A symmetric as well as nonproximal defected ground structure has been conceived for a square microstrip patch to achieve high co- to cross-polarized (XP) isolation over the principal radiation planes. This design does not follow the thumb rule of earlier works where the defect was deployed either underneath or in close proximity to the patch boundary. The proposed configuration, therefore, appears to be ideal for some specific applications, such as dual-polarized or circularly polarized patches with improved polarization purity. A representative design in C-band has been discussed, leading to the proof of concept. Experimental verification confirms up to 8-10 dB improvement in XP level, particularly in the H-plane. © 2002-2011 IEEE.

DEBATOSH GUHA

Radio Physics and Electronics

C KUMAR

M I PASHA

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Microstrip Patch With Nonproximal Symmetric Defected Ground Structure (DGS) for Improved Cross-Polarization Properties over Principal Radiation Planes

IEEE Antennas and Wireless Propagation Letters

Radiation performance of a circularly polarized (CP) truncated corner square patch on a conventional ground plane (GP) has been enhanced by using a simple and novel configuration of stacked dual GP. The proposed configuration employs a single fed truncated corner square patch etched onto a substrate grounded with a patch shaped small GP and having second square shaped GP of standard size separated from the first one with an air gap at an optimized distance. This configuration is ideal for many wireless and satellite communication applications. Simulated results indicate the best achievable axial ratio (AR) of about 0.4 dB for a stacked dual GP CP antenna compared to an AR of 2.7 dB for a conventional single GP CP antenna, indicating an improvement in cross polarized (XP) isolation of about 18 dB. AR bandwidth has also been improved by almost 100% with the stacked dual GP configuration when compared with conventional CP antenna. Improved radiation performance has been achieved without affecting impedance bandwidth and peak gain of the patch. Analysis based on GP size variation of the conventional CP antenna and stacked dual GP antenna reveals that stacked dual GP configuration results in compact CP antenna with good radiation performance. © 2017 IEEE.

2017 IEEE International Conference on Antenna Innovations and Modern Technologies for Ground, Aircraft and Satellite Applications, iAIM 2017

Improvement in circularly polarized square patch design by double-layered ground structure

This communication proposes a new idea of compensating spurious radiations usually occurring from the sharp transitions at patch to feed and feed to impedance transformer junctions which result in added cross-polarized (XP) fields in planar microstrip-fed patches. A strategic design and deployment of defected ground structure (DGS) have been explored successfully as a potential means to resolve such long-standing radiation issues. The quantum of radiations from the feed has been theoretically estimated. These along with the main source of XP fields (higher order mode) have been addressed by introducing a composite type of DGS. The experimental validation executed at the C-band establishes this simple low-cost solution with a promise of 10 to 14 dB improvement in the H-plane XP fields. It is also ensured that the proposed technique is equally useful in realizing dual-fed dual-polarized configurations without affecting the primary radiation and antenna performance. © 1963-2012 IEEE.

IEEE Transactions on Antennas and Propagation

Simultaneous Compensation of Microstrip Feed and Patch by Defected Ground Structure for Reduced Cross-Polarized Radiation

The radiation performance of a circularly polarized (CP) single probe-fed truncated corner square microstrip patch has been enhanced by employing (i) a metal (PEC) ring contouring the patch on the patch side of the CP antenna, and (ii) a multi-section ring defect in the ground plane (GP) of the CP antenna. The concept has been validated by designing a CP patch with a conventional GP, a CP patch with a PEC ring contouring the patch and a ring type defect in the GP of the conventional CP patch. Proposed configurations appear to be ideal for many circularly polarized wireless and satellite communication applications. Simulated results confirm axial ratio (AR) of about (i) 1.1 dB for a CP antenna with a PEC ring contouring the patch and (ii) 0.1 dB for a CP antenna with ring type defect in the ground plane; compared to an AR of 2.7 dB for a conventional CP antenna, indicating an improvement in cross polarized (XP) isolation. AR bandwidth has also been improved by 70% in case of PEC ring contoured CP patch and almost 100% in case of ring type defected ground structure (DGS) integrated CP patch when compared with conventional CP antenna. These improvements have been achieved without affecting any other parameters such as impedance bandwidth and peak gain of the antenna. © 2016 IEEE.

