平衡式宽带Doherty射频功率放大器  

Design of Balanced Broadband Doherty RF Power Amplifier

作　　者：李瑞阳[1] 刘太君[1] 叶焱[1] 

机构地区：[1]宁波大学信息科学与工程学院,浙江宁波315211

出　　处：《移动通信》2015年第3期133-137,共5页Mobile Communications

基　　金：国家自然科学基金(61171040);浙江省自然科学基金(Y1101270);宁波大学学科项目(XKL141038)

摘　　要：为了满足未来通信系统对多波段多模式的射频功率放大器的要求，需要对传统Doherty结构予以改进。在传统Doherty结构基础上，通过分析其输出合路结构的阻抗变换比，阐明了阻抗变换比对带宽的影响，并运用平衡式的结构来拓展合路的带宽。最后，采用CREE公司的GaN功放管设计了一款工作于1盘5-2．65GHz频带的Doherty功率放大器，并实现了频率在整个频带内输出功率回退5～6dB时漏极效率大于38％、最大输出功率大于44dBm且整体合路增益10dB左右，从而验证了该合路结构的可行性。In order to meet the requirements of future communication system for multi-band multi-mode RF power amplifier, the structure of traditional Doherty amplifier should be improved. Based on the structure of traditional Doherty amplifier, with the impedance conversion ratio of its output combiner analyzed, the impact of impedance conversion ratio on bandwidth is illustrated and the combiner bandwidth is expanded by means of balanced structure. Finally, an improved Doherty power amplifier using GaN power tube produced by CREE Corporation working in 1.85-2.65GHz is designed. It achieves following performance： when the output power back-off is 5-6dB, the drain efficiency is higher than 38% in 1.85-2.65GHz; the maximum output power is greater than 44dBm with the combination gain around 10dB. Therelbre, the feasibility of the improved structure is verified.

关 键 词：DOHERTY 功率放大器 平衡式 宽带 

分 类 号：TN42[电子电信—微电子学与固体电子学]