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Author

Niraj Kumar

Bio: Niraj Kumar is an academic researcher from VIT University. The author has contributed to research in topics: Antenna (radio) & Patch antenna. The author has an hindex of 4, co-authored 12 publications receiving 46 citations.

Papers
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Journal ArticleDOI
TL;DR: An ultrawideband (UWB) meander-line electromagnetic band gap structure for mutual coupling reduction in E-plane of MIMO antennas operating in the frequency range 3.1-10.6 GHz was presented in this article.
Abstract: This paper presents an ultrawideband (UWB) meander-line electromagnetic band gap structure for mutual coupling reduction in E-plane of MIMO antennas operating in the frequency range 3.1–10.6 GHz. Planar UWB MIMO antenna with edge to edge gap of 8 mm has been designed and fabricated on FR4 substrate with dielectric constant 4.4 and height 1.6 mm. An array of four unit cells of electromagnetic bandgap structures arranged in top and bottom layers of the substrate connected through vias has been placed in between antennas to achieve the reduced mutual coupling in the ultrawideband range. Minimum 1 dB and maximum 14 dB reduction in mutual coupling is achieved for 3.4–8 GHz frequency range. Minimum 8 dB and maximum 24 dB mutual coupling reduction is achieved for range of 8–10.6 GHz. Measured results and surface current of MIMO antennas also validate the mutual coupling reduction. Envelope correlation coefficient (ECC) less than 0.02 and channel capacity loss (CCL) less than 0.5 bps/Hz are achieved.

26 citations

Journal ArticleDOI
TL;DR: In this paper, the proposed E-plane spiro meander line uniplanar compact electromagnetic bandgap (E-SMLUC-EBG) structure was applied in mutual coupling reduction of a dual-element MIMO antenna system for WLAN.
Abstract: This paper presents designs of novel E-plane spiro meander line uniplanar compact electromagnetic bandgap (E-SMLUC-EBG) and H-plane spiro meander line uniplanar compact electromagnetic bandgap (H-SMLUC-EBG) structures. The proposed EBG has been applied in mutual coupling reduction of a dual-element multiple input multiple output (MIMO) antenna system for WLAN by placing an EBG structure between the radiating antennas. Compact size of EBG helps in reducing the edge to edge distance between antennas which is 0.14λ0 in this case, and it increases the compactness of integrated circuit. It gives 19 dB and 11 dB simulated mutual coupling reduction in E-plane and Hplane respectively at 5.8 GHz. Measured isolation improvement of 20.3 dB for E-plane and 14.7 dB for H-plane has been achieved. This coupling reduction is also confirmed by surface current and correlation coefficient plots. The four-element (2×2) MIMO antenna system with proposed EBG is also simulated.

26 citations

Proceedings ArticleDOI
Ankit Arora1, Niraj Kumar1
01 Mar 2017
TL;DR: In this article, the authors proposed an EBG structured antenna, which provides better compactness, easy integrated feature and 2-D band gap properties than traditional EBG structures, and can reduce the mutual coupling due to surface wave propagation.
Abstract: The demand for today is to have a Compact and reduced size devices, hence requires reduced sized antenna. For reduced sized, array elements can be placed closer to each other. However, the problem of mutual coupling, depending on interelement separation and their relative orientation, becomes a challenge [3][4]. To overcome this, we proposed an EBG structured antenna. The most used characteristics of Electromagnetic Band Gap (EBG) structure are the surface wave suppression effect within its band gap. Hence, they can reduce the mutual coupling due to surface wave propagation [2][9][10]. EBG provides better compactness, easy integrated feature and 2-D band gap properties. Also, by using EBG structure, antenna array characteristics like total size and radiation efficiency can also be improvised [1].

14 citations

Journal ArticleDOI
TL;DR: In this article, an uniplanar compact Electromagnetic Band Gap (EBG) structure and its application in enhancement of isolation in H-Plane of MIMO antenna system for WLAN (5.8 GHz) is presented.
Abstract: This paper presents design of novel uniplanar compact Electromagnetic Band Gap (EBG) structure and its application in enhancement of isolation in H-Plane of MIMO antenna system for WLAN (5.8 GHz). Isolation enhancement or coupling reduction of 5.6 dB is achieved by etching out the proposed EBG structure from the ground plane of microstrip patch MIMO antenna. Center to center distance is reduced to 0.45λ0 due to compactness of EBG. A metal line strip between radiating patches is used for further reduction in mutual coupling at 5.8 GHz. There is significant enhancement of 16.2 dB in isolation due to the introduction of metal line strip. Hence the total 21.8 dB reduction in mutual coupling is achieved and this coupling reduction is also verified by surface current plots and measured result. The envelope correlation coefficient (ECC) is less than 0.01 and channel capacity loss (CCL) is less than 0.1 bps/Hz at operating frequency.

9 citations

Proceedings ArticleDOI
02 Apr 2015
TL;DR: The aim of the research was to create band-notch properties in the WiMAX, lower WLAN and higher WLAN bands using EBG structures and to do so, different types of E BG structures were used.
Abstract: This paper presents a design of an UWB antenna, which is considered as a basic design. Under the basic antenna design EBG structures were added in order to create notches. These notches were created at the frequencies of existing services. The aim of the research was to create band-notch properties in the WiMAX (3.3–3.6GHz), lower WLAN (5.15–5.35GHz) and higher WLAN (5.725–5.825GHz) bands using EBG structures and to do so, different types of EBG structures were used. The antenna system consists of a sheet of Rogers Duroid 5880 substrate having relative permittivity as 2.2. Firstly basic UWB antenna was designed and then two mushroom type rectangular EBG cells were included on both the sides of feed line of the antenna, which will create notch at higher WLAN band. Further another notch was created using fork type EBG structures on both the sides of feed line of the antenna and above rectangular EBG structure. Through the proposed design notch at the frequency of higher WLAN band was successfully achieved.

