Abstract: A scanning antenna comprises a non-magnetic, electrically conductive radiation horn defining an antenna opening having a predetermined central line of focus, and at least one magnetically switchable conductive element such as a reed relay mounted to extend across the antenna opening perpendicular to and spaced from the central line of focus. A magnetic field generator such as an electromagnet is positioned to generate a magnetic field to control switching of the conductive element between its conductive and non-conductive states, and a control circuit controls operation of the magnetic field generator.

Abstract: A modified subterranean antenna structure for use in boreholes that pivotally balances a separate core member within the hollow interior of a fixed winding member in order to filter out mechanically induced vibrations from the core. The mechanical natural resonant frequency of the core is reduced and becomes less than the lowest electromagnetic signal frequency intended to be transmitted to and received by the subterranean antenna. In this way, mechanically induced vibrations will not create mechanically generated frequency signals sympathetic to the frequencies chosen for the antenna communication band frequencies.

Abstract: Antenna apparatus has two laterally spaced waveguide horns with apertures covered by layers of gyrotropic ferrite material. The layers are angled to present opposite angles of incidence to radiation from a common distant source. Electromagnets produce magnetic fields in and parallel with the ferrite layers. The relative phase or amplitude of energy received on the horns is compared to indicate the direction of the source.

Abstract: A microstrip antenna is improved by applying a thin coating of ferrite maial to the surface of the metal ground plane of the antenna by flame spraying or arc plasma spraying. The applied ferrite coating is not exposed to a high temperature anneal cycle.

Abstract: A microstrip phase scan antenna array is provided having a columnar array microstrip radiating patches mounted on a dielectric substrate. Each column of the array is fed by a separate variable, reciprocal ferrite rod phase shifter which is mounted on the substrate and is coupled to the column which it controls and to a source of millimeter wave energy by microstrip to dielectric waveguide transitions. Each of the phase shifters is controlled by a helical biasing coil surrounding the ferrite rod. All of the biasing coils are serially interconnected by a single scanning control drive wire and the numbers of turns of the coils are related to each other by an arithmetic progression in which the number of turns of a particular biasing coil differs from the number of turns of the adjacent biasing coil in the sequence of biasing coils controlling the array by a constant amount.

Abstract: An antenna having provision for mounting to a printed circuit board and method for making the antenna is described. The antenna includes a generally elongate, magnetically permeable core having a major axis and an insulating substrate affixed along an axis parallel to the major axis. The insulating substrate has a plurality of opposed pairs of spaced conductive runners positioned at generally regular intervals along the substrate normal to the major axis. A plurality of discrete capacitors are and perpendicular to secured between the opposed pairs of conductive runners. An electrically conductive split sleeve substantially surrounds the core and has pairs of opposed tabs on the edge portions in electrical connection with the opposed pairs of conductive runners. The sleeve further includes integral mounting tabs for securing the antenna assembly to the printed circuit board to establish electrical connection to the antenna without the use of wire leads.

Abstract: An electronically steerable antenna which refracts an electromagnetic wave travelling through an electrooptic deflector, steers an electromagnetic wave to a desired angle. The electrooptic deflector includes first and second sections of electrooptical material. A voltage changes the indices of refraction of the electrooptical material, thereby causing a change in the angle of refraction at the interface between the first and second sections. Input and output impedance matching sections are provided effecting maximum power transfer of the electromagnetic wave travelling through the antenna.

Abstract: A phase scan antenna array for planar radar scanning in a single plane with pencil-shaped beam is provided comprising a plurality of ferrite rod line source antennas. Each rod antenna has a plurality of beam-emitting slots spaced along one side thereof and is end fed in phase with the other antennas from a single hollow metallic waveguide by means of coupling slots in the waveguide which are spaced apart one wavelength of the radar frequency. The rods are mounted in a two-dimensional columnar array with the beam-emitting slots of each rod aligned in rows with the corresponding slots of the other rods by a mounting member having a plurality of mutually-parallel slots in which the rods are disposed. The walls of the mounting member slots suppress Faraday rotation of the waves in the rods and the bottom of the slots enhance the single beam emitted from the face of the array.

