# Time-reversal Symmetry in Antenna Theory

## TL;DR

This paper explores the implications of time-reversal symmetry in lossless antenna systems, explaining polarization and impedance matching, and proposing a method to generate time-reversed fields using Herglotz waves.

## Contribution

It offers a novel explanation for antenna matching conditions based on time-reversal symmetry and introduces a method to produce time-reversed electromagnetic fields.

## Key findings

- Time-reversal symmetry explains polarization and impedance matching.
- A method to generate time-reversed fields with Herglotz waves is proposed.
- Provides intuitive understanding of antenna reciprocity principles.

## Abstract

Here, I discuss some implications of the time-reversal invariance of lossless radiating systems. I highlight that time-reversal symmetry provides a rather intuitive explanation for the conditions of polarization and impedance matching of a receiving antenna. Furthermore, I describe a solution to generate the time-reversed electromagnetic field through the illumination of a matched receiving antenna with a Herglotz wave.

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Source: https://tomesphere.com/paper/1902.09580