Traditional RF front ends have become increasingly inefficient as more data is packed into the radio spectrum through standards such as 3G, 4G and Digital TV. Envelope Tracking is the most effective wide-band power optimisation technology for the RF front end of 3G and 4G handsets.
Originally developed in the 1930’s, ET is now increasingly seen as the only viable solution for energy efficient, broadband 3G and 4G products. For consumers it promises smartphones that will last far longer on a single charge, and can support multiple frequency bands for global roaming. For network operators and broadcasters it offers the potential of a 66% reduction in transmitter-site energy costs.
Commenting from the Alliance's Cambridge headquarters, Steven Baker, Technical Director of the OpenET Alliance, said, It is significant that our membership is drawn from right across the supplier ecosystem, embracing chipset platform, PA and modulator vendors, OEMs and academic institutions. No one supplier has all the answers, so this kind of industry collaboration is key to effective development in the sector.
The updated interface specification for terminals, which has now been published to OpenET members, includes recommended system noise specifications to support full bandwidth LTE signals.
In addition to publishing ET interface specifications, the OpenET Alliance, through its systems working group, is developing a common system simulation model to ensure that all participants share a deep understanding of system issues that underpin specification and design choices. It is expected that this will lead to earliest delivery of effective components and products.
Following the success of this early work, additional specification development is planned this year for 'medium power' pico- and femto-infrastructure, public safety and military applications.
Recent research has also highlighted the fact that ET-enabled terminals have a direct beneficial impact on operator economics. This topic - along with specifications, system simulations and ET case studies - will be presented in more detail at the OpenET Alliance Envelope Tracking Conference to be hosted by Sony Europe in Weybridge on 2 May 2012.