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Showing papers in "International Journal of Rf and Microwave Computer-aided Engineering in 2018"


Journal ArticleDOI
TL;DR: In this paper, decoupling network isolation approach, parasitic element approach, defected ground structure, Neutralization line, isolation improvement based on metamaterials, isolation improved using PIN diode, varactor diode and feeding structure have been incorporated, and their merits and demerits have been discussed.
Abstract: The present technology fulfills the requirement of high data rate and high channel capacity using multiple input multiple output (MIMO) technology. The MIMO capacity of the system is increased linearly but due to the multiple antennas placed near to each other, problem of mutual coupling exists, which degrades the maximum achievable performance of the system. The problems of multipath propagation can be solved using MIMO system. The isolation improvement methods decrease the mutual coupling among antenna elements, and improve the gain and efficiency of the system. In this paper, decoupling network isolation approach, parasitic element approach, defected ground structure, Neutralization line, isolation improvement based on metamaterials, isolation improvement using PIN diode, varactor diode, and feeding structure have been incorporated, and their merits and demerits have been discussed. The effect of different permittivity material on antenna parameters has also included.

53 citations





Journal ArticleDOI
TL;DR: In this article, a band notched ultra wideband (UWB) antenna is presented as a good prospect for multiple-input multiple-output (MIMO)/diversity application.
Abstract: A band notched ultra-wideband (UWB) antenna is presented in this article as a good prospect for multiple-input multiple-output (MIMO)/diversity application. The proposed MIMO antenna is constituted of two modified rectangle-shaped patch antenna elements. A stepped stub is extended from the modified ground plane as a decoupling element between the radiators to realize a good isolation level between them. A band rejection response is obtained by connecting an open resonant stub to each of the radiators. The simulated prototype is fabricated and tested for verification. Results reveal that the proposed prototype provides a 10 dB return loss bandwidth from 3.08 to 10.98 GHz with band notch characteristics from 4.98 to 5.96 GHz, and a good port isolation level (S21 ≤ 20). Diversity performances are ensured in terms of total active reflection coefficient, envelope correlation coefficient (<0.013 except notch band), diversity gain (≈9.51 dB), mean effective gain ratio (≈1), and channel capacity loss (≤0.35 bps/HZ except notch band). It evidences that the presented band notched UWB antenna can be a good prospective for MIMO/diversity applications.

41 citations





Journal ArticleDOI
TL;DR: In this paper, a coplanar waveguide fed ring slot antenna is proposed for the generation of circular polarization, which can be improved by adding a stub antenna to the ring slot.
Abstract: In this article, a coplanar waveguide fed ring slot antenna is proposed for the generation of circular polarization. It is shown that the bandwidth can be improved by adding a stub. Characteristics mode analysis is used to understand the wideband behavior and generation of circular polarization in different antenna configurations. Parametric analysis is used to optimize the performance of the antenna. The proposed antenna is fabricated and the measured results are compared with the simulated performance. The measured impedance bandwidth (|S11| ≤ -10 dB) is 64.6% (2.25 GHz–4.4 GHz) and a 3 dB axial ratio bandwidth is 64.6% (2.25 GHz–4.4 GHz).

31 citations





Journal ArticleDOI
TL;DR: In this article, the authors used COSTAction MiMed (TD1301) in the framework of the BioElecPro project to develop a system for the detection of cancer.
Abstract: The research leading to these results has received fundingfrom the European Research Council under the EuropeanUnion’s Horizon 2020 Programme/ERC Grant Agreement BioElecPro n. 637780, Science Foundation Ireland (SFI)grant number 15/ERCS/3276, and the Natural Sciences andEngineering Research Council of Canada (NSERC). Thiswork has been developed in the framework of COSTAction MiMed (TD1301)

Journal ArticleDOI
TL;DR: A novel efficient rectenna is proposed in this paper for radio frequency (RF) energy harvest from ambience at 2.45 GHz ISM band and the results indicate that the antenna is characterized with a good matching characteristic with a stable omnidirectional radiation pattern.









Journal ArticleDOI
TL;DR: The proposed method is validated using 6 different cells with unified parameterization to identify the smallest rectangular‐like rat‐race coupler described by 2 design specifications, and attest that circuit topology and electrical parameters of the reference design are critical factors determining the final miniaturization rate.


Journal ArticleDOI
TL;DR: In this paper, a metasurface-based low-profile crossed dipole antenna with wide circularly polarized bandwidth for 2.45 GHz ISM band wireless communications is proposed and fabricated.
Abstract: A metasurface-based low-profile crossed dipole antenna with wide circularly polarized bandwidth for 2.45 GHz ISM band wireless communications is proposed and fabricated in this article. Consisting of four slit-loaded rectangular patches, the double-sided printing crossed dipoles are fed by a pair of vacant-quarter printed rings which circularly polarized (CP) radiation could be generated. With slits loaded, by properly combining the fundamental mode of the two inverted L-shaped dipole, the slot mode and extra resonance generated by the AMC surface, a wideband circularly polarized operation can be obtained. After optimization, the final design with an overall size of 0.44λ0 × 0.44λ0 × 0.1448λ0 at 2.4 GHz had measured a 31.6% (2–2.75 GHz) impedance bandwidth and 3 dB axial ratio bandwidths of measured were 23.2% (2.1–2.65 GHz), respectively. In addition, the antenna performed a small gain variation (7.0–7.5 dBic) and a front-to-back ratio (FBR) of over 25 dB across the whole CP region.


Journal ArticleDOI
TL;DR: In this article, a compact 27-bit linearly polarized chipless radio frequency identification tag is presented, which is designed with an overall tag dimension of 23 × 23 mm2.
Abstract: A compact 27-bit linearly polarized chipless radio frequency identification tag is presented in this research. The proposed tag is designed with an overall tag dimension of 23 × 23 mm2. The tag comprises of metallic (copper) rings-based structure loaded with slots. These slots correspond to a particular sequence of bits. The circular tag is analysed using 2 different substrates, that is, Rogers RT/duroid/5870 and flexible Rogers RT/duroid/5880. The radar cross-section response of frequency signatured tag is analysed for humidity and temperature sensor designs. Humidity sensing is achieved by deploying a DuPont Kapton HN heat resistant sheet on the shortest slot of the tag, that is, the sensing slot. Temperature sensing is attained using Rogers RT/duroid/5870 and Stanyl polyamide as a combined substrate. Hence, the miniaturized, robust, and flexible tag can be deployed over irregular surfaces for sensing purposes.