High Efficiency Radar Transmit Module

UHF radar is used for surveillance from unmanned aerial vehicles (UAVs). A typical transmitter must produce multi-kilowatt pulses, but the efficiency of existing transmitters is only 20 to 30 percent. Low efficiency results in transmitters that are unnecessarily large and heavy. It also taxes the limited power available on a UAV and limits the capabilities of the UAV payloads. GMRR proposes to develop a new, high-efficiency transmitter for UHF radar. Efficiency is achieved through a combination of high-efficiency power amplifiers (class D, E, or F), RF-power transistors (GaN or LDMOS), electronic tuning, optimized combiners, and signal processing and control. The efficiency of this architecture is expected to be in the range of 60 to 70 percent. BENEFITS: This technology can be applied directly to UHF radars used for wind profiling and ground penetration (mine detection). With the addition of a wide-band modulator, it can be used in emerging UHF land-mobile and HDTV transmitters. With modification of the power amplifier for operation at higher frequencies, it can be used in cellular base stations. In all of these applications, the new transmitter will offer efficiencies that are double to triple those of the currently available transmitters. Other military applications include the JTRS, manpacks, and hand-held transmitters.