Abstract: Between a circular conductor plate and a grounding conductor plate, lumped constant elements such as coils and capacitors are connected. As a result, the resonance frequency of an antenna can be changed in a wide range.

Abstract: A circularly polarized antenna including first and second multiple patch antenna structures dimensioned to operate at two distinct frequencies, each antenna structure consisting of four shorted patches, the patches of the first structure being spaced from a ground plane by dielectric material, the patches of the second structure being spaced from the patches of the first structure by dielectric material, the patches of the second structure each overlying a corresponding patch of the first structure and each having a dimension .lambda..sub.m.sup.(2) /4 which is less than the dimension .lambda..sub.m.sup.(1) /4 of the corresponding patch of the first structure, with feed means for each of the patches, the patches of both structures being disposed in the planes of the patches so that the radiating edges of the two patch structures form superimposed antenna structures.

Abstract: An antenna system for mounting on a glass plate with a radiator extending from one side of the glass plate and with an electrical connector and a cable extending from the opposite side of the glass plate whereby energy is transferred through the glass plate. Coupling means for a cable is provided, defining a receptacle for retaining the coupled end of the coaxial cable at an angle of essentially 15 to 60 degrees to said glass plate in said mounted position. Also, the antenna may define a helical base portion which may be attached to the glass plate on the side opposite to the coupling means. The helical base serves to shorten the antenna, and also to simultaneously serve as an electrical phase cancelling coil. Additionally, improvements are disclosed in the design of field cancelling conductors used.

Abstract: The antenna is adapted to be connected to a coaxial cable and includes a dielectric carrier board and a radiating element undulating longitudinally of the carrier board. The carrier board and radiating element are disposed in a conductive channel which has side walls adjacent the side edges of the carrier board. An input transition means is provided between the center conductor of the coaxial connector and the undulating track to provide a transition from the impedance of the coaxial cable to the impedance of the radiating element of the sandwich-wire antenna. When the antenna may, or may not, be connected to a coaxial cable, the side walls extend above the carrier board for such a height that the radiating aperture, which comprises the gap between the top edges of the side walls, presents a resistive load in the plane of the radiating element.

Abstract: An antenna element including a microstrip radiating element having a microstrip feed line and a ground plane on opposite sides of a substrate, with at least one of a plurality as resonators on the same side of the substrate as the microstrip feed line, and a dipole radiator having an increased bandwidth and insulated from the feed line and from the plurality of resonators.

Abstract: A patch-type antenna is disclosed for radiating electromagnetic radiation in the microwave band. The antenna comprises first and second electrically conductive plates which are supported in spaced-apart parallel relationship. The first plate serves as a ground plane, whereas the second plate forms a patch antenna element. A feed element supplies RF energy to the patch antenna without physically contacting it. This feed element is formed by an elongate, electrically conductive strip line arranged between the two plates and extending from one edge of the second plate to an interior point thereof. The length of this feed element, in its longitudinal direction, is approximately equal to one fourth of the wavelength of the EMR radiation by the antenna at the radio frequency applied thereto.

Abstract: A microstrip antenna system is comprised of either a single antenna element (patch) or a plurality of stacked antenna elements having one or more feedpins connected to a corresponding number of conductive elements (flags) capacitively coupled to the antenna element or elements. The one or more feedpins have an inductive reactance which is cancelled by trimmed flags to provide the capacitance necessary to cancel the inductance for tuning the one or more antennas and providing maximum gain and minimum VSWR.

Abstract: An antenna is disclosed which is particularly suitable for use with a cellular mobile phone. The antenna may be mounted on the rear window of a vehicle, and it includes a current fed one-quarter wavelength radiator adapted for mounting on one side of the window. An electrically conductive inner transfer member is mounted on the inside of the window in alignment with the radiator and a pair of spaced field-cancelling conductors are attached to the inside of the window and are spaced from the inner transfer member. The central conductor of an RF coaxial cable is coupled to the inner transfer member and the surrounding ground conductor of the coaxial cable is coupled to the field-cancelling conductors. In one embodiment, the one-quarter wavelength radiator comprises a pair of parallel, spaced radiator elements. RF energy is transferred through the vehicle window and the drilling of a hole for coupling the radiator to the coaxial cable is unnecessary.

Abstract: A circularly polarized microstrip antenna for microwaves has a two layer substrate with a first layer of dielectric material spaced above the ground plate by an air gap comprising the second layer of the substrate, so arranged that the effective dielectric constant of the substrate in the range of 1.25 to 1.4 (for an infinite ground plane) and 1.25 to 1.6 (for a finite ground plate).The preferred values of the effective dielectric constant are respectively 1.3 and 1.5 for the infinite and finite ground plane forms of the antenna.

