Metasurface Antennas Embedded in Small Circular Cavities for Telemetry Applications

Loïc Bernard,Ronan Sauleau,Sylvain Collardey,Kouroch Mahdjoubi,Mario Martinis

doi:10.3390/app9122496

Abstract

This paper introduces a metasurface-inspired antenna embedded in a circular metallic cavity with a very small diameter (from 0.25 λ0 down to 0.12 λ0, where λ0 is the wavelength in vacuum at the operating frequency). The proposed concept is introduced and explained: It consists of placing a capacitive surface at the cavity aperture. This capacitive effect is obtained using multi-layer capacitively coupled strips. Our numerical results demonstrate that the impedance bandwidth is larger than that of standard patch antennas embedded in the same cavity size. Various prototypes have been manufactured, and measurements are found to be in good agreement with numerical results in all cases. The practical applications of these small metasurface antennas are demonstrated with telemetry applications for flying vehicles.

Highlights

Microstrip antennas are commonly used in modern wireless communications, as they present the advantages of low cost, low profile, and ease of fabrication, they might suffer from a narrow bandwidth (BW) in certain configurations [1,2]
Metasurface-inspired antennas have been proposed to enlarge the bandwidth of small antennas embedded in miniature circular cavities
The design is inspired from the distribution of the Metasurface-inspired antennas have been proposed to enlarge the bandwidth of small antennas fields of cavity mode

Summary

Introduction

Microstrip antennas are commonly used in modern wireless communications, as they present the advantages of low cost, low profile, and ease of fabrication, they might suffer from a narrow bandwidth (BW) in certain configurations [1,2]. The integration of microstrip antennas into small cavities leads to antenna performance degradations. These have been investigated over the past decades in [3,4,5,6], and more recently in [7,8,9]. The reduction of the antenna diameter and its integration into a metallic cavity result in a significant decrease of its BW. It was demonstrated in [7] that, for small cavities of rectangular shape As introduced in previous works [7,8,9,11], loading the aperture of a metallic cavity antenna with a capacitance-only impedance offers two benefits: Increasing the antenna BW [7], compared to stacked patch antennas embedded in a larger cavity [11]; or reduction of the antenna and cavity size for a given BW [9]

Methods

Results

Conclusion