Abstract: A mode transformer for a waveguide and microstrip lines capable of obtaining sufficient cross polarization isolation and a receiving converter comprising the same is provided. Transformers of horizontal and vertical polarized waves comprise orthogonal first and second microstrip lines and a circular waveguide. By placing a metal bar connected to the waveguide between the first and second microstrip lines, the metal bar has the ground potential which is the same as the potential of the circular input waveguide and the electric fields excited in the first and second microstrip lines have a polarity that move toward the direction of the metal bar, so that electric field coupling of the first and second microstrip lines may be avoided.

Abstract: An antenna module capable of finely adjusting the resonant frequency and having an antenna element exclusively used for radio transmission and reception to provide a broad frequency band characteristic. This antenna module is composed of a dielectric substrate molded in a predetermined shape, a grounding conductor in the form of sheet provided on one surface of the dielectric substrate, and antenna element conductor in the form of sheet provided on the opposite surface to the above one surface and having end portion being almost V-shaped end folded, and an adjusting member inserted into the almost V-shaped folded end portion.

Abstract: An antenna unit whose resonance frequency is switchable, the antenna unit including an antenna body (11) having a distributed inductance component (L.sub.1), an impedance adjusting inductance component (L.sub.1) and a capacitance (C.sub.1) provided between the same and the ground potential, and a capacitor (C.sub.2) and a diode (D.sub.1) being connected in parallel with the capacitance (C.sub.1) and in series with each other, so that a voltage for bringing the diode (D.sub.1) into an ON or OFF state is applied to a node (16) between the capacitor (C.sub.2) and the diode (D.sub.1), thereby switching the resonance frequency of the antenna unit by switching ON and OFF states of the diode (D.sub.1).

Abstract: A bandwidth-enhanced antenna system for operating on one of a plurality of selected frequency bands includes a whip or wire antenna element having band selection wires and a contiguous set of inductors arranged in series, each of the inductors being sufficiently separated from one another and being arranged such that the resonant frequency of any of said inductors is greater than the highest operating frequency of the plurality of frequency bands. Selector means is included provide a band select signal, and a plurality of switches each having a first terminal connected to a corresponding one of the inductors and a second terminal connected to the feed-end of the antenna element. The switches are responsive to the bandwidth select signal to allow communication using a selected one of the plurality of the frequency bands. An impedance matching network may be used for coupling an external receiver or transmitter to the feed-end of the antenna element.

Abstract: A switching device for adjusting the impedance of a self-inductance (3) forming part for example of the radiator of a VHF/UHF antenna for aircraft switchable by short-circuiting a part of the self-inductance. A PIN diode (12) is raised to a blocking or a transmitting voltage in response to control signals which are transmitted thereto by an optical link (8). Preferably the optical signals are transmitted to a hybrid opto-electronic circuit, which renders the PIN diode operative in conjunction with insulated conductors (11, 13) plated on the self-inductance and raised to the desired voltage.

Abstract: 12 and 17 meter adapter assemblies for a vertical antenna which includes an air wound inductance coil and winged capacitor straps. The adapter assemblies include a coil and wing capacitor straps at one end of the coil where the one end of each coil connects to the antenna and the other end of each coil, including the wing capacitor straps, mechanically connects to the antenna and is electrically insulated from the antenna.

Abstract: A monopole inductively loaded antenna system is disclosed in which the antenna system is tuned to resonance and impedance matched without making changes to the loading inductance or other antenna elements. The monopole inductively loaded antenna is supported by a base insulator having an antenna side and ground plane side. A variable capacitor is positioned on the ground plane side of the base feed insulator for tuning the antenna system to resonance. One of a plurality of impedance matching transformers is selectively switched into the antenna system to match the antenna load to the transmitter.

Abstract: A bar-type antenna unit is installed at a normally non-visible point on the lower side of a vehicle body. The unit includes an antenna element, a metal plate, and noise shielding means. The metal plate functions to adjust the reactance of the antenna to obtain a desired sensitivity and protects the antenna from water, mud, or snow splashed from the vehicle's wheels to ensure good insulation between the vehicular body and the antenna element. By selecting capacitance of the metal plate, the length of the antenna can be shortened without reducing sensitivity of the unit. The shielding means shields the antenna from noise generated by for example an engine or electrical equipment which would otherwise interfere with radio broadcasts.