Abstract: A millimeter wavelength monolithic ferrite circulator/antenna device is pided comprising a four-sided ferrite rod having one end which is to be selectively coupled to millimeter wavelength radar transmitter and receiver apparatus and the other end coupled to a load. The rod end coupled to the radar apparatus has a pair of permanent magnets disposed on opposite sides of the rod and is shaped as a right prism having prism bases formed by sections of the rod sides on which the magnets are mounted and prism faces formed by sections of the remaining two rod sides and by the cross-section of the rod itself. The dc magnetic field produced by the magnets is perpendicular to the longitudinal axis of the rod and causes the prism to act as a ferrite circulator with respect to millimeter wave energy transmitted through the prism faces and along such rod axis. The remainder of the rod is utilized as a ferrite rod antenna of the leaky-wave type by providing energy emitting perturbations on one of the rod sides.

Abstract: A phase scan antenna suitable for millimeter wave radar applications is pided comprising a four-sided ferrite rod having a series of electromagnetic energy emitting slots along one side of the rod. The remaining three rod sides are enclosed by a metal, channel-shaped member which is spaced from the rod by a plastic, channel-shaped substrate member, so that energy emitted from the rod side which is opposite from the slotted rod side will be reflected to pass out the slotted rod side, to thereby enhance the antenna beam produced by the slotted rod side. A magnetic biasing coil having serially-interconnected coil portions is helically wound about the metal channel-shaped member with the coil portions disposed between the slots in the first rod side to cause scanning of the antenna beam. The ferrite rod may be end fed by either dielectric waveguide sections or hollow, metallic waveguide sections.

Abstract: The invention is a miniature antenna useful for portable radios, pocket pager receivers, etc. A plurality of sequentially wound windings is located on a ferrite core, each winding being connected in series with a capacitor. The resulting series circuits are connected in parallel with each other. Preferably the resonant frequency of each series circuit is approximately 80% to 90% of a receive frequency. An external tuning capacitance resonates with the net inductance of the antenna at the receive frequency. The antenna exhibits low hand effect while maintaining output EMF.

Abstract: An electromagnetic medical applicator for tissue-heating comprises a single resonant element (1) in contact with one surface of a layer of material (5) whose opposite surface faces the body of a patient (6). The material has a wave-impedance which approximately matches that of the human body and a dielectric constant not less than for a material having unity magnetic permeability which produces this match. In one form the element is a patch resonator (1) on a substrate (2) backed by a ground-plane (3) and overlaid by the layer (5); at least the substrate may include both dielectric and magnetic material in order to combine a desired resonator size-reduction and wave-impedance. In another form a needle-type applicator is coated with the layer of material.

Abstract: An electromagnetic medical applicator for heating tissue comprises a patch resonator (1) on a substrate (4) of dielectric material backed by a ground-plane (3), and having a layer (7) of dielectric material overlying the resonator inter alia to effect impedance-matching to tissue, in which the substrate includes a volume of magnetic material (5) adjacent the maximum-current region of the resonator in order to reduce the length of the resonator at its resonant frequency.

Abstract: A radiating element having a continuous aperture substantially greater than one-half the center frequency wavelength for use in an electronically scanned phased array antenna operating in the range of 94 GHz. The new radiating element comprises a ferrite block having a radiating aperture which measures 5.lambda. by 5.lambda. in contrast to the conventional discrete radiating element which measures one-half .lambda. by one-half .lambda.. Thus, where a phased array antenna comprised of an array of the new radiating elements would require only a single radiating element to fill an aperture measuring 5.lambda. by 5.lambda., a phased array antenna of conventional design would require one hundred discrete radiating elements to fill the same aperture. A tapered magnetization is applied to the continuous aperture ferrite block. Thus electromagnetic energy traveling through the block and exiting the radiating surface is phase shifted, with respect to the energy entering the block, in a similar tapered fashion.

Abstract: A directionally sensitive receiving antenna, particularly for microwave radiation, utilizes the change in impedance, as a function of the angle between the energy vector of incident radiation on a gyrotropic medium, e.g. a ferrite material, and a magnetic field passing through the medium, enabling a highly directional antenna of small physical dimensions to be constructed.

Abstract: Methods and apparatus for electronically steering a radio frequency signal beam (RF) along at least one of "X" and/or "Y" coordinates with respect to the axis of the signal beam (RF) and comprising n pairs of back-to-back prisms (20, 21) formed of ferroelectric dielectric material such, for example, as BaTiO.sub.3, LiNbO.sub.3, LiTaO.sub.3, Bi.sub.12 SiO.sub.20 (BSO) and Bi.sub.12 GeO.sub.

Abstract: Substantial weight reduction and size reduction in phased array radiators are obtained by coupling a dielectrically loaded waveguide directly to a short horn radiator whose electrical length is less than one half wavelength at an operating frequency. Coupling is obtained by positioning the waveguide with its end in the interior of the short horn radiator and by causing the dielectric material of the waveguide to protrude beyond the end of the waveguide and to terminate inside the horn.

