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Journal ArticleDOI

Nature of Cross-Polarized Radiations from Probe-Fed Circular Microstrip Antennas and Their Suppression Using Different Geometries of Defected Ground Structure (DGS)

01 Jan 2012-IEEE Transactions on Antennas and Propagation (IEEE)-Vol. 60, Iss: 1, pp 92-101
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.
Citations
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Journal ArticleDOI
TL;DR: In this paper, the authors present an introduction and evolution of DGS and how DGS is different from former technologies: PBG and EBG, and several theoretical techniques for analysing the Defected Ground Structure are discussed.
Abstract: Slots or defects integrated on the ground plane of microwave planar circuits are referred to as Defected Ground Structure. DGS is adopted as an emerging technique for improving the various parameters of microwave circuits, that is, narrow bandwidth, cross-polarization, low gain, and so forth. This paper presents an introduction and evolution of DGS and how DGS is different from former technologies: PBG and EBG. A basic concept behind the DGS technology and several theoretical techniques for analysing the Defected Ground Structure are discussed. Several applications of DGS in the field of filters, planar waveguides, amplifiers, and antennas are presented.

273 citations


Cites background from "Nature of Cross-Polarized Radiation..."

  • ...The suppression in cross-polarized radiations is improved to the value of 10–12 dB by using arc-shaped defects [98]....

    [...]

Journal ArticleDOI
TL;DR: In this article, a parasitic isolator is used to suppress mutual coupling between two patch antennas, and a defected ground structure is employed to suppress the cross-polarization (XP) level.
Abstract: A novel approach to suppress mutual coupling (MC) between two patch antennas is presented in this letter. A parasitic isolator, which is printed between the two patches, controls the polarization of the coupling field to reduce the antenna coupling. Furthermore, a defected ground structure is employed to suppress the cross-polarization (XP) level. There exists a tradeoff between the MC reduction and XP improvement in this approach. As an example, a two-element patch array with an optimized isolator is fabricated and measured. The measured results show that, at the resonant frequency, the achieved isolation enhancement and XP level are 19.6 dB and $-$ 13.2 dB, respectively.

110 citations


Cites background from "Nature of Cross-Polarized Radiation..."

  • ...In order to realize XP suppression, a DGS is introduced in the design [16]–[18]....

    [...]

Journal ArticleDOI
Kun Wei1, Jianying Li1, Lei Wang1, Rui Xu1, Zijian Xing1 
TL;DR: In this article, a new technique to design single-feed circularly polarized (CP) microstrip antenna is proposed, which is obtained by adjusting the dimension of the etched fractal defected ground structure (FDGS) in the ground plane.
Abstract: A new technique to design single-feed circularly polarized (CP) microstrip antenna is proposed. The CP radiation is obtained by adjusting the dimension of the etched fractal defected ground structure (FDGS) in the ground plane. Parameter studies of the FDGS are given to illustrate the way to achieve CP radiation. The CP microstrip antennas with the second and third iterative FDGS are fabricated and measured. The measured 10-dB return-loss bandwidth of the CP microstrip antenna is about 30 MHz (1.558 to 1.588 GHz), while its 3-dB axial-ratio bandwidth is 6 MHz (1.572 to 1.578 GHz). The gain across the CP band is between 1.7 and 2.2 dBic.

103 citations


Cites methods from "Nature of Cross-Polarized Radiation..."

  • ...The annular-ring shaped defect integrated circular microstrip patch has been explored for the CP radiation [16], but the defected ground structure (DGS) is used to increase the antenna polarization purity....

    [...]

Journal ArticleDOI
TL;DR: In this paper, a defect ground structure (DGS)-integrated rectangular microstrip patch has been experimentally investigated with an aim to improve polarisation purity in radiated fields.
Abstract: 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.

82 citations

Journal ArticleDOI
TL;DR: A meaningful comparative study where all commonly used feed mechanisms such as coaxial probe, microstrip line, and rectangular aperture for both antennas operating near the same frequency is considered, indicating relative advantages and disadvantages.
Abstract: Microstrip patches and dielectric resonators (DRs) are two low-profile variants of modern microwave and wireless antennas. However, the DR antenna (DRA) is relatively new and still passing through the stages of development. Both variants are quite similar in terms of performance and characteristics. This article focuses on a meaningful comparative study where we have considered all commonly used feed mechanisms such as coaxial probe, microstrip line, and rectangular aperture for both antennas operating near the same frequency. Circular geometry, i.e., cylindrical DRA (CDRA) and circular microstrip patch antenna (CMPA), have been chosen, and a systematic investigation based on thorough experiments has been executed. Multiple sets of prototypes have been fabricated and measured at 4 GHz. All available data have been furnished and compared, indicating relative advantages and disadvantages. This comparative study should provide qualitative and quantitative instructions to a designer for choosing the right element and corresponding feed based on design requirement and feasibility.

71 citations


Cites background from "Nature of Cross-Polarized Radiation..."

  • ...Some of its inherent limitations, such as narrow operating bandwidth and high cross-polarized (XP) radiation, have been addressed [6]–[12] and resolved....

    [...]

