Mitigating Backside Radiation Issues of Defected Ground Structure Integrated Microstrip Patches
TL;DR: In this article, the authors proposed a DGS-based solution to the problem of excess backside radiation caused by the cross-polarized (XP) fields, which is being faced by all defected ground structure (DGS) integrated patches.
Abstract: This letter addresses a practical issue of excess backside radiation caused by the cross-polarized (XP) fields, which is being faced by all defected ground structure (DGS) integrated patches. Defects or slots on the ground plane (GP) suppresses the H -plane XP fields. These strategic slots cause leakage of XP fields toward the backside of the antenna. This letter, for the first time, explores the physical insight behind this phenomenon with an aim to find a solution. Engineering on the backside of the GP has been conceived and systematically developed in the form of a pair of electric walls with varied geometries. Serrated comb-shaped geometry has been proposed finally. A thorough DGS-based design along with its experimental validation in the X -band ensures a reduction in XP radiation nearly by 10 dB in the backside maintaining its front-side reduction by 16–18 dB. This also reduces the usual backward radiation originated from the copolarized fields. Although the GP engineering makes the structure nonplanar, its advanced features may find potential applications where significantly low XP standalone antennas are required, such as wireless base stations, to onboard satellite systems.
Citations
More filters
TL;DR: In this paper, a fractal shape based MIMO antenna with microstrip feeding for sub 6 GHz applications is proposed, which is a flower-shaped construct with added rectangular strips patch and circular, rectangular slots are introduced into the ground plane to reduce the isolation between the patches.
Abstract: This article presents fractal shape based MIMO antenna with microstrip feeding for sub 6-GHz applications. The proposed fractal based structure is a flower-shaped construct with added rectangular strips patch and circular, rectangular slots are introduced into the ground plane to reduce the isolation between the patches. The main purpose in designing 2 × 1 MIMO system antenna is to enhance the scattering signals and optimize the performance. The proposed structure uses FR-4 material with a dimension of 25 mm × 38 mm. The 2 × 1 MIMO structure resonate at 3.5 GHz for the sub 6 GHz 5 G communications with directional radiation pattern. The performance characteristics of the antenna such as surface current distributions, radiation patterns and S-parameters are investigated. In addition the performance of diversity system of MIMO structure including the total active reflection coefficient (TARC), multiplexing efficiency, envelope correlation coefficient (ECC) and diversity gain (DG) are studied. For this proposed MIMO structure all antenna parameters are found that within an acceptable range.
22 citations
TL;DR: In this article, a high-isolation Fabry-Perot (FP) antenna array with wide bandwidth and high gain is proposed for Ku-band vehicle satellite communications. But the antenna array is not suitable for the MIMO and beamforming antennas.
Abstract: A high-isolation Fabry–Perot (FP) antenna array with wide bandwidth and high gain is proposed for Ku -band vehicle satellite communications. Each antenna element consists of a pair of tandem circular parasitic patches (TCPPs), a radial gradient partially reflective surface (PRS), and a reflector, respectively, separated from the ground plane with a double-dumbbell-shaped slot (DDSS) by air layer and foam dielectric. The slot radiator steers the TCPPs to create multiple resonant frequencies and then the impedance bandwidth is widened. The impedance matching could be improved by adjusting four circular slot diameters of the DDSS. The gain is raised by TCPPs and radial gradient PRS, which function to guide the electromagnetic field and uniformize the aperture near-field, successively. The reflector with several resonator elements is used to reduce the backside radiation. As proof of concept, the FP antenna array prototype with a height of $0.613\lambda _{0}$ has been fabricated and measurements confirming simulations are provided. Experimental results show that the impedance bandwidth ranges from 13.48 to 16.95 GHz [22.8% fractional bandwidth (FBW)], and the realized gain is up to 21.59 dBi. A decoupling metallic strip could achieve over 40.8 dB isolation. The proposed antenna element is easily extended for the multiple-input multiple-output (MIMO) and beamforming antennas, further improving the directivity.
21 citations
TL;DR: In this paper, a strategic metal pole has been introduced to control the modal current of an orthogonal higher mode (TM02) but leaving the fundamental radiating mode untouched, and the pole height can be reduced by 40% −63% by accepting a tradeoff in XP suppression by 3 dB.
Abstract: This letter explores a new concept for the first time to control a specific unwanted higher mode in a microstrip patch with a target to reduce its cross-polarized (XP) radiation over the orthogonal plane. A strategic metal pole has been introduced to control the modal current of an orthogonal higher mode (TM02) but leaving the fundamental radiating mode (TM10) untouched. The conjecture has been successfully verified in S -band. The approach is the simplest of all explored earlier, requiring no multiparameter optimization or fabrication complexity except requiring an additional vertical space. Antenna impedance and primary radiations are insensitive to this technique but it ensures 11dB XP suppression over the orthogonal plane. The pole height can be reduced by 40%–63% by accepting a tradeoff in XP suppression by 3 dB.
12 citations
Cites background from "Mitigating Backside Radiation Issue..."
...vertically extended structures are not new in practical applications [19]–[22]....
[...]
[...]
01 Jan 2022
TL;DR: This study examined to what degree performance on WAIS-IV verbal subtests predicts performance on executive functioning measures (Trails Making-B, Category, and Wisconsin Card Sort Test) and found Categories is the best predictor.
