# New Approach in Designing Resonance Cavity High-Gain Antenna Using Nontransparent Conducting Sheet as the Superstrate

TL;DR: In this article, a resonance cavity antenna (RCA) employing nontransparent solid metal sheet as superstrate is proposed for the first time, and the proposed configuration is much advantageous in terms of design, simplicity, structural stability, fabrication, and cost without compromising in gain, efficiency, and bandwidth.

Abstract: A resonance cavity antenna (RCA) has been explored employing nontransparent solid metal sheet as superstrate which, to the best of our knowledge, is reported for the first time. The proposed configuration is much advantageous in terms of design, simplicity, structural stability, fabrication, and cost without compromising in gain, efficiency, and bandwidth. A probe-fed dielectric resonator antenna (DRA) with ${\boldsymbol{\varepsilon} _r} = {\bf 10}$ has been used as the primary radiator. Proposed RCA bearing overall size ${\bf 1}.{\bf 1}{\boldsymbol{\lambda}} \times {\bf 1}.{\bf 1}{\boldsymbol{\lambda}} \times {\bf 0}.{\bf 6}{\boldsymbol{\lambda}}$ promises for large impedance bandwidth ( ${\sim} {\bf 23}\% $ ) with considerably high gain (11.8–12.2 dBi). The superstrate size is relatively compact compared to its semitransparent versions, investigated earlier. Present design has been experimentally validated indicating as much as 12 dBi peak gain with more than 96.5% efficiency.

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01 Nov 1984

TL;DR: In this article, a substrate-superstrate printed antenna geometry which allows for large antenna gain is presented, asymptotic formulas for gain, beamwidth, and bandwidth are given, and the bandwidth limitation of the method is discussed.

Abstract: Resonance conditions for a substrate-superstrate printed antenna geometry which allow for large antenna gain are presented. Asymptotic formulas for gain, beamwidth, and bandwidth are given, and the bandwidth limitation of the method is discussed. The method is extended to produce narrow patterns about the horizon, and directive patterns at two different angles.

568 citations

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TL;DR: In this paper, the authors presented a design methodology for a compact low-cost partially reflecting surface (PRS) for a wideband high-gain resonant cavity antenna (RCA) which requires only a single commercial dielectric slab.

Abstract: This communication presents a design methodology for a compact low-cost partially reflecting surface (PRS) for a wideband high-gain resonant cavity antenna (RCA) which requires only a single commercial dielectric slab. The PRS has one nonuniform double-sided printed dielectric, which exhibits a negative transverse-reflection magnitude gradient and, at the same time, a progressive reflection phase gradient over frequency. In addition, a partially shielded cavity is proposed as a method to optimize the directivity bandwidth and the peak directivity of RCAs. A prototype of the PRS was fabricated and tested with a partially shielded cavity, showing good agreement between the predicted and measured results. The measured peak directivity of the antenna is 16.2 dBi at 11.4 GHz with a 3 dB bandwidth of 22%. The measured peak gain and 3 dB gain bandwidth are 15.75 dBi and 21.5%, respectively. The PRS has a radius of 29.25 mm ( $1.1\lambda _{0}$ ) with a thickness of 1.52 mm ( $0.12\lambda _{g}$ ), and the overall height of the antenna is $0.6\lambda _{0} $ , where $\lambda _{0}$ and $\lambda _{g}$ are the free-space and guided wavelengths at the center frequency of 11.4 GHz.

89 citations

### Cites methods from "New Approach in Designing Resonance..."

...This new approach is opening a new door into the RCA design methodology and configuration and provides a more flexible adjustment to the aperture field of RCAs [17]–[19]....

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TL;DR: In this paper, a hybrid topology of fully metallic spatial phase shifters is developed for the AMPCS, resulting in an extremely lower prototyping cost as that of other state-of-the-art substrate-based PCSs.

Abstract: This article addresses a critical issue, which has been overlooked, in relation to the design of phase-correcting structures (PCSs) for electromagnetic bandgap (EBG) resonator antennas (ERAs). All the previously proposed PCSs for ERAs are made using either several expensive radio frequency (RF) dielectric laminates or thick and heavy dielectric materials, contributing to very high fabrication cost, posing an industrial impediment to the application of ERAs. This article presents a new industrial-friendly generation of PCS, in which dielectrics, known as the main cause of high manufacturing cost, are removed from the PCS configuration, introducing an all-metallic PCS (AMPCS). Unlike existing PCSs, a hybrid topology of fully metallic spatial phase shifters are developed for the AMPCS, resulting in an extremely lower prototyping cost as that of other state-of-the-art substrate-based PCSs. The APMCS was fabricated using laser technology and tested with an ERA to verify its predicted performance. The results show that the phase uniformity of the ERA aperture has been remarkably improved, resulting in 8.4 dB improvement in the peak gain of the antenna and improved sidelobe levels (SLLs). The antenna system including APMCS has a peak gain of 19.42 dB with a 1 dB gain bandwidth of around 6%.

72 citations

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TL;DR: In this paper, an approach to correcting electric near-field phase and magnitude over a wideband for Fabry-Perot resonator antennas (FPRAs) is presented, where a time-average Poynting vector in conjunction with a phase gradient analysis is utilized to suggest the initial configuration of the NFCS for wideband performance.

