A 110–170GHz Phase-Invariant Variable-Gain Power Amplifier Module with 20–22dBm Psat and 30dBm 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° 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 Psat, 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 Pout) and 64-QAM (36-Gb/s with 8.6% EVM at 15.5 dBm Pout) are demonstrated at 140 GHz. The output power×bandwidth performance of the packaged all-silicon module is better than the state-of-the-art commercially available III-V parts.