Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

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. © 2020 Elsevier GmbH

Electronics

School of Electronics Engineering

Chennai Campus

World University root node

AEU - International Journal of Electronics and Communications

Meander-line electromagnetic bandgap structure for UWB MIMO antenna mutual coupling reduction in E-plane

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. © 2019 RADIOENGINEERING.

Fulltext

Radioengineering

MIMO Antenna H-Plane Isolation Enhancement using UC-EBG Structure and Metal Line Strip for WLAN Applications

In this paper, return loss (S11) of the antenna is discussed. Several antenna size miniaturization techniques are discussed, and few are implemented to design a medical antenna for neural data transfer operating in the Medical Implant Communication Service (MICS) band as assigned by the FCC. The antenna also operates in bands near ISM band which makes the antenna to operate for other medical application as well. The current path is lengthened by using combination of spiral-slot and meander slot antenna. Shorting pin is used to lower down the frequency, and use of superstrate is made to isolate the antenna from getting in direct contact with the human body. The design of the antenna is done using High-Frequency Simulation Software (HFSS), and the simulated results are discussed in the paper. © 2018, Springer Nature Singapore Pte Ltd.

Lecture Notes in Electrical Engineering

Wideband Antenna for Medical Application

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 H-plane 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. © 2018, Electromagnetics Academy. All rights reserved.

Progress In Electromagnetics Research C

MIMO antenna mutual coupling reduction for WLAN using spiro meander line UC-EBG

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]. © 2017 IEEE.

VIT Unitversity

2017 International Conference on Nextgen Electronic Technologies: Silicon to Software (ICNETS2)

To reduce mutual coupling in microstrip patch antenna arrays elements using electromagnetic band gap structures for X-band

A multi-layer tilted beam planar microstrip array for FMCW-SAR application is presented. The proposed 8×4 array antenna exhibits a beam tilt of 30 degrees in E-plane with a sidelobe level of 18dB and 20dB in H-plane without tilt. The inherent radiation pattern degradation of the array due to feed radiation is minimized with the proposed multilayered concept. The proposed design exhibits an improvement in sidelobe level of the order of 6dB in both E-and H-planes with better cross-polarization level. In the multi-layered design, the common ground plane separating the two stacked substrate layers, shields the antenna half-space from spurious radiation emitted from the feed network. The simulation results show that the radiation pattern in the operating frequency provides a 3dB beamwidths of 25° and 9° in E-plane and H-plane respectively. Array exhibits a gain of 20dBi at the centre frequency and cross polarization level of better than 15dB. © 2016 IEEE.

2016 Asia-Pacific Microwave Conference (APMC)

A multi-layer X-Band microstrip array with beam tilt for FMCW-SAR application

This paper describes about the design of a smooth multi-flared conical horn antenna which can operate at multi-frequency bands. This work has been carried out at National Atmospheric Research Laboratory (NARL), Gadanki, India, as a part of development of satellite earth station. It is designed to operate for some selected free to air meteorological satellites, which are operating in L-band (1.694-1.703GHz), S-band (2.0-2.06GHz), C-band (4.5-4.6GHz) and X-band (7.8-7.9GHz). The simulated results of horn alone and horn including 4-meter parabolic reflector are shown. After including reflector with horn we have achieved Gain > 30dB, Beamwidth around 2-3 degrees, VSWR < 1.5dB and Return-loss < -15dB for the desired range of frequencies. © 2016 IEEE.

2016 International Conference on Wireless Communications, Signal Processing and Networking (WiSPNET)

Design of smooth multi-flare multi-frequency conical horn antenna for satellite earth station

The paper describes about multiband antenna which is suitable for various applications like Bluetooth, WiMax and WLAN. This antenna is designed to operate in three different frequency bands 2.4/5.2/5.8-GHz for WLAN and 2.5/3.5/5.5-GHz for WiMAX. It is basically a microstrip-fed antenna which mainly consist of three different structures i.e. pentagonal ring, V-shaped strip, and a defected ground plane. By adding V-shaped strip in the pentagonal ring, the antenna excites in two resonant modes without increasing the size of structure. As we include the defected ground plane which consists of isosceles triangular defect, our third band with improved impedance matching was obtained. © 2016 IEEE.

Triple band microstrip-fed antenna with defected ground plane for Bluetooth/WiMAX/WLAN

A multi-layer planar microstrip array at X-band is presented for FMCW-Synthetic Aperture Radar application. A comparative study is provided for conventional corporate fed array and multilayered (proposed) array configurations. The proposed design exhibits an improvement in sidelobe level of the order of 6dB in both E-and H-planes with better cross-polarization level. The common ground plane separating the two stacked substrate layers, shields the antenna half-space from spurious radiation from the feed lines. The simulation results show that the radiation pattern in the operating frequency provides sidelobe level better than 23dB and 21dB with a 3dB beamwidths of 23° and 9° in E-plane and H-plane respectively. Array exhibits a gain of 21dBi at the centre frequency and cross-polarisation level of better than 30dB. © 2016 IEEE.

A multilayer X-band FMCW-SAR microstrip array

In this paper meander slot antenna is thoroughly investigated for dual band applications. The antenna is mounted on high dielectric substrate and fed by a 50 ohm micro strip feedline. Meander slot antenna has finite ground plane and operated at frequency range of 2400MHz to 3500MHz for WLAN and Fixed WI-Max. This simulated result show stable radiation patterns and good return loss of less than-10 dB in the frequency range of 2.4-3.5GHz. © 2015 IEEE.

2015 International Conference on Communications and Signal Processing (ICCSP)

Dual band meander slot antenna for mobile applications

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. © 2015 IEEE.

Wideband antenna with notches at frequencies of existing services band using EBG

In mobile communication, dual band antenna plays a vital role in recent time. This paper presents the simulation analysis of dual band antenna using SMTL for bandwidth and gain enhancement. It's range of frequency is from 2.4GHz to 3.5GHz for WLAN & Wi-MAX application. Various govt. and private sector organizations make use of dual bands antenna to solve the problem of antenna bandwidth in mobiles or wireless and WI-MAX, WLAN etc. Two different unit cells of metamaterial transmission line are introduced in antenna geometry which is resonated at different frequencies. So, the paper reports a brief description of bandwidth enhancement of antenna fed by coplanar feed line on finite size of ground plane. The dual meander slot antenna supports two frequencies of 2.4GHz and 3.5GHz respectively. The simulated results demonstrate the optimum bandwidth of antenna and its radiation characteristics which can be used for various mobile applications. © 2015 IEEE.