Abstract: A monopole antenna is mounted on a ground plane and incorporates a radiating structure such as a disc or hollow cap parallel to the ground plane, for loading the antenna. An elevated feed is formed by a biconical central post between the radiating structure and the ground plane. Tuning is also accomplished by a partial or total circumferential dielectric (which may also function as a support) having an outer electrically conducting sheet spaced apart from the central post to provide shunt capacitance, and by outboard inductive posts which connect between the ground plane and the radiating structure to provide shunt inductance. Alternatively, additional tuning may be accomplished by a circuit between the upper and lower portions of the central post.

Abstract: A microstrip antenna having approximately an octave bandwidth comprises a planar radiating element disposed approximately coplanar with and in front of an upper ground plane and spaced above a lower ground plane at a distance equal to approximately one-tenth wavelength at the lowest operating frequency (one-quarter wavelength at the upper operating frequency). A thin dielectric layer is disposed on top of the upper ground plane which is coupled to the lower ground plane. The antenna, which is linearly polarized, is fed from the rear by a launcher that is approximately coplanar with the radiating element and mounted above the dielectric layer. Impedance matching means are provided for improved performance.

Abstract: A low profile antenna structure includes a substantially planar conductive sheet having a substantially planar conductive member extending from one end at a normal angle. A driven radiating element and a parasitic radiating element are disposed adjacent the conductive sheet. A feed point is coupled to the driven element for coupling RF energy to and from the antenna. Both the driven and the parasitic elements are approximately one quarter wavelength long and are approximately parallel to one another and are situated approximately 1/20th of a wavelength apart.

Abstract: An antenna structure includes a radiator element secured at one end to a ground plane. Two conducting plates separated by an axial spacer are secured to the opposite end of the radiator element.

Abstract: A low profile antenna is provided which includes a counterpoise above which are situated three parallel oriented L-shaped elements. Each of the elements includes leg and foot portions. One common end of the leg portions of the elements are electrically coupled together and to an antenna trimming stub. The remaining end of the middle element constitutes the feedpoint of the antenna together with the remaining ends of the other two elements. The dimensions of the counterpoise top surface are selected to be substantially less than one wavelength at the desired operating frequency of the antenna. In this manner, the antenna generates or is responsive to radio frequency waves exhibiting two polarizations.

Abstract: A relatively short broad band monopole coaxial antenna is provided with a center conductor and an outer radiator. The antenna is mounted above a ground plane and comprises a bare outer radiator portion adjacent the ground plane and a portion remote from the ground plane which is covered with a variable thickness microwave absorbent material. The signal to be transmitted is applied to the base of the monopole antenna adjacent the ground plane. Non-radiated signals propagate up the antenna. The high frequency components are absorbed by the microwave absorbing material. A tip matching network and a base matching network are coupled between the outer conductor and the ground plane for attenuating and matching the low frequency components of the non-radiated signals. The resulting monopole coaxial antenna has no undesirable reflections and has the appearance of infinite effective length antenna.

Abstract: There is provided a new and useful radio antenna comprising a mast; a pair of radiating elements mounted on the mast, and being oriented in a plane, and having one end of one element adjacent to one end of the second element; a coaxial feeder the outer conductor of which is joined to the first element of the pair at approximately the midpoint of the first element and having its center conductor extending to a predetermined feedpoint on the second element, this predetermined point being that at which the center conductor will be substantially impedance matched with the antenna; and, wherein the spacing of the gap between the adjacent ends of the first and second elements is such that the elements are fed by the feedpoint across the gap to provide a matched output of the pair of elements having the desired beam tilt.This application relates to radio wave transmission and reception antennas.

Abstract: A microstrip antenna with a linearly polarized radiating patch is varied in resonant frequency by an electronic tuning technique. A dc bias voltage is combined with the excitation signal to regulate the capacitance of a varactor diode mounted in the antenna structure. In one embodiment the varactor is in shunt with a half wave open circuited radiator and adds electrical length to the antenna, while in another embodiment the varactor is in series with a shorted quarter wave radiator and subtracts electrical length therefrom.

