Showing papers on "Patch antenna published in 1983"
TL;DR: In this article, three types of single-feed circularly polarized microstrip antennas, namely, a diagonal fed nearly square, a truncated-corners square and a square with a diagonal slot, are presented.
Abstract: Analysis and optimized designs are presented of three types of single feed circularly polarized microstrip antennas, namely, a diagonal fed nearly square, a truncated-corners square and a square with a diagonal slot. The Green's function approach and the desegmentation methods are used. The resonant frequencies are calculated for two orthogonal modes which together yield circular polarization. Optimum feed locations are determined for the best impedance match to a 50 \Omega coaxial feed line. Axial-ratio bandwidths, voltage standing-wave ratio (VSWR) bandwidths and radiation patterns are evaluated and verified experimentally.
602 citations
TL;DR: In this article, an antenna which consists of a resonant rectangular parallelepiped dielectric on top of a ground plane is described, and the effects of feed probe length variations are discussed.
Abstract: An antenna which consists of a resonant rectangular parallelepiped dielectric on top of a ground plane is described. Calculated radiation patterns and measured impedances are presented, and the effects of feed probe length variations are discussed.
322 citations
TL;DR: In this paper, the authors employed the uniform geometrical theory of diffraction (GTD) for calculating the edge diffracted fields from the finite ground plane of a microstrip antenna.
Abstract: The uniform geometrical theory of diffraction (GTD) is employed for calculating the edge diffracted fields from the finite ground plane of a microstrip antenna. The source field from the radiating patch is calculated by two different methods: the slot theory and the modal expansion theory. Many numerical and measured results are presented to demonstrate the accuracy of the calculations and the finite ground plane edge effect.
274 citations
23 May 1983
174 citations
TL;DR: In this paper, a single-element rectangular microstrip antenna which can operate simultaneously for two different frequency bands is described, and the antenna can operate at different frequencies for different applications.
Abstract: The letter describes a single-element rectangular microstrip antenna which can operate simultaneously for two different frequency bands.
121 citations
TL;DR: In this article, the validity of using planar antenna patches to characterize microstrip antennas is examined, including the simplest planar patch modes having no field variation normal to the patch surface.
Abstract: Resonant frequencies f_{r} of a cylindrical-rectangular microstrip antenna are theoretically calculated. Comparison is made to f_{r} for a planar rectangular patch antenna, including the simplest planar patch modes having no field variation normal to the patch surface. The validity of using planar antenna patches to characterize microstrip antennas is examined.
109 citations
TL;DR: In this paper, a rectangular microstrip patch antenna has been extensively analyzed with regard to its input impedance and resonant frequency, both for infinite and finite ground plane dimensions, and the contribution from the ground plane edge diffraction has been accounted for in an equivalent radiation conductance and an equivalent diffraction susceptance.
Abstract: The rectangular microstrip patch antenna has been extensively analyzed with regard to its input impedance and resonant frequency, both for infinite and finite ground plane dimensions. For infinite ground planes existing formulas have been compared and improved parameters presented. The influence from the side current radiation has been discussed as well. For finite ground plane dimensions the contribution from the ground plane edge diffraction has been accounted for in an equivalent radiation conductance and an equivalent diffraction susceptance. Formulas for these parameters have been developed on the basis of different theories. They are valid under the condition that only one of the ground plane dimensions are finite at the same time. Experimental investigations are carried out to test the accuracy of the developed formulas, showing good accuracy under the given conditions.
100 citations
Patent•
29 Aug 1983
TL;DR: In this paper, the first antenna for radiating a signal at a predetermined frequency employing at least one 1/4 wavelength microstrip resonator positioned below a metal 1.4 wavelength radiator was presented.
Abstract: A first antenna for radiating a signal at a predetermined frequency employing at least one 1/4 wavelength microstrip resonator positioned below a metal 1/4 wavelength radiator. A circularly polarized antenna including a 1/2 wavelength radiator electromagnetically coupled to a 1/4 wavelength resonator is further disclosed.
88 citations
Patent•
02 Sep 1983TL;DR: In this paper, PIN diodes are placed at predetermined locations on the antenna coaxial cable radiating elements for higher frequency band use and biased short circuiting segments of the antenna.
Abstract: An antenna is tuned in separate discrete frequency bands by changing the ctrical length of the antenna. PIN diodes are placed at predetermined locations on the antenna coaxial cable radiating elements. When it is desired to shorten the antenna for a higher frequency band use, the diodes are biased short circuiting segments of the antenna. When the lower frequency band use is desired, diodes are unbiased so that the diodes act like a very small capacitance shunted by a large resistance which is essentially an open circuit permitting the entire length of the antenna to operate.
