A 122-GHz system-in-package radar sensor with BPSK modulator in a 130-nm SiGe BiCMOS technology

This paper presents a 122-GHz bistatic radar sensor for short-range applications. The chip features a fully differential frequency multiplier (×30 or × 6) to realize a frequency-modulated continuous-wave radar with a binary phase-shift keying modulator in the transmit chain and a fully-differential IQ-receiver. The bare die is packaged in an embedded-wafer-level-ball-grid-array (eWLB) technology. The redistribution layer of the eWLB package is utilized to realize eight-element tapered rhombic transmit and receive antenna arrays. The packages are fabricated with and without backside metallization to demonstrate the effect on radiation pattern symmetry and sidelobe levels. On-wafer measurement results show a maximum transmit output power of 2.7 dBm and a 3-dB bandwidth of 17 GHz. The in-package TX/RX antennas provide a measured gain of 11 dBi which results in an effective isotropic radiated power of 13.7 dBm. The entire chip consumes a DC power of 540 mW at a supply voltage of 3.3 V.