ABSTRACT
In modern wireless communication systems, it is required that the power amplier operates with high efciency over a wide frequency range to simultaneously provide multiband and multistandard signal transmission. The conventional design of a highefciency switchmode Class-E power amplier requires a high value of the loaded quality factor QL to satisfy the necessary harmonic impedance conditions at the output device terminal. However, if a sufciently small value of QL is selected, a high-efciency broadband operation of the Class-E power amplier can be realized by applying the reactance compensation technique. Usually, the bandwidth limitation in power ampliers comes from the device’s low-transition frequency and large output capacitance; therefore, silicon LDMOSFET technology has been the preferred choice up to 2.2 GHz. As an alternative, GaN HEMT technology enables high efciency, large breakdown voltage, high-power density, and signicantly higher broadband performance due to higher transition frequency and smaller periphery, resulting in the smaller input and output capacitances and less parasitics.
