Dual Notch Microwave Sensors Based on Complementary Metamaterial Resonators

Tanveerul Haq,Ayesha Kosar Fahad,Shahid Ullah,Cunjun Ruan

doi:10.1109/access.2019.2948868

Tanveerul Haq, Ayesha Kosar Fahad + Show 2 more

Open Access

https://doi.org/10.1109/access.2019.2948868

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Abstract

In this paper, three dual notch microwave sensors are presented based on a microstrip transmission line and complementary metamaterial resonators. The main aim of this paper is to compare the constitutive parameters and sensitivity of all three dual notch sensors which are based on complementary symmetric split ring resonator (CS-SRR), complementary asymmetric split ring resonator (CAS-SRR) and complementary bisymmetric split ring resonator (CBS-SRR). The main motivation beyond the presented work is to use dual notches to estimate the relative permittivity of material under test (MUT). Electromagnetic simulation elucidates the origin of dual mode resonance of all the three resonators. Sensitivity analysis is performed on each sensor by using fifteen MUTs with relative permittivity ranges from 1.006 to 16.5 and constant dimensions 10 mm × 10 mm × 1 mm. To verify the concept, a sensor is fabricated and its response is measured using a vector network analyzer (AV3672). Using curve fitting technique the shift in the resonance frequencies of the fabricated sensor due to interaction with MUT is presented as a function of permittivity. Simulated, measured and formulated results are in good agreement with each other.

Highlights

In recent years, complementary metamaterial resonators are widely used in designing useful microwave sensors for evaluation of dielectric substrates [1], [2], dielectric characterization of ethanol-water mixture [3], [4], testing of oils [5], [6] measurement of thickness and permittivity [7], [8]
The fundamental principle of complementary metamaterial based microwave sensor is to sense the variation in resonance frequency and notch depth due to volume or permittivity perturbation of material under test (MUT) or symmetry disruption of a resonator for differential sensing [9], [10]
For MUTs with high values of relative permittivity the sensitivity of the complementary symmetric split ring resonator (CS-SRR) sensor is below 25% due to the first resonance and below 40% due to second resonance

Summary

INTRODUCTION

Complementary metamaterial resonators are widely used in designing useful microwave sensors for evaluation of dielectric substrates [1], [2], dielectric characterization of ethanol-water mixture [3], [4], testing of oils [5], [6] measurement of thickness and permittivity [7], [8]. Later on band-pass and band-stop characteristics are used for sensing based on variation in resonance frequency due to interaction with the MUTs. Currently reported complementary metamaterial based microwave sensors are operating at a single [24]–[27], dual [28], [29], tri [30], and tetra [31] frequency bands. The aforementioned complementary metamaterial sensors are based on stop-band characteristics which have sensitivity limitations due to low operating frequency and poor coupling due to multiple resonators. CBS-SRR was initially presented in [35], it is called bisymmetric resonator because it shows two symmetric planes (electric and magnetic) at resonance [33] All these sensors are simulated with a frequency sweep of 1 GHz to 12 GHz for constitutive parameters and sensitivity analysis.

SENSOR DESIGN AND SIMULATION

FABRICATION AND MEASUREMENT

Findings

CONCLUSION