Abstract: An antenna comprising a radiating element, a tuning coil having a rod located coaxially within the coil and positionable along the longitudinal axis of the tuning coil, the rod having a wiper attached which urges against the internal surface of the coil and means for positioning the rod such that with the coil connected to a radiating element and the wiper connected to a radio frequency transceiver, tuning of the antenna can be effected by control of the positioning means to adjust the position of the wiper along the tuning coil.

Abstract: A short monopole RF antenna tuned over a predetermined RF frequency band in response to binary control signals includes a conductive tubular radiating element extending generally at right angles to a ground plane on which the antenna is mounted. A conductive top load inductively coupled to the element extends approximately parallel to the ground plane so that stray capacitance subsists between the ground plane and top load. The antenna is tuned in response to the control signals to a frequency in the band by selectively short-circuiting different plural series-connected inductors in proximity with the top load. Plural leads extend through the interior of the tubular element between a source of the control signals and switches for selectively short circuiting the inductors. The inductors are electrical conductors in a tube-like structure. The leads extend through the interior of the tube-like structure. Electrical conductors in the tube-like structure are in a return path to the control signal source.

Abstract: An antenna and its electronic circuit combination is presented to comprise a ground conductor plane 30, a radiating conductor plane 40 disposed in parallel spaced relation to the ground plane 30 and shorted at its one end to the ground plane 30. A ground plane 30 is preferably formed on a printed board 10 which is disposed in parallel relation to the radiating plane 40 to define therebetween an open air space. Mounted on the printed board 10 and received within the open air space are electronic components which form a receiving or transmitting electronic circuit 60 associated with the antenna structure and electrically coupled by means of a feed element 20 to a feed point 44 on the radiating plane 40.

Abstract: A transmitting and receiving radio frequency antenna of arcuate shape, serving as a radio frequency radiator of wave lengths between about 2 meters to about 160 meters. A tuning and loading coil is connected to one end of said antenna for tuning and matching said arcuate radiator. A capacitance is connected at the other, coupling to ground. Advantage of vertical and horizontal polarization is obtained.

Abstract: A ten-band vertical antenna includes completely automatic band switching for the amateur radio frequencies of eighty, seventy-five meters, forty meters, thirty meters, twenty meters, seventeen meters, fifteen meters, twelve meters, ten meters and six meters. The vertical antenna has a low angle of radiation and a low standing wave ratio on all frequencies which provides for direct coaxial cable transmission line feed. The seventy-five-meter, a switchable eighty-meter, and forty-meter inductor-capacitors are in parallel, while the thirty-meter inductor-capacitor is in series with a portion of the forty-meter circuit thereby providing inductive reactance for operation on eighty meters, seventy-five meters, forty meters, and thirty meters with a series inductor-capacitor connected between an upper vertical radiating element and the forty-meter inductor while permitting simultaneous resonance on each of the three higher frequencies of twenty, fifteen and ten meters.

Abstract: A microwave patch antenna, comprising a substrate of high dielectric constant, an aperture in the substrate, a patch conductor positioned on one side of the conductor and juxtaposed over said aperture, a ground plane on the other side of the substrate and having an aperture juxtaposed to at least a substantial proportion of the patch conductor. A conductive cavity is RF-coupled to the ground plane at the aperture, the cavity extending away from the substrate and being short-circuited at its end remote therefrom; in the operating frequency range of the antenna, the cavity forms a waveguide constituting an inductance. The length of the cavity may be adjustable to tune the antenna, the length of the cavity being sufficient for the resonant frequency of the antenna to decrease with increasing cavity length.

Abstract: A three-wave common antenna for AM/FM and ultra high frequency waves combined in a single unit and mounted on vehicles including AM/FM antenna element mounted on a vehicle body at its base, a non-grounded type ultra high frequency antenna element disposed on top of the AM/FM antenna element such that the beam in a vertical plane thereof is close to the horizontal direction, a coaxial feeder cable for ultra high frequency which, along the AM/FM antenna element, is led into a vehicle body with one end thereof connected to the ultra high frequency antenna element, a characteristic compensating circuit connected to the AM/FM antenna element, and a feeder cable for AM/FM waves connected to the characteristic compensating circuit.