65 citations
Patent•
15 Jul 1983TL;DR: In this paper, a microstrip antenna system having one or more conductively isolated resonantly dimensioned radiator structures disposed less than about one-tenth wavelength above a ground plane is nonconductively coupled to an intermediate layer of microstrip feedline structure.
Abstract: A microstrip antenna system having one or more conductively isolated resonantly dimensioned radiator structures disposed less than about one-tenth wavelength above a ground plane is nonconductively coupled to an intermediate layer of microstrip feedline structure. The microstrip feedline structure includes various microstrip transmission line segments fed with reference to the ground plane an including predetermined coupling locations positioned an odd integer number of one-fourth wavelength(s) from an effective r.f. short circuit to the underlying ground plane. Such coupling locations are also disposed proximate a predetermined corresponding feedpoint region of the radiating structure such that electromagnetic fields concentrated at the coupling location operate to nonconductively couple r.f. energy to/from the radiator structure from/to the feedline structure. The coupling location is preferably disposed at a widened and relatively lowered r.f. impedance coupling tab segment of the transmission line having a width dimension which is sufficient to provide matched impedance coupling to the corresponding feedpoint region but which is also substantially less than the dimension of the radiator structure transverse to its resonant dimension. The effective r.f. short circuit may be provided by an actual conductive connection to the underlying reference surface or by an r.f. open circuit termination located an additional one-fourth wavelength therefrom along the feedline structure.
57 citations
TL;DR: In this paper, the effect of substrate thickness on the characteristics of a circular disk microstrip antenna is examined and experimental results explicitly showing the effect on resonant frequency, input impedance, and bandwidth are provided.
Abstract: The effect of substrate thickness on the characteristics of a circular-disk microstrip antenna is examined. In the literature this effect has been dealt with theoretically, but experimental results explicitly showing the effect of substrate thickness on resonant frequency, input impedance, and bandwidth do not seem to be readily available.
Patent•
15 Sep 1983TL;DR: In this paper, a three-element active device is physically and electrically integrated onto shaped conductive areas in a thin conformable microstrip structure which includes a microstrip antenna radiator.
Abstract: A three-element active device is physically and electrically integrated (e.g., by soldering) onto shaped conductive areas in a thin conformable microstrip structure which includes a microstrip antenna radiator. Two of the elements of the active device are connected to microstrip reactance structures which form a series-resonant partial oscillator circuit. The third (output) element of the active device is connected directly to the microstrip antenna radiator via a microstrip transmission line which, together, directly provide the r.f. load impedance for the thus completed oscillator circuit. Quarter wavelength r.f. microstrip segments are also provided to facilitate the feeding of d.c. bias to the active device without disturbing the r.f. circuitry. The oscillator load impedance to be provided by the microstrip radiator is predetermined in accordance with conventional device-line or loadpull impedance measurements so as to maximize the power output of the active device.
Patent•
19 Sep 1983TL;DR: In this paper, a radar antenna is shown to have a ground plane and a feed line on opposite sides of a dielectric sheet and a ring-shaped antenna element on another sheet to form a microstrip assembly wherein such antenna element is capacitively coupled to the feed line.
Abstract: A radar antenna is shown in a first embodiment to have a ground plane and a feed line on opposite sides of a dielectric sheet and a ring-shaped antenna element on another dielectric sheet to form a microstrip assembly wherein such antenna element is capacitively coupled to the feed line. In a second embodiment the radar antenna has a parasitic antenna element on still another dielectric sheet, such parasitic antenna element being in register with the ring-shaped antenna element.
TL;DR: In this article, an approximate expression for the resonant frequency of a rectangular patch antenna is derived, which shows explicitly the dependence of the resonance frequency on the characteristic parameters of the antenna and the accuracy of the expression is established by comparing the theoretical results with available measured results.
Abstract: An approximate expression is derived for the resonant frequency of a rectangular patch antenna. It shows explicitly the dependence of the resonant frequency on the characteristic parameters of the antenna. Accuracy of the expression is established by comparing the theoretical results with available measured results.
Patent•
06 Dec 1983TL;DR: In this paper, a microstrip antenna consisting of a first dielectric layer having a permittivity of 2.5-12.5 and a second layer with permittivities between 2.2-2.5 is matched by varying the spacing between the two layers.
