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arXiv · 2405.20471

Equivalent External Noise Temperature of Time-Varying Receivers

Kurt Schab·K. C. Kerby-Patel
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Abstract

The equivalent external noise temperature of time-varying antennas is studied using the concept of cross-frequency effective aperture, which quantifies the intermodulation conversion of external noise across the frequency spectrum into a receiver's operational bandwidth. The theoretical tools for this approach are laid out following the classical method for describing external noise temperature of linear time-invariant antennas, with generalizations made along the way to capture the effects of time-varying components or materials. The results demonstrate the specific ways that a time-varying system's noise characteristics are dependent on its cross-frequency effective aperture and the broadband noise environment. The general theory is applied to several examples, including abstract models of hypothetical systems, antennas integrated with parametric amplification, and time-modulated arrays.

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Kurt Schab, K. C. Kerby-Patel. 2024-06-12. Equivalent External Noise Temperature of Time-Varying Receivers. https://arxiv.org/abs/2405.20471

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