Abstract: The
7 citations
TL;DR: In this article , the surface current distribution in a rectangular microstrip patch is modified to reduce the H-plane cross-polarized (XP) radiations along with minimizing the backside radiation to some extent.
Abstract: This work explores an idea of modifying surface current distribution in a rectangular microstrip patch which contributes to reducing its H-plane cross-polarized (XP) radiations along with minimizing the backside radiation to some extent. A pair of grounded spikes has been strategically used and the physics behind its operation in weakening the XP generating TM02 mode has been thoroughly discussed. The vertical height of the spike is typically $\lambda $ /4 and a further investigation demonstrates shortening of its effective height by folding the same by 90°. A set of prototypes has been experimentally studied to ensure the predicted characteristics viz. the 12 dB consistent suppression of XP level over the whole range of elevation in H-plane and an average of 5–7 dB suppression in backside radiation. These achievements are also associated with more than 1 dB improvement in peak gain. The design is straightforward, low cost, and commercially viable. The nonplanar feature restricts its use only to those applications where antenna front is open or can accommodate the vertically extended or 90° bent spikes.
5 citations
References
More filters
TL;DR: In this paper, a new type of metallic structure has been developed that is characterized by having high surface impedance, which is analogous to a corrugated metal surface in which the corrugations have been folded up into lumped-circuit elements and distributed in a two-dimensional lattice.
Abstract: A new type of metallic electromagnetic structure has been developed that is characterized by having high surface impedance. Although it is made of continuous metal, and conducts dc currents, it does not conduct ac currents within a forbidden frequency band. Unlike normal conductors, this new surface does not support propagating surface waves, and its image currents are not phase reversed. The geometry is analogous to a corrugated metal surface in which the corrugations have been folded up into lumped-circuit elements, and distributed in a two-dimensional lattice. The surface can be described using solid-state band theory concepts, even though the periodicity is much less than the free-space wavelength. This unique material is applicable to a variety of electromagnetic problems, including new kinds of low-profile antennas.
4,264 citations
"Mitigating Backside Radiation Issue..." refers background or methods in this paper
...Therefore, these cannot be controlled by the known techniques, such as the articles presented in [11]–[18]....
[...]
...Edge diffraction is considered as the reason for the backside radiations of a conventional patch with finite GP [11] and various techniques were explored earlier to mitigate it using mushroomlike structures [11]–[15], chocks, serrations, metallic protrusions on the GP, etc....
[...]
TL;DR: In this article, a periodic surface texture is used to alter the electromagnetic properties of a metal ground plane by covering the surface with varactor diodes, and a tunable impedance surface is built, in which an applied bias voltage controls the resonance frequency and the reflection phase.
Abstract: By covering a metal ground plane with a periodic surface texture, we can alter its electromagnetic properties. The impedance of this metasurface can be modeled as a parallel resonant circuit, with sheet inductance L, and sheet capacitance C. The reflection phase varies with frequency from +/spl pi/ to -/spl pi/, and crosses through 0 at the LC resonance frequency, where the surface behaves as an artificial magnetic conductor. By incorporating varactor diodes into the texture, we have built a tunable impedance surface, in which an applied bias voltage controls the resonance frequency, and the reflection phase. We can program the surface to create a tunable phase gradient, which can electronically steer a reflected beam over +/- 40/spl deg/ in two dimensions, for both polarizations. We have also found that this type of resonant surface texture can provide greater bandwidth than conventional reflectarray structures. This new electronically steerable reflector offers a low-cost alternative to a conventional phased array.
702 citations
TL;DR: In this article, a defected ground structure (DGS) pattern is proposed to reduce the cross-polarized (XP) radiation of a microstrip patch antenna, which is simple and easy to etch on a commercial microstrip substrate.
Abstract: 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.
275 citations
"Mitigating Backside Radiation Issue..." refers methods in this paper
...D EFECTED ground structure (DGS) has become a popular tool for improving the radiation properties of microstrip patches since its inception [1]....
[...]
TL;DR: In this article, the authors investigated the effect of defected ground structure (DGS) on cross-polarized (XP) electric fields and associated radiations and found that the arc-DGS appears to be highly efficient in terms of suppressing XP fields.
Abstract: 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.
114 citations
"Mitigating Backside Radiation Issue..." refers background in this paper
...Table I summarizes the radiation features obtained in the earlier studies [2], [5], [9] and it helps understanding a specific inherent issue....
[...]
...The approach aims to reduce cross-polarized (XP) radiations and the design has been improved over the years ensuring co- to XP isolation of 15–18 dB [2]–[9]....
[...]
TL;DR: In this paper, a defected ground structure (DGS) consisting of concentric circular rings in different configurations is experimentally studied to examine the stopband characteristics, and a metallic shielding is introduced at the back of the DGS to suppress any leakage or radiation.
Abstract: A new defected ground structure (DGS) consisting of concentric circular rings in different configurations is experimentally studied to examine the stopband characteristics. Unlike previous DGS designs, a metallic shielding is introduced at the back of the DGS to suppress any leakage or radiation, and this would be advantageous for microwave circuit applications. A wide stopband is demonstrated with a set of prototypes designed for X-band. Its application to suppressing mutual coupling in microstrip patch arrays is demonstrated
110 citations
"Mitigating Backside Radiation Issue..." refers background in this paper
...A secondary GP may help but at the cost of frontal XP isolation [19]....
[...]