Pattern analysis of corrugated horn antennas
TL;DR: In this paper, the authors used a knowledge of the aperture fields to predict the pattern using aperture integration and diffraction theory, and verified the assumptions made concerning the aperture field were verified by probing the internal fields and aperture fields of an X band corrugated horn.
Abstract: The corrugated horn has been established as an antenna with low sidelobes and backlobes, rotationally symmetric patterns (for square pyramidal and conical horn shapes), and broad-band performance [1]-[9]. These properties make this horn useful for many applications. Previous studies have used conventional aperture integration techniques to evaluate the patterns of the corrugated horn. In general, the near axis E -plane radiation pattern of a pyramidal corrugated horn may be adequately predicted from standard analysis established for the H -plane patterns of conventional horn geometries [3]. This method, however, fails to predict the far-out sidelobe and backlobe radiation levels. The work presented here uses a knowledge of the aperture fields to predict the pattern using aperture integration and diffraction theory. The assumptions made concerning the aperture fields were verified by probing the internal fields and aperture fields of an X band corrugated horn. The results of this field probing are contained in the Appendix. The method of solution used in this paper parallels that used in previous publications [10]-[12]. Specifically, the pattern in the main beam region is computed using conventional aperture integration procedures, the contribution of the H -plane edges is found using a slope diffraction analysis, and the contribution of the E -plane edges is found by use of duality.
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TL;DR: In this paper, a photonic bandgap (PBG) structure for guiding surface waves in a parallel-plate waveguide was proposed, and the relation between the dimensions of the metal posts and the required refraction index in the lens was derived with transmission-line theory and the transverse resonance method.
Abstract: Periodic and regular metal posts, a photonic bandgap (PBG) structure for guiding surface waves in a parallel-plate waveguide is proposed. The isotropic PBG structure is applied to the design of an asymmetric parallel-plate waveguide Luneburg lens (APWLL). The relation between the dimensions of the metal posts and the required refraction index in the lens is derived with transmission-line theory and the transverse resonance method. Different lattices for the entire lens are also investigated. For verification, an antenna for a 76.5 GHz adaptive-cruise control radar is fabricated, consisting of an APWLL, a primary feed, and symmetric corrugated flares to improve the property of the antenna in elevation. Measured results verify the PBG structure design in the APWLL.
146 citations
Cites methods from "Pattern analysis of corrugated horn..."
...Now, the -plane radiation patterns are calculated by the aperture integration method without considering the edge diffraction [ 17 ]....
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01 Jan 1992
TL;DR: In this paper, a new class of leaky-wave antennas based on open millimeter waveguides has been proposed and investigated, and substantial progress has been achieved in integrated antennas where active and passive circuits, possibly in monolithic form, are combined with the radiating elements in one compact unit.
Abstract: Major advances in millimeter-wave antennas have been made in recent years, in particular in two areas. A new class of leaky-wave antennas based on open millimeter waveguides has been proposed and investigated, and substantial progress has been achieved in integrated antennas where active and passive circuits, possibly in monolithic form, are combined with the radiating elements in one compact unit. Interesting developments have taken place also in a third group of millimeter-wave antennas, that of microstrip antennas and printed circuit antennas in general. An attempt is made to summarize these developments. >
81 citations
TL;DR: In this paper, a pyramidal horn antenna with a transverse slot on the top metallic surface at the end of an integrated waveguide (SIW) is deployed to drive the horn antenna.
Abstract: Due to the low atmospheric absorption over W-band, numerous applications are expected, which should be developed at low cost. Short wavelength makes the dimension of antennas in this frequency range small, which usually requires sophisticated and expensive fabrication process. This communication presents a class of integrated wideband pyramidal horn antennas which can be made of low-cost multilayered printed circuit board (PCB) process. The proposed horn antenna radiates along the broadside to the substrate and uses substrate integrated waveguide (SIW) as its feeder. Transverse slot on the top metallic surface at the end of SIW is deployed to drive the horn antenna. Metalized via holes are used to synthesize the horn walls. The opening of the horn antenna is discretely flared from the bottom to the top layer. Measured bandwidth of the antenna is 35 GHz (70-105 GHz) while a relatively constant gain of 10 ± 1 dB is obtained over most of the bandwidth.
54 citations
TL;DR: In this paper, several parasitic dipole elements served as director cell are added to the shorter end of the printed Log-periodic dipole array (PLPDA) antenna for the gain enhancement.
Abstract: In this communication, several parasitic dipole elements served as director cell are added to the shorter end of the printed Log-periodic dipole array (PLPDA) antenna for the gain enhancement. This novel antenna is based on the combination of the PLPDA antenna and the quasi-Yagi antenna techniques, so called printed Log-Yagi dipole array antenna (PLYDA). The number and the distribution of the director cell are discussed and optimized. A prototype PLYDA antenna fed by half mode substrate integrated waveguide (HMSIW) is manufactured, as well as a HMSIW PLPDA antenna for comparison. The return loss and far-field radiation patterns were measured and presented in this work. The proposed PLYDA antenna exhibits gain enhancement of 0.2-2 dB in comparison with the equal size PLPDA antenna over the operating frequency range 21-40 GHz. The simulated and measured results are in good agreement, and the gain enhancement using the director cell is verified.
48 citations
TL;DR: Using a single offset cylindrical parabolic reflector and a parallel-plate Luneburg lens, a novel high-gain and high-efficiency antenna was developed for automotive radar at mm-wave frequencies as mentioned in this paper.
