Showing papers on "Patch antenna published in 1975"

Microstrip Excitation of Magnetostatic Surface Waves: Theory and Experiment

Abstract: A model is developed for excitation of magnetostatic surface waves (MSSW) with microstrip transmission lines. Energy carried away in MSSW propagating perpendicular to the microstrip is related to electromagnetic (EM) energy propagating along the microstrip line by an equivalent radiation resistance. Supporting experimental results are in excellent agreement with predictions derived from this model.

Microstrip-dipole antenna elements and arrays thereof

Abstract: Herein disclosed are antenna elements comprised of a dipole reactively coupled to a feed line on a microstrip board; and linearly and circularly polarized arrays of such elements.

Multiple resonance radio frequency microstrip antenna structure

Abstract: A multiple resonance microstrip antenna radiator which includes a plurality of stacked electrically conductive element surfaces disposed above an electrically conductive reference surface with each element surface dimensioned so as to resonate at a different radio frequency. The various element surfaces are spaced one from another and from the reference surface with a dielectric material and an rf feed is attached to at least one of the element surfaces. Non-resonant element surfaces provide inductive capacitive coupling of rf energy to/from a resonant element surface.

Asymmetrically fed electric microstrip dipole antenna

Abstract: An asymmetrically fed electric microstrip dipole antenna consisting of a n electrically conducting, rectangular-shaped element formed on one surface of a dielectric substrate, the ground plane being on the opposite surface The length of the element determines the resonant frequency The feed point is located along the centerline of the antenna length and the input impedance can be varied by moving the feed point along the centerline from the center point to the end of the antenna without affecting the radiation pattern The antenna bandwidth increases with the width of the element and spacing between the element and ground plane

Dual frequency microstrip antenna structure

Abstract: A conformal microstrip antenna structure formed by a plurality of separated spaced-apart electrically conducting elements on a dielectric substrate overlying a ground plane. The innermost edges of the separated conducting elements define two sets of two intersecting radiators which are fed by microstrip transmission circuits disposed within the space between the separated conducting elements to individually feed the various radiators and/or segments thereof from the common feed point. The dimensions of the conducting elements also determine the resonant frequency of the radiators and their relative phases such that dual frequency operation as well as circular and/or elliptical polarization of the received/transmitted electromagnetic radiation can be conveniently achieved.

Notch fed electric microstrip dipole antenna

Abstract: A notch fed electric microstrip dipole antenna consisting of a thin electally conducting, rectangular-shaped element formed on one surface of a dielectric substrate, the ground plane being on the opposite surface. The length of the element determines the resonant frequency. The feed point is located in a notch along the centerline of the antenna length and the input impedance can be varied by moving the feed point along the centerline of the antenna without affecting the radiation pattern. Of all the many types of microstrip antennas built to date, this antenna offers the best advantages as far as arraying of the elements are concerned. The notched antenna can be arrayed using microstrip interconnecting transmission lines. The corner losses in the clad material and the width of the notch determines how narrow the element can be made. The purpose of the notch feed system is to interconnect any array of elements at the elements' optimum feed point using microstrip transmission lines.

Analysis of the log-periodic V-dipole antenna

Abstract: The log-periodic V-dipole antenna (LPVA) operating in the 3\lambda/2 mode is analyzed numerically using the projective technique. The antenna is treated as a parallel connection of an array of V-dipoles and a feeder transmission line. This decoupling of the circuits enables one to obtain the dipole currents simply by considering the array of V-dipoles as a boundary value problem and solving the necessary integral equations. The currents can then be used to give the various properties of the antenna. Effects on the antenna behavior obtained by changing its parameters are illustrated, and general characteristic curves presented.

