Can Phase Change Materials Put the Radio into Software Defined Radio?

A new class of high performance switches has been created based on the conducting-to-insulating phase transitions in the semiconductor materials germanium telluride and vanadium dioxide. The exceptional small signal RF performance of these switches points to a future where generic RF radios can be constructed and programmed for a specific application after manufacture. In order to realize this potential, further improvements in switch power handling, tighter integration with other RF components, and increases in switch reliability are needed. This paper reviews some of the history of the development of the switch, some of the decisions made during the development, and the perspective of where the development might go next.