150W RF transistor for ultra wideband asymmetrical Doherty amps in DVB-T

March 09, 2016 // By Graham Prophet
Ampleon – the RF power device specialist spun-out from NXP - has added the BLF888E RF power transistor, designed for DVB-T UHF asymmetrical wideband Doherty amplifier applications. Fabricated in a SOT539 package using a sixth generation high voltage LDMOS process, the BLF888E has greater than 50% power efficiency, this being typically up to 10% more efficient compared to previous devices.

With its high efficiency rating, the device helps reduce the energy consumption profile of the end-application. The average DVB-T power output is 150W, representing typically a 25% increase in output power of previous devices making it one of the highest power levels available from a single transistor for such broadcast applications.

 

The characteristics of the BLF888E provide a typical 120 MHz bandwidth per sub-band compared to the industry norm of 40 – 50 MHz narrow bands for similar applications.

 

To aid development of asymmetrical wideband Doherty amplifiers for UHF DVB-T applications a set of three evaluation boards is available that caters for the 470 – 590 MHz, 580 – 690 MHz and 650 – 790 MHz sub-bands. The amplifiers have a 1:1.5 main/peak power ratio and are driven from a 50VDC supply.

 

Thijs Tullemans, Senior Director Marketing BU Multi-Market, Ampleon comments, “...in the RF Power Broadcast ... crossing the 50% mark [takes] efficiency to the next level. Along with the BLF888E, our application specialists have also developed three evaluation boards that cover the entire UHF band (470-800MHz).”

 

Ampleon Netherlands; www.ampleon.com