Multiport Antenna Q-factor

TL;DR

This paper introduces a generalized Q-factor for multiport antennas to estimate bandwidth, using port parameters and stored energy conversion, validated through examples with dipole and patch arrays.

Contribution

It extends the single-port Q-factor concept to multiport antennas, enabling bandwidth estimation based on port parameters and stored energy analysis.

Findings

Derived formulas utilize total active reflection coefficient.

The method allows single-frequency bandwidth evaluation.

Validation with dipole and patch antenna arrays confirms the theory.

Abstract

This article proposes an estimate of multiport antenna bandwidth based on a generalization of a single-port Q-factor. The explicit derivation is based on converting the stored energy matrix to its port equivalent and on the port parameters themselves. The work discusses the bandwidth dependencies on feeding and matching. Derived formulas are shown to utilize the total active reflection coefficient and allow for a single-frequency bandwidth evaluation. Examples comprising two different dipole arrays and electrically large patch antenna arrays validate the theory.