Abstract: This invention concerns an antenna switchable between the VHF and UHF frequency bands. This antenna incorporates a capacitive element, disposed at a specified distance from a reflecting surface mounted on the body of the vehicle. For VHF, tuning is obtained by a fixed self-inductance in parallel and a variable self-inductance in series with the capacitive element. The latter comprises various sections which can be short-circuited by switches. For UHF, the variable self-inductance is totally short-circuited and the fixed self-inductance is disconnected by a switch; then, plates form, with the reflecting surface and the capacitative element, a "manchette" antenna. This switchable antenna can in particular be mounted on an airplane.

Abstract: An eight-band vertical antenna which is omnidirectional and includes completely automatic band switching for the amateur radio frequencies of eighty/seventy-five meters, forty meters, thirty meters, twenty meters, seventeen meters, fifteen meters, twelve and ten meters. The vertical antenna has a low angle of radiation and a low standing wave ratio on all frequencies which provides for direct coaxial cable transmission line feed. The eighty-meter and forty-meter inductor-capacitors are in parallel while the thirty-meter inductor-capacitor is in series with a portion of the forty-meter circuit providing inductive reactance for operation on eighty/seventy-five meters, forty meters, and thirty meters with a series inductor-capacitor connected between an upper vertical radiating element and the forty-meter inductor while permitting simultaneous resonance on each of the three higher frequencies of twenty, fifteen and ten meters.

Abstract: Emitting and receiving antenna system for accommodating all bands and frequencies and for operating selectively adjustably in resonance at a given emitting or receiving frequency, formed by one antenna component or two counterpart antenna components, each component containing therewithin a variable inductor and a variable capacitor, a drive mechanism for shifting the shiftable inductor part relative to the fixed inductor part of each such inductor for varying the inductance and conjointly for shifting the shiftable capacitor part relative to the fixed capacitor part of each such capacitor for varying the capacitance, and a control mechanism for controlling the drive mechanism for selectively shifting the corresponding shiftable parts conjointly for achieving selective antenna resonance tuning at an exact point corresponding to the desired operating band and frequency, such as with the shiftable inductor part and shiftable capacitor part of each antenna component being connected together for common shifting mo

Abstract: A tuned radio antenna for a frequency agile communication system has a plurality of tuning inductors in series with a short-circuiting switch for each inductor, each switch being formed by a pair or a plurality of pairs of P.I.N. diodes, control means being provided for applying biasing potentials to the diodes to effect switching of the antenna tuning.

Abstract: An antenna suitable for use in the high frequency (HF) ranges includes a resonator tunable over a predetermined frequency band. The resonator consists of an insulated wire wound over a dielectric rod. Tuning is effected by sliding a metallic sleeve disposed in frictional contact over the wire. A multiplicity of these resonator units may be mounted on a single collar at different angles. Each of the resonator units will respond to a particular frequency. The remaining devices operate as a load on the antenna assembly. The antenna assembly may also be mounted on a conventional mobile antenna by means of an adaptor unit.

Abstract: A six-band vertical antenna which is omnidirectional and includes completely automatic band switching for the amateur radio frequencies of eighty/seventy-five meters, forty meters, thirty meters, twenty meters, fifteen meters, and ten meters. The vertical antenna has a low angle of radiation and a low standing wave ratio on all frequencies which provides for direct coaxial cable transmission line feed. The eighty-meter and forty-meter inductor-capacitors are in parallel while the thirty-meter inductor-capacitor is in series with a portion of the forty-meter circuit providing inductive reactance for operation on eighty-seventy-five meters, forty meters, and thirty meters with a series inductor capacitor connected between an upper vertical radiating element and the forty-meter inductor while permitting simultaneous resonance on each of the three higher frequencies of twenty, fifteen, and ten meters.

