results demonstrate that the proposed switch achieves an insertion loss of 2.2 (2.6) dB with an isolation of 33 (33.4) dB in the antenna-to-low noise amplifier input (power amplifier output-to-antenna) direction. The chip, including the transmitter and re-ceiver for a 79 GHz FMICW radar front-end is fabricated in 65 nm CMOS technology, and its size is 0.96 [mm]^2. The power amplifier output power is 10 dBm at 79 GHz, and the low noise amplifier gain is 15 dB at 79 GHz. The VCO tuning range is 38.24 GHz to 40.96 GHz. Divider chain output range is 4.78 ~ 5.12 GHz.