The OpenET Alliance has released a new API specification for 4G handsets to support further industry collaboration. The release of this API will simplify collaboration among semiconductor vendors, OEMs and EDA providers through the complete development lifecycle of Envelope Tracking solutions for 3G and 4G handsets, from early design and prototyping through to mass production.

Commenting, Steven Baker, Technical Director, OpenET Alliance said, “The new API will help the industry deliver efficient 4G transmitters more quickly by providing a platform for closer and more effective co-operation between component suppliers. Envelope Tracking is a key enabler for compact, power efficient 4G handsets. Without it, using traditional power supply architectures, 4G RF PAs will use up to 65 percent more energy than today’s 3G PAs. Using Envelope Tracking technology based on the new OpenET API, manufacturers can rapidly develop 4G handsets that require 30 to 50 percent less energy and support a larger number of LTE frequency bands.”

The API document builds on the widely adopted OpenET hardware interface specifications for terminals. It defines an implementation-independent software interface between the high level calibration, configuration and control functionality required for Envelope Tracking and the low level transceiver and modulator hardware blocks. The API will speed development by enabling common software and firmware routines to be validated and deployed across EDA tools, development systems, test and calibration rigs and production hardware. The API specification is owned by the OpenET Alliance Systems Working Group who will maintain and further develop the APIs.

“In addition, the API document serves as a useful tutorial for engineers wishing to understand the impact of Envelope Tracking on the chipset firmware, as it is a self-contained document which describes all the hooks required to implement ET-enabled solutions for TX power control and calibration in a handset,” added Steven Baker.