Abstract: A downhole magnetic hollow core dipole antenna has a high permeability material magnetic core composed of laminated sections placed around a section of drill pipe and running substantially along the length of the pipe. The magnetic core is then surrounded by electrically conductive windings, which in turn are surrounded by a protective sleeve which, if conductive, is split to prevent power-robbing eddy current generation.

Abstract: The invention concerns a transponder arrangement in which the transponder is disposed on a conductive surface. According to the invention, the coils forming the transponder antenna are aligned at a slight distance from the metal surface with their main magnetic field direction parallel to this surface.

Abstract: An antenna device, comprising an antenna unit including basic body comprising at least one of dielectric ceramic and magnetic ceramic, at least one conductor disposed at least one of inside and on a surface of the basic body, and a feeding electrode for applying a voltage to the conductor disposed on the surface of the basic body; a mounting board on which the antenna unit is mounted; a ground part in association with the mounting board and adapted to resonate with the antenna unit; and a length in the polarization direction of a radio wave of the ground part being about &lgr;/4 or more, where &lgr; is a wavelength of the radio wave, the basic body comprising a first generally planar sheet having a plurality of spaced, first conductors formed on one major surface thereof and a second generally planar sheet having a plurality of spaced second conductors formed on one major surface thereof; the first and second generally planar sheets being laminated together to form an elongated structure wherein respective pa

Abstract: A continuous transverse stub element array structure which forms a coaxial geometry formed from a plurality of cylindrical segments, wherein each of the cylindrical segments has a rim at a top end and a bottom end, wherein each rim extends transversely away from the cylindrical segment relative to a longitudinal axis thereof to thereby form a stub element, wherein the individual cylindrical transverse stub elements are aligned end-to-end to thereby form a coaxial cable structure which surrounds a central core material. The series of these stubs form reactive or radiating elements for microwave, millimeter-wave, and quasi-optical filters and antennas. Purely reactive elements are formed by leaving the conductive coating on the terminus of the stub elements, whereas radiating elements are formed when stub elements of moderate radius are opened to free space.

Abstract: A method and a device is disclosed for the generation of a lens device including a plate of ferroelectric material, the transmission phase gradient of which is be varied over the lens by means of a controllable static electric field. The lens may involve an entire antenna aperture, e.g. a feeder horn or constitute a body covering a slotted wave-guide antenna, be a portion of an antenna aperture or an element in a conventional array aperture. The division of the aperture depends on the number of degrees of freedom to be controlled simultaneously. In a general case N lobes and M nulls are to be controlled at the same time. In the most simple case with N=1 and M=0 the lens should be the entire antenna aperture. The invention is based on the fact that the direction of the wires of the control grids (1, 2) in the lens device must run perpendicular to the direction of the E-field direction of a penetrating high frequency radio wave.

Abstract: To control the temperature sensitivity of a ferroelectric microwave device, a microwave waveguide in the device is loaded with a modified ferroelecc material of reduced grain size less than 100 nm, preferably about 50 nm. The electrical properties of this material are less sensitive to temperature change. Thus, when a dc bias voltage is applied across the ferroelectric to tune the dielectric constant, changes in temperature will have a minimal effect on the desired tuning of the device.

Abstract: An RF antenna includes an input terminal for receiving an RF signal, a supporting element, an electrically conductive coil on the supporting element and disposed to receive the RF signal from the input terminal, and an RF shield formed of an electrically conductive material and disposed under the coil and further including contacts for connection to a ground electrical potential. The antenna generates a circularly polarized RF field. A method of generating an RF field includes generating an RF signal, providing the RF signal to an electrically conductive coil disposed on a magnet core and separated from the magnet core by a supporting element, shielding the electrically conductive coil using an electrically conductive material, and connecting the RF shield to a ground electrical potential so as to provide a current return for the RF signal through the RF shield.

Abstract: A first fractal antenna of iteration N.gtoreq.2 in free space exhibits characteristics including at least one resonant frequency and bandwidth. Spacing-apart the first fractal conductive element from a conductive element by a distance .DELTA., non-planarly or otherwise, preferably .ltoreq.0.05.lambda. for non-planar separation for frequencies of interest decreases resonant frequency and/or introduces new resonant frequencies, widens the bandwidth, or both, for the resultant antenna system. The conductive element may itself be a fractal antenna, which if rotated relative to the first fractal antenna will alter or tune at least one characteristic of the antenna system. Forming a cut anywhere in the first fractal antenna causes new and different resonant nodes to appear. The antenna system may be tuned by cutting-off a portion of the first fractal antenna, typically increasing resonant frequency.

Abstract: An ultra-wideband magnetic antenna includes a planar conductor having a first and a second slot about an axis. The slots are substantially leaf-shaped having a varying width along the axis. The slots are interconnected along the axis. A cross polarized antenna system is comprised of an ultra-wideband magnetic antenna and an ultra-wideband dipole antenna. The magnetic antenna and the dipole antenna are positioned substantially close to each other and they create a cross polarized field pattern. The present invention provides isolation between a transmitter and a receiver in an ultra-wideband system. Additionally, the present invention allows isolation among radiating elements in an array antenna system.

Abstract: The present invention is directed to provide a compact chip antenna for mobile communication comprising a base member which comprises either of a material having a dielectric constant .epsilon. of 1<.epsilon.<130 or a material having a relative permeability .mu. of 1<.mu.<7, at least one conductor formed on the surface of the base member and/or inside the base member, and at least one feeding terminal provided on the surface of the substrate for applying a voltage to the conductor. The conductor comprises a metal mainly containing any one of copper, nickel, silver, palladium, platinum, or gold.

Abstract: A method to transmit and receive electromagnetic waves which comprises generating opposing magnetic fields having a plane of maximum force running perpendicular to a longitudinal axis of the magnetic field; generating a heat source along an axis parallel to the longitudinal axis of the magnetic field; generating an accelerator parallel to and in close proximity to the heat source, thereby creating an input and output port; and generating a communications signal into the input and output port, thereby sending the signal at a speed faster than light.

Abstract: A low profile, receiving and/or transmitting antenna is adapted to be mounted onto an interior portion of a building or other structure to receive or transmit radiation through a first dielectric material, such as a window, associated with the building or other structure. The antenna includes a receiving/transmitting horn filled with a second dielectric material and a surface for mounting the antenna to the first dielectric material so that the horn is disposed at a particular angle with respect to a surface of the first dielectric material. A matching layer may be disposed between the first dielectric material and the second dielectric material to provide for a reflectionless match between the first and second dielectric materials.

Abstract: A novel loop antenna containing a thin-walled ferrite box or other hollow; magnetic core structure of high permeability (considerably greater than 100), particularly useful for crossed loop antennas, and of optimal geometry and configuration for minimum volume, weight and space.

Abstract: An antenna includes a radiating resonant member for transmitting polarized microwaves. A first diffracting system radiates waves at an angle greater than the transmission angle of the