References
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Book
31 Oct 2000
TL;DR: Feeding Techniques and Modeling, Design and Analysis of Microstrip Antenna Arrays: Parallel and Series Feed Systems, and Theory and Design of Active Integrated Micro Strip Antenna Amplifiers.
Abstract: Microstrip Radiators: Various Microstrip Antenna Configurations. Feeding Techniques and Modeling. Applications. Radiation Field. Surface Waves and Photonic Band-Gap Structures. Analytical Models for Microstrip Antennas: Transmission Line Model. Cavity Model. Generalized Cavity Model. Multi-port Network Model (MNM). Radiation Fields. Aperture Admittance. Mutual Admittance. Model for Coaxial Probe in Microstrip Antennas. Comparison of Analytical Models. Full-Wave Analysis of Microstrip Antennas: Spectral Domain Full-Wave Analysis. Mixed-Potential Integral Equation Analysis. Finite-Difference Time Domain Analysis.Rectangular Microstrip Antenna: Models for Rectangular Patch Antenna. Design Considerations for Rectangular Patch Antennas. Tolerance Analysis of Rectangular Microstrip Antennas. Mechanical Tuning of Patch Antennas. Quarter-wave Rectangular Patch Antenna. Circular Disk and Ring Antennas: Analysis of a Circular Disk Microstrip Antenna. Design Considerations for Circular Disk Antennas. Semicircular Disk and Circular Sector Microstrip Antennas. Comparison Of Rectangular And Circular Disk Microstrip Antennas. Circular Ring or Annular Ring Microstrip Antenna. Circular Sector Microstrip Ring Antenna. Microstrip Ring Antennas of Non-Circular Shapes. Dipoles and Triangular Patch Antennas: Microstrip Dipole and Center-Fed Dipoles. Triangular Microstrip Patch Antenna. Design of an Equilateral Triangular Patch Antenna. Microstrip Slot Antennas: Microstrip-Fed Rectangular Slot Antennas. CPW-Fed Slot Antennas. Annular Slot Antennas. Tapered Slot Antennas (TSA). Comparison of Slot Antennas with Microstrip Antennas. Circularly Polarized Microstrip Antennas and Techniques: Various Types of Circularly Polarized Microstrip Antennas. Singly-Fed Circularly Polarized Microstrip Antennas. Dual-Orthagonal Feed Circularly Polarized Microstrip Antennas. Circularly Polarized Traveling-Wave Microstrip-Line Arrays. Bandwidth Enhancement Techniques. Sequentially Rotated Arrays. Broad-Banding of Microstrip Antennas: Effect of Substrate Parameters on Bandwidth. Selection of Suitable Patch Shape. Selection of Suitable Feeding Technique. Multi-Moding Techniques. Other Broadbanding Techniques. Multifrequency Operation. Loaded Microstrip Antennas and Applications: Polarization Diversity Using Microstrip Antennas. Frequency Agile Microstrip Antennas. Radiation Pattern Control of Microstrip Antennas. Loading Effect of a Short. Compact Patch Antennas. Planar Inverted F Antenna. Dual-Frequency Microstrip Antennas. Dual-Frequency Compact Microstrip Antennas. Active Integrated Microstrip Antennas: Classification of Active Integrated Microstrip Antennas. Theory and Design of Active Integrated Microstrip Antenna Oscillators. Theory and Design of Active Integrated Microstrip Antenna Amplifiers. Frequency Conversion Active Integrated Microstrip Antenna Theory and Design. Design and Analysis of Microstrip Antenna Arrays: Parallel and Series Feed Systems. Mutual Coupling. Design of Linear Arrays. Design of Planar Arrays. Monolithic Integrated Phased Arrays.

3,612 citations

Journal ArticleDOI
TL;DR: In this article, a simple theory based on the cavity model was developed to analyze microstrip antennas, and the theoretically predicted radiation patterns and impedance loci closely agree with those measured for many antennas of various shapes and dimensions investigated thus far.
Abstract: A simple theory based on the cavity model is developed to analyze microstrip antennas. Formulas for numerous canonical shapes are given. In general the theoretically predicted radiation patterns and impedance loci closely agree with those measured for many antennas of various shapes and dimensions investigated thus far. In fact, this theory enables the computation of both patterns and impedance loci with little effort. The input admittance locus generally follows a circle of nearly constant conductance, but its center is shifted to the inductive region in the Smith chart plot. Peculiar properties for the case with degenerate or slightly degenerate eigenvalues are discussed. An accurate formula for determining the resonant frequency of a rectangular microstrip antenna is also given.

882 citations

Journal ArticleDOI
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

Journal ArticleDOI
TL;DR: In this paper, the 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.
Abstract: 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.

82 citations

Journal ArticleDOI
TL;DR: In this paper, the crosspolarisation characteristics of coaxially fed microstrip patch antennas were studied using the cavity model, and numerical results showing the variation of cross-polarization level for different feed positions, substrate thicknesses, substrate permittivities and resonance frequencies were given when the antenna is excited in the TM 11 mode.
Abstract: The crosspolarisation characteristics of coaxially fed microstrip patch antennas are studied using the cavity model. Numerical results showing the variation of crosspolarisation level for different feed positions, substrate thicknesses, substrate permittivities and resonance frequencies are given when the antenna is excited in the TM 11 mode

78 citations