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Showing papers on "Slot antenna published in 1985"


Book
01 Mar 1985
TL;DR: Aperture Distributions and Arrays Synthesis as discussed by the authors is a technique used to synthesize antenna arrays, which are then used to measure the distance from the source to the sink. But it requires the antenna array to be symmetric.
Abstract: Preface. 1. Properties of Antennas. 2. Radiation Structures and Numerical Methods. 3. Arrays. 4. Aperture Distributions and Arrays Synthesis. 5. Dipoles, Slots, and Loops. 6. Microstrip Antennas. 7. Horn Antennas. 8. Reflector Antennas. 9. Lens Antennas. 10. Traveling Wave Antennas. 11. Frequency-Independent Antennas. 12. Phased Arrays. Index.

816 citations


Journal ArticleDOI
TL;DR: In this article, a good general agreement is obtained for curves of beamwidth versus length, normalized to wavelength, when one compares the data with that for traveling-wave antennas published by Zucker.
Abstract: Endfire tapered slot antennas are suitable for many integrated circuit applications, imaging and phased arrays. We report on an investigation of single elements of such antennas, including slots which are exponentially tapered (Vivaldi), linearly tapered (LTSA) and constant width (CWSA). For antennas of all types, a good general agreement is obtained for curves of beamwidth versus length, normalized to wavelength, when one compares the data with that for traveling-wave antennas published by Zucker. An important condition for this agreement is that the effective dielectric thickness, defined in the text, is in a certain optimum range. This condition is qualitatively explained in terms of the theory for traveling-wave antennas.

453 citations


Journal ArticleDOI
Makoto Ando1, K. Sakurai1, Naohisa Goto1, K. Arimura, Y. Ito 
TL;DR: In this paper, the authors proposed a planar antenna which can radiate circularly polarized pencil beams in the x-band for the application of receiving direct broadcast from a satellite (DBS).
Abstract: The analysis and design of novel planar antennas which can radiate circularly polarized pencil beams in x -band are presented for the application of receiving direct broadcast from a satellite (DBS). This antenna belongs to a class of slotted waveguide antennas and high efficiency is expected in principle. A circular two-dimensional aperture is located on the top plate of a twofold radial waveguide and is excited by a radially inward traveling transverse electromagnetic (TEM) mode in the upper waveguide. Slots are arrayed on the aperture spirally in such a way that they can couple with the radial currents flowing over the aperture plate to produce a circularly polarized broadside beam. Promising performances of the antenna are predicted theoretically. Experiments are performed with respect to basic characteristics of the antenna and they show the validity of the design and analysis.

274 citations


Journal ArticleDOI
TL;DR: In this paper, the moment method in the Fourier transform domain was used to calculate the impedance, resonant length, and radiation pattern for the isolated antennas and the reflection coefficient for infinite phased arrays.
Abstract: The printed dipole or slot antenna on a semi-infinite substrate and infinite phased arrays of these elements are investigated. The solution is based on the moment method in the Fourier transform domain. The generalized impedance or admittance matrix can be expressed in rapidly converging infinite-integral or infinite-summation forms, allowing the accurate determination of the current distributions. Using the present formulation, the input impedance, resonant length, and radiation pattern for the isolated antennas, and the reflection coefficient for infinite phased arrays, are calculated.

195 citations


Journal ArticleDOI
17 Jun 1985
TL;DR: In this article, the authors reviewed the theory for the design of longitudinal slot arrays and its dependence on the dominant mode scattering off a single slot is pinpointed and the critical need to know resonant length versus slot offset is emphasized and the desirability of determining this information theoretically rather than experimentally is argued.
Abstract: Pertinent theory for the design of longitudinal slot arrays is reviewed and its dependence on the dominant mode scattering off a single slot is pinpointed. The critical need to know resonant length versus slot offset is emphasized and the desirability of determining this information theoretically rather than experimentally is argued. Then method of moments solutions are used to calculate resonant length versus slot offset for given waveguide dimensions and frequency. These theoretical results are compared to new, carefully obtained experimental data. Agreement is found to be so good, it is concluded that one can dispense with the costly gathering of experimental input data when designing longitudinal slot arrays fed by standard rectangular waveguide. A critical look is taken at the validity of representing the longitudinal slot as a shunt element on an equivalent transmission line. This assumption is found to be more and more questionable as the b dimension is reduced. For quarter-height guide, an alternate design procedure is suggested as being more accurate.

