Cambridge Consultants has introduced a new architecture, ModStar, for the design of low power and efficient software defined radios (SDRs) for military communications. The ModStar architecture has been designed to enable implementation of SDR modules that can link multiple communication platforms in a lightweight device that would be portable for troops. Portability is further enhanced by Nujira's highly efficient Coolteq envelope tracking technology for power amplifiers, that can extract double the power output from a given power transistor. Equipment and battery size are minimised by reducing filtering and power consumption requirements, allowing new smaller form factors or wider bandwidths to be achieved.

In recent years, defence organisations around the world have invested in a variety of custom radio systems, using many different air interfaces, to perform specific tasks. However, a key challenge for operations today is ensuring that all of these different air interfaces can be interoperable in the field, and that seamless communications can be conducted on any of the legacy systems. SDR can provide exactly this capability, delivering support for multiple air interfaces within a single, flexible implementation.

SDR architectures have been used for military and defence applications, such as the Joint Tactical Radio System (JTRS). This makes use of the platform’s ability to be reprogrammed from a high level description of the new radio waveform to use new communications protocols. However, the SDR challenge is to find a practical implementation that meets a demanding range of requirements that often leads to complex power amplifier, filtering and antenna switching arrangements. For troops on the ground this can mean bulky, heavy radio equipment that can only be moved in a vehicle.