RF power potential of HEMTs

The growing demand for mobile communication is not only driven by hand-held phones. Wireless local area network and personal digital assistants are also requiring high frequency power amplifiers with high power added efficiency. Even higher frequencies of operation are required for base station interlinks and sensor applications like automotive collision avoidance radar. Several watts of output power at millimeter wave frequencies is a very demanding target with the high electron mobility transistor (HEMT) as the most promising candidate. In this paper the present status of millimeter wave transistors and circuits as well as future applications are discussed.