Closed-Form Design Equations for Class-EM Power Amplifier with Isolation Circuit

The main circuit of the Class-EM power amplifier fulfils the ZVS/ZVDS/ZCS/ZCDS conditions while the auxiliary circuit thereof fulfils the ZVS condition. Hence, enabling high-efficiency operations at higher operating frequencies while using active devices with slower switching time, resulting in a low-cost high-efficiency power amplifier. This paper presents a new Class-EM power amplifier configuration that incorporates an isolation circuit between the main and the auxiliary circuit. Explicit design equations for the load network parameters which fulfils the operational conditions of the Class-EM power amplifier are derived. The analytical results correlate with the ADS simulations results, showing the potential of achieving a theoretical efficiency of 100% at higher frequencies while using low-cost, slow switching active devices.