包络线跟踪电源多电感选择开关电路设计

Multi-inductor Selective Switching Circuit Design for Envelope Tracking Power Supply

包络线跟踪(ET)技术可以大幅降低高峰均比射频(RF)线性功放的能耗。针对包络线跟踪电源(ETPS)中开关变换器开关频率高、拟合精度较低的问题,提出了多电感选择开关电路结构,用不同的电感对RF信号的包络上升周期进行拟合跟踪,在保证拟合精度的情况下,开关频率低于信号带宽。此处建立了多电感开关变换器损耗模型,并对电感配比的方法和不同电感配比的开关变换器损耗以及跟踪精度进行了详细讨论。最后,以5MHz带宽、10.07dB峰均功率比的正交频分复用(OFDM)调制测试信号为例,搭建了多电感选择ETPS原理样机,输出电压为8.3~22.4V,实验结果验证了该架构和方法的可行性。

Envelope tracking(ET)technology can dramatically reduce the power consumption of high peak-to-average ratio radio frequency(RF)linear amplifiers.To address the problems of high switching frequency and low fitting accuracy of switching converter in the envelope tracking power supply(ETPS),a multi-inductor selective switching circuit structure is proposed to fit and track the envelope rise cycle of RF signals with different inductors,and the switching frequency can be lower than the signal bandwidth under the guarantee of the ftting accuracy.A multi-inductor switching converter loss model is established,and the methods of inductor rationing and the switching converter losses and tracking accuracies of different inductor ratios are discussed in detail.Finally,the principle prototype of the multi-inductor selective ETPS is built with an orthogonal frequency division multiplexing(OFDM)modulation test signal with 5 MHz bandwidth and 10.07 dB peak-to-average ratio,the output voltage is 8.3~22.4 V,and the experimental results verify the feasibility of the architecture and method.