Low Profile EBG Resonator Antennas

An Electromagnetic Band Gap (EBG) antenna is a planar structure which is composed of a cavity and an EBG material. In most applications, the height of the EBG antenna is half wavelength. We present in this paper the conditions to reduce the profile of an EBG antenna to subwavelength values. It could be achieved by using a cavity upper interface which exhibits negative reflection phase. Frequency Selective Surface (FSS) based on Babinet principle, that satisfies this condition, will be described using full wave analysis. These periodic metallic arrays are employed in the design of a low profile EBG antenna which has a directivity of 10 dBi. As this EBG antenna design is similar to a small antenna over an Artificial Magnetic Conductors (AMC) surfaces or High Impedance Surface (HIS), the EBG antenna principle could be a new theory approach for the AMC or HIS. This point is discussed in this paper.

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Sievenpiper HIS and its influence on antenna correlation

Advances in Radio Science ◽

10.5194/ars-6-39-2008 ◽

2008 ◽

Vol 6 ◽

pp. 39-44 ◽

Cited By ~ 1

Author(s):

S. K. Hampel ◽

O. Schmitz ◽

I. Rolfes

Keyword(s):

Antenna Arrays ◽

Performance Criteria ◽

Electromagnetic Analysis ◽

Planar Antenna ◽

High Impedance ◽

Full Wave ◽

Low Profile ◽

Artificial Magnetic Conductors ◽

Low Profile Antennas ◽

Antenna Correlation

Abstract. \\label{sec:abstract} This paper deals with the influence of artificial magnetic conductors (AMC), so-called Sievenpiper High Impedance Surfaces (HIS), on the MIMO and Diversity performance of a planar linear-polarized 2×2 dipole array in the ISM-band at 2.45 GHz. The characteristic performance criteria such as envelope correlation coefficient, spectral efficiency, Mean Effective Gain (MEG) and Diversity gain of a coupled 2×2 dipole array are investigated. By means of full-wave electromagnetic analysis as well as Monte-Carlo simulations applying statistical channel models the characteristic antenna pattern just as the MIMO and Diversity analysis is performed, respectively. The obtained results show that the application of Sievenpiper High Impedance Surfaces to planar antenna arrays enables good MIMO and Diversity performance compared to ideal configurations in free-space while offering the design of low profile antennas with simultaneously enhanced characteristics.

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Impedance Enhancement of Textile Grounded Loop Antenna Using High-Impedance Surface (HIS) for Healthcare Applications

Sensors ◽

10.3390/s20143809 ◽

2020 ◽

Vol 20 (14) ◽

pp. 3809

Author(s):

Mohammed M. Bait-Suwailam ◽

Isidoro I. Labiano ◽

Akram Alomainy

Keyword(s):

Impedance Matching ◽

Loop Antenna ◽

Healthcare Applications ◽

Impédance Surface ◽

Antenna Structure ◽

Impedance Surface ◽

High Impedance ◽

Low Profile ◽

Close Proximity ◽

High Impedance Surface

In this paper, impedance matching enhancement of a grounded wearable low-profile loop antenna is investigated using a high-impedance surface (HIS) structure. The wearable loop antenna along with the HIS structure is maintained low-profile, making it a suitable candidate for healthcare applications. The paper starts with investigating, both numerically and experimentally, the effects of several textile parameters on the performance of the wearable loop antenna. The application of impedance enhancement of wearable grounded loop antenna with HIS structure is then demonstrated. Numerical full-wave simulations are presented and validated with measured results. Unlike the grounded wearable loop antenna alone with its degraded performance, the wearable loop antenna with HIS structure showed better matching performance improvement at the 2.45 GHz-band. The computed overall far-field properties of the wearable loop antenna with HIS structure shows good performance, with a maximum gain of 6.19 dBi. The effects of bending the wearable loop antenna structure with and without HIS structure as well as when in close proximity to a modeled human arm are also investigated, where good performance was achieved for the case of the wearable antenna with the HIS structure.

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