Abstract: A broadband antenna in either the monopole or dipole configuration has an impedance broadbanding potentiality superior to those of known broadband antennas such as the triangular, helical and log-periodic antennas. Compared with the forementioned antennas in corresponding operating frequency ranges (expressed by the ratio of maximum to minimum frequency), the `Elliptic sheet antenna` has the merits of: (i) markedly lower variation of input resistance (R.sub.in) as expressed by the ratio of maximum-to-minimum of R.sub.in, (ii) markedly lower values of input reactance (X.sub.in) and lower reactive content in the impedance, as expressed by the ratio .vertline.X.sub.in .vertline./.vertline.Z.sub.in .vertline.

Abstract: A monopole antenna or the like including a sleeve antenna and a stub antenna having means for decoupling the antenna from surrounding electrically conductive elements. Such elements may consist, for example, of the conductive skin of an aircraft and, typically, of other antennas mounted on this skin, or they may comprise conductive portions of a ship. In order to provide the decoupling, a radial transmission line is disposed at the base of the antenna and concentric with the coaxial transmission line used to excite the antenna. The radial transmission line includes an upper and a lower electrically conductive plate, each having a small central opening and means for electrically interconnecting the plates about the opening. The antenna may be fed by a coaxial transmission line extending through the conductive element and the central opening. The inner conductor of the coaxial transmission line may extend beyond the radial transmission line to form a monopole antenna.

Abstract: A communications antenna is disclosed having improved mechanical strength, gain and reduced lateral dimensions. The antenna includes a three quarter wave length vertically disposed elongated radiating element and a plurality of one-quarter wave length diverging elements connected at their bottom end to the bottom of the vertical radiator. The diverging elements flare upwardly and outwardly from the radiator at an acute angle, typically between about five degrees and about thirty degrees. The band width of the antenna may be broadened by interconnecting the free ends of the diverging elements such as by a conductive hoop.

Abstract: Disclosed is a multiple band antenna assembly for communicating electromagnetic radiation. An antenna element stack is constructed of a plurality of elliptical lamina antenna elements mutually separated by layers of dielectric material, and separated from a ground plane by dielectric material. The antenna assembly is coupled through a feed line in contact with the top antenna element. A conductor joins the remaining antenna elements to the ground plane. Each individual antenna element is operable for communication reception and transmission within a frequency band determined by the size of the particular antenna element. The antenna elements are arranged in order of decreasing size with the largest antenna element closest to the ground plane. The sizes of the antenna elements may be selected to provide electromagnetic radiation communication over several distinct frequency bands, or to connect the individual bands into a broad band.

Abstract: Vertical antenna including a vertical radiator having a height of three-half wavelengths, a cancellation stub electrically connected to the vertical radiator three-quarters wavelength upward from a feed point at the base of the vertical radiator and extending downwardly one-quarter wavelength and upwardly one-half wavelength from the electrical connecting point of the vertical radiator, an insulation member mounted in a mounting post and supporting the base of the vertical radiator, quarter wavelength radials extending outwardly in the same plane and at right angles to the vertical radiator from the mounting post, and a transmission line connected between the feed point at the base of the vertical radiator and the radials. The gain of the vertical antenna is theoretically 3.2 db over a half wavelength dipole antenna. The vertical antenna is particularly lended to operation in the VHF spectrum and above.

Abstract: An omnidirectional, vertically polarized antenna having a lower, 1/4 wavelength skirt made up of circumferentially-spaced arms which extend down from the lower end of a vertical, 1/4 wavelength, upper radiator at an angle between 12 degrees and 25 degrees, and preferably 17 degrees. The upper radiator carries a multi-spoke capacity "hat" to increase its electrical length.

Abstract: An electrically small, microstrip radiator designed for small-diameter mile applications. The preferred embodiment comprises a cylindrical tube of epoxy fiberglass dielectric having a spiral conducting strip formed thereon. The tubular construction permits the antenna to be conformally mounted to the surface of the missile. RF input coupling may be achieved by an inductive post, and high radiation efficiency is obtained by strongly coupling RF currents to the body of the missile and exciting the dipolar mode of radiation. The design includes means for mechanically tuning the antenna over a narrow frequency range. The resultant spiral-slot antenna produces an axially polarized radiation field and a dipole radiation pattern with isotropic gain in a low cost and rugged construction.

Abstract: A microstrip antenna design according to which a plurality of resonant frencies can be obtained for a given size radiator, to increase the usefulness of the antenna by providing for frequency diversity operation and by making the microstrip antenna tunable over a range of frequencies. As will be seen, the microstrip antenna is provided with an output termination which can be open-circuited or short-circuited, and at varying lengths, to change the frequency at which the microstrip antenna can be made resonant.

