利用SuPA给手持设备射频功率放大器供电

Powering for RF Power Amplifier of the Handheld Device by SuPA

在手持设备中给射频功放供电一直是一个比较难做的设计,因为一方面需要提高射频功放的工作效率用来延长电池的工作时间,另一方面又不能在提高工作效率的同时降低功放的工作性能,所以必须为其提供一个满足要求的高效直流电源。常规的方式,是将功放的电源端与电池直接连接供电,但是这种工作模式会使得功放的工作效率很低,不能满足高效低功耗要求。德州仪器公司推出的SuPA(Supply for Power Amplifier)系列的DC-DC产品,从工作机理上做了创新,采用平均功率跟踪(Average Power Track)技术和包络跟踪技术(Envelop Tracking),优化了射频功放工作时功率消耗,从而提高了功放的工作效率,延长了电池的工作时间。本文着重阐述平均功率跟踪技术的工作原理和SuPA的应用设计,从而方便设计工程师能够快速地理解和应用此项技术,实现高效的功放电源设计。

One needs to improve the work efficiency of RF （Radio Frequency） power amplifier to extend battery＇s operation time. Meanwhile, its working performance shouldn＇t be reduced. Therefore, among handheld devices, powering RF power amplifier has always been a comparatively hard design, for which an adequate efficient DC power must be provided. The conventional way is directly connecting its power supply port with battery. However, such a way makes it a very low work efficiency, unsatisfying the requirement of high efficiency and low power consumption. DC-DC product of SuPA （Supply for Power Amplifier） series that Texas Instruments launched makes creation in working mechanism and adopts APT （Average Power Track） technology and Envelop Tracking technology, lowering the power consumption of the working RF power amplifier, thus improving its work efficiency and extending battery＇s operation time. In this paper, the operation principle of APT technology and the applied design of SuPA are emphatically elaborated so that design engineers can understand and use them rapidly, leading to efficient amplifier power designs.