Linear and Nonlinear Ultra-Short Pulse Looped Antennas: Radiation and Parametric Oscillations

TL;DR

This paper demonstrates that specially designed loop antennas can generate and receive ultra-short pulses with minimal dispersion, and introduces a nonlinear loop system capable of broadband amplification, useful for advanced communication and quantum systems.

Contribution

The study presents novel ultra-short pulse loop antennas and a nonlinear loop system that achieves broadband amplification, surpassing traditional narrowband parametric amplifiers.

Findings

Loop antennas produce pulses under 400 ps with minimal dispersion.

Nonlinear loop inside a loop system enables broadband signal amplification.

The system's bandwidth scales inversely with loop diameter.

Abstract

Modern optical systems send and receive ultra-short temporal pulses (USP). While ultra-broad band antennas do exist in the microwave region (e.g., log-periodic antennas), their short temporal response is typically limited by the antenna's large dispersion, hence, resulting in a substantial pulse broadening. The issue becomes more severe when one considers both the transmitted and received pulses. Through simulations and experiments one can show that properly designed loop antennas, either thick loops or 3-loop antennas, exhibit USP attributes, 280 ps upon transmission and 380 ps upon reception (or, an overall equivalent coherent channel exceeding 2.5 GHz). Finally, most parametric amplifiers are narrow band and one may ask if a broadband amplification is possible. A loop inside a loop system, coupled by a nonlinear impedance element exhibits a line narrowing and signal amplification with large bandwidth, which is inversely scalable with the loops' diameter. In all, these elements could be advantageous for applications such as ultra-wide bandwidth communication and non-linear quantum information systems.