Synthesizing Aperture Fields Over the Superstrate of Resonance Cavity Antenna for Modifying Its Radiation Properties
TL;DR: In this article, a new approach of aperture field synthesis over the superstrate has been proposed to improve the radiation characteristics of a resonance cavity antenna (RCA) with the aim of reducing the sidelobe level (SLL) and increasing the gain.
Abstract: Modification and improvement in the radiation characteristics of a resonance cavity antenna (RCA) have been addressed from a new approach of aperture field synthesis over the superstrate. This concept has been established through a series of systematic studies, which are based on the exciting observations reported very recently by these authors. A process of modification or engineering on the superstrate has been conjectured in view of obtaining reduced sidelobe level (SLL) and/or increased gain. The same has been successfully designed and experimentally demonstrated indicating as much as 10 dB suppression in SLL along with 3 dB improvement in gain compared to its nearest contender. This study promises a potential technique in RCA design along with several attractive features.
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TL;DR: This work demonstrates an interesting transformation of a metal superstrate from rectangle to an ellipse or anEllipse-circle combination to achieve significant improvements in the aperture fields and hence the sidelobe level (SLL).
Abstract: An insight based on a new theoretical approach has been developed to facilitate the design of a superstrate which plays a key role in realizing a high gain resonance cavity antenna (RCA). The work is aimed to address a profound theoretical basis of controlling the aperture fields by proper shaping of superstrate and to apply it to alleviate the earlier shortcomings along with further improvement in radiation characteristics. This demonstrates an interesting transformation of a metal superstrate from rectangle to an ellipse or an ellipse-circle combination to achieve significant improvements in the aperture fields and hence the sidelobe level (SLL). The antenna characteristics have been verified using simulated data followed by experiments using different sets of prototypes. About 50% reduction in size along with an improvement in the SLL by 5–17 dB compared to its immediate predecessor has been experimentally demonstrated. Proposed theory should find the potential applications in conceiving efficient RCA designs in the future.
26 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 3D-printed polarizer with an inserted partially reflective surface (PRS) was proposed for generating millimeter-wave (MMW) circular polarization in a Fabry-Perot cavity (FPC) antenna.
Abstract: This communication introduces a new structure of polarizer for generating millimeter-wave (MMW) circular polarization (CP) in a Fabry–Perot cavity (FPC) antenna. It is the first of its kind, which integrates a 3D-printed polarizer with an inserted partially reflective surface (PRS), which contributes to a wideband CP operation with high antenna gain. The realization of CP and gain enhancement can be controlled independently by optimizing the structures of the dielectric part and the PRS of the polarizer, respectively. The proposed antenna consists of a feeding source, a substrate-integrated quasi-curve reflector, and the proposed polarizer. The feeding source and the reflector are able to be fabricated by the conventional PCB technology which is low-cost and convenient in circuitry integration. For validation, a prototype of the FPC antenna with the proposed polarizer operating at 60 GHz has been designed, fabricated, and measured. The peak gain of the antenna reaches to 20 dBic. The antenna achieves an impedance bandwidth of 20% from 54.5 to 66.7 GHz for the reflection coefficient of less than −10 dB. The axial ratio (AR) bandwidth is 12.7% from 56.5 to 64 GHz for AR ≤3 dB. The experimental results confirm a good agreement between simulation and measurement.
17 citations
Cites background from "Synthesizing Aperture Fields Over t..."
...Various frequency-selective surfaces (FSSs), metasurfaces, and metal sheet-based superstrates have been proposed to enhance the performances of FPC antenna [1]–[9]....
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TL;DR: A compact design of microstrip patch antenna with annular metal-ring used as a superstrate as well as an inductive load to the rectangular patch to realize wideband characteristics is presented.
