High-efficiency power amplifier for multipurpose portable radio

There is a need for a portable command-post transmitter that can be deployed in an emergency situation. Interoperability among the different military services and civilian agencies is required. Consequently, the transmitter must operate at allfrequencies from 200 MHz to 3 GHz. It must also be capable of generating a wide variety of different signals. The proposed phase-I program will investigate the feasibility of a high-efficiency transmitter for this purpose. The proposed transmitter willbe based upon a combination of a high-efficiency RF-power amplifier (PA), high-efficiency modulation technique, and electronic tuning. The high-efficiency RF PA ensures the maximum efficiency at peak output, while the modulation technique ensures thatefficiency remains high for all signal amplitudes. Electronic tuning allows the transmitter to maintain optimum performance at all frequencies in its band of operation. This technology will enable small, light-weight radios capable of operating over a wide range of frequency and for a long time from a single battery. Military applications include airborne jammers and portable communication transceivers. Similarbenefits are possible in a variety of commercial applications. Cellular base stations have similar output power and frequency range, but the average efficiency of current transmitters is no more than 10 percent. Application of this technology canincrease the output power by 20 percent and reduce the power consumption by a factor of 4 to 6. The resultant transmitter will not only cost less to buy, but also less to operate. Broadcast transmitters and a variety of communication radios can alsobenefit from this technology.