LONDON NXP Semiconductors has started sampling integrated Doherty amplifiers for cellular basestations, based on its RF transistor technology.
Initial parts are targeting W-CDMA and TD-SCDMA air interfaces and the company's road map includes high power versions of the parts.
The initial BLD6G21-50 and BLD6G22-50 amplifiers are designed to deliver efficiency of greater than 40 percent at an average power of 10W.
NXP says this enables 35 percent lower power dissipation under multi-carrier signal operation compared to class AB amplifiers.
“Integrated Doherty technology is considered a holy grail in amplifiers,” said Mark Murphy, director of marketing for RF power products at NXP Semiconductors. “We have achieved the smallest realized Doherty design and record efficiency, cutting total system power consumption significantly,” he added.
The Doherty amplifier is designed to be plug-and-play and can be applied in the same way as a standard class AB transistor.
The BLD6G21-50 incorporates an integrated Doherty concept based on the company's GEN6 LDMOS technology which is designed specifically for TD-SCDMA operation at frequencies from 2010MHz to 2025MHz, while the G22 version is set to operate at frequencies between 2110MHz to 2170MHz for W-CDMA transmission.
Both main and peak devices and delay lines as well as the input splitter and output combiner are integrated into a standard transistor package with single input and output leads, thus minimising required board space.
The package has two additional pins, one of which is being used for external biasing purposes.