Abstract: A corner fed electric microstrip dipole antenna consisting of a thin eleccally conducting, square shaped radiating element formed on one surface of a dielectric substrate, the ground plane being on the opposite surface. The feed point is located at one corner of the antenna element and the input impedance is matched with a matching microstrip transmission feed line connected to the corner of the antenna. The sides of the radiating element are all equal. The length of the element determines the resonant frequency along the Y axis and the width determines the resonant frequency along the Z axis. This antenna is capable of generating elliptical and circular polarized radiation when reactively loaded using a single element and single feed point.

Abstract: An antenna including a conductive support for supporting a plurality of radiating elements in line next to one another above the conductive support and transmission lines serially connecting the radiating elements. The radiating elements of the loop or helix type with a turn length of substantially one wavelength at the operating frequency and configured to support the equivalent of a ring of current with a traveling wave to radiate circularly polarized radiation.

Abstract: The configuration consists of two antennae on the same mast. The upper anna is a ground plane capable of two frequency bands of operation. The lower antenna comprises a sleeve and radial elements.The upper antenna consists of four radials 36" long and an upper element. The two bands of operation covered by the upper antenna are 80 MHz and 150 MHz. Band selection is accomplished by selection of the correct upper mast element. This element is removable. A 34" long element is used for 80 MHz operation and a 14" long element for 150 MHz operation. This antenna is nondirectional and is used for transmitting.The lower antenna consists of four radials 22" long and an upper and lower sleeve. The radials are insulated from the mast and connected to the center conductor of the coax. The upper sleeve is a portion of this antenna and also isolates the antenna from the mast. The only use of the lower sleeve is to provide isolation of the antenna from the mast and coaxial cable.

Abstract: Circularly polarized microstrip antennas consisting of thin electrically ducting, square-shaped radiating elements formed on one surface of a dielectric substrate and having a ground plane on the opposite surface of the substrate. Two feed points are used to provide a circular polarized radiation pattern. The feed points are located along the centerlines of the antenna length and width or along the diagonal lines of the element and the input impedances can be varied by moving the feed points along both centerlines or both diagonal lines from the centerpoint of the element. The antennas can be notched in from the edges of the radiating element along the centerlines of the element width and length, or along opposite diagonal lines of the element, to the optimum input impedance match feed point.

Abstract: Circularly polarized microstrip antennas consisting of thin electrically ducting, square-shaped radiating elements formed on one surface of a dielectric substrate and having a ground plane on the opposite surface of the substrate. Two feed points are used to provide a circular polarized radiation pattern. The feed points are located along the centerlines of the antenna length and width or along the diagonal lines of the element and the input impedances can be varied by moving the feed points along both centerlines or both diagonal lines from the centerpoint of the element. The antennas can be notched in from the edges of the radiating element along the centerlines of the element width and length, or along opposite diagonal lines of the element, to the optimum input impedance match feed point.

Abstract: Circularly polarized microstrip antennas consisting of thin electrically ducting, square-shaped radiating elements formed on one surface of a dielectric substrate and having a ground plane on the opposite surface of the substrate. Two feed points are used to provide a circular polarized radiation pattern. The feed points are located along the centerlines of the antenna length and width or along the diagonal lines of the element and the input impedances can be varied by moving the feed points along both centerlines or both diagonal lines from the centerpoint of the element. The antennas can be notched in from the edges of the radiating element along the centerlines of the element width and length, or along opposite diagonal lines of the element, to the optimum input impedance match feed point.

Abstract: A disc antenna which consists of a conductor ground plate and a conductor disc provided in parallel to it, signals of a desired frequency being fed between one point on the conductor disc and the point opposite to it on the conductor ground plate and a point on said conductor disc other than said feeding point on the conductor disc being grounded, so as to radiate non-directional electric waves from the space between said conductor disc and conductor ground plate.

Abstract: A new type of radiating structure with rugged high frequency design comprng essentially a single hybrid monopole which utilizes capacitive coupling from a open-ended transmission line to accomplish its broadband characteristics. The monopole is a metal conductor concentric with the transmission line and is separated from a ground plane by an adjustable gap that may be effectively used for fine tuning the antenna. By utilizing helical springs as the conductors this hybrid monopole antenna has self-erecting or pop-up design capability.

