Version 2.0 of the MIPI RF Front-End (RFFE) Control Interface specification adds new features that enhance the controls of complex RF front-end environments with up to 20 components. The interface can be applied to a range of RFFE components to simplify design, configuration, and integration, as well as facilitate interoperability.

The updated MIPI Alliance spec brings five key features to the interface of front-end devices, such as power amplifiers, low-noise amplifiers, filters, switches, power-management modules, antenna tuners, and sensors. For example, an extended range of bus operating frequencies effectively doubles the number of command sequences that can be transferred on the bus in a given timeframe. In addition, synchronous read allows for more types of data propagation on the bus via slave devices, leading to extended bus-loading and frequency ranges.

To support carrier-aggregation system architectures and use of multiple transceivers and dual-SIM designs, the spec includes multi-master configuration. An interrupt-capable slave functionality enables a quick polling method of slave devices to the master controller on the bus. Finally, a new reserved register helps improve the efficiency of hardware and software developments.

Version 2.0 of the spec was worked on by the MIPI RFFE Working Group which surveyed MIPI Alliance and International Wireless Industry Consortium (IWPC) members to assess the market’s needs and identify necessary features. The group is currently working on further refinements to RFFE regarding electrical and digital details, flexible bus configurations, and multiple message types.

The MIPI Alliance’s charter is to develop interface specifications for mobile and mobile-influenced industries.