Abstract: A microstrip antenna comprises a first dielectric layer having a permittivity of 2.5-12.5 carrying the ground plane on one face and a feeder-resonator on the opposite face; a second dielectric layer thereover having a permittivity of 2.2-2.5 and carrying on its outer face a radiator electromagnetically coupled to the feeder-resonator; and spacing means spacing the second dielectric layer from the first a distance of up to seven times the thickness of the first, and providing a permittivity between the two dielectric layers which is approximately that of air. Matching of the antenna is obtained by varying the spacing between the two dielectric layers. The gain of the radiating element is better than 7.5 dbi for bandwidth of 15%. Sidelobe level is less than 15 dB in azimuth and elevation plan. The radiation pattern of the antenna is symmetric in both azimuth and elevation plan.
TL;DR: A geometrical theory of the resonant frequencies and radiation factors of 45°deg-45°deg −90°deg, 60°deg -60deg-60deg −60°deg−60deg, and 30°deg°60-deg − 90°deg triangular microstrip patch antennas is developed in this article, based upon the rereflection of rays making up the field underneath the patch.
Abstract: A geometrical theory of the resonant frequencies and radiation Q -factors of 45\deg-45\deg-90\deg, 60\deg-60\deg-60\deg , and 30\deg-60\deg-90\deg triangular microstrip patch antennas is developed, based upon the rereflection of rays making up the field underneath the patch. Extremely simple formulas for Q_{r} are obtained, which enables an extensive comparison of relative radiation Q for various patch shapes to be made. This theory replaces other much more cumbersome expressions from the literature, or gives new formulas for some cases for the first time.
TL;DR: In this article, the effectiveness and bandwidth of a new class of diode-switched integrated antenna phase shifter were examined, and the operation of this type of antenna was found to be for circular polarization only.
Abstract: The effectiveness and bandwidth of a new class of diode-switched integrated antenna phase shifter are examined. A well-known example of this type of antenna is the "spiraphase." The operation of this type of antenna is found to be for circular polarization only. When used as a reflecting element, the effectiveness of the antenna is not broadband. A much wider bandwidth is expected by using this antenna as a direct radiating device.
TL;DR: A modular approach is utilized in which a given antenna is used as a building block for higher gain antennas, and the results seem to validate the usefulness of the method.
Abstract: A method for the design of medium gain (15-25 dB) microstrip array antennas is described. A modular approach is utilized in which a given antenna is used as a building block for higher gain antennas. A series of X -band antennas were built in this way, and the results seem to validate the usefulness of the method.
Patent•
06 Apr 1983TL;DR: In this paper, a microstrip cylindrical antenna comprised of two concentric subelements on a ground cylinder, a vertically polarized (E-field parallel to the axis of the antenna cylinder) subelement on the inside and a horizontally polarized (e.g., E-field perpendicular-to-the-axis) sub element on the outside is used for improved azimuthal pattern uniformity.
Abstract: A microstrip cylindrical antenna comprised of two concentric subelements on a ground cylinder, a vertically polarized (E-field parallel to the axis of the antenna cylinder) subelement on the inside and a horizontally polarized (E-field perpendicular to the axis) subelement on the outside. The vertical subelement is a "wraparound" microstrip radiator. A Y-shaped microstrip patch configuration is used for the horizontally polarized radiator that is wrapped 1.5 times to provide radiating edges on opposite sides of the cylindrical antenna for improved azimuthal pattern uniformity. When these subelements are so fed that their far fields are equal in amplitude and phased 90° from each other, a circularly polarized EM wave results. By stacking a plurality of like antenna elements on the ground cylinder, a linear phased array antenna is provided that can be beam steered to the desired elevation angle.
01 Jan 1983
TL;DR: In this paper, a multi-element microstrip antenna applicator for microwave local hyperthermia is described and the design criteria for such a micro-strip antenna array are presented.
Abstract: A multi-element microstrip antenna applicator designed for microwave local hyperthermia is described Design criteria for such a microstrip antenna array are presented Various antennas were built and compared Experimental measurements of heating patterns show the multiple microstrip spiral antenna provides controlled heating over a large area
TL;DR: Theory and numerically computed results for mutual coupling between two rectangular microstrip antenna patches are presented in this article, where E -plane alignment and H-plane alignment are the two patch orientations considered.
Abstract: Theory and numerically computed results are presented for mutual coupling between two rectangular microstrip antenna patches. E -plane alignment and H -plane alignment are the two patch orientations considered. The s -parameter matrix element s_{11} is used to study the mutual coupling. Extensive results are provided for s_{11} covering several relative substrate dielectric constants, antenna patch widths, and antenna patch separations. Results are also given for resonant frequency, resonant impedance behavior, and radiation pattern at resonance.