Abstract: A devise adapted to be attached to an omni-directional antenna having an elongated conductive element adapted to be mounted vertically. The devise comprises a non-conductive core member having means for attaching said core member to the elongated conductive element and having an inner metallic sleeve disposed about the nonconductive core member and electrically isolated from the elongated conductive element and an outer open-wound coil attached to the non-conductive core member in spaced relationship from the inner sleeve and electrically isolated therefrom. The outer coil has its coil turns wound at an angle to the inner. In another embodiment of the invention, the inner sleeve comprises a metallic wire mesh sleeve.

Abstract: An improved tunable citizen band antenna includes an adjustable tuning assembly located at the tip of a wire wound fiberglass core antenna to lengthen or shorten the effective electrical length of the antenna, so that the antenna can be tuned to a specific, desired resonant frequency, resulting in enhanced antenna radiation, reception, and power transmission.

Abstract: A trimming device for a whip antenna, and the like, wherein two coaxial coils are connected in series with each other and with the antenna whip; and a tuning ring is positioned in the combined external magnetic field of both coils. The tuning ring, being in the external field, has an annular flow of electricity induced therein which in turn produces a magnetic field which opposes that of the coils. In the preferred arrangement, an insulating spacer sheet is wrapped over the inside coil, and the outside coil is wound tightly over the spacer sheet to provide a predetermined amount of intercapacitance between the coils, which can be changed by changing the thickness of the spacer sheet.

Abstract: An antenna suitable for use in the high frequency (HF) ranges includes a resonator tunable over a predetermined frequency band. The resonator consists of an insulated wire wound over a dielectric rod. Tuning is effected by sliding a metallic sleeve disposed in frictional contact over the wire. A multiplicity of these resonator units may be mounted on a single collar at different angles. Each of the resonator units will respond to a particular frequency. The remaining devices operate as a load on the antenna assembly. The antenna assembly may also be mounted on a conventional mobile antenna by means of an adaptor unit.

Abstract: A multisegment collapsible self-erecting AM/FM broadcast band power antenna for mobile receiving units includes a tip segment having a restrictor cooperating with a removable collar to limit the antenna extension to an optimum value for the AM/FM broadcast bands. Conversion of the antenna to a length and load impedance commensurate with reception of signals in the AM/FM broadcast bands and transmission/reception in the CB band is effected by replacement of the collar with a loading coil module together with extension of the lower end of the tip segment into the loading coil module and out of physical connection with the adjacent segment. Normal extension and collapse of the antenna remains unaffected and the conversion is reversible.

Abstract: A device adapted to be attached to an omni-directional antenna having an elongated conductive element adapted to be mounted vertically. The device comprises a non-conductive core member having means for attaching said core member to the elongated conductive element and having an inner open-wound coil having coil turns tightly wound about the non-conductive core member and electrically isolated from the elongated conductive element and an outer open-wound coil attached to the non-conductive core member in spaced relationship from the inner coil and electrically isolated therefrom. The outer coil has its coil turns wound at an angle to the inner coil turns.

Abstract: An electromagnetic tuning device for RF circuits and particularly loading coils for antennas is disclosed. The preferred devices have a coil which produces a generally torroidal shaped electromagnetic field that is intensified by either a core of ferromagnetic material or a second coil inside the other coil. An insulating material surrounds and hermetically seals the coil and field intensifying device that is inside said coil; and an electrically conductive tuning ring is positioned outside of the insulating material for producing a counter magnetic field which opposes and cuts down the field produced by the first mentioned coil. In one embodiment, the tuning ring is threaded and it threadably engages the insulating material so it can be adjustably positioned relative to the torroidal field. In another embodiment the tuning ring is connected in electrical series circuit with a variable resistor.

Abstract: A vertical antenna which is omnidirectional and includes completely automatic band switching for the amateur radio frequencies of, eighty/seventy-five meters, forty meters, twenty meters, fifteen meters, and ten meters. The vertical antenna has a low angle of radiation and a low standing wave ratio on all frequencies which provides for direct coaxial cable transmission line feed. The eighty-meter and forty-meter resonator capacitor sections provide inductive reactance for operation on eighty/seventy five meters and forty meters while permitting simultaneous resonance on each of the three higher frequencies of twenty, fifteen, and ten meters. The entire radiator length of the vertical antenna is active on all frequencies except for fifteen meters where the upper portion of the antenna is decoupled above an end of a fifteen-meter quarter-wave decoupling stub in a first embodiment. The entire radiator length of the vertical antenna is active on all frequencies in a second embodiment.

