NASA's Earth Science Division will find immediate use for the HESPEROS amplifier in earth observation sensor systems. This design enables operation over multiple radar bands with a single RF PA. Ultimately, other applications for this proposed high efficient PA for radar based applications include other primary mission critical communication functions like telemetry, telecommand, navigation and guidance control, flight termination, craft-to-craft communications, and TDRSS reply and relay. The proposed high efficiency RF PA for radar applications may be adapted to other areas requiring high power transmitters. Additional applications within and around the satellite, space, scientific, industrial, university funded, low altitude and low earth orbital experiments, and aerospace industries include: 1) S-band, C-band, and X-band Telemetry and Telecommand 2) Radar Transponder 3) Flight Termination Transmitter 4) LEOS/MEOS mini-satellite and cube-satellite (ARISS and AM-SAT) The applications of this technology within the Department of Defense (DoD) are numerous. Military aviation will benefit from the SWaP improvements from a single multi-band PA unit. Additionally, land and sea radar systems will benefit from the increased capability of a multi-band PA unit.