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arXiv · 2604.02498

A Self-Calibrating SDR for High Fidelity Beam- and Null-forming Arrays

Yongjun Kim·Aditya Dhananjay·Sundeep Rangan·Sachin Shetty·C. Nicolas Barati·Michael Zappe·Kimberly Gold·Junil Choi
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Abstract

Null forming is increasingly essential in modern wireless systems for spectrum-sharing, anti-jamming, and covert communications in contested and congested environments. Achieving deep nulls, however, is far more demanding than conventional beam steering: nulls are intrinsically narrow, and even small phase, timing, or gain mismatches across RF chains can significantly degrade suppression. This work develops and validates a self-calibrating SDR architecture tailored for high-fidelity null forming using a compact reference transmitter directionally coupled to the antenna feeds. We demonstrate the effectiveness of the approach through simulation and experimental measurements on an SDR platform operating from 3.0 to 3.5GHz, a band of growing importance for Department of Defense spectrum-sharing initiatives.

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Yongjun Kim, Aditya Dhananjay, Sundeep Rangan, Sachin Shetty, C. Nicolas Barati, Michael Zappe, Kimberly Gold, Junil Choi. 2026-04-02. A Self-Calibrating SDR for High Fidelity Beam- and Null-forming Arrays. https://arxiv.org/abs/2604.02498

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