Skyworks SKY65338-21 is a high-efficiency Front-End Module (FEM) that incorporates a transmit and receive path, and an antenna transmit/receive (T/R) switch. The transmit path consists of a high efficiency Power Amplifier (PA) followed by an harmonic filter for rejection of harmonic frequencies. The PA is implemented using Skyworks high reliability Heterojunction Bipolar Transistor (HBT) process and is Class AB biased to provide maximum efficiency with a low spurious output. A high linearity and high isolation Single-Pole Double-Throw (SPDT) switch is used at the common antenna interface between the transmit and receive paths. The receive path is a low insertion loss through-path with input and output ports internally matched to 50 Ω. The device is mounted in a 12-pin, 8 x 8 mm Multi-Chip Module (MCM) Surface-Mounted Technology (SMT) package, which allows for a highly manufacturable low-cost solution.