Abstract: A compact design of microstrip patch antenna is presented to realize wideband characteristics. An annular metal-ring has been used as a superstrate as well as an inductive load to the rectangular patch. Robust analytical technique is applied to choose the dimensions of the ring and the patch where they resonate very close to each other. This strategic approach ensures a wide matching bandwidth with a broadside radiation pattern. An additional enhancement of bandwidth has been achieved by employing a unique design strategy. A set of antenna prototype has been fabricated for experimental validation. As much as 34% matching bandwidth has been revealed experimentally using a compact antenna (~λ × λ). The boresight gain is maintained about 10 dBi over the operating frequency band. The cross-polarized isolation in E- and H-planes are maintained above 40 dB and 30 dB respectively over the operating bandwidth. The back-radiation of the antenna is also maintained below −20 dB over the wide matching bandwidth.
8 citations
01 Dec 2018
TL;DR: In this paper, a new Fabry-Perot cavity antenna (FPCA) has been presented with a unique as well as the most desirable feature of very high gain maintained over its wide matching bandwidth.
Abstract: A new design of Fabry-Perot cavity antenna (FPCA) has been presented with a unique as well as the most desirable feature of very high-gain maintained over its wide matching bandwidth. About 15.5 dBi average broadside-gain has been achieved over the 19% matching bandwidth. A flat-gain characteristic has been attained using a specially designed conical sidewall. In addition to that, the sidewall will play an important role in reducing the mutual coupling arises due to nearby RF elements. About −16 dB and −19 dB side lobe levels have been obtained satisfactorily in two principle-plane patterns (E- and H-plane) respectively. The cross-polarization purity of the antenna is maintained reasonably below −25 dB over the frequency band.
5 citations
Cites background from "Synthesizing Aperture Fields Over t..."
...The aperture field distribution over the superstrate has been found to be the most crucial factor to decide the radiation properties [5]....
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References
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Book•
01 Dec 1950
TL;DR: In this article, Lehto and Vainikainen discuss the relationship between aperture distribution and far-field pattern and the Fourier Transform Relation between Aperture Distribution and Far-Field Pattern.
Abstract: 1 Introduction 2 Antenna Basics 3 The Antenna Family 4 Point Sources 5 Arrays of Point Sources 6 The Electric Dipole and Thin Linear Antennas 7 The Loop Antenna 8 End Fire Antennas: The Helical Beam Antenna and the Yagi-Uda Array 9 Slot, Patch and Horn Antennas 9II Slot and Horn Antennas II 10 Flat Sheet, Corner and Parabolic Reflector Antennas 11 Broadband and Frequency-Independent Antennas 12 Antenna Temperature, Remote Sensing and Radar Cross-Section 13 Self and Mutual Impedances 14 The Cylindrical Antenna and the Moment Method (MM) 15 The Fourier Transform Relation Between Aperture Distribution and Far-Field Pattern 16 Arrays of Dipoles and of Apertures 17 Lens Antennas 18 Frequency-Selective Surfaces and Periodic Structures by Ben A. Munk 19 Practical Design Considerations of Large Aperture Antennas 20 Some Examples of Large or Unique Antennas 21 Antennas for Special Applications 22 Terahertz Antennas 23 Baluns, etc. By Ben A. Munk 24 Antenna Measurements. By Arto Lehto and Pertti Vainikainen Appendix A Tables for Reference Appendix B Books and Video Tapes Appendix C Computer Programs (Codes) Appendix D Absorbing Materials Appendix E Measurement Error
1,130 citations
"Synthesizing Aperture Fields Over t..." refers background or methods in this paper
...Here, we address the SLL issue, which, according to [13], could be solved by introducing Gaussiantype fields over and above the “inverse taper” distribution....
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...radiations [13]: (a) our conjecture to realize a combination of “inverse taper”...
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TL;DR: In this article, a ray analysis is employed in order to give physical insight into the performance of AMCs and derive design guidelines, and the bandwidth and center frequency of AMC surfaces are investigated using full-wave analysis and the qualitative predictions of the ray model are validated.
