Investigation of antennas with non-reciprocal radiation characteristics

Cain, Sasha Seneca Yamada

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https://hdl.handle.net/2142/129690 Copy

Description

Title

Investigation of antennas with non-reciprocal radiation characteristics

Author(s)

Cain, Sasha Seneca Yamada

Issue Date

2025-04-17

Director of Research (if dissertation) or Advisor (if thesis)

Bernhard, Jennifer

Doctoral Committee Chair(s)

Bernhard, Jennifer

Committee Member(s)

• Ilie, Raluca
• Schutt-Ainé, Jose
• Zhao, Yang

Department of Study

Electrical & Computer Eng

Discipline

Electrical & Computer Engr

Degree Granting Institution

University of Illinois Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• antennas
• electromagnetics
• non-reciprocal antennas
• modal analysis

Abstract

Antennas are essential in all wireless systems, serving as the link between a guided signal and free space. Since their invention in the late 1880s, antennas have been designed almost exclusively as reciprocal devices. This assumption of reciprocity allows us to design an antenna from a transmit perspective and have confidence that it will work just as well as a receiver. However, as wireless systems become more advanced, the routine assumption of reciprocity denies us of a useful degree of freedom. This work explores a new paradigm in antenna engineering by investigating antennas deliberately designed to display non-reciprocal behavior. Specifically, unidirectional true-time delays are explored as a means to achieve non-reciprocal radiation. The result is a wideband and low-loss method to induce non-reciprocity into an antenna system, supported by several design-focused models and experimental results. Additionally, an excitation-dependent electromagnetic modal analysis technique is developed. This analytical method builds on previous work to mathematically separate the surface currents responsible for radiation and energy storage. This methodology is validated by analyzing the modal results of simple wire antennas and connecting the results back to known behavior. More complex geometries, such as planar single-element antennas and small arrays, are also discussed. This modal analysis work supports the overarching goal of developing non-reciprocal antenna systems because of its excitation-dependent formulation, which makes it uniquely appropriate for systems that exhibit distinct transmit and receive behavior.

Graduation Semester

2025-05

Type of Resource

Thesis

Handle URL

https://hdl.handle.net/2142/129690

Copyright and License Information

Copyright 2025 Sasha Seneca Yamada Cain

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