3 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, an efficient T-shaped decoupling network is proposed to decouple closely spaced two-element E-plane antenna array based on network analysis and implementation deduction, which is extended to a three-element one by combining with a fine transmission line and further generalized to a multielement linear one.
Abstract: Strong mutual coupling between both adjacent and nonadjacent elements is unavoidable, especially when antenna array is densely arranged. In this paper, an efficient T-shaped decoupling network is primarily proposed to decouple closely spaced two-element E-plane antenna array based on network analysis and implementation deduction. Subsequently, it is extended to a three-element one by combining with a fine transmission line and further generalized to a multielement linear one. All the accordant simulation and measurement results demonstrate that as compared to the coupled arrays, impedance matching, radiation patterns, and scanning characteristics of the decoupled arrays are evidently improved through adding the decoupling network, while mutual coupling between every two elements is greatly reduced. Moreover, such combined decoupling network is effective in the H-plane array and monopole antenna array, implying its huge potential for large-scale array and various arrays.

83 citations

Journal ArticleDOI
10 Oct 2019
TL;DR: In this paper, a printed rectangular slot microstrip antenna array of two elements based on an Electromagnetic Band Gap (EBG) structure is proposed to improve the isolation between the radiating elements for multiple-input multiple-output (MIMO) application.
Abstract: This paper presents a printed rectangular slot microstrip antenna array of two elements based on an Electromagnetic Band Gap (EBG) structure. The proposed EBG structure is invented to improve the isolation between the radiating elements for multiple-input multiple-output (MIMO) application. Single and two slotted rectangular microstrip antennas are designed on an FR-4 substrate with a dielectric constant (er) of 4.3 and loss tangent (tanδ) of 0.025 with thickness of 1.6 mm. The proposed EBG structure is designed as one planar row of 24 slots. The proposed array performance is tested numerically using Computer Simulation Technology Microwave Studio (CSTMW) of Finite Integration Technique (FIT) formulations. The antenna performance in terms of reflection coefficient (S11), isolation coefficient (S21), radiation patterns, boresight gain and Envelope Correlation Coefficient (ECC) are investigated before and after introducing the EBG structure to identify the significant enhancements. The proposed EBG structure is located between the radiating antenna elements to reduce the mutual coupling of the proposed antenna array. The edge to edge separation distance of the proposed antennas is λ0/16, where the λ0 is the free space wavelength at 2.45 GHz. The simulated results show a significant isolation enhancement from –6 dB to –29 dB at the first resonant frequency 2.45 GHz and from –10 dB to –25 dB at the second resonant frequency 5.8 GHz after introducing the EBG structure to the antenna array.

31 citations

Journal ArticleDOI
TL;DR: An ultrawideband (UWB) meander-line electromagnetic band gap structure for mutual coupling reduction in E-plane of MIMO antennas operating in the frequency range 3.1-10.6 GHz was presented in this article.
Abstract: This paper presents an ultrawideband (UWB) meander-line electromagnetic band gap structure for mutual coupling reduction in E-plane of MIMO antennas operating in the frequency range 3.1–10.6 GHz. Planar UWB MIMO antenna with edge to edge gap of 8 mm has been designed and fabricated on FR4 substrate with dielectric constant 4.4 and height 1.6 mm. An array of four unit cells of electromagnetic bandgap structures arranged in top and bottom layers of the substrate connected through vias has been placed in between antennas to achieve the reduced mutual coupling in the ultrawideband range. Minimum 1 dB and maximum 14 dB reduction in mutual coupling is achieved for 3.4–8 GHz frequency range. Minimum 8 dB and maximum 24 dB mutual coupling reduction is achieved for range of 8–10.6 GHz. Measured results and surface current of MIMO antennas also validate the mutual coupling reduction. Envelope correlation coefficient (ECC) less than 0.02 and channel capacity loss (CCL) less than 0.5 bps/Hz are achieved.

26 citations

Journal ArticleDOI
TL;DR: In this paper, a new design of a compact dual-band MIMO antenna with high isolation for WLAN and X-band satellite applications is presented. But the proposed antenna is realized in a single-input multiple-output (SIMO) channel.
Abstract: This paper presents a new design of a compact dual-band Multiple Input Multiple Output (MIMO) antenna with high isolation for WLAN and X-band satellite applications. The proposed antenna is realize...

23 citations

Journal ArticleDOI
TL;DR: In this article, the authors proposed a MIMO antenna with the defective ground structure of the H-shape slot inserted on the bottom ground layer to achieve high isolation, which can be used for WiMAX, Wi-Fi, and future 5G services all over the world.
Abstract: The isolation between the microstrip patches has a great significance to examine the performance of the multiple-input-multiple-output (MIMO) antennas. The patch antennas are placed on the top of 1.46 mm thick Rogers RO3003 substrate having a length of 60 mm, a width of 50 mm, and relative permittivity of 3. The distance between the resonators is 0.06λ and they are stimulated by two coaxial probes extended from the bottom ground layer. The defective ground structure of the H-shape slot is inserted on the bottom ground layer to achieve high isolation (mutual coupling reduction). The proposed MIMO antenna operates at 5.3 GHz frequency, which can be used for WiMAX, Wi-Fi, and future 5G services all over the world. The results of the designed structure have been simulated in a finite element method-based solver high-frequency structure simulator (HFSS). The simulated results show that the reflection coefficient (S11) and isolation (S21) at the desired frequency are −32 dB and −41 dB, respectively.

22 citations