Ultra-wideband High Efficiency Power Amplifier for Multifunction RF Systems

OUSD (R&E) MODERNIZATION PRIORITY: Microelectronics TECHNOLOGY AREA(S): Sensors; Electronics OBJECTIVE: Research and develop ultra wideband, high efficiency power amplifier (PA) technology suitable for multifunction transmitter systems. DESCRIPTION: The proliferation of wireless technologies has posed significant challenges to future DoD systems. One of the challenges for sensor technology is the near-peer threats creating highly contested and congested EM environment. The net result is the demand for efficient transmit power ever more critical to achieving battlespace dominance with increase power, efficiency, and spectral coverage. In order to support this vision, this topic is seeking the development and demonstration of multifunctional power amplifier technology capable of wideband and high efficiency operation. The bandwidth coverage may be either instantaneous or tunable for contiguous wideband operation. In essence, we are seeking novel power amplifier concepts to enable wideband coverage, while attaining narrow band like efficiency performance with a size suitable to fit within a Ku-band phased array grid. In this research, ultra wideband power amplification technologies will be explored. This includes the investigation of novel PA topologies to take advantage of advanced processes such as gallium nitride (GaN) where it has the combination of high breakdown and gain bandwidth product. Critical performance parameters for the novel PA include ultra-wideband (2-18 GHz), high gain (saturated power gain > 15 dB), medium output power (Pout > 2W, 10W max.), and high power added efficiency (PAE > 50%). The improved PA performance will enable development of next generation transmit/receive (T/R) modules suitable for airborne and space applications. Current state-of-the-art PA technology provides broadband performance (multi-octave bandwidth), but operates at relatively low efficiency (PAE < 30%). The aim of this research is to explore advanced PA design techniques leveraging advanced technologies to yield the combined contiguous wideband and high efficiency performance suitable for future DoD radar, communication, and EW systems. PHASE I: Perform trade study to provide power amplifier architecture & specifications. Research candidate fabrication technologies and explore design topologies to achieve an ultra-wideband, medium output power, and high efficiency power amplifier. PHASE II: Design and build a prototype of the power amplifier to demonstrate the proof of concept. The proof of concept should be demonstrated in a packaged environment. PHASE III DUAL USE APPLICATIONS: Improve power amplifier bandwidth and efficiency for multifunction RF applications; radar and EW techniques. REFERENCES: J. Gassmann, P. Watson, & L. Kehias, Wideband, High-Efficiency GaN Power Amplifiers Utilizing a Non-Uniform Distributed Topology , IEEE MTT-S International Microwave Symposium digest. IEEE MTT-S International Microwave Symposium, 2007 ; C. Campbell, C. Lee, V. Williams, M. Kao, H. Tserng, P. Saunier, and T. Balisteri, A Wideband Power Amplifier MMIC Utilizing GaN on SiC HEMT Technology, IEEE Journal of Solid-State Circuits, vol. 44, no. 10, pp. 2640 2647, 2009 ; H. Wu, Q. Lin, L. Zhu, S. Chen, Y. Chen, and L. Hu, A 2 to 18 GHz Compact High-Gain and High-Power GaN Amplifier, in 2019 IEEE MTT-S International Microwave Symposium (IMS), 2019, pp. 710 713. ; U. Schmid, H. Sledzik, P. Schuh, J. Schroth, M. Oppermann, P. Bruckner, F. van Raay, R. Quay, and M. Seelmann-Eggebert, Ultra- Wideband GaN MMIC Chip Set and High Power Amplifier Module for Multi-Function Defense AESA Applications, IEEE Trans. Microw. Theory Techn., vol. 61, no. 8, pp. 3043 3051, 2013. KEYWORDS: microelectronics; power amplifier; transmitter