Analysis of Dissipated Power in Envelope Amplifier Output Filters
Analysis of Dissipated Power in Envelope Amplifier Output Filters
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包络放大器输出滤波器的耗散功率分析
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
O. Bengtsson
中科院分区：
文献类型：
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作者：
Sophie Paul;N. Wolff;C. Delepaut;V. Valenta;W. Heinrich;O. Bengtsson
本文研究了基于降压变换器的包络放大器（EA）输出滤波器内的功耗及其对包络跟踪（ET）系统整体效率的影响。对于工作在1620mhz和40v电源下的57w峰值功率gan ET系统，将EA输出滤波器的功耗与整个ET系统的功耗进行比较。研究了三种截止频率为10 MHz的四阶LC低通滤波器在静态和动态EA工作时的负载相关耗散功率，即恒定和调制的EA输出电压，用于8 MHz的ofdm调制RF输入信号。研究发现，在较宽的输出功率范围内，滤波器中耗散的功率占ET系统总耗散的相当大的一部分。相似阶数和截止频率的替代滤波器显示估计EA效率差异可达5个点。此外，研究表明，仅考虑静态情况，其中滤波器由固定阻抗加载，对于ET系统中更现实的动态条件可能会得出完全错误的结论。
The paper addresses power dissipation within the output filter of a buck-converter-based envelope amplifier (EA) and its effect on the overall envelope tracking (ET) system efficiency. For a 57 W peak-power GaN-based ET system operating at 1620 MHz and 40 V supply, the power dissipated in the EA output filter is compared to the power loss in the entire ET system. Three different fourth-order LC low-pass filters with 10 MHz cut-off frequency are investigated regarding their load-dependent dissipated power during static and dynamic EA operation, i.e., with constant and modulated EA output voltages, for an 8 MHz OFDM-modulated RF input signal. It is found that the portion of the power dissipated in the filter constitutes a considerable part of the overall power dissipation of the ET system for a wide range of output power. Alternative filters of similar order and cut-off frequency show an estimated EA efficiency difference of up to 5 % points. Furthermore, the investigations show that considering the static case alone, where the filter is loaded by a fixed impedance, may lead to totally wrong conclusions for more realistic dynamic conditions in the ET system.