189 citations


Patent
23 Sep 1985
TL;DR: In this paper, a multidirectional feed which can be used by itself or incorporated within a surface wave structure to form a flush-mounted antenna on, for example, a mobile unit is presented.
Abstract: The present invention relates to a multidirectional feed which can be used by itself or preferably incorporated within a surface wave structure to form a flush-mounted antenna on, for example, a mobile unit. The feed arrangement comprises a ground plane including an annular cavity with a smaller annular slot. The annular slot is connected by multiple, spaced-apart, leads to an associated transceiver. The annular cavity is also formed to prevent both a shorting of the radio waves therein and the radio waves from propagating away from the cavity in a direction opposite the slot. A surface wave structure is disposed preferably with the feed centrally mounted and can comprise any suitable structure including annular corrugations and/or a dielectric layer to provide a flush-mounted antenna arrangement which provides radiation in azimuth in all directions with moderate elevation gain.

134 citations


Journal ArticleDOI
TL;DR: In this paper, an approach to the analysis of microstrip antennas on cylindrical bodies is presented, where the printed radiator is replaced by as assumed surface current distribution, and the fields are solved taking into account the presence of the dielectric layer and the metallic cylinder.
Abstract: An approach to the analysis of microstrip antennas on cylindrical bodies is presented. The printed radiator is replaced by as assumed surface current distribution, and the fields are solved taking into account the presence of the dielectric layer and the metallic cylinder. Calculation takes place in the Fourier domain. The far field, calculated asymptotically from this solution, is used to get the radiation patterns of the wraparound antenna for any dielectric and the half-wavelength patch for \epsilon_{r} = 1 .

132 citations


Journal ArticleDOI
TL;DR: The theory of the linear, insulated antenna embedded in an electrically dense medium is applied to microwave antennas used for hyperthermia cancer therapy and the pattern of power deposition is computed.
Abstract: The theory of the linear, insulated antenna embedded in an electrically dense medium is applied to microwave antennas used for hyperthermia cancer therapy. The pattern of power deposition is computed for a square array of four antennas with a side length of 3 cm under the assumption of no coupling among antennas. The driving frequency is set to seven values between 300 and 915 MHz, and the antenna halflength is set to three values: 3 cm, 6 cm, and the resonant value.

82 citations


Patent
30 Sep 1985
TL;DR: A parasitically coupled, complementary slot dipole antenna element includes a driven, cavity-backed slot antenna element and a parasitic dipole element transverse to the slot of the cavity-supported antenna element as discussed by the authors.
Abstract: A parasitically coupled, complementary slot dipole antenna element includes a driven, cavity-backed slot antenna element and a parasitic dipole element transverse to the slot of the cavity-backed slot antenna element. The cavity-backed slot and parasitic dipole antenna elements resonate at about the center frequency of the excitation signals supplied to the cavity-backed slot antenna element in order to generate a relatively symmetrical electromagnetic signature and an increased bandwidth.

79 citations


Journal ArticleDOI
TL;DR: In this article, an integral equation for a coaxially fed annular aperture antenna is formulated for the unknown tangential aperture electric field and solved numerically by the Method of Moments.
Abstract: An integral equation is formulated for a coaxially fed annular aperture antenna. The integral equation in terms of the unknown tangential aperture electric field is solved numerically by the Method of Moments. The coaxial feed line is air filled while the exterior region consists of i) air, ii) fat or bone, and iii) muscle. Results are given for the aperture electric field, apparent input admittance, and contours of constant power absorption when the excitation frequency is 2.45 GHz.