Abstract: An electrically small antenna designed for operation in the 25 to 50 megatz frequency range which may be constructed in two basic forms. The first embodiment comprises a conductive coil in the form of a copper ribbon that is electroless-plated on a thin cylindrical silicone fiberglass substrate which is loaded with a ferrite core. The loaded coil assembly comprises a radiating element that operates over a metal ground plane. The second embodiment comprises a coiled ribbon conductor which is electroless copper plated directly on a cylindrical ferrite rod surface. The latter embodiment provides closer coupling of the magnetic field into the ferrite. Each embodiment preferably utilizes variable input and output capacitors which are respectively coupled to a source of RF power and to the ground plane.

Abstract: First and second elements mounted in parallel spaced apart relation with one end shorted to form a quarterwave transmission line at a base frequency and a halfwave transmission line at an even harmonic thereof, with the spacing being .lambda./8 at the base frequency and .lambda./4 at the harmonic and a feedline being connected between the elements and positioned so the impedance of the antenna matches the impedance of the feedline at the base frequency and the diameter of the feedline being adjusted so the impedance of the antenna matches the impedance of the feedline at the harmonic frequency.

Abstract: An offset FED magnetic 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 with the radiating element shorted to the ground plane. 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.

Abstract: Circularly polarized microstrip antennas consisting of thin electrically ducting, square-shaped radiating elements formed on one surface of a dielectric substrate and having a ground plane on the opposite surface of the substrate. Two feed points are used to provide a circular polarized radiation pattern. The feed points are located along the centerlines of the antenna length and width or along the diagonal lines of the element and the input impedances can be varied by moving the feed points along both centerlines or both diagonal lines from the centerpoint of the element. The antennas can be notched in from the edges of the radiating element along the centerlines of the element width and length, or along opposite diagonal lines of the element, to the optimum input impedance match feed point.

Abstract: A cavity antenna having an aperture which may be mounted flush to the gro plane. A chamber positioned above a rectangular resonant cavity allows the antenna to achieve normal bandwidth and normal gain with a very thin cavity depth.

Abstract: A notched/diagonally fed electric microstrip dipole antenna consisting of a hin 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 in a notch 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.

Abstract: Constructions for radio antennae, whose size is made appreciably less than the size of conventional antennae by using the dielectric properties of a mixture of barium titanate and strontium titanate.

Abstract: A wide relative frequency band and reduced size-to-wavelength ratio antenna comprising essentially a first part in the form of a conductor ring and a second part in the form of a skirt respectively connected to the central and outer conductors of a coaxial feeder. The first part has a conductive path in the form of a circumference and one of its diameters; the central conductor of the feeder is connected to the mid-point of the said diameter. The second part is in the form of a skirt and has a conductive path formed by a circular ring connected to one of the ends of each one of a plurality of conducting strands having the form of broken lines inscribed in isosceles trapezoid forming an assembly defining the faces of a frusto-pyramid, while an annular and conical end member is connected to the feeder outer conductor and is in contact with the other ends of the strands.

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.

Abstract: The invention relates to an antenna structure comprising a number of parallel conductors having dimensions and spacings which are small against operating wavelength, and positioned perpendicular to a conducting ground plane; the upper ends of the conductors are terminated by metal plates acting as capacitors against the ground plane, and interconnected by inductive elements, the lower ends of some of said conductors are electrically connected to said ground plane, while another one of these conductors is connected to a power source to impress a voltage between the lower end of said other conductor and said ground plane.

Abstract: At least one but preferably two shorted transmission line antenna sections, ach comprised of a vertical member shorting a horizontal printed circuit transmission line member to a ground plane with the transmission lines being adjustable in length for tuning by utilization of a flexible braid transmission line member connected between the printed circuit transmission line member and a take-up spindle which is adapted to be rotated and accordingly wind or unwind the braid member thereon. The feed point is at the connection of a pair of fixed capacitors, one of which is connected to ground plane while the other is connected to the take-up spindle.

Abstract: A double omni-directional antenna for use with a transponder is disclosed allowing simultaneous operation within two different frequency bands. A double coaxial line is provided having outer, central, and inner concentric conductors. The outer and central conductors form a coaxial feed for a lower frequency antenna and the central and inner connectors form a coaxial feed for a high frequency antenna. The higher frequency antenna is located directly above the lower frequency antenna and each is either a unipole for vertically polarized radiation or a slot radiator for horizontally polarized radiation.

Abstract: An inductive, internally fed, ferrite-loaded antenna mounted at the geomecal center of a helicopter. The antenna is capable of transmitting in the 2-30 MHZ range with particularly good characteristics between 2.0-3.5 MHZ and employs the air frame as a radiating element. The radiation pattern is circular and extends for a radius greater than 200 mi. at an altitude of 300 feet.