Abstract: An antenna including a first elongated magnetic member having at least one diamagnetic portion and a first magnetic pole orientation, a second elongated magnetic member having at least one diamagnetic portion and a second magnetic pole orientation opposite to the first magnetic pole orientation and provided adjacent and parallel to first elongated magnetic member, a pair of third elongated magnetic members connecting the ends of the first and second elongated members to form a magnetic loop and a coil wound on each of the first and second elongated magnetic members.

Abstract: Electrically conducting magnetic recording tape having a coating of .gamma.-Fe.sub.2 O.sub.3 particles on a polyester substrate is used as leads for probes in oven cavities and other microwave fields. The tape leads are flexible, have a high resistance per unit length, and are nearly transparent to electromagnetic waves. Electric diode-dipole probes with such leads are uniquely electric and a magnetic loop detector is uniquely magnetic.

Abstract: Disclosed is a low profile wideband VHF antenna wherein impedance matching ver the required operating band is provided without the use of multiple circuit components, for tuning, switched into and out of the antenna by an assembly of switch contacts. The antenna is comprised of an end and preferably a bottom fed vertical radiating rod or monopole element whose upper end is terminated in a substantially flat circular top capacitance disc via a frequency sensitive inductance constructed of a ferrite core inductor whose .mu. characteristic varies approximately inversely with respect to frequency.

Abstract: A method and apparatus for controlling reradiation from conductors, such as guy wires, by controlling the current distribution on the conductors, is provided. The invention comprises a cylindrical annular shaped sleeve that is positioned at predetermined distances along an electrically conducting structure to eliminate the reradiation caused by electromagnetic waves. The sleeve is made of a high magnetic permeability material, and a plurality of sleeves is positioned at predetermined spaced-apart distances along the conductor. The predetermined positioning of the sleeve renders the conductor electrically equivalent to a plurality of discrete cable lengths separated by insulators.

Abstract: An activatable, and deactivatable ferromagnetic marker useful in tagging objects to permit selective detection of tagged objects depending upon the activation state of the marker. The marker comprises a pair of ferromagnetic elements capable of generating harmonics of an exciting oscillatory interrogating field. Both elements of each pair are essentially identical, having identical dimensions, weights and ferromagnetic properties. In one activation state, the pair generates predominately the even harmonics of the oscillatory field, while in a second activation state the pair generates predominately the odd harmonics of the oscillatory interrogating field. The system includes the marker attached to, or built within, selected objects, a means for selectively switching between the two activation states, an interrogation field, and detection means.

Abstract: A line source antenna adapted for a light weight, compact phased array ra and consisting of a plurality of series fed radiating slots periodically located in the narrow side wall of a length of waveguide together with non-reciprocal latching ferrite phase shifters including dielectric loading sections and matching transformer sections on either side of phase shifters located between adjacent slot pairs.

Abstract: A radio receiver and a battery are housed in a button adapted to fit in the ear cavity. The button is attached to the ear by a hook. The radio receiver has an antenna tuned to intercept a single frequency radio signal, means for producing an audio signal from the radio signal intercepted by the antenna, and means for converting the audio signal to sound waves. The antenna comprises a coil wrapped around an insulated core made of compressed barium ferrite particles of controlled size and a capacitor in parallel with the coil. Due to the high effective permeability of the barium ferrite core, a sufficiently narrow band width and signal strength for satisfactory radio reception in the A.M. broadcast band can be obtained with very small core dimensions.

Abstract: An electromagnetic wave radiation system includes an array of stationary antenna elements, a multiplicity of phase modulator units coupled to the antenna elements, a source of high frequency energy supplying energy to the antenna array, and modulator driving means activating the same to cause phase displacement and rotation of the beam transmitted by the antenna elements. The antenna may be a discone assembly or an assembly of antenna elements in a circular configuration, and the modulator units may be passive ferrite members located in the aperture of the antenna. The modulator driving units may comprise electromagnets located below the ground plane of the antenna and alternatively or selectively energized by in-phase and phase shifted sine wave voltages.

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.

Abstract: A multi-rod broadband antenna consisting of a plurality of elementary radiators arranged as directrices of a cylinder each consisting of a conductor surrounded with a ferromagnetic core designed so that each one has a resonant frequency value different from any other one, the resonant frequency values being related so as to form a series. The arrangement of the rods around the cylinder is such that the frequency values of two adjacent rods do not correspond to two adjacent terms of the series.