A 90–98-GHz FMCW Radar Transceiver Supporting Broadband Modulation in 65nm CMOS

A 90-98-GHz frequency-modulation-contiguous-wave (FMCW) radar with four transmitters (4TX), four receivers (4RX), a frequency synthesizer and a local oscillator (LO) distribution network is fabricated in 65-nm CMOS. An ultra-wideband mixer without stacked transconductance is proposed to operate across 20–110 GHz. A multi-state cascaded topology using a magnetically coupled resonator (MCR) with two resonant peaks is employed for the low noise amplifier and the power amplifier. An LO distribution network integrates three frequency doublers for frequency octupling from an 11–13 GHz frequency synthesizer, which facilitates broadband modulation. Measurements show the transmitters deliver a maximum output power of 13.2 dBm with 11.9% efficiency and 1.4 dB flatness across 90–99 GHz. The receivers achieve a conversion gain of 63.4 dB and a minimum single-sideband noise figure NFssb of 8.3 dB @3MHz across 88–98 GHz. The measured phase noise is -93.83 dBc/Hz at 1-MHz offset with a 90.4-GHz carrier. The root-mean-square (rms) frequency error is 9.36 MHz (0.12%) for a sawtooth chirp with an 8-GHz chirp-range and a 160-MHz/µs chirp-rate. The radar chip occupies a chip area of 4.5×3.8mm² including TRX front end, synthesizer and baseband, where the power consumptions are 210/78 mW for each TX and RX element, respectively.