Broadband high performance laterally diffused metal–oxide–semiconductor power amplifier for mobile two‐way radio applications

Abstract

This paper highlights achievement of broadband high performance power amplifier (PA) line up for mobile two-way radio applications. In typical two-way radio applications the input radio-frequency signal to the first PA stage comes directly from the voltage controlled oscillator, with typically 3 dBm power. Owing to high output power requirement (∼80 W) of mobile radio applications, up to three PA device stages are normally cascaded (pre-driver, driver and final PA stage). The key point in the design of the PA line up concerns the final stage. Here, this paper introduces a design methodology based on parallel-combined impedance matching technique (from theoretical derivation) enables the designers to develop broadband PA with actual PA device impedance (implementation of new generation laterally diffused metal–oxide–semiconductor device). Experimental results demonstrated output power of ∼80 W and gain of 45 dB, while preserving efficiency of 55% over the bandwidth from 760 to 870 MHz. According to author's knowledge, this amplifier demonstrated highest efficiency with 13 V DC supply (operating at 80 W) in UHF broadband frequency with high gain operation (more than 45 dB) up to date.