A compact outphasing power amplifier with integrated reactive compensation

Abstract

An innovative design methodology is presented to simplify the architecture of outphasing power amplifier (PA). The proposed design, by absorbing transistor parasitic capacitance into reactance compensating network intrinsic for a Chireix outphasing amplifier, greatly reduces the complexity of impedance modulation network at the output side, hence reducing the overall circuit size. Theoretical formulations regarding the introduced design technique are fully described and the effectiveness is verified through the implementation of a 2.6‐GHz PA prototype intended for long term evolution application. The realized circuit achieves maximum power of 44.8 dBm based on two 10‐W gallium nitride (GaN) high electron mobility transistor (HEMTs), accompanying maximum 73.3% drain efficiency between the saturation point and 6‐dB output back‐off point. At the 6‐dB output back‐off point, the drain efficiency reaches 63.5%.

A high efficiency dual‐band outphasing power amplifier design

“…To better guide the design of the introduced PA and evaluate its performance, two independent single‐band outphasing PAs are first designed using Keysight ADS. Each PA is carefully optimized based on the design procedures given in Reference 31. To be specific, the same transistor applied in this particular design, CGH40010 from Wolfspeed, is used with the large‐signal model provided by the manufacture.…”

“…However, due to the dispersive effect of distributed microstrip lines and the deficiency of lumped elements, it was difficult to fulfill these requirements simultaneously at more than one frequency 25 . For this reason, the outphasing structure has not been as popular as the Doherty PA, for which multiband or wideband operations have become more feasible 26‐32 …”

“…25 For this reason, the outphasing structure has not been as popular as the Doherty PA, for which multiband or wideband operations have become more feasible. [26][27][28][29][30][31][32] Inspired by the aforementioned facts, a novel methodology for the dual-band outphasing PA is proposed in Reference 33. The key idea is to devise some dual-band components to replace the corresponding ones found in a traditional single-band configuration.…”

Analysis of the impact of prototyping‐related parasitic effects in a hybridGaNpower amplifier for5G FR1applications

“…The linearity of the PA may be a more or less stringent requirement compared to other performance indicators such as output power, operating bandwidth, gain, and efficiency, depending on the targeted application. 20 While linearization solutions such as predistortion [21][22][23][24] or dual-input architectures 12,25,26 can enhance linearity and make it compatible with standards, they can also make PA circuit design more challenging. However, in some cases, it is essential to design a PA that is intrinsically compliant with stringent linearity requirements.…”

“…To address this issue, specific back-off efficiency enhancement techniques have been proposed and developed over the years. These techniques, such as load modulation [8][9][10][11][12] and supply modulation, [13][14][15][16] have shown great potential for improving efficiency in OBO. It is sometimes the case that these techniques are both applied to the same PA, such as in.…”