LDMOS Technology for RF Power Amplifiers

Abstract

We show the status of laterally diffused metal-oxide-semiconductor (LDMOS) technology, which has been the device of choice for RF power applications for more than one decade. LDMOS fulfills the requirements for a wide range of class AB and pulsed applications, such as base station, broadcast, and microwave. We present state-of-the-art RF performance of the LDMOS transistor measured with a load-pull test setup, achieving class-AB drain efficiencies of 70% at 2 GHz for on-wafer and packaged devices. Furthermore, the results for several class-AB and Doherty amplifier implementations constructed with this technology are shown. As an illustration, a three-way Doherty application is demonstrated, which has a 7.5-dB back-off efficiency of 47% at 1.8 GHz with a peak power of 700 W and linearity numbers better than 65 dBc.Index Terms-Microwave amplifiers, MOSFET power amplifiers (PAs), power amplifiers, semiconductor device fabrication.

A Review of Watt-Level CMOS RF Power Amplifiers

“…Lateral double-diffused MOS (LDMOS) transistors have proven to be successful in base station applications [94], [95]. The advantages of LDMOS for RF PA applications are its thermal stability, high ruggedness, and good linearity characteristics.…”

Improving Linearity and Robustness of RF LDMOS by Mitigating Quasi-Saturation Effect

“…Robustness is the ability of LDMOS to withstand the power from output mismatched or the power from electronstatic discharge. Robustness of LDMOS correlated with the inherently presented parasitic bipolar NPN transistor [6], and more body doping was suggested to suppress the turn-on of NPN transistor. The device could fail because of formation of early filament [7,8]; deep implantation drain contact [9] and ESD implantation at drain side [10] were suggested to address the formation of early filament issue.…”

Nonlinear modeling of LDMOS transistors for high‐power FM transmitters

“…Despite the availability of new compound semiconductors, silicon technology still plays an important role in telecommunication applications. As a matter of fact, laterally diffused metal oxide semiconductor (LDMOS) field effect transistors (FETs) are the most used active components in high-power electronic circuits for frequencies up to few gigahertz, thanks to their low cost [1][2][3][4].…”