基于非对称架构的双频段大回退Doherty功放设计

Design of Dual-band Large Rollback Doherty Power Amplifier Based on Asymmetric Architecture

射频系统对多频功放需求越来越大,基于有源动态负载调制技术的Doherty功率放大器(DPA)作为射频前端的关键部件,其效率和性能是设计的关键,但是传统单频段回退6dB的DPA已无法满足发展需求。本文设计了一款工作在2.6/3.5 GHz的双频段大回退Doherty功率放大器。采用改进型双频宽带匹配网络的方法对Doherty的各个模块设计,并通过非对称架构实现高回退范围。通过仿真验证,该DPA在两个频段的饱和漏极效率(DE)分别超过70%和66.5%,回退9 dB时的DE分别超过52.5%和47.3%,对应的饱和增益都大于7 dB,且在3GHz附近的输出功率及效率趋近于0,使得功率放大器实现了较好的带间隔离性。满足无线通信系统多频段大回退的工作需求。

The demand for multi-frequency power amplifier in RF system is increasing.Doherty power amplifier(DPA)based on active dynamic load modulation technology is a key component of RF front-end,and its efficiency and performance are the key to design,but the traditional single-band DPA with 6dB rollback can no longer meet the development needs.In this paper,a dual-band large rollback Doherty power amplifier operating at 2.6/3.5GHz is designed.Each module of Doherty is designed by the method of improved dual-band broadband matching network,and the high fallback range is realized by the asymmetric architecture.Through simulation verification,the saturation drain efficiency(DE)of the DPA in the two frequency bands exceeds 70%and 66.5%re-spectively,and the DE in the backtracking of 9 dB exceeds 52.5%and 47.3%respectively.The cor-responding saturation gain is greater than 7 dB,and the output power and efficiency near 3GHz are close to 0.The power amplifier achieves better isolation between bands.Meet the wireless communi-cation system multi-band large rollback requirements.