A L-Band Class AB Power Amplifier Based on the Lateral Double-diffused Metal Oxide Semiconductor Device

This paper presents a Class AB power amplifier operating at the frequency band of 1.91 GHz-2.01 GHz. The lateral double-diffused metal oxide semiconductor (LDMOS) MW6S004N manufactured by Freescale is used to design the power amplifier for the high efficiency, good linearity and low cost features. The design procedure and evaluation of the presented power amplifier are described. The $\pi$-network topology and two-stage low-pass filter network are used to design the proposed input and output matching network, which are converted to the optimum source impedance and load impedance to enhance the power transmission performance of the power amplifier. The proposed matching networks enable improvements in both linearity and efficiency. The simulation results show that the output power $P_{1 dB}$ is greater than 37.5 dBm, the power added efficiency is 52.5 % for the optimized power amplifier circuit with 1.96 GHz frequency. With two tone input signals, the power amplifier delivers 35 dBm output power, IMD3 of below than -20 dBc, IMD5 of below than -34 dBc.