Low-profile quadrature-plate UHF antenna

Abstract: A low-profile UHF antenna comprises two orthogonally positioned parallel te radiators that are semi-circular in shape. The base of each radiator (filled with dielectric material) is connected to a circular metal ground plane. The radiators can be collectively excited with a single input feed or they can be independently excited in any phase relationship for changing direction or polarization of the radiation field. Thus, the antenna is capable of operating in either a linear or circular polarization mode. The antenna can also be switched rapidly from one linear polarization to a second linear polarization in a perpendicular plane by using techniques familiar to the art.

New Design Techniques for Microstrip Antenna Arrays

Abstract: The radiation resistance of an open-circuit microstrip termination is to a good approximation, a simple function of the strip width thus suggesting a straightforward yet effective means of element control when used in a large array; furthermore the array bandwidth can be controlled to some extent. The design of linear and two dimensional resonant arrays based on this design procedure is formulated and examples at X and J band are outlined; the beamwidths and sidelobe levels are of the order ± 4.5° and -16dB respectively. The extension of the new technique to travelling wave arrays, circular polarisation and various substrates is under investigation and will be mentioned; computational aspects throughout will be discussed.

Windshield antenna system with resonant element and cooperating resonant conductive edge

Abstract: An antenna system responsive to both the E and H fields in a radiated electromagnetic signal relies upon the placement within the influence of a conductive edge formed by an opening in a closed conductive body of an element having an effective electrical length which approximates a resonant length in free space in the intended range of operating frequencies for the antenna.

Dual slot microstrip antenna device

Abstract: A dual slot antenna assembly is disclosed herein and generally includes a pair of concentrically positioned and radially spaced cylindrical conductors defining a pair of circumferential slots which are longitudinally spaced one-half wavelength apart at the anticipated operating frequency of the antenna device. An electrical signal feed assembly is connected with the conductors for exciting the slots so as to provide overlapping radiation patterns emanating in the same direction.

Diagonally fed electric microstrip dipole antenna

Abstract: A diagonally fed electric microstrip dipole antenna consisting of a thin ctrically conducting, rectangular-shaped element formed on one surface of a dielectric substrate, the ground plane being on the opposite surface. The length of the element determines the resonant frequency. The feed point is located along the diagonal with respect to the antenna length and width, and the input impedance can be varied to match any source impedance by moving the feed point along the diagonal line of the antenna without affecting the radiation pattern. The antenna bandwidth increases with the width of the element and spacing between the element and ground plane. Singularly fed circular polarization is easily obtained with this antenna.

The Microstrip Double-Ring Resonator (Short Papers)

Abstract: The resonance frequencies and the fields of a microstrip double-ring resonator are discussed. It is shown that no pure even or odd mode can be excited on the resonator. Therefore it is concluded that the rnicrostrip double-ring resonator principally cannot be used to measure the phase velocities of the even and the odd modes on a coupled microstrip line.

End fed electric microstrip quadrupole antenna

Abstract: An end fed electric microstrip quadrupole antenna consisting of a thin elrically conducting, rectangular-shaped element formed on one surface of a dielectric substrate, the ground plane being on the opposite surface. The feed point is located at one end of the centerline of the antenna length. The antenna bandwidth increases with the width of the element and spacing between the element and ground plane. The end fed microstrip quadrupole antenna operates in a degenerate mode, i.e., two oscillation modes occurring at the same frequency. Along the element length, the oscillation occurs in a dipole mode (fundamental mode) whereas along the element width the oscillation occurs in a quadrupole mode (higher order mode). The corners nearest the feed point may be used for fine tuning of the antenna by trimming small strips of copper from the corner.

Resonant ring transmission line having a high Q mode

Abstract: A resonant ring transmission line capable of exhibiting a Q greater than 6000 at 4.3 gigahertz and a transmission line loss of less than 1 db per kilometer. This is accomplished by means of a resonant ring transmission line coupled to a microstrip transmission line and which resonates in the surface wave mode so that a very pure surface wave mode is created and caused to propagate along the resonant ring transmission line.