Abstract: An antenna for communication sets on military vehicles is provided which is interchangeable with existing military antennae, and is suitable to operate with the VRL-12 family. It is adequate to an input impedance of 50 ohm nominally, operates in the frequency band of 30-76 MHZ and is thus suitable for all communication sets operating in this frequency band. It accommodates transmitter power of 100 watts.The coupler is made of armoured steel and the whip is shorter and thinner than that of prior units. It is made of such materials which make it a more rugged and less vulnerable in the battle field.

Abstract: An antenna for remote and continuous adjustment within a wide frequency range, by variation of the inductance, and hence the length of a small diameter coil, by means of a slide which short circuits the turns thereof, until a full short circuit is reached.

Abstract: A radio antenna having linear radiating elements, a loading coil electrically connected to these linear radiating elements and a tuning disc located within the loading coil and rotatable about a diameter of the loading coil whereby said antenna can be easily and accurately tuned to the exact frequency of operation selected. The disc is preferably electrically conductive such that when its plane is perpendicular to the axis of the coil the coil will have a minimum inductance.

Abstract: A motor vehicle is provided with a transceiver which is coupled to a rear mounted antenna system constructed to be unobtrusive and virtually undetectable in addition to being a good radiator.

Abstract: An adjustable mobile antenna comprising an upper metal mast and a lower metal mast, the upper mast being telescopically received in the lower mast and adjustably movable longitudinally therein to vary the length of the antenna and thereby effect tuning thereof, a clamping member for releasably locking the upper mast in a selected position relative to the lower mast, a dielectric rod extending upwardly from the upper end of the upper metal mast, and a loading coil helically wound on the dielectric rod with a lower end of the coil connected to the upper metal mast adjacent the upper end thereof, and a protective outer jacket covering the loading coil, the antenna being tunable by simply adjusting its length.

Abstract: In a whip-type antenna which can be used for either mobile or fixed station, the improvement is characterized in that the antenna has at least a portion of an antenna element thereof wound in turns so as to impart the inductance to the antenna element and a power-operated motor is capable of varying the turns and pitches of the above wound antenna element for varying the inductance, which leads to the variation of tuning frequency of the antenna.

Abstract: This invention relates generally to a 5/8 wave mobile whip antenna using a re-entrant resonant cavity as an electrically and physically integral component to obtain a narrow bandwith necessary to attenuate off channel interference. One embodiment is a coaxial type of re-entrant cavity resonator as an electrically and physically integral part of a 5/8 wave whip antenna. A second embodiment is a hybrid type of re-entrant cavity resonator referred to as a helical cavity resonator as an electrically and physically integral part of a 5/8 wave whip antenna.

Abstract: An extendable half-wave dipole is capacitively coupled to a driven resonant helical antenna for use as on a hand-held, two-way portable radio, the helix being end fed. The dipole may be mounted adjacent to or collinear with the axis of the helix. The collinear mounting requires non-conductive portions on each end of the dipole. Optimum dimensional and performance characteristics are available without switching.

Abstract: A radio antenna which can be readily tuned to the exact frequency of operation, easily coupled to a coaxial feed-line with minimum standing wave ratio and/or which is normally vertical and can be used where horizontal space is at a premium, such as: indoors or on boats. The antenna has a center loading coil, the inductance of which is adjusted by means of a split coaxial sleeve axially moveable relative to the coil. The input impedance of the antenna is adjusted relative to the impedance of the feed-line by means of a coupling transformer, the transformation ratio of which is controlled by means of a coaxial split metal sleeve axially adjustable relative thereto. A coaxial cable wound into a coil around a ferrite core attenuates the high ratio frequency voltage on the end of the antenna to the feed-line. For indoor use, the antenna is housed in an extensible tubular housing which can be extended to engage the ceiling and floor of a room to hold the antenna in vertical position.

Abstract: A method of forming a top-loaded waveguide for radio antennas and the structure of said waveguide comprising the steps of helically winding a wire around a removable mandrel, encasing said mandrel and wire with impregnated fiberglass, encasing said mandrel, wire, and fiberglass with a sheath, liquefying the fiberglass by heating such that the wire is encapsulated by the fiberglass, and removing the mandrel. Top and bottom ferrules are provided for electrically connecting the ends of the wire.

