Metamaterials: Theory, Classification and Application Strategies (Review)

Barad

Int J RF Mic Comp-Aid Eng

2021

This work proposes a novel compact artificial magnetic conductor (AMC) surface backed microstrip antenna of dimension (0.29λ 0 Â 0.17λ 0 Â 0.015λ 0 ) for improving the antenna radiation characteristics. The microstrip antenna considered here for performance improvement has a defected ground plane; thus, giving rise to undesired back-lobe radiation. Thanks to the, in-phase reflection characteristics of the AMC surface, gain improvement of more than 3 dBi has been achieved with a front-to-back lobe ratio improvement of 12 dB. This structure resonates at 5.8 GHz with an impedance bandwidth improvement of 13%. The overall antenna dimensions are (0.67λ 0 Â 0.8λ 0 Â 0.13λ 0 ), where λ 0 is the free space wavelength. To prove the concept, a physical prototype of the proposed antenna structure has been fabricated and the return loss, radiation pattern and gain have been verified. The obtained results are satisfactory and matching with the estimated results.

Section: Configuration Of Amc Backed Patch Antennasupporting

confidence: 52%

Section: Configuration Of Amc Backed Patch Antennasupporting

confidence: 52%

Back‐lobe mitigation of a compact DGS microstrip patch antenna using an artificial magnetic conductor surface

Barad

Int J RF Mic Comp-Aid Eng

2021

IEEE Trans. Wireless Commun.

“…In fact, with metasurfaces e.m. waves can be shaped almost arbitrarily to obtain a given functionality. There exists a rich literature describing their possible realizations, considering patches of simple geometry and design for the realization of holographic metasurfaces or many other solutions [9]- [11], [13]- [16]. Notably, several of metasurfaces functionalities can be realized with layers of bulk metamaterials, and the possible applications include, but are not limited to, transmitarrays [17], metamirrors [16], [18], [19], reflectarrays [20], [21] and holograms [10], [14].…”

Section: Arxiv:200313505v1 [Eesssp] 30 Mar 2020mentioning

confidence: 99%

Using MetaPrisms for Performance Improvement in Wireless Communications

Dardari

Massari

2021

In this paper, we put forth the idea of metaprism, a passive and non-reconfigurable metasurface acting as a metamirror with frequency-dependent reflecting properties within the signal bandwidth. We show that, with an appropriate design of the metaprism, it is possible to control that each data stream in an orthogonal frequency division multiplexing (OFDM) system is reflected in the desired direction without the need for control channels and channel state information (CSI) estimation between the base station and the metaprism, but simply by correctly assigning subcarriers to users. Furthermore, the metaprism can also be designed so that it focuses the signal towards a specific position depending on the subcarrier, provided that it is in the near-field, with consequent path-loss reduction. A critical discussion is also presented about the path-loss gain obtainable from metaprisms and, more generally, from metasurfaces. The numerical results show that this solution is surprisingly effective in extending the coverage in areas experiencing severe non line-of-sight (NLOS) channel conditions, thus making it a very appealing alternative to reconfigurable metasurfaces when low-cost, no energy consumption, and backward compatibility with existing wireless standards are required.

Anais Do XXXIX Simpósio Brasileiro De Telecomunicações E Processamento De Sinais

“…The unit cell is composed of conventional materials, such as metals and dielectrics, arranged in a specific geometric pattern. The array of unit cells forms the electromagnetic metamaterial [2]. The ability to control the electromagnetic wave properties, with different metamaterial structures, had significant impact on the development of advanced microwave devices in the last years [3][4][5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

High Gain, Low Cost, Low Profile Transmitarray Antenna

Arigony¹,

Müller²,

Castro³

et al. 2021

This paper presents a double layer double ring unit cell for circular polarization transmitarrays. The proposed unit cell is evaluated with Rogers 4003 and FR4 substrates. Both models are applied to the design of a 13 x 13 elements transmitarray with a log spiral feeder at 10 GHz. Results show that the transmitarray achieves a directivity of 20.7 dBi and 20.0 dBi at the boresight, with Rogers 4003 and FR4 substrates, respectively, which is nearly 12 dB above the log spiral gain. The results of the proposed transmitarray are compared with a horn antenna and a toroidal plasma lens. When compared with solutions that present equivalent boresight directivity, the proposed transmitarray achieves significantly reduced profile, showing to be a high gain low cost, low profile and easy to prototype solution.