37 citations



Patent
15 Mar 1985
TL;DR: A reduced height monopole/crossed slot antenna having generally parallel spaced ground planes, the upper one of which has a capacitively loaded slot therein formed by crossed slot portions as mentioned in this paper.
Abstract: A reduced height monopole/crossed slot antenna having generally parallel spaced ground planes, the upper one of which has a capacitively loaded slot therein formed by crossed slot portions A stripline is located between the ground planes offset toward the upper ground plane, and is formed by crossed stripline portions A monopole extends from the intersection of the crossed stripline portions through the intersection of the crossed slot portions orthogonally to the upper ground plane, and is top hat loaded at the outer end thereof The stripline is fed at selective ends thereof

Patent
26 Dec 1985
TL;DR: An improved excitation system for a microwave oven employing a circular rotating disk antenna configured to radiate peripherally from its outermost edge to provide backgound radiation in the oven cavity is described in this paper.
Abstract: An improved excitation system for a microwave oven employing a circular rotating disk antenna configured to radiate peripherally from its outermost edge to provide backgound radiation in the oven cavity. Primary microwave energy radiation is emitted from a pair of transverse radiating slots formed in the disk antenna. A first slot is positioned radially outwardly relative to the second slot. The first slot alternately functions as a relatively strongly coupled series and shunt radiating slot and the second slot concurrently alternately functions as a moderately coupled shunt and series slot with each quarter revolution of the disk antenna. Both slots are louvered for improved coupling to the load being heated in the cavity.

Journal ArticleDOI
TL;DR: A brief account of some concepts and developments in my experience with antennas is presented under three headings: A-wide-band matching to a long line; B-small antennas; C-planar arrays.
Abstract: A brief account of some concepts and developments in my experience with antennas is presented under three headings: A-wide-band matching to a long line; B-small antennas; C-planar arrays. They cover the half-century from 1935 to date.

Journal ArticleDOI
TL;DR: A quasi-optical frequency-multiplying slot array for high-power millimeter-wave applications has been demonstrated in this article, where single slot conversion loss measured for X- and Ka-band models produced results that were similar to in-waveguide multipliers using the same type of diodes.
Abstract: A quasi-optical frequency-multiplying slot array for high-power millimeter-wave applications has been demonstrated Single slot conversion loss measured for X- and Ka -band models produced results that are similar to in-waveguide multipliers using the same type of diodes An eight-element multiplying array exhibited better than --12-dB sidelobe level at 70 GHz The simple planar structure makes millimeter IC fabrication of the slot array feasible

Journal ArticleDOI
01 Jun 1985
TL;DR: In this paper, the authors describe, analyze, and validate a new feeding method for exciting transverse slots in a boxed stripline, which is provided by running the strip at an angle centrally underneath the transverse slot, and the amount of power coupled to the slot is controlled by the angle between the strip and the slot.
Abstract: This paper contains the description, analysis, and experimental validation of a new feeding method for exciting transverse slots in a boxed stripline. The feed is provided by running the strip at an angle centrally underneath the transverse slot. The amount of power coupled to the slot is controlled by the angle between the strip and the slot. The electric field generated in the slot is assumed to be an equiphase, half cosinusoid. Based on this assumption, an equation for the resonant resistance of the transverse slot is derived. A comparison of theoretical predictions and experimental results serves to justify the assumption. An antenna design procedure is next presented. This procedure includes an accounting of the external mutual coupling between slots. The active impedance of each slot in the presence of other slots is described by a pair of design equations. These equations relate the active slot impedance to the physical parameters of the circuit. An equispaced, eight element, array was designed to give a broadside 20 dB Dolph-Chebyshev pattern. Experimental results on pattern and input impedance were good.