Abstract: Using a single offset cylindrical parabolic reflector and a parallel-plate Luneburg lens, a novel high-gain and high-efficiency antenna is developed for automotive radar at mm-wave frequencies. Particularly, a pair of small corrugated extensions is added to the lens for a cylindrical wave. Thus, by feeding a cylindrical wave to the reflector, especially the performance in elevation is enhanced, keeping the complete antenna compact. For verification, a prototype antenna for an adaptive cruise control radar at 76.5 GHz is designed and measured. The theoretical results are verified with good agreement.
43 citations
Cites methods from "Pattern analysis of corrugated horn..."
...[ 5 ] G. P. Junker, A. A. Kishk, and A. W. Glisson, “Input impedance of...
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...is the far field of the APWLL antenna obtained using the aperture field known for the corrugated pyramidal horn [ 5 ], [6]....
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References
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TL;DR: The mathematical justification of the theory on the basis of electromagnetic theory is described, and the applicability of this theory, or a modification of it, to other branches of physics is explained.
Abstract: The geometrical theory of diffraction is an extension of geometrical optics which accounts for diffraction. It introduces diffracted rays in addition to the usual rays of geometrical optics. These rays are produced by incident rays which hit edges, corners, or vertices of boundary surfaces, or which graze such surfaces. Various laws of diffraction, analogous to the laws of reflection and refraction, are employed to characterize the diffracted rays. A modified form of Fermat’s principle, equivalent to these laws, can also be used. Diffracted wave fronts are defined, which can be found by a Huygens wavelet construction. There is an associated phase or eikonal function which satisfies the eikonal equation. In addition complex or imaginary rays are introduced. A field is associated with each ray and the total field at a point is the sum of the fields on all rays through the point. The phase of the field on a ray is proportional to the optical length of the ray from some reference point. The amplitude varies in accordance with the principle of conservation of energy in a narrow tube of rays. The initial value of the field on a diffracted ray is determined from the incident field with the aid of an appropriate diffraction coefficient. These diffraction coefficients are determined from certain canonical problems. They all vanish as the wavelength tends to zero. The theory is applied to diffraction by an aperture in a thin screen diffraction by a disk, etc., to illustrate it. Agreement is shown between the predictions of the theory and various other theoretical analyses of some of these problems. Experimental confirmation of the theory is also presented. The mathematical justification of the theory on the basis of electromagnetic theory is described. Finally, the applicability of this theory, or a modification of it, to other branches of physics is explained.
3,032 citations
"Pattern analysis of corrugated horn..." refers methods in this paper
...0, = - as obtained from Keller [ 14 ]. This form may be used even though D + co on the shadow boundaries (i.e,, as t+b + 180°), since the aperture integration is used in the vicinity of $ = 180"....
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TL;DR: In this paper, the authors used the geometrical theory of diffraction to obtain the backscattered field for plane-wave incidence on a target with particular emphasis on those regions that are usually avoided, namely, the caustic region and its immediate vicinity.
Abstract: The fields diffracted by a body made up of finite axially symmetric cone frustums are obtained using the concepts of the geometrical theory of diffraction. The backscattered field for plane-wave incidence on such a target is obtained with particular emphasis on those regions that are usually avoided, namely, the caustic region and its immediate vicinity. The method makes use of equivalent electric and magnetic current sources which are incorporated in the geometrical theory of diffraction. This solution is such that it is readily incorporated in a general computer program, rather than requiring that a new program be written for each shape. Several results, such as the cone, the cylinder and the conically capped cylinder, are given. In addition, the method is readily applied to antenna problems. An example which is reported consists of the radiation by a stub over a circular ground plane. This present theory yields quite good agreement with experimental results reported by Lopez, whereas the original theory given by Lopez is in error by as much as 10 dB.
191 citations
TL;DR: Symmetrical radiation feed patterns which are consequence of specified form of hybrid mode fields as disclosed by focal plane analysis are described in this article, where the authors show that the feed pattern is a consequence of the hybrid mode field.
Abstract: Symmetrical radiation feed patterns which are consequence of specified form of hybrid mode fields as disclosed by focal plane analysis
160 citations
01 Sep 1971
TL;DR: In this article, the propagation and radiation properties of corrugated waveguides were investigated and the attenuation of the dominant HE11 mode was shown to be less than that of the H11 mode in a uniform waveguide over at least a 2:1 frequency bandwidth.
Abstract: An investigation of the propagation and radiation behaviour of circular corrugated waveguides is described. Particular attention is given to modes of unity azimuthal dependence because of their importance in antennafeed applications. It is shown that the radiation pattern of a corrugated waveguide exhibits nearly perfect symmetry over a 1.5:1 frequency band, and, when the corrugations are approximately λ/4 deep, the pattern is symmetric and there is no crosspolarised component of radiated field. The attenuation of the dominant HE11 mode is investigated theoretically and is shown to be less than that of the H11mode in a uniform waveguide over at least a 2:1 frequency bandwidth. An important similarity is described between the propagation behaviour of a corrugated waveguide and that of a dielectric rod of low relative permittivity, such as those used in fibre optics and optical waveguides. Finally, the determination of the input voltage standing-wave ratio (v.s.w.r.) at the junction between homogeneous and corrugated waveguides is theoretically and experimentlly studied.
121 citations
Journal Article•
103 citations