A Word About RF Power Transistors

Sept. 10, 2009
MOSFETs used in cellular and other PAs are virtually 100% discrete RF power transistors. The laterally diffused metal-on-silicon (LDMOS) FETs are the most popular type. Freescale Semiconductor is a leader here, with a wide range of devices. The

MOSFETs used in cellular and other PAs are virtually 100% discrete RF power transistors. The laterally diffused metal-on-silicon (LDMOS) FETs are the most popular type. Freescale Semiconductor is a leader here, with a wide range of devices.

The company’s recent products include the MRF8S9100H/HS, which operates in the 920- to 960-MHz range. It’s designed for class AB or C operations in GSM/EDGE systems. It can deliver 45-W average power, a gain of 19.1 dB, and an efficiency of 44%. The MRF8S18120H/HS is made for the 1800- to 1900-MHz bands, where it can deliver 46-W average power with an efficiency of 42% (see the figure).

But for the higher power levels needed in more rugged applications, gallium-nitride (GaN) transistors are gaining converts. They offer higher power density, higher gate-todrain breakdown voltages, and higher operating voltages. In addition, they can operate at higher junction temperatures. Some deliver up to 100 W in the 1- to 3-GHz range.

Nitronex and NXP offer such devices. BC Systems supplies complete power amplifiers with those power and frequency ranges. GaN devices are seen as gradually replacing traveling-wave-tube (TWT) vacuum tube amps in some high-power microwave applications such as in satellites.

Sponsored Recommendations

Board-Mount DC/DC Converters in Medical Applications

March 27, 2024
AC/DC or board-mount DC/DC converters provide power for medical devices. This article explains why isolation might be needed and which safety standards apply.

Use Rugged Multiband Antennas to Solve the Mobile Connectivity Challenge

March 27, 2024
Selecting and using antennas for mobile applications requires attention to electrical, mechanical, and environmental characteristics: TE modules can help.

Out-of-the-box Cellular and Wi-Fi connectivity with AWS IoT ExpressLink

March 27, 2024
This demo shows how to enroll LTE-M and Wi-Fi evaluation boards with AWS IoT Core, set up a Connected Health Solution as well as AWS AT commands and AWS IoT ExpressLink security...

How to Quickly Leverage Bluetooth AoA and AoD for Indoor Logistics Tracking

March 27, 2024
Real-time asset tracking is an important aspect of Industry 4.0. Various technologies are available for deploying Real-Time Location.

Comments

To join the conversation, and become an exclusive member of Electronic Design, create an account today!