A sige-based 140-GHz four-channel radar sensor with digital beamforming capability

This paper presents a multi-channel radar sensor operating at 140 GHz. The sensor employs fundamental-wave SiGe-based chips that feature HBTs with 340-GHz ƒmax. A separate voltage-controlled oscillator chip provides the LO signal with frequencies from 136 to 150GHz for four cascaded transceiver chips. The saturated transceiver output power is approximately 4 dBm, the maximum receiver gain is 19.5 dB, and the minimum double-sideband noise figure is 13.5 dB. The equivalent isotropically radiated power of a single channel is 5 dBm. The sensor was field-tested with frequency-modulated continuous-wave chirps from 140 to 145 GHz. Targets were resolved in range and angle by means of digital beamforming.