Digital Predistortion at RF using Superconductor Electronics
Agency / Branch:
DOD / ARMY
The implementation of RF transmitters for the Joint Tactical Radio System (JTRS) requires the use of very broadband, multi-carrier power amplifiers covering large sections of the complete 2 MHz - 2 GHz range. However, nonlinearity in these amplifiers enforces an unfavorable tradeoff between power efficiency and spectral purity. Conventional linearization techniques involve analog or baseband corrections, but are unable to achieve the desired improvement across a broad multi-octave band. In Phase I, HYPRES verified the concept of "digital-RF predistortion", showing that direct digital synthesis of a predistortion correction can suppress spurs due to intermodulation and harmonics by more than 30 dB across a range of 30 - 450 MHz and beyond. This requires the use of superconducting electronics, with ultrafast digital sampling and processing rates of 20 GHz and above. In Phase II, HYPRES will develop and demonstrate the circuit components that can achieve this performance in the mid- and high-band ranges (up to 2 GHz), for state-of-the-art power amplifiers. This will lead in Phase III to a full demonstration of a prototype linearization system, for use with JTRS transmitters.
Small Business Information at Submission:
VP Research and Developme
175 Clearbrook Road Elmsford, NY 10523
Number of Employees: