A 110-170 GHz Phase-Invariant Variable-Gain Power Amplifier Module with 20-22 dBm P-sat and 30 dBm OIP3 Utilizing SiGe HBT RFICs

A phase-invariant variable-gain PA RFIC in 130-nm SiGe BiCMOS supporting multi-QAM waveforms over the entire D-band (110-170 GHz) is presented. The chip has a very low phase variation of +/- 2 degrees over a 15 dB gain control range as well as self-testing and fault-detection features (power detectors, temperature sensors, ADC, SPI control) to ease the implementation and testing of multi-chip PA modules. A WR-6 interface packaged module combining four RFICs on a glass substrate achieves an average P-sat, OIP3 and gain of 21 dBm, 30 dBm and 14 dB, respectively over 110-170 GHz while the return-losses are better than 10 dB. TX constellations of 256-QAM (16-Gb/s with 3.6% EVM at 11 dBm P-out) and 64-QAM (36-Gb/s with 8.6% EVM at 15.5 dBm P-out) are demonstrated at 140 GHz. The output powerxbandwidth performance of the packaged all-silicon module is better than the state-of-the-art commercially available III-V parts.