A Low-Loss Load Correction Technique for Self-Healing Power Amplifiers Using a Modified Two-Tap Six-Port Network
A Low-Loss Load Correction Technique for Self-Healing Power Amplifiers Using a Modified Two-Tap Six-Port Network
复制标题
使用改进的两抽头六端口网络的自愈功率放大器低损耗负载校正技术
DOI：
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发表时间：
2021
影响因子：
4.3
通讯作者：
L. D. de Vreede
中科院分区：
文献类型：
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作者：
Gaganpreet Singh;H. Nemati;L. D. de Vreede
本文提出了一种低损耗校正技术的自愈负载不敏感的功率放大器（PA）使用一个修改的两抽头六端口网络，其中的变化（复杂）的负载首先补偿其不必要的磁阻部分，其次是调整晶体管输出级的欧姆负载的变化，通过修改其电源电压和驱动电平。这种两步方法避免了可调匹配网络解决方案中出现的高Q条件，其目的是校正真实的和虚负载偏差，例如提供较低的插入损耗和电压应力。接下来，为了便于在不需要校准的情况下进行全自动负载失配校正，提出了用于阻抗检测和控制回路方法的改进的两抽头六端口网络。作为原则的证明，一个原型900 MHz AB类PA具有建议的校正技术，以及，六端口反射计和控制回路，已被实施为PCB演示。测试结果表明，在负载不匹配的情况下，自愈负载不敏感功率放大器的性能得到了显著提高，接近50 Ω性能。在2：1 VSWR 360°失配轨迹上，由64 QAM 3.86 MHz信号驱动时，PA可实现22 dBm的线性输出功率，变化仅为±0.1 dB，邻道功率比（ACPR）优于−45 dBc。
This article presents a low-loss correction technique for a self-healing load-insensitive power amplifier (PA) using a modified two-tap six-port network, wherein the varying (complex) load is first compensated for its unwanted susceptance part, followed by adjustment of the transistor output stage to the ohmic load variation, by modifying its supply voltage and drive level. This two-step approach avoids the high-Q conditions that occur in tunable matching network solutions, which aims to correct for both the real and imaginary load deviations, such as providing lower insertion loss and voltage stress. Next, to facilitate a fully automated load mismatch correction without the need for calibration, a modified two-tap six-port network for impedance detection and control loop approach is proposed. As proof of principle, a prototype 900-MHz class-AB PA featuring the proposed correction technique, as well as, the six-port reflectometer and the control loop, has been implemented as a PCB demonstrator. Measurement results show that the self-healing load-insensitive PA in the events of load mismatch significantly improves the performance and approaches the 50- $\Omega $ performance. On a 2:1 VSWR 360° mismatch trajectory and driven by a 64-QAM 3.86-MHz signal, the PA achieves a linear output power of 22 dBm with only ±0.1-dB variation and better than −45-dBc adjacent channel power ratio (ACPR).