Harmonic‐tuned high‐efficiency GaN power amplifier with precise AM‐AM and AM‐PM characteristics

Abstract

An optimal balance between high efficiency and high linearity is one of the main performance metrics of modern base stations to handle the deep compression of the power amplifier (PA) module. In principle, the plethora of amplitude-to-amplitude (AM-AM) and amplitude-to-phase (AM-PM) distortions are issues worth exploring. Therefore, this paper presents a linearized harmonic-tuned PA that operates at 2.4 GHz. The presented PA utilizes a compact input matching network (IMN) and output MN (OMN) with shuntconnected tunable resonant circuits augmented by the stabilization network, whose presence greatly reduces the transistor parasitics and high-order effects.Hence, a joint embodiment of each other gives optimal fundamental impedance matching alongside harmonic terminations and precise AM/PM waveform properties. The measurement results have shown that the fabricated PA exhibits peak saturated output power of 40.9 dBm and peak drain efficiency (DE) of 67%. In addition, the AM-AM and AM-PM curves under continuous-wave excitation yield a gain flatness of 0.5 dB over a 37.5 dBm power range and ±3.5°phase distortion, respectively, when the input power level is swept up to the saturation level of 40 dBm. When driven with a 5 MHz 64-QAM OFDM signal and 6.9 dB power back-off, the manufactured PA meets the adjacent channel leakage ratio specification of −30 dBc at an average output power of 34.5 dBm.

A Dual Load-Modulated Doherty Power Amplifier Design Method for Improving Power Back-Off Efficiency

“…This inevitably requires the power amplifier (PA) to work in the output power back-off (OBO) region, and the traditional PA architecture usually exhibits low efficiency in the OBO region. This will lead directly to a serious reduction in the efficiency of the entire transmitter [ 6 , 7 , 8 , 9 , 10 , 11 ]. As a PA architecture with high OBO efficiency, the Doherty power amplifier (DPA) [ 12 , 13 , 14 , 15 , 16 , 17 , 18 ] has attracted the attention of a large number of researchers due to its simple circuit structure and easy broadband design.…”

A High Efficiency Broadband Gallium Nitride Power Amplifier with Harmonic Control technology

“…Therefore, the appropriate harmonic control network needs to be developed. Moreover, a suitable network for controlling harmonics can increase its efficiency [8]- [9]. Therefore, high efficiency and broadband PA are still the focal points with high research value and significance [10].…”