NXP describes ultra-wideband amplifiers in Doherty configuration

May 22, 2013 // By Jean-Pierre Joosting
NXP Semiconductors has made available its ultra-wideband Doherty reference design using the BLF884P and BLF884PS, yielding what it says are the first wideband Doherty power amplifiers capable of broadband operation (470 to 806 MHz).

The 70 W DVB-T LDMOS designs bring the high-efficiency gains of Doherty topologies to broadcast transmitters, using NXP’s  architecture capable of operating over an ultra-wideband spectrum. Whereas traditional UHF technologies such as class AB typically reach only 30% efficiency, Doherty solutions are capable of reaching 45-50% power amplifier efficiency — a significant improvement.
The ultra-wideband Doherty design uses the company’s 50-V LDMOS technology, and the ruggedness of the BLF884P and BLF884PS make them ideal for digital broadcast transmitters. “By leveraging NXP’s expertise and IP in Doherty architectures, we’ve been able to design a unique ultra-wideband Doherty solution which achieves high efficiency without incurring additional costs, or delaying time to market: With a single Doherty design, we’re able to cover the full band from 470 to 806 MHz. In testing our first high-bandwidth Doherty power amplifiers, our lead customers have been able to demonstrate tremendous efficiency gains, further validating our approach,” said Mark Murphy, director of marketing, RF power and base stations, NXP Semiconductors. “Given the immense pressure to deliver richer content via high-performance TV transmitters, we believe that the impact of ultra-wideband Doherty architectures on the overall digital broadcast market will be wide-ranging. At an average DVB-T power level of 70 W, the BLF884P/PS ultra-wideband Doherty reference design is extremely well suited for gap filler applications.”
NXP; www.nxp.com