I. Introduction
With the rapidly increasing demands for high data rate and wide-bandwidth wireless communications, two or more individual component carriers of the same or different bandwidths belonging to contiguous or noncontiguous frequency bands are aggregated for the concurrent multichannel operation. Hence, the RF front-end module (FEM) designers are required to optimize the broadband wireless communication system to obtain high data rate and low power consumption. The essential building blocks in the RF FEM are power amplifier (PA) and switch. To meet the stringent requirements of the next-generation wireless communication system using the high peak-to-average-power ratio (PAPR) orthogonal frequency-division multiplexing modulation scheme, the multipower-mode operation, high-isolation path selection, high efficiency, and high-linearity characteristics are critical for the PA and switch designs in the advanced RF FEM [1], [2].