2016 IEEE Annual India Conference, INDICON 2016

Investigations into improved isolation in Co- to cross-polar radiation fields of a single-fed circularly polarized patch antenna

Defected ground structure (DGS)-integrated rectangular microstrip patch has been experimentally investigated with an aim to improve polarisation purity in radiated fields. Width to length ratio (aspect ratio) of a patch attributes different characteristic features. Therefore present experimental studies have been executed for four different aspect ratio values like 1.6, 1.3, 1.0 and 0.8. Folded defects have been employed in H-plane. Possibility of achieving high polarisation purity (over 25 dB isolation between co- to cross-polarised fields) with improved impedance bandwidth has been demonstrated. The variation in XP fields as a function of the patch aspect ratio has been investigated and a strong physical insight into the modal fields with and without DGS has been developed. © The Institution of Engineering and Technology 2014.

IET Microwaves, Antennas and Propagation

Defected ground structure (DGS)-integrated rectangular microstrip patch for improved polarisation purity with wide impedance bandwidth

Experiments with probe-fed circular patches using conventional and defected ground planes flashed some interesting features relating to cross-polarized (XP) electric fields and associated radiations before the present authors. Those led to a series of new investigations for understanding the nature of XP fields and to deal with them using defected ground structure (DGS) for improved XP performance. In the first phase of investigation, the XP radiations of a probe-fed circular patch with conventional ground plane have been critically studied as a function of the radial probe location. Remarkably significant effect is experimentally demonstrated. New information about orthogonal resonant fields and its importance in designing an antenna is provided. In the second phase of investigation, limitations of dot-shaped DGS in reducing XP level are experimentally studied. As its improved variants, two new DGS geometries such as annular ring and circular arcs have been explored. The arc-DGS appears to be highly efficient in terms of suppressing XP fields. Suppression by 10-12 dB has been experimentally demonstrated. Each design has been experimented in both C- and X-bands to earn confidence on the measured data. © 2006 IEEE.

Nature of cross-polarized radiations from probe-fed circular microstrip antennas and their suppression using different geometries of defected ground structure (DGS)

Microstrip and Printed Antennas: New Trends, Techniques and Applications

Preface

Application of defected ground structure (DGS) to suppress cross-polarized (XP) radiation from a microstrip patch antenna has been reinvestigated using a new DGS geometry for much improved characteristics. Arc-shaped defect has been used in pair, symmetrically located under a circular patch. A number of optimization parameters have been examined using simulated results, leading to a design indicating improved XP behavior. A set of identical prototypes, with and without DGS, have been experimentally studied. The presence of the DGS shows as much as 30 dB isolation of the XP level from its peak radiation, and that compared to an identical patch without DGS indicates an improvement by as much as 12 dB. The relative suppression in XP values are found to be around 7-12 dB over ±75° elevation around the boresight of the patch. © 2010 IEEE.

Improved cross-polarization characteristics of circular microstrip antenna employing arc-shaped defected ground structure (DGS)

A defected ground structure (DGS) is proposed to reduce the cross-polarized (XP) radiation of a microstrip patch antenna. The proposed DGS pattern is simple and easy to etch on a commercial microstrip substrate. This will only reduce the XP radiation field without affecting the dominant mode input impedance and co-polarized radiation patterns of a conventional antenna. The new concept has been examined and verified experimentally for a particular DGS pattern employing a circular patch as the radiator. Both simulation and experimental results are presented. © 2005 IEEE.

Journal	Data powered by TypesetIEEE Antennas and Wireless Propagation Letters
Publisher	Data powered by TypesetInstitute of Electrical and Electronics Engineers Inc.
ISSN	1536-1225
Open Access	No