E类放大电路中晶体管的功率损耗

Transistor Power Losses in the Class E Power Amplifier

在理想情况下,E类放大电路的效率可以达到100%,因此E类放大电路适用于高功率,高频率电路的设计,但在实际情况下,由于所有的器件都不是理想的。例如,电感、电容中会有寄生电阻的存在,晶体管的饱和电压,饱和电阻以及集电极电流的下降时间不为零,这些因素的存在都会导致E类放大电路的效率降低,但当电路的负载匹配且处于谐振状态,则引起电路功率损耗的主要因素也就是晶体管中的功率损耗。对E类放大电路中由晶体管引起的损耗进行分析,并得出简单的估算方法,并用实验的方法验证。

The class E power amplifier offers efficiency approaching 100 percent under ideal condition,so the class E power amplifier can apply to design high power and high frequency circuit. But in practical all the component is not ideal, for example, there are parasitic parameters exist in the inductor and the capacitance, the saturation voltage, saturation resistance and the collector current fall time is nonzero. All this factors will cause the efficiency decrease. When the amplifier is properly loaded and tuned, the power losses primarily caused by the transistor saturation voltage, saturation resistance and the fall time of the collector current. This paper shows the analysis of the transistor power losses in the class E power amplifier and prove the conclusion by experiment.