Journal ArticleDOI
TL;DR: In this article, the power gain radiation patterns of mobile antennas mounted in six different locations on a test vehicle were measured with and without typical lights and sirens mounted on the roof.
Abstract: Power gain radiation patterns of mobile antennas mounted in six different locations on a test vehicle were measured with and without typical lights and sirens mounted on the roof. The measurements were performed at frequencies representing the frequency bands of 25 to 50, 150 to 174, 400 to 512, and 806 to 866 MHz. In addition, special antennas consisting of three disguised antennas operating at discrete frequencies of 40.27, 162.475, and 416.975 MHz and one slot antenna operating at 413 MHz were also measured. Plots of power gain radiation patterns are given for the mobile antennas mounted in six different locations on the test vehicle and for the special antennas. Results showing the effects of poor grounding characteristics are also included. Recommended locations for mounting the mobile antennas are given for specific frequency bands.

Patent
30 Sep 1985
TL;DR: In this article, an antenna element that is defined by a substantially Y-shaped slot formed in the broad face of a section of dielectrically-filled waveguide is described, and various design parameters including leg length, leg width and angle formed between the legs permit the antenna element to be configured for circularly polarized radiation of a controlled portion of the electromagnetic energy propagates along the waveguide.
Abstract: Disclosed is an antenna element that is defined by a substantially Y-shaped slot (22) formed in the broad face (12) of a section of dielectrically-filled waveguide (10). Various design parameters including leg length, leg width and angle formed between the legs permit the antenna element to be configured for circularly polarized radiation of a controlled portion of the electromagnetic energy that propagates along the waveguide.

Journal ArticleDOI
TL;DR: In this article, a new theoretical approach to the analysis of a single-slot antenna is presented, leading to explicit expressions for the antenna input impedance and radiation efficiency, which are in good agreement with laboratory measurements.
Abstract: Transverse slots in the "upper" plate of a dielectric-loaded parallel plane waveguide (H-guide) operating in the dominant mode (zero cutoff frequency) are proposed as slot antennas. A new theoretical approach to the analysis of a single-slot antenna is presented, leading to explicit expressions for the antenna input impedance and radiation efficiency. The computed values of the VSWR and radiation efficiency are in good agreement with laboratory measurements. The radiation efficiency of a single slot exceeds 10 percent in the 8-11-GHz frequency band, reaching a 50-percent theoretically predicted maximum at the slot resonance frequency, when the guide is terminated by a matched load. Experimental checks prove that the leakage, or parasitic, radiation power level is less than -40 dB relative to the measured radiated power.

Proceedings ArticleDOI
17 Jun 1985
TL;DR: In this article, the authors discuss a propagation model consiting of two types of SUE wave propagation in a land mobile system and suggest that the base station antenna height is equal or lower than that of the building height.
Abstract: An extrendy d l zone land mobile system (with radio zone radius less than 1 b) is most suitable for realizing low pm2r portable radio cannmication services. However, m y base stations rmst be constructed very close together,and the base station antenna height mst be approximately 10 to 30 m to re& co-channel interference and to decrease the construction cost. In the land mobile system, the path loss vitally depends on the base station antenna height, and when the base station antenna height s l m r than building height the propagation mechanism may differ fran that of the propagation mechanism using a high antenna base Station. It is suggested that w en the base station antenna height is equal or lower than that of s u r r m d i n g buildings, SUE waves diffract at the tops of surrounding buildings and the other waves propagate along roads [l] . kmver, the detailed mechani sm, which well explains actual propagation ph-, has been left for H e r investigation. This paper discusses a propagation model consiting of two types

