Array Antenna Limitations

TL;DR

This paper introduces a physical bound-based array figure of merit to evaluate array antennas' performance across parameters like return-loss, thickness, and scan-range, extending existing limits and analyzing high-performance arrays.

Contribution

It develops a new array figure of merit based on Rozanov-type sum-rule bounds, incorporating scan-range and unit-cell structure, to compare single and multi-band array antennas.

Findings

Arrays with a figure of merit >0.6 are high-performance antennas.

The bound extends existing limits to include entire scan-range and unit-cell effects.

Analysis of wideband and wide-scan antennas demonstrates the measure's effectiveness.

Abstract

This letter defines a physical bound based array figure of merit that provides a tool to compare the performance of both single and multi-band array antennas with respect to return-loss, thickness of the array over the ground-plane, and scan-range. The result is based on a sum-rule result of Rozanov-type for linear polarization. For single-band antennas it extends an existing limit for a given fixed scan-angle to include the whole scan-range of the array, as well as the unit-cell structure in the bound. The letter ends with an investigation of the array figure of merit for some wideband and/or wide-scan antennas with linear polarization. We find arrays with a figure of merit >0.6 that empirically defines high-performance antennas with respect to this measure.