LONDON After 30 months of privately-funded development fabless VT Silicon Inc. (Atlanta, Georgia) has announced a silicon-based power amplifier capable of meeting the operating requirements of 4G wireless data transmissions. The company is planning to launch an integrated RF front-end for WiMax and LTE communications.
The company develops multi-band radio frequency ICs for the mobile wireless broadband market, based on novel linearization and efficiency enhancement technologies.
VT Silicon was founded in 2002, and focused on military applications for the first five years of its existence. The company then began to look at commercial applications for some of its technology and materials expertise.
The use of silicon germanium instead of the traditional, more expensive gallium arsenide (GaAs) allows a lower cost device with the potential for a higher level of integration, VT claimed.
As a next step the company is attempting to create a single-chip front-end RFIC initially targeting the WiMax market, with future versions designed for LTE. The first chip of the family (VFM2500) will be available for testing in the first quarter of 2010 with production targeted at the fourth quarter of 2010. The initial design will cover the 2.5-GHz to 2.7-GHz WiMax band as well as the 2.4-GHz WiFi band, and will include the power amplifier, low-noise amplifier, transmit/recieve switch, and transmit and receive filtering and baluns. Other key features include support for transmit antenna diversity, 2 by 2 MIMO, and dynamic bias control via the serial interface for battery life optimization.
The chip includes multiple power modes to allow for efficient operation over a wide range of transmit powers, as well as providing efficient operation in WiFi mode. The Front-End RFIC is housed in a single 5-mm by 5.5-mm by 1-mm QFN package that requires two external bypass capacitors.
"This breakthrough design allows us to take full advantage of the power of silicon integration to implement very advanced, intelligent functionality that helps us minimize current consumed by the battery. By communicating with a baseband processor via our SPI bus we can re-optimize performance burst-by-burst so that each power level consumes the absolute least current possible while still meeting EVM and mask specifications." said Michael Hooper, CEO of VT Silicon, in a statement. "In the past it has not been cost effective for RF front ends to achieve this level of sophistication. However, by leveraging our patented LET technology to implement silicon PAs we now have the ability to create very complex digital and analog control into the front end RFIC. This is a first in the industry. This new FEIC will reduce the component count of a typical discrete 1 by 2 WiMax front end from approximately 50 components to only 3."
VT Silicon received its Series A funding in April 2007, and Series B funding in October 2008 from California-based Menlo Ventures.
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