Journal ArticleDOI
TL;DR: In this article, a comparison of the technology, performance, and power limitations of different types of ICRH antenna configurations is presented, as well as the causes of the power and frequency limitations.
Abstract: Ion cyclotron resonance heating (ICRH) is expected to become the dominant contributor to the supplemental heating needs of plasmas in future toroidal devices. The severity of the environments that will be imposed on the ICRH antennas by the plasma in such devices requires the investigation of different approaches to providing adequate life and reliability in addition to the necessary coupling. This work, which is part of the National Ion Cyclotron Heating Program, addresses these issues. The rf coupling capabilities and characteristics of various antennas have been measured. The tested antenna configurations include the simple loop antenna operated at resonant lengths as used on Alcator-C, the cavity antenna proposed for Doublet III-D, and the resonant double loop, asymmetric resonant double loop, and U-slot antennas. Models of the voltage, magnetic fields outside the structure, and current have been correlated with the measurements made on these antennas. From these measurements and from typical observations of ICRH coupling in tokamaks, we are studying power and frequency limitations on each antenna and the causes of the limitations. A comparison of the technology, performance, and power limitations of each type of antenna is presented.

Journal ArticleDOI
H. Schrank1
01 Apr 1985
TL;DR: In this paper, a front feed reflector antenna with a dish reflector has a reflector focal length to reflector diameter ratio of less than 0.25, and a wave guide is coupled to a proximal end of the antenna, projecting into the reflector along a longitudinal axis.
Abstract: A front feed reflector antenna with a dish reflector has a reflector focal length to reflector diameter ratio of less than 0.25. A wave guide is coupled to a proximal end of the dish reflector, projecting into the dish reflector along a longitudinal axis. A dielectric block is coupled to a distal end of the waveguide and a sub-reflector is coupled to a distal end of the dielectric block. A shield is coupled to the periphery of the dish reflector. The sub-reflector diameter is dimensioned to be 2.5 wavelengths or more of a desired operating frequency.

01 Jan 1985
TL;DR: In this paper, the square dumbbell shunt slot is characterized by the moment method and the resonant length is shorter than a conventional rectangular slot, and changing the width of the dumbbell slot has the same effect as changing the length of the rectangular slot.
Abstract: : Dumbbell slots are often used for an array to reduce their resonant length, and hence, their internal and external mutual coupling. The square dumbbell shunt slot is characterized by the moment method. As expected, the resonant length is shorter than a conventional rectangular slot. Also, changing the width of the dumbbell slot has the same effect as changing the length of the rectangular slot. However, for a small offset such that a part of the dumbbell is across the center line, changing the width of the dumbbell slot has little influence to its admittance.

Proceedings ArticleDOI
01 Oct 1985
TL;DR: In this article, a comparison between calculated and experimentally observed values of one of the field components for both amplitude and phase at the front aperture of the antenna is made, and a fairly good agreement has been obtained between them.
Abstract: The present paper deals with the H-Plane Sectoral Solid Dielectric Horn Antenna. Attempts have been made to determine theoretically the approximate surface fields (Ampli tude and Phase) under several simplifying assumptions. A comparison has been made between calculated and experimentally observed values of one of the field components for both amplitude and phase at the front aperture of the antenna. A fairly good agreement has been obtained between them.

Patent
30 Aug 1985
TL;DR: In this paper, a polarization separating reflector is constructed for use in microwave transmitting antennas or in microwave receiving antennas, where the signal supply to the transmitting antennas and the signal retrieval from the receiving antennas may be symmetrical or nonsymmetrical.
Abstract: A polarization separating reflector is constructed for use in microwave transmitting antennas or in microwave receiving antennas. The signal supply to the transmitting antennas and the signal retrieval from the receiving antennas may be symmetrical or nonsymmetrical. Such antennas may or may not be equipped with subreflectors. Such antennas have a polarization selectively reflecting lattice structure on or within a dielectric carrier. This antenna structure is resonantly constructed out of separate dipoles having different lengths, preferably in the form of a linear dipole lattice. The dipoles are arranged in a staggered manner, colinearly, or at an angle relative to a reference line, such as the vertical, as desired.

