A Q-band High Power SiGe HBT Doherty Power Amplifier Leveraging 8-Shaped Inductor-Embedded Ultra Compact Doherty Passive Network

초록

This brief presents a compact, high power Q-band SiGe HBT Doherty power amplifier (PA) for very low earth orbit (VLEO) satellite communication (SATCOM). An 8-shaped inductor-based λ/4 impedance inverter, embedded into an output transformer (TF) balun, results in magnetic coupling cancellation (MCC) between the two, enabling to implement compact Doherty network in a single footprint. Also, an adaptive bias circuit (ABC) helps abruptly turn on and off a peaking (PK) amplifier, leading to true Doherty operation as evidenced by clear PAE peaking at 6-dB power back-off (PBO). A prototype is fabricated in 0.13-μm SiGe HBT BiCMOS, with an active area of 0.46 mm2. It attains peak output power (POUT) and power added efficiency (PAE) of 24.5 dBm and 23.9% at 38 GHz. At a 6-dB PBO, the PA achieves a PAE of 22.7%. The PA was also evaluated by a 200 MHz 5G NR FR2 64-QAM CP-OFDM with 9.7 dB peak-to-average power ratio (PAPR) signals, achieving 13.1 dBm average POUT (Pavg) with 13.8% average PAE (PAEavg) at EVM of −25.0 dB. © 2004-2012 IEEE.

키워드