Low Refractive Metamaterials for Gain Enhancement of Horn Antenna

Abstract-In this paper, a new high performance slotted waveguide antenna incorporated with negative refractive index metamaterial structure is proposed, designed and experimentally demonstrated. The metamaterial structure is constructed from a multilayer two-directional structure of electrically split ring resonator which exhibits negative refractive index in direction of the radiated wave propagation when it is placed in front of the slotted waveguide antenna. As a result, the radiation beams of the slotted waveguide antenna are focused in both E and H planes, and hence the directivity and the gain are improved, while the beam area is reduced. The proposed antenna and the metamaterial structure operating at 10 GHz are designed, optimized and numerically simulated by using CST software. The effective parameters of the eSRR structure are extracted by Nicolson Ross Weir (NRW) algorithm from the s-parameters. For experimental verification, a proposed antenna operating at 10 GHz is fabricated using both wet etching microwave integrated circuit technique (for the metamaterial structure) and milling technique (for the slotted waveguide antenna). The measurements are carried out in an anechoic chamber. The measured results show that the E plane gain of the proposed slotted waveguide antenna is improved from 6.5 dB to 11 dB as compared to the conventional slotted waveguide antenna. Also, the E plane beamwidth is reduced from 94.1 degrees to about 50 degrees. The antenna return loss and bandwidth are slightly changed. Furthermore, the proposed antenna offered easier fabrication processes with a high gain than the horn antenna, particularly if the proposed antenna is scaled down in dimensionality to work in the THz regime.

Section: Introductionmentioning

confidence: 99%

High Gain Slotted Waveguide Antenna Based on Beam Focusing Using Electrically Split Ring Resonator Metasurface Employing Negative Refractive Index Medium

Abdelrehim¹,

Ghafouri‐Shiraz²

2017

“…Finally, it is worth to mention that applications of metamaterials are a developing area in designing horn antennas. For example, metamaterials are used for gain enhancement in [14] and for sidelobe reduction in [15].…”

Section: Introductionmentioning

confidence: 99%

Rectangular Horn Antennas With Limiting Plates for Symmetrical Pattern and Beam Efficiency Improvement

Fartookzadeh¹,

Ghaffarian²,

Zamani³

et al. 2016

Abstract-This paper proposes a horn antenna with limiting plates inside to produce symmetrical pattern in E-plane and H-plane. Sidelobes of the antenna are reduced using the limiting plates, and therefore, the beam efficiency of the antenna is improved up to 90% without changing the antenna dimensions. The antenna dimensions are adjusted to achieve the best beam efficiency. Simultaneously, the reflection coefficient is maintained lower than −15 dB. In addition, it is indicated that this antenna has wide bandwidths without reducing the efficiency and performance of the antenna. Finally, the reflection coefficient is improved to −20 dB without degradation of the antenna performance.

“…However, ZRI is realized lately to the microwave frequencies by scaling its dimensions toward practical wireless applications [14]. Currently, different categories of the ZRI structures are utilized in the antenna applications such as Electromagnetic Band Gap (EBG), Photonic Band Gap (PBG) structures and Frequency Selective Surface (FSS) [15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

A Miniaturized Lotus Shaped Microstrip Antenna Loaded With Ebg Structures for High Gain-Bandwidth Product Applications

Elwi¹,

Imran²,

Alnaiemy³

2015

Abstract-In this paper, the design of a printed circuit antenna based on lotus flower patch of a miniaturized profile is proposed. The antenna consists of three layers including a patch and a ground plane of a thin copper layer separated by a Roger RT/duroid R 5880 substrate for high gain-bandwidth product applications including microwave imaging systems. The patch structure is patterned with triangular defects to provide a fractal structure. Nevertheless, the ground plane is defected with Electromagnetic Band Gap (EBG) structures. The antenna is found to show a first resonant mode around 3 GHz, while the other frequency modes are obtained around 4.2 GHz and 6 GHz which are below −10 dB. Moreover, the antenna operates over the frequency range from 7.8 GHz up to 15 GHz with a bore-sight gain varing from 4 dBi up to 6 dBi when operates in free-space environments. The antenna size is reduced to a 32 mm × 28 mm × 0.5 mm using shorting plates on the substrate edges. The antenna performance characteristics are examined using CST and HFSS commercial software packages, which are based on the Finite Integration Technique (FIT) and the Finite Element Method (FEM), respectively. Finally, the antenna performance is tested experimentally for both S 11 spectrum and radiation patterns to show an excellent matching with the obtained numerical results.