Tubular strain energy deployable linear element antenna with stitched wire conductors

Abstract: A relatively low frequency linear element antenna characterized by its lightweight construction, relatively wide band width, and elastic strain energy deployment capability. The antenna has a plurality of slender electrical conductors such as wires forming radiating elements secured to a supporting tube with the conductors extending lengthwise of and spaced about the tube wall and electrically joined at the base end of the tube in such a way that the antenna has the same radiation characteristic as a conventional cylindrical antenna of the same diameter as the tube. The base ends of the conductors are gathered for connection to the center conductor of a coaxial antenna feed line to provide an impedance match between the antenna and coaxial line. The antenna supporting tube may comprise a thin-walled, resiliently flexible, strain energy deployable tube to permit contraction of the antenna to a folded or coiled packaged configuration and antenna deployment by elastic strain energy stored in the contracted tube.

Offset fed electric microstrip dipole antenna

Abstract: An offset fed electric microstrip dipole antenna consisting of a thin eleically conducting, element formed on one surface of a dielectric substrate, the ground plane being on the opposite surface. The length of the element determines the resonant frequency. The feed point is located along one edge of the antenna length and the input impedance can be varied by moving the feed point along the edge of the antenna to obtain optimum match for the resonant mode without affecting the radiation pattern. The antenna bandwidth increases with the width of the element and spacing between the element and ground plane. Slanting one end of the element will provide a slightly wider bandwidth.

Customized antenna with insertable antenna elements

Abstract: An antenna primarily for receiving electromagnetic signals and for converting the same to electrical signals for input to a television, FM receiver, or the like, is readily adapted for customizing for maximum efficiency in signal reception at close, normal, and fringe areas relative to the broadcasting antenna. The customized antenna may include elongated generally tubular elements of different sizes, bow tie-shape reflector elements, and/or relatively flat elements, all of which are readily mounted on a support structure that may be attached to an interior or exterior wall, a conventional antenna mast, or the like. Moreover, various ones of the longitudinal elements may be electrically coupled by a conductive harness, and the transmission line leads may be adjustably connected to respective ones of the longitudinal elements. Further, the support structure may include a decorative panel behind which the various signal receiving elements are mounted.

Characteristics and Applications of Coupled Microstrip Lines

Abstract: A genarl formation extending conventional Kirchhoff's Line theory appears to be a convenient tool for defining the main characteries of coupled lines and for studying various applications.

Method for forming a high frequency antenna

Abstract: A method for forming a high frequency antenna such as a horn-reflector antenna. In fabricating the horn antenna a mold may be used which comprises a paraboloid-cylindrical section and a pair of half cone shells for forming respectively the paraboloid-cylindrical portion and the cone portion of the antenna. In assembling the mold, the shells are secured together and then the cylindrical section is fastened to the assembled shells. After the antenna has been formed, the mold is disassembled by first removing the paraboloid-cylindrical section, thereafter removing one of the shells and then the remaining shell; and all such mold parts being removed via the radiating aperture of the paraboloid-cylindrical portion of the antenna.

An Experimental Investigation of the T-Bar Fed Slot Antenna on Planar and Cylindrical Surfaces

Abstract: : The report describes the results of an intensive experimental effort directed toward the electrical improvement and size reduction of slot antennas In particular, the T-bar fed cavity backed slot antenna mounted on both a planar surface and also transversely mounted on a circular cylinder are investigated over the four to one frequency bandwidth of 500 to 2000 MHz

Measurement of the Zo of Microstrip Lines

Abstract: Expressions for the calculation of characteristic impedance and phase constant are derived from the scattering matrix coefficients for the coaxial line microstrip transmission. A simple technique is used for connecting the microstrip under test to the coaxial system on which measurements are made. A variable open circuit method is adopted for obtaining the scattering matrix co-efficients of the transmissions. Measurements on narrow ‘microstrip’ lines are presented with polystyrene as the dielectric substrate.