Cambridge, UK, 23 February 2011 – Nujira and Xilinx today announced the first successful integration of envelope tracking (ET) technology with a third-party digital pre-distortion (DPD) solution running on an FPGA. The two companies have delivered a reference design for a cellular base station PA circuit with Nujira’s Coolteq.h envelope tracking modulator linearised by a Xilinx DPD block running on a Xilinx Virtex 6 FPGA platform. Envelope signal generation in the FPGA was implemented using Nujira’s Envelope Generation Interface, which is compliant with the openET Alliance’s specification for infrastructure ET modulators.

“Xilinx is fully committed to supporting the cellular industry in minimising the environmental impact and operating cost of the next generation of 3G and 4G infrastructure,” said Dave Hawke, senior product marketing manager, wireless communications at Xilinx. “Envelope tracking technology is increasingly being recognised as a must-have power optimisation technology and Xilinx has therefore integrated an envelope tracking port into its 3rd generation Multimode Radio Targeted Design Platform (TDP). The combination of Nujira’s leadership in market ready envelope tracking power modulators and Xilinx’s leadership in DPD and Crest Factor Reduction (CFR) LogiCORE IP, results in the industry best power efficiency, in a low cost and highly flexible package. 

Commenting, Simon Whittle, Nujira’s design centre manager, said, “The integration of the openET Envelope Generation Interface with Xilinx DPD and CFR LogiCORE IP was extremely straightforward, and the design was up and running within a few hours with no major issues. The project shows that Coolteq can easily be integrated with market leading DPD solutions, and that Envelope Tracking Power Amplifiers based on Coolteq-h can be linearised using Xilinx DPD technology.”

The integration was based on Nujira’s NCT-B1110 Envelope Generation Interface VHDL code integrated with Xilinx’s v4.0 Digital Predistortion LogiCORE IP block, running on a Xilinx ML605 reference platform for the Virtex 6 FPGA.  A Nujira NCT-H4010 ET modulator was used with a simple FMC interface adaptor for direct connection to the ML605.  The RF path was generated by Analog Devices’ AD-MSDPD-EVB Mixed Signal Digital Pre-Distortion Evaluation Platform, and the power amplifier was a Nujira NCT-T4503 power amplifier using a SEDI EGN21B090IV GaN power transistor. 

About Xilinx

Xilinx is the worldwide leader in complete programmable logic solutions. For more information, visit http://www.xilinx.com.  

About Nujira

Nujira enables efficient, wide-band Power Amplifier modules for the next generation of cellular, broadcast and defence communication systems. Its CoolTeq™ Envelope Tracking technology is the most effective wideband power optimisation technology for RF transmissions in 3G and 4G cellular networks and terminals, digital broadcast transmissions and military communications. Not only does it offer attractive transmitter efficiency of 50% plus with high peak to average ratio signals, but it maintains this performance over a very wide frequency band.