A Low-Power <i>Ka</i>-Band Transceiver With 5.2-GHz Bandwidth for FMCW Radar Applications

This brief presents a Ka-band frequency-modulation continuous wave (FMCW) transceiver (TRX) in 65-nm CMOS for low-power, high-resolution radar detection. The low-noise amplifier (LNA) employs current multiplexing and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$G_{m}$ </tex-math></inline-formula>-boosting techniques to enhance energy efficiency. The proposed primary-coil current splitter improves the gain and minimizes crosstalk between the I/Q mixers. The transceiver achieves a 15.6-dBm maximum transmitter (TX) output power with a 35.3% drain efficiency (DE) at 34.6 GHz, a 49-dB receiver (RX) conversion gain (CG), and a 4.9-dB minimum double-sideband noise figure (NFdsb). When operating at low-voltage mode, it achieves a 7.68-dBm TX output power with a 23.8% DE, a 41-dB RX CG, and a 9.17-dB RX NFdsb. The measured phase noise is −100.6 dBc/Hz at 1-MHz offset with a 32.4-GHz carrier. The rms frequency error is 2.94 MHz (0.073%) for a sawtooth chirp with a 4-GHz chirp bandwidth and a 200-<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>s chirp-up time. The proposed transceiver achieves wide bandwidth and low power consumption among Ka-band FMCW radar TRXs. An inverted shunt-fed patch antennas are also fabricated on an evaluation board using Rogers 4550F to demonstrate high gain and broadband operation over the air (OTA).