A Robust, Efficient Distributed Power Amplifier Achieving 96 Gbit/s With 10 dBm Average Output Power and 3.7% PAE in 22 nm FD-SOI

Abstract

A pseudo-differential distributed power ampli- fier (DPA) based on complementary gain stages is presented for wideband femtocell 5G indoor communications in 22 nm fully depleted silicon-on-insulator (FD-SOI) technology. Capac- itive equalization is used to achieve flat bandwidth over the desired frequency range. Due to the complementary gain stages, no expensive bias-Ts are required. In order to improve reverse isolation and increase the output power, stacking is utilized. The design uses back-biasing to set the drain voltages of the DPA instead of the sensitive gate biases. The differences in the design process between a distributed amplifier (DA) and a DPA are presented. Tradeoffs between gain–bandwidth (GBW), reliability, peak power-added efficiency (PAE), output power, and amplitude- to-phase (AMPM) linearity are explored. The DPA achieves an 11.6 dB gain, a 0.4–31.6 GHz 3 dB small-signal bandwidth, and a 16.4 dBm peak-saturated output power ( P SAT) with a 17.2% PAE from the 2.5 V supply. AMPM distortion at output-referred 1 dB compression point (OP 1d B )a n da tPSAT is less than 2◦/5◦ up to the 31 GHz, respectively. It achieves 10 dBm average output power reaching 80/96 gigabit per second (Gbit/s) at 17 GHz with 16/64 QAM modulation. At 28 GHz, it achieves 6.4/4.5 dBm output power with 12/8 Gbit/s data rate with 64/256 QAM modulation.