Journal ArticleDOI
TL;DR: In this paper, the theory of radiation from discontinuities in the ground plane of a dielectric image line has been described and experimental verifications of the radiation theory as well as millimeter-wave antennas realized on the basis of the theory are described.
Abstract: In the first part of this paper the theory of radiation from discontinuities in the ground plane of a dielectric image line has been described. In this second part experimental verifications of the radiation theory as well as millimeter-wave antennas realized on the basis of the theory are described. In the antennas slots and holes in the ground plane of the dielectric image line are used as discontinuities. Experimental results for the radiation characteristics are discussed.

DOI
01 Dec 1985
TL;DR: In this article, a simple method is described for analysis of a slot antenna on dielectric substrate of finite thickness, which consists in using several transformations for reducing the original structure to approximately complementary/dual structure; i.e. to a cylindrical dipole of circular cross-section with a coaxial magnetic cover.
Abstract: A simple method is described for analysis of a slot antenna on dielectric substrate of finite thickness. The method consists in using several transformations for reducing the original structure to approximately complementary/dual structure; i.e. to a cylindrical dipole of circular cross-section with a coaxial magnetic cover. The structure thus obtained is then analysed using well-known methods. A model of the slot on dielectric substrate fed by a coplanar waveguide was realised, and experimental results for slot impedance agreed well with the theory.

Patent
25 Jan 1985
TL;DR: In this article, an antenna for providing a broadband omnidirectional circumferential radion pattern is formed by an array of arcuate waveguide radiators arranged to form a cylindrical antenna.
Abstract: An antenna for providing a broadband omnidirectional circumferential radion pattern is formed by an array of arcuate waveguide radiators arranged to form a cylindrical antenna. Each waveguide radiator has a ridged waveguide cavity and a plurality of longitudinally-oriented slots communicating with the waveguide cavity. The slots are arranged in two parallel rows on either side of the longitudinal centerline in a staggered relationship along the outside surface of the radiator. Each radiator is fed from the interior of the cylindrical array at a feed point located at the center of the radiator.

Proceedings ArticleDOI
24 Oct 1985
TL;DR: A wide variety of antennas have been designed or are currently under study for the millimeter wave region as discussed by the authors, and an overview over these antennas is presented in this paper. But, as mentioned before, the antennas of conventional configuration and antennas based on new design approaches are distinguished, and antennas with significant features that are peculiar to the mm-wave band can be distinguished.
Abstract: A wide variety of antennas has been designed or is currently under study for the millimeter wave region. An overview over these antennas is presented. Two classes of antennas are distinguished, i.e., antennas of conventional configuration and antennas based on new design approaches. The former class consists of radiating structures, such as reflector, lens and horn antennas, whose characteristics are well established. The latter class is comprised of antennas with significant features that are peculiar to the mm-wave band and includes radiating structures such as microstrip mm-wave antennas, dielectric antennas and integrated antennas.

Journal ArticleDOI
TL;DR: In this paper, the fabrication of various iris-fed millimeter-wave rectangular microstrip patch antennas is described, and a mathematical model is proposed to describe the irisfed antenna.
Abstract: The fabrication of various iris-fed millimeter-wave rectangular microstrip patch antennas is described. A mathematical model is proposed to describe the iris-fed antenna. An iris having 15 percent of the area of the patch is used to couple energy into the antenna. Resonance of the antenna is observed to be insensitive to the size of the iris for irises up to 115 percent of the size of the patch. A study is also made of the coupling to the antenna as a function of position of the iris with respect to the transverse plane of the waveguide, the iris always being centered with respect to the patch. In general, the antenna has a VSWR in the waveguide feed of roughly 5:1 at resonance, except for the fully open waveguide which gives rise to a VSWR of 2.9:1 at resonance. Far-field antenna power patterns are observed to be quite broad with H-plane beamwidths about 130°. Maximum antenna gain observed was 4.5 dB relative to an isotropic source (dBi), with 2 dBi typical. An initial study is made of the microstrip patch antenna fed from a longitudinal waveguide wall. Results indicate that this feed structure is likely to prove valuable for microstrip patch antennas, with coupling at least as good as for the transverse-fed patch, added to the possibility of feeding multiple patches from a single waveguide.