A design of 1 to 4 GHz broadband high‐efficiency power amplifier with two‐way concurrent active load modulation method

Abstract

Active load modulation and harmonic injection can be used to boost the power amplifier's (PA) efficiency, but these techniques must add a fundamental external source or a harmonic generator. In this paper, a two-way power amplifier architecture is introduced to extend high-efficiency operation bandwidth by utilizing concurrent active load modulation with a waveform mapping method. Active load modulation is realized in between the two branches with the aid of independent input amplitude and phase control. Based on a calculated waveform database, high-efficiency operations for both transistors from 1 to 4 GHz are designed in a self-defined optimization platform considering waveform distance and input parameters. Finally, this PA is fabricated and measured to offer 41.6 to 45.0 dBm power, 8.2 to 11.7 dB gain, and 56% to 89% drain efficiency from 0.85 to 3.85 GHz.

8‐12 GHz single‐input GaN load modulated balanced amplifier monolithic microwave integrated circuit

“…The rapid development of modern communication systems puts forward higher requirements on the efficiency and linearity of the broadband power amplifier (PA) in the transmitter 1,2 . In the scenario of signal transmission with high peak‐to‐average power ratio (PAPR), the efficiency of PA at power back‐off (PBO) is urgently required to be enhanced.…”

“…The rapid development of modern communication systems puts forward higher requirements on the efficiency and linearity of the broadband power amplifier (PA) in the transmitter. 1,2 In the scenario of signal transmission with high peak-to-average power ratio (PAPR), the efficiency of PA at power back-off (PBO) is urgently required to be enhanced. A variety of innovative efficiency enhancement techniques based on load modulation were introduced to break the tradeoff between linearity and efficiency, among which Doherty PA and Outphasing PA are mostly prevalent.…”