一种基于包络跟踪的宽带Doherty放大器设计

Design of a Broadband Doherty Amplifier Based on Envelope Tracking

效率可重构宽带Doherty在实际应用中需要手动调节主功放的漏压和辅助功放的栅压,包络跟踪是解决此问题的有效方法。然而,包络跟踪设计比较复杂。为此,提出了线性映射的设计方法,设计实现了1.0～1.4 GHz包络跟踪宽带Doherty放大器,在10 d B大回退范围较固定偏压Doherty放大器效率提升了8%。同时,包络跟踪显著降低了手动调节偏压的人力和时间成本,仿真结果验证了设计的有效性。

In the application of efficiency reconfigurable broadband Doherty amplifiers,it is necessary to manually adjust the drain voltage of main power amplifier and the grid voltage of auxiliary power amplifier.Envelope Tracking(ET)is an effective method to solve the problem.However,the design of ET is more complex.In this paper,the design method of linear mapping is used in ET broadband Doherty,the efficiency in operating frequency band1.0~1.4GHz is higher than that using fixed bias.The efficiency increases8%in10dB large back-off range,by automatically regulating the drain bias of main amplifier and the gate bias of auxiliary amplifier according to the envelope amplitude.This method significantly reduces the costs of labor and time to adjust bias manually.The feasibility of this method is verified by simulation results.