Current Issue : April-June Volume : 2024 Issue Number : 2 Articles : 5 Articles
This paper presents a compact multifrequency reconfigurable patch antenna in terms of design and fabrication for operating in the S and C bands of the RF spectrum, which are overwhelmed by wireless applications. Reconfiguration is achieved by using a single PIN diode on the ground plane. By varying the voltage applied to the diode, three modes can emerge, exhibiting main resonant frequencies at 2.07, 4.63, and 6.22 GHz. Resonance switching requires a voltage of less than 0.9 V. The antenna fabricated on an FR-4 substrate, with a volume of 70 × 60 × 1.5 mm3, has a radiating patch element of a rectangular ring shape. The proposed low-cost antenna is easily implemented in a typical university lab-based environment. The total bandwidth for the three modes is close to 1 GHz, while the voltage standing wave ratio (VSWR) of the fabricated version of the antenna does not exceed 1.02, and the return loss is well below −40 dB for the three primary resonant frequencies....
In this study, a novel microfluidic frequency reconfigurable and optically transparent water antenna is designed using three-dimensional (3D) printing technology. The proposed antenna consists of three distinct parts, including a circularly shaped distilled water ground, a sea waterbased circular segmented radiator, and a circularly shaped distilled water-based load, all ingeniously constructed from transparent resin material. The presented antenna is excited by a disk-loaded probe. The frequency of the antenna can be easily tuned by filling and emptying/evacuating sea water from the multisegmented radiator. The radiator consists of three segments with different radii, and each segment has a different resonant frequency. When the radiator is filled, the antenna resonates at the frequency of the segment that is filled. When all the radiator segments are filled, the antenna operates at the resonant frequency of 2.4 GHz and possesses an impedance bandwidth of 1.05 GHz (40%) in the range of 2.10–3.15 GHz. By filling different radiator segments, the frequency could be tuned from 2.4 to 2.6 GHz. In addition to the frequency-switching characteristics, the proposed antenna exhibits high simulated radiation efficiency (with a peak performance reaching 95%) and attains a maximum realized gain of 3.8 dBi at 2.9 GHz. The proposed antenna integrates water as its predominant constituent, which is easily available, thereby achieving cost-effectiveness, compactness, and transparency characteristics; it also has the potential to be utilized in future applications, involving transparent and flexible electronics....
A wideband, low-profile, dual-polarized antenna using a metasurface (MS) is proposed in this paper. This design consists of a pair of crossed dipoles, an MS, a metal cavity and two baluns. The proposed MS acts as an artificial magnetic conductor (AMC), which is designed for the ±90◦ reflection-phase bandwidth of 1.4–2.9 GHz. Compared with the 0.25λ0 profile of the traditional crossed dipoles, the profile is reduced to 0.15λ0 by using the in-phase reflection characteristics of the MS, which realizes the utilization of space. The measured results show that the antenna has a 10 dB return loss of 68.2% with isolation of more than 30 dB (1.45–2.95 GHz). The realized gain is 9 dBi with ±1 dBi variation, especially exceeding 10 dBi from 2.1 to 2.8 GHz....
This article presents an antenna with compact and simple geometry and a low profile. Roger RT6002, with a 10 mm × 10 mm dimension, is utilized to engineer this work, offering a wideband and high gain. The antenna structure contains a patch of circular-shaped stubs and a circular stub and slot. These insertions are performed to improve the impedance bandwidth of the antenna. The antenna is investigated, and the results are analyzed in the commercially accessible electromagnetic (EM) software tool High Frequency Structure Simulator (HFSS). Afterwards, a two-port multiple– input–multiple–output (MIMO) antenna is engineered by orthogonalizing the second element to the first element. The antenna offers good value for mutual coupling of less than −20 dB. The decoupling structure or parasitic patch is placed between two MIMO elements for more refined mutual coupling of the proposed MIMO antenna. The resultant antenna offers mutual coupling of less than −32 dB. Moreover, other MIMO parameters like envelop correlation coefficient (ECC), mean effective gain (MEG), diversity gain (DG), and channel capacity loss (CCL) are also studied to recommend antennas for future applications. The hardware model is fabricated and tested to validate the results, which resembles software-generated results. Moreover, the comparison of outcomes and other important parameters is performed using published work. The outcome of this proposed work is performed using already published work. The outcomes and comparison make the presented design the best option for future 5G devices....
A single-layer differential-fed (DF) wideband metasurface (MTS) antenna is proposed in this paper. As the prototype, a three-bythree MTS formed by identical rectangular patches is investigated at first. We observe that there are many unwanted higher-order modes (HOMs) resonating near the wanted fundamental mode. Two probes with differential signals feed MTS on its centerline to suppress the majority of HOMs. The remaining HOM can be removed from the discussed frequency range by modifying the prototype MTS to a nonuniform structure. Then, the optimal feeding positions (FPs) are determined by a quantitative prediction of the impendence bandwidth (IBW) without any physical feeds involved. The processes of HOMs suppression and FPs determination are based on characteristic mode analysis with the virtual probes. Moreover, two interdigital capacitor plates are loaded on the probes to improve the impedance matching of the antenna. Finally, the proposed DF MTS antenna is fabricated and measured. The measured −10-dB IBW is 18.4% (4.93 to 5.93 GHz) with broadside radiation, stable high gains, and front-to-back ratios better than 21 dB....
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