Bredbånds PA med uhørt høj effektivitet

RF Micro Devices og Nujira demonstrerer verdens formentlig mest effektive bredbånds power amplifier (in english).

Nujira and RF Micro Devices ill be demonstrating the world's most efficient broadband power amplifier (PA) design for 4G base stations at Mobile World Congress, Barcelona, February 2010. The design integrates the new RFMD RFG1M family of high performance gallium nitride (GaN) amplifiers with Nujira's Coolteq.h envelope tracking power modulators.

Using just one RFG1M device with a Coolteq.h module, the RFMD Nujira RF front end transmits over a 728 - 960 MHz band with over 50% efficiency, covering seven of the frequency bands defined for LTE by 3GPP. The results of this broadband GaN-based PA platform surpass competitive wideband Doherty LDMOS solutions.

Furthermore, using future GaN devices currently in development at RFMD, the two companies expect to cover the full range of the cellular frequency band from 700 MHz - 2,600 MHz with just three broadband PAs, allowing wireless infrastructure vendors to develop a single, highly-efficient multimode, broadband RF front end that can be deployed to meet various transmission standards anywhere in the world.

Lance Wilson, Research Director, RF Components & Systems, ABI Research, says:
- "Expect to see GaN, coupled with envelope tracking, in many new RRH designs. With a GaN/envelope tracking amplifier promising such high-efficiency operation, the Doherty circuit configuration can be disposed of and bandwidth will increase incrementally.

Commenting, Tim Haynes, CEO, Nujira says:
- In partnership with RFMD, we have created a PA which covers the entire 700 MHz - 1000 MHz band without compromising on efficiency. Nujira's Coolteq modulators feature the only technology that can deliver this level of efficiency across such a broad bandwidth, extending the Software Defined Radio approach to the high-value power amplifier.

Bob Van Buskirk, president of RFMD's Multi-Market Products Group (MPG), says:
- We're delighted to be collaborating with Nujira in setting new standards for energy efficient transmission performance based on our new RFG1M products and on our state-of-the-art GaN process. We see the combination of Envelope Tracking and RFMD's superior GaN devices and technology as a disruptive combination that changes the way base stations are designed.

According to Haynes, the joint design addresses a major issue in the 4G cellular base station market:
- Infrastructure vendors are facing a portfolio management crisis, with more than 60 product variants needed to cover all worldwide frequency bands, cellular standards, and power levels, he says.
- Even if they had the specialist engineering resources available to develop each product, the development costs and timescales would be prohibitive, with each and every variant costing hundreds of thousands of dollars to design, test, type approve, and qualify for production. We have delivered a high efficiency, broadband PA platform which can be deployed across multiple product variants, reducing time-to-market, development costs, and the cost of ownership associated with inventory management.

The design is based on RFMD's RFG1M09180 180W GaN broadband power transistor. RFMD's GaN devices can provide high efficiency across a broad RF bandwidth, enabling the entire cellular spectrum (from 700 MHz to 2700 MHz) to be covered with a reduced number of PA platforms.