Fully Integrated 94-GHz Dual-Polarized TX and RX Phased Array Chipset in SiGe BiCMOS Operating up to 105 °c

Abstract

94-GHz dual-polarized phased array transmitter and receiver ICs in 130 nm BiCMOS technology are reported. The transmitter IC integrates 16 transmitter front ends with two independent outputs, a 1-to-16 power splitter, and an intermediate frequency (IF)-to-RF up-converter. The receiver IC integrates 32 front ends, two separate 16-to-1 power combiners, and two RF-to-IF down-converters, which can either support a 32-element phased array or a 16-element polarimetric phased array if connected to 16 dual-polarized antennas. Both transmitter and receiver ICs include IF/baseband circuitry, a frequency synthesizer with continuous lock detection, a temperature sensor, and digital circuitry, including serial interface and front-end memory. On-wafer TX measurements at 94 GHz taken at 25 °C show an IF-to-RF conversion gain of 35 dB, oP1dB of 4 dBm, PSAT of 7.8 dBm per channel with a total power consumption of 3 W. On-wafer RX measurements at 94 GHz and 25 °C show a maximum RF-to-IF array conversion gain of 40 dB and an noise figure (NF) of 6 dB. The total RX power consumption varies from 3 to 4.6 W as it is configured from its minimum to its maximum RF front-end gain settings. RF phase shifting elements used in both TX and RX demonstrate a 1.6° phase resolution with 360° tuning range and gain variation (rms) lower than 0.5 dB. Phase-invariant gain tunability in TX and RX front ends has been achieved for independent tapering and beam steering, demonstrating the measured phase variation within ±0.5° for 10-dB gain tuning. Both TX and RX ICs are functional up to 105 °C, maintaining PSAT>6.5 dBm per channel in TX and NF < 12 dB in RX. The TX and RX ICs each have a chip size of 6.7 mm × 5.6 mm.