Description: An improved efficiency amplifier for high power pulse applications at P-Band will be investigated that will support space based RADAR systems. Current P-Band pulsed amplifier technologies use Silicon Bi-polar and LDMOS device technologies that have increased internal device parasitic characteristics that lead to lower gain and more difficult power matching over GaN technologies. Integra Technologies has experience with all three device technologies. Integra also has the design and manufacturing processes in place to optimize transistor design and amplifier design for P-Band pulsed applications. The preliminary effort will investigate GaN devices at 150W (TBD) levels to determine the overall gain and efficiency at UHF frequencies using Class AB bias and Switch Mode matching techniques to achieve greater than 70% efficiency for a pulsed amplifier application. Longer term device investigation will include geometry modifications to optimize the chip size and cell dimensions for the P-Band RADAR application. Ultimately, the GaN device will be scaled into a target 1kWatt output stage with an appropriate driver device to enable a greater than 40dB gain amplifier. The final amplifier module will include bias modulation techniques for efficiency. The amplifier will include material selections and layout techniques for reliability under high RF energy signal levels and low pressure environments.

Benefits: A target application for this pulsed power amplifier can be RADAR imaging of surface features for Mars or other non-terrestrial objects. The use of a very high efficiency power amplifier will allow for higher power levels in an energy limited environment such as a space craft operations. Higher power ratings of this proposal will allow for greater standoff distances and improved signal to noise for the receivers used for an imaging application. The successful development of this high efficiency amplifier concept can be leveraged by NASA for other RADAR imaging applications at other wavelengths, as Integra Technologies GaN devices can be used at L-Band, S-Band, C-Band and X-band.

The use of higher efficiency and higher power GaN pulsed amplifiers will allow for improved power management for commercial and military applications for RADAR and medical imaging systems. Integra Technologies will continue to push the 'state of the art' for GaN devices and amplifier modules that enable imaging technologies for UHF, L-Band, S-Band, C-Band, and X-Band, which will be enabled by the technology research. The International Telecommunication Union (ITU) and the US gov't has specified the defined the UHF radar band from 420-450MHz primarily for radiolocation. One popular non-government use would be for wind profiler radars. Other non-government customers may have future interest if the band is opened to telecommunication and land/mobile public safety systems.