Spaceborne 35-W GaN Power Amplifiers at 71-76 GHz

ABSTRACT: QuinStar Technology proposes to develop an efficient, solid-state power amplifier (SSPA), operating over the 71 to 76 GHz band, for use in high data rate satellite transmitters. The goals of an efficient >35 watt, power amplifier at these frequencies will be met by employing a combination of state-of-the-art (SOA) wide-bandgap gallium nitride (GaN) HEMT device technology and innovative power combining techniques. Existing programs have focused on developing higher power MMIC amplifiers. However, efficient high power devices have not been realized to date. To achieve the power and efficiency goals QuinStar proposes use low loss high order combining networks to power combine a large number of smaller high efficiency MMIC amplifier blocks. BENEFIT: Future warfighters will require increased SATCOM capacity for improved situational awareness. Current SATCOM bands are already overly congested indicating the need to exploit nontraditional frequency spectra, such as the E-band up and down links at 81-86 GHz and 71-76 GHz, respectively. This proposal addresses the downlink requirement by proposing a >35 W high-efficiency power amplifier for the transmitter. High efficiency is required to reduce the prime power requirements and to reduce self-heating. This, in turn, will increase the amplifiers reliability or lifetime (MTTF). In addition to SATCOM UAV applications, this linear, high-efficiency SSPA technology can be utilized in space-based applications including broadband RF cross-link communications in satellite constellations and the Air Forces V/W-band communications system. Specific examples include the Joint Arial Layered Network (JALN) and AISR architectures. Furthermore, this high-efficiency power MMIC technology can be readily applied to other military/NASA missions in the adjacent frequency bands, V and W. QuinStar, as a merchant supplier of high-rel microwave and millimeter-wave components, is uniquely positioned in the marketplace to capitalize on this opportunity to become a major supplier of high-rel, high-efficiency SSPAs for airborne, space and broadband point-to-point communications transceivers.