Abstract: A systematic approach to correcting electric near-field phase and magnitude over a wideband for Fabry–Perot resonator antennas (FPRAs) is presented. Unlike all other unit-cell-based near-field correction techniques for FPRAs, which merely focus on phase correction at a single frequency, this method delivers a compact near-field correcting structure (NFCS) with a wide operational bandwidth of 40%. In this novel approach, a time-average Poynting vector in conjunction with a phase gradient analysis is utilized to suggest the initial configuration of the NFCS for wideband performance. A simulation-driven optimization algorithm is then implemented to find the thickness of each correcting region, defined by the gradient analysis, to complete the NFCS design. According to the predicted and measured results, the phase and magnitude distributions of the electric near field have been greatly improved, resulting in a high aperture efficiency of 70%. The antenna under NFCS loading has a peak measured directivity of 21.6 dB, a 3 dB directivity bandwidth of 41% and a 10 dB return loss bandwidth of 46%, which covers the directivity bandwidth. The diameter of the proposed NFCS is $3.8\lambda _{0c}$ , which is around half that of all the other unit-cell-based phase-correcting structures, where $\lambda _{0c}$ is the free-space wavelength at the central frequency of the NFCS (13.09 GHz).

67 citations

### Cites background from "New Approach in Designing Resonance..."

...Nontransparent fully reflecting surfaces (FRSs) have been recently proposed in [11]–[13] for FPRAs....

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TL;DR: In this paper, the authors proposed an all-metal wideband phase correcting structure (AWPCS) with none of these limitations and is designed based on the relative phase error extracted by postprocessing the actual near-field distributions of any EM sources.

Abstract: Electromagnetic (EM) metasurfaces are essential in a wide range of EM engineering applications, from incorporated into antenna designs to separate devices like radome. Near-field manipulators are a class of metasurfaces engineered to tailor an EM source’s radiation patterns by manipulating its near-field components. They can be made of all-dielectric, hybrid, or all-metal materials; however, simultaneously delivering a set of desired specifications by an all-metal structure is more challenging due to limitations of a substrate-less configuration. The existing near-field phase manipulators have at least one of the following limitations; expensive dielectric-based prototyping, subject to ray tracing approximation and conditions, narrowband performance, costly manufacturing, and polarization dependence. In contrast, we propose an all-metal wideband phase correcting structure (AWPCS) with none of these limitations and is designed based on the relative phase error extracted by post-processing the actual near-field distributions of any EM sources. Hence, it is applicable to any antennas, including those that cannot be accurately analyzed with ray-tracing, particularly for near-field analysis. To experimentally verify the wideband performance of the AWPCS, a shortened horn antenna with a large apex angle and a non-uniform near-field phase distribution is used as an EM source for the AWPCS. The measured results verify a significant improvement in the antenna’s aperture phase distribution in a large frequency band of 25%.

54 citations

##### References

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01 Jun 1961

TL;DR: In this paper, a revised version of the Revised edition of the book has been published, with a new introduction to the concept of plane wave functions and spherical wave functions, as well as a detailed discussion of the properties of these functions.

Abstract: Foreword to the Revised Edition. Preface. Fundamental Concepts. Introduction to Waves. Some Theorems and Concepts. Plane Wave Functions. Cylindrical Wave Functions. Spherical Wave Functions. Perturbational and Variational Techniques. Microwave Networks. Appendix A: Vector Analysis. Appendix B: Complex Permittivities. Appendix C: Fourier Series and Integrals. Appendix D: Bessel Functions. Appendix E: Legendre Functions. Bibliography. Index.

5,655 citations

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TL;DR: In this paper, the authors investigated the effect of placing a partially reflecting sheet in front of an antenna with a reflecting screen at a wavelength of 3.2 cm and showed that large arrays produce considerably greater directivity but their efficiency is poor.

Abstract: Multiple reflections of electromagnetic waves between two planes are studied, and the increase in directivity that results by placing a partially reflecting sheet in front of an antenna with a reflecting screen is investigated at a wavelength of 3.2 cm. The construction and performance of various models of such arrays is discussed. Thus, for example, a "reflex-cavity antenna" with an outer diameter of 1.88 \lambda and an over-all length of only 0.65 \lambda is described which has half-power beamwidths of 34\deg and 41\deg in the E and H planes, respectively, and a gain of approximately 14 db. It is shown that larger systems produce considerably greater directivity but that their efficiency is poor.

977 citations

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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

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TL;DR: The method is extended to produce narrow patterns about the horizon, and directive patterns at two different angles, and the bandwidth limitation of the method is discussed.

Abstract: Resonance conditions for a substrate-superstrate printed antenna geometry which allow for large antenna gain are presented. Asymptotic formulas for gain, beamwidth, and bandwidth are given, and the bandwidth limitation of the method is discussed. The method is extended to produce narrow patterns about the horizon, and directive patterns at two different angles.

594 citations

01 Nov 1984

TL;DR: In this article, a substrate-superstrate printed antenna geometry which allows for large antenna gain is presented, asymptotic formulas for gain, beamwidth, and bandwidth are given, and the bandwidth limitation of the method is discussed.

Abstract: Resonance conditions for a substrate-superstrate printed antenna geometry which allow for large antenna gain are presented. Asymptotic formulas for gain, beamwidth, and bandwidth are given, and the bandwidth limitation of the method is discussed. The method is extended to produce narrow patterns about the horizon, and directive patterns at two different angles.

568 citations