23 May 1983
Patent•
21 Mar 1983
TL;DR: In this paper, a microstrip antenna which includes a ground member, a dielectric element mounted on the ground member and a radiating element on the dielectrics element, has been improved by means of a distinct grounding ring of conductive material which is spaced apart from and extends around the radiating elements.
Abstract: A microstrip antenna which includes a ground member, a dielectric element mounted on the ground member and a radiating element on the dielectric element, has been improved by means of a distinct grounding ring of conductive material which is spaced apart from and extends around the radiating element. The grounding ring is connected to a ground member, thereby laterally isolating the antenna and permitting a closer spacing with adjacent antennas. The gap between the radiating element and the grounding ring is different in different directions.
23 May 1983
23 May 1983
TL;DR: In this paper, a spherical-rectangular microstrip structure is studied based on the assumption that the thickness of the dielectric layer is much smaller than the radius of the ground sphere.
Abstract: Microstrip antennas may be mounted on spherical surfaces on some vehicles of practical interest such as missiles and satellites. One possible application, for example, might be to build phased array microstrip radiators on a spherical surface to give wide angle scan capability much like that of a Luneberg lens antenna. The cavity model method is used to obtain the electric field at the edge of the radiating patch. Then, the radiation field may be evaluated from the edge field for a given excitation current. A spherical-rectangular microstrip structure is studied. The study is based on the assumption that the thickness of the dielectric layer is much smaller than the radius of the ground sphere. Then, the radiation frequency for single mode radiation is defined and the radiation patterns for typical spherical-rectangular microstrip antennas are presented.
TL;DR: In this article, a theoretical analysis of circular microstrip antenna on a ferrimagnetic substrate predicts significantly reduced resonant radii and improved bandwidth as compared to those of similar antennas built on purely dielectric substrates, when operated in the lower range of UHF.
Abstract: A theoretical analysis of circular microstrip antenna on a ferrimagnetic substrate predicts significantly reduced resonant radii and improved bandwidth as compared to those of similar antennas built on purely dielectric substrates, when operated in the lower range of UHF. The impedance characteristics, return loss, and radiation pattern studied experimentally for antennas built upon a typical ferrite substrate are found to be in good agreement qualitatively with the theoretical results.
Patent•
12 Apr 1983TL;DR: In this article, a microstrip array antenna, including spaced radiator elements supplied with microwave power, is separated from an underlying ground reference plane by a layer of dielectric material, in which the antenna beam is phase scanned by periodically closing switching devices connected between the reference plane and at least one null point of each radiator element.
Abstract: A microstrip array antenna, including spaced radiator elements supplied w microwave power and separated from an underlying ground reference plane by a layer of dielectric material, in which the antenna beam is phase scanned by periodically closing switching devices connected between the reference plane and at least one null point of each radiator element. In one embodiment, the radiator elements are identical rectangular patches disposed along a path, each patch having a length parallel to the path of one-half wavelength and a width transverse to the path not exceeding one wavelength in the underlying dielectric material at the antenna operating frequency. The patches are connected in series to receive microwave power by conductive strip elements whose widths are selected to effect a desired distribution of radiated microwave power from the patches.
Patent•
05 May 1983TL;DR: In this paper, a compact and integrated high-gain radar augmented system, including a cylindrical microstrip receive antenna mounted on a cylinder for providing nominal omni-directional coverage, is presented.
Abstract: A compact and integrated high-gain radar augmented system, including: a cylindrical microstrip receive antenna mounted on a cylinder for providing nominal omni-directional coverage, a transmit antenna similar to the receive antenna mounted on the same cylinder, isolating radio-frequency (RF) absorbing means located between the two antennas, and a high-gain amplifier located within the body of the cylinder and connected to the two antennas. The entire assembly can be covered by an RF radome for component protection.
TL;DR: In this paper, the variation of voltage standing-wave ratio (VSWR) with frequency for microstrip antennas on stepped and wedge-shaped dielectric-substrates is measured for a band of frequencies, and is compared with those of an equivalent rectangular microstrip resonator.
Abstract: The variation of voltage standing-wave ratio (VSWR) with frequency for microstrip antennas on stepped and wedge-shaped dielectric-substrates is measured for a band of frequencies, and is compared with those of an equivalent rectangular microstrip resonator. The results indicate a considerable improvement in bandwidth.
23 May 1983