Adaptive Pre-Distortion Linearizer (ALIN) and Adaptive ExLINC Branch Matching (ABM) for Broadband Power Amplification

This Small Business Innovation Research Phase II project demonstrates a combination of two powerful adaptive digital signal processing technologies that enable broadband, high-power amplification with high linear dynamic range and high output efficiency. The technologies are the Adaptive Pre-Distortion Linearizer (ALIN), and the Adaptive Branch Matching (ABM) algorithm. Combined, these two unique technologies will significantly improve the performance of LINC architecture power amplifiers, as well as being directly applicable to a very wide range of other military and commercial RF Power Amplifiers. The Adaptive Pre-Distortion Linearizer (ALIN) uses a real-time digital signal processing technique to reduce harmonic and intermodulation distortion over a wide range of input frequencies, signal types, and amplitudes, and in rapidly changing environments. Pre-distortion is necessary to enable power amplifiers to perform efficiently and is required in the LINC configuration to meet performance requirements. The technology adaptively tracks nonlinear distortion and cancels the errors The Adaptive Branch Matching (ABM) technology accurately matches the gain and phase of the branches in the ExLINC power amp architecture to insure optimal cancellation of the nonlinear distortion components. The ability to maintain gain and phase matching between the branches of LINC power amplifiers is critical and has been a limiting factor in previous LINC systems. This technology overcomes this important limitation which improves stability and performance. Both the ALIN and ABM technologies are blind adaptive algorithms that automatically track parameters that drift without requiring external calibration signals. During Phase II, the ALIN and ABM algorithms will be implemented and tested in real-time FPGA hardware and applied to a number of different amplifier modules, including a broadband Extended-Range Dual-LINC (ExLINC) prototype amplifier system (to be developed in conjunction with OnQ Technologies, Inc. and Omega Wireless, Inc.) with preliminary target goals of compact size (<36 sq. in), broadband (tunable from 500 MHz to 2.5 GHz), and high-output for extended range (100W). Also as a goal, the technologies implemented in the Phase II will be directly applicable to Rockwell Collins Quad LINC architecture to significantly enhance its performance and operating stability. The processing will be demonstrated with this and other amplifier modules in operationally relevant environments in partnerships with industry (such as Analog Devices, Digital Receiver Technologies, and Raytheon -- testimonials attached) to achieve a Technology Readiness Level (TRL) of 7 (via a Phase II Option).