High Performance RF TechZone
Welcome to the HPRF TechZone. The online portal to find the latest on our broad RF portfolio or to reach out to application experts.
LDMOS (Laterally Diffused Metal Oxide Semiconductor) is the dominant device technology used in high power RF amplifiers for frequencies ranging from 10 MHz to 3.8 GHz. It offers significant advantages over silicon bipolar transistors, such as very high ruggedness and efficiency, high gain, and compatibility with low cost packaging platforms. And in all but a few markets LDMOS is the most commercially viable solution in comparison with GaN based power amplifiers.
NXP's LDMOS technology platforms are designed for devices to run from supply voltages in the range 28 to 50 V, with outstanding efficiency, power and ruggedness. The technology draws on NXP's heritage of proven product and technology innovation in RF spanning over 35 years. Now in its 8th-generation, our LDMOS devices deliver record performance up to 3.8 GHz and, for example, help wireless network operators realize best-in-class efficiencies for wireless base stations and hence reduce operating costs.
Advanced processes and architectures
These high efficiencies are actually achieved through a combination of the Gen8 LDMOS devices with specific amplifier circuit designs such as Doherty. The technology enables Doherty amplifiers with higher power, higher efficiencies, less memory effects and better pre-distortion capabilities. Doherty amplifiers are available, which are fully integrated into a single transistor package - engineers do not need to worry about the quite intricate design of such a circuit any more - all splitters, delay lines and combiners are already included and the design challenge boils down to a class AB circuit design.
Higher power densities and ruggedness
For the aerospace and defense, broadcast and ISM markets NXP uses the proven Gen6 & Gen7 LDMOS platforms for devices fine-tuned to the specific needs required by these applications. For example, the Gen6 technology has been re-optimized for 42 to 50 V operation with the Gen6HV process, and then improved further again as Gen6XR to enable devices with extreme ruggedness, equivalent to the older VDMOS technology. The Gen6XR process is essential for ISM applications that suffer from severe mismatch conditions, the technology enables products that withstands them all without compromising the RF performance.
Historically the broadcast market has led the way in terms of power demands, a challenge NXP has risen to time and again with a succession of LDMOS products that set new milestones in terms of power density. These products clearly demonstrate the strengths of NXP’s LDMOS to deliver new levels of consistency in power distribution over a die and also in production from batch to batch, year to year.
The improvements in LDMOS technology have enabled the aerospace and defense radar markets to migrate from designs using Si bipolar power transistors to LDMOS. LDMOS RF performance now equals Si bipolar in most respects and exceeds it in the remaining few. Plus LDMOS is an easier technology to apply and has significant cost of ownership benefits in these markets. In these markets NXP have managed to raise the bar for LDMOS with 350 W S-band devices in the range 2.7 to 3.5 GHz.