Abstract: Planar periodic metallic arrays behave as artificial magnetic conductor (AMC) surfaces when placed on a grounded dielectric substrate and they introduce a zero degrees reflection phase shift to incident waves. In this paper the AMC operation of single-layer arrays without vias is studied using a resonant cavity model and a new application to high-gain printed antennas is presented. A ray analysis is employed in order to give physical insight into the performance of AMCs and derive design guidelines. The bandwidth and center frequency of AMC surfaces are investigated using full-wave analysis and the qualitative predictions of the ray model are validated. Planar AMC surfaces are used for the first time as the ground plane in a high-gain microstrip patch antenna with a partially reflective surface as superstrate. A significant reduction of the antenna profile is achieved. A ray theory approach is employed in order to describe the functioning of the antenna and to predict the existence of quarter wavelength resonant cavities.
907 citations
TL;DR: In this article, a leaky-wave analysis is used to explain the narrow-beam resonance gain phenomenon in which narrow beams may be produced from a printed antenna element in a substrate-superstrate geometry.
Abstract: A leaky-wave analysis is used to explain the narrow-beam resonance-gain phenomenon in which narrow beams may be produced from a printed antenna element in a substrate-superstrate geometry. It is demonstrated that the phenomenon is attributable to the presence of both transverse electric and transverse magnetic-mode leaky waves, that are excited on the structure. Asymptotic formulas for the leaky wave are compared with the exact patterns to demonstrate the dominant role of the leaky waves in determining the pattern. Results are presented as a function of frequency, the scan angle, and the permittivity of the superstrate. >
343 citations
"Synthesizing Aperture Fields Over t..." refers background in this paper
...Their gain enhancement was explained by the principle of a Fabry–Perot cavity [1] or leaky waves [2]....
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...The superstrate layer is normally made of metal, dielectric, or a composite structure, and the primary radiator is realized by hertzian dipole [1], microstrip patch [2]–[4], or dielectric resonator antenna (DRA) [5], [6]....
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TL;DR: In this paper, two different defects, one introduced by the ground plane of the antenna and the other produced by a row of defect rods with different dielectric constants in the EBG structure, are simultaneously used as key controllers of directivity enhancement.
Abstract: We present some applications of an electromagnetic bandgap (EBG) superstrate as a spatial angular filter for filtering undesired radiation by sharpening the radiation pattern. Two different defects, one introduced by the ground plane of the antenna and the other produced by a row of defect rods with different dielectric constants in the EBG structure, are simultaneously used as key controllers of directivity enhancement. Initially, we study the unit cell of the EBG structures by varying several parameters, in order to understand how they influence the locations of the bandgap and defect frequencies. Next, the defect frequencies of the unit cell of the EBG cover, and those with high directivity for the EBG antenna composite, are compared to validate the proposed design scheme. Finally, we introduce some interesting applications of EBG superstrates for various types of patch antennas as spatial angular filters, such as a dual-band orthogonally-polarized antenna, a wide-band directive antenna, and an array antenna with grating lobes.
260 citations
TL;DR: In this communication a high directive electromagnetic bandgap (EBG) antenna operating in wide frequency band for both return loss (RL) and directivity is examined.
Abstract: In this communication a high directive electromagnetic bandgap (EBG) antenna operating in wide frequency band for both return loss (RL) and directivity is examined. In this EBG antenna an aperture coupled microstrip antenna (ACMA) is used as a feeding source and a frequency selective surface (FSS) is used as a superstrate layer. Suitable use of the superstrate layer, microstrip patch and coupling aperture simultaneously, leads to produce separate resonance frequencies and therefore the wide frequency band for RL. Also, high directivity is achieved only by using the superstrate layer that has been made by the FSS layer with square loop elements. At first, a wideband ACMA is designed to operate in x-band. In this step appropriate design of coupling aperture is of a great importance. Secondly, after the design of optimum superstrate layer by the FSS structure, it is added to the ACMA in order to increase both bandwidth and directivity.
165 citations
"Synthesizing Aperture Fields Over t..." refers background in this paper
...A wide variety of superstrate geometry has been explored, which includes metal surface grids [3], [6], dielectric slab [4], [5], double-negative and engineered materials [7]–[10], and frequency selective surfaces [11]....
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