# Microwave Detection of Carbon Monoxide Gas via a Spoof Localized Surface Plasmons-Enhanced Cavity Antenna

## TL;DR

This paper introduces a new all-metal microwave sensor that detects carbon monoxide gas by measuring tiny changes in dielectric properties, offering improved accuracy and environmental adaptability.

## Contribution

The novel all-metal sensing antenna combines spoof localized surface plasmons and cavity resonance for enhanced CO detection.

## Key findings

- The system achieved a figure of merit of 183.2 RIU−1, resolving dielectric contrasts below 0.1%.
- It successfully differentiated CO (εr = 1.00262) from air (εr = 1.00054) under standard conditions.

## Abstract

This paper presents a carbon monoxide (CO) detection mechanism achieved through further improvement of the sensing antenna based on hybrid spoof localized surface plasmons (SLSPs) and cavity resonance. Unlike conventional approaches relying on chemical reactions or photoelectric effects, the all-metal configuration detects dielectric variations through microwave-regime resonance frequency shifts, enabling CO/air differentiation with theoretically enhanced robustness and environmental adaptability. The designed system achieves measured figures of merit (FoMs) of 183.2 RIU−1, resolving gases with dielectric contrast below 0.1%. Experimental validation successfully discriminated CO (εr = 1.00262) from air (εr = 1.00054) under standard atmospheric pressure at 18 °C.