This brief provides a detailed loop gain and stability analysis of hybrid power amplifier supply modulators. Design considerations, including the relations between the voltage and current loops, the rationale of current loop compensation to ensure stability and improve bandwidth, and the impacts of current loop on the overall system stability and efficiency, are studied with combined system loop gain modeled mathematically. The theoretical analysis is proven by simulation results. Based on the study, a hybrid supply modulator has been designed and fabricated in 65-nm CMOS. In measurements, stable voltage and current closed-loop operations have been verified, with a peak efficiency of 85% when tracking a 20-MHz LTE envelope.

中文翻译：

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混合 PA 电源调制器的环路分析和稳定性考虑


本简介提供了混合功率放大器电源调制器的详细环路增益和稳定性分析。通过对组合系统环路增益进行数学建模，研究了设计考虑因素，包括电压环路和电流环路之间的关系、电流环路补偿以确保稳定性和提高带宽的基本原理，以及电流环路对整个系统稳定性和效率的影响。仿真结果验证了理论分析。基于该研究，我们采用 65 nm CMOS 设计并制造了混合电源调制器。在测量中，稳定的电压和电流闭环操作已得到验证，在跟踪 20 MHz LTE 包络时峰值效率为 85%。