Abstract: An antenna matching network for matching a citizens band radio transceiver to a standard automotive whip or windshield antenna utilizes a matching section for matching the nominal 50 ohm output of the citizens band transceiver to the generally lower impedance of the automotive antenna. A trap tuned to the citizens band prevents the output of the citizens band transmitter from damaging the automotive broadcast receiver when transmitting. The matching section is tunable over a sufficient range to match the citizens band transceiver to most automotive antennas, and a dual sensitivity indicator is utilized to aid the operator in tuning the matching network to provide optimum matching without the use of specialized equipment.

Abstract: A loading coil connects between an antenna and ground and has an intermediate feed point. A conductive member opposes at least several turns of the loading coil and is disposed in distributed capacitive relationship therewith. The conductive member and coil are separated by a dielectric member. The conductive member is preferably movable with respect to the coil to change the resonant frequency of the antenna and may be a conductive ring or disk axially shiftable with respect to the coil or a vane pivotable with respect to such coil. In one embodiment, the conductive member is fixed and the dielectric member, having a dielectric constant different from air, is shiftable to change the distributed capacitance of the conductive member and coil and hence the resonant frequency of the antenna apparatus.

Abstract: An electrical component such as a base loading coil assembly for a fixed length mobile radio antenna is disclosed featuring an electrical coil having a series of windings and an adjustable shorting screw disposed in line with the longitudinal axis of the coil and being rotatable on at least a portion of the windings so as to translate along the longitudinal axis of the coil to vary the inductance thereof.

Abstract: A vertical dipole antenna for the ELF (extremely low frequency) range. The antenna provides a series resonant circuit consisting of an inductor and the distributed capacitance of the conductor such as a wire which may be carried by lighter-than-air craft. The lighter-than-air craft may be conductive, in which case it contributes to the capacitance or the capacitance may be solely represented by the wire. The antenna may be frequency or phase modulated. In case of frequency modulation the frequency of the generator must be changed accordingly so that the series resonant circuit remains resonant at the frequency to be radiated. The antenna can be readily moved. A plurality of antennas may be provided to form a super-radiant array.

Abstract: A top termination for short monopoles is disclosed which reduces transmisn losses by placing the series inductor outside the top-capacitor-to-ground field while coupling the top capacitor to the monopole through said series inductor.BACKGROUND OF THE INVENTIONIn the field of transmission of radio waves by means of a monopole antenna it is well known that the optimum physical length of the monopole should be equal to a quarter wavelength to provide a purely resistive impedance at the antenna base without the use of compensating inductance or capacitance. At lower frequencies, however, wavelengths become sufficiently long so as to make monopole antennas having the ideal 1/4 wavelength dimension cumbersome and impractical. Accordingly, the antenna length has been reduced while a compensating inductance or capacitance or both have been added so that the electrical length of the shortened antenna approaches the electrical length of the idea 1/4 wavelength antenna.

Abstract: A device adapted to be attached to an omnidirectional mobile antenna for a citizens band radio and having an elongated conductive element adapted to be mounted vertically. The device comprises an adjustable clamp adapted to be coupled to the elongated conductive element of the antenna and a bendable metallic member having a generally planer loop-shaped portion surrounding the clamp with two end portions extending inward from the loop and connected to the clamp. The metallic member which forms the loop-shaped portion is coiled such that it defines an angle greater than 360.degree. and only the two end portions of the bendable metallic member are fixed relative to each other whereby the diameter of the loop-shaped portion may be enlarged or contracted.

Abstract: A driven quad antenna unit includes four perpendicularly arranged antenna elements, each element containing therein a high Q load coil in order to reduce the overall size of the antenna structure. A similarly configured parasitic loop unit functioning as a director or reflector (or both may be employed) is located in front or behind, as the case may be, the driven antenna unit. As with the driven unit, each side of the parasitic unit has a coil connected therein, the number of turns in each coil of the director being somewhat less than in the number in the coils of the driven unit and somewhat greater in the coils of the reflector.