A Linearity-enhanced 28-GHz Class-F−1 SiGe Power Amplifier

This paper presents a Class-F
⁻¹
power amplifier (PA) targeting 28-GHz 5G communication. A common emitter (CE) topology with a degeneration inductor for linearity enhancement is analyzed. The optimum harmonic terminations for Class-F
⁻¹
operation are provided by a transformer-based harmonic tuned network. Fabricated in
$0.13-\mu \text{mSiGe}$
process, the PA achieves a measured output 1-dB compression point
$(\text{OP}_{1\text{dB}})$
of 16.5 dBm and a maximum power-added efficiency (PAE) of 37.2% at 28 GHz with a 1.6-V supply. The high linearity of the PA is demonstrated by a 64-QAM signal measurement with 2.4 Gb/s data rate at 28 GHz. The proposed PA exhibits a 12.5-dBm average output power (P
avg
) and 17.8% PAE with a corresponding EVM of -26 dB. The proposed PA fulfills the high linearity and high efficiency requirement of 5G applications.