RF POWER PERFORMANCE OF AN LDMOSFET ON FM BROADCAST BAND II POWER AMPLIFIER APPLICATIONS

Abstract

The performance, analysis, design, and evaluation of medium-voltage laterally diffused metal oxide semiconductor (LDMOS) transistors for band II applications up to 108 MHz is presented. Using an optimized N-LDMOS transistor, the current state of laterally diffused metal-oxide-semiconductor (LDMOS) technology, which for over ten years has been the preferred tool for RF power applications. LDMOS satisfies the needs for numerous Class AB applications. The performance per unit gate width has been found to decline with increasing width, even when RF transmitter power amplifiers employ larger transistors to deliver higher power. A field solver and circuit simulator are used in this work to identify the mutual inductance in the system as a primary reason for the performance deterioration in RF LDMOSFET power amplifiers. For RF power applications, laterally diffused metal-oxide-semiconductor (LDMOS) technology has been the preferred device for more than ten years. LDMOS meets the specifications for a variety of Class AB and pulsed applications, including broadcast, microwave, and base station. We demonstrate the LDMOS transistor's cutting-edge RF performance using a load-pull test system, attaining class-AB drain efficiencies of 80% at FM broadcast band II , 88-108 MHz for both packaged and on-wafer devices. Additionally, the outcomes of a number of Class AB amplifier implementations built using this method are displayed.