Date: 05/06/2009

New Doherty amplifier based on the LDMOS transistor

NXP Semiconductor is sampling world's first new 3-way Doherty amplifier for wireless/RF cellular communication base stations. Doherty circuit offers greater than 47% efficiency at an average power output of 48dBm, a gain of 15dB and peak to average ratio of 8dB for a multicarrier W-CDMA signal. The current design covers the W-CDMA standard for band I operation. The design is tailored towards high yield, minimum tuning, volume manufacturing.

From the design point of view, Doherty amplifiers behave like ordinary class AB transistor but offer approx 10% more efficiency than class AB amplifier. They don't require any tuning.

"With the innovative 3-way Doherty concept, we uniquely combined the advantages of the Doherty amplifier with our Doherty-optimized seventh generation LDMOS technology to deliver the highest efficiency levels and good pre-distort ability, while providing significant cost savings," says Mark Murphy, Director of marketing for RF power products, NXP Semiconductors. "We developed the Doherty technology in direct response to customer demand for high efficiency amplifiers in emerging cellular standards, such as LTE. This way, we significantly lower the total system power consumption by achieving record power efficiency and performance," concludes Murphy.


NXP will be displaying this device at IMS 2009 exhibition in Boston, MA going to be held on 9-11th June. A technical presentation on the Doherty concept will be provided during the IMS 2009 conference, held between 7-12th June.

To learn more on Doherty amplifier visit, http://www.nxp.com/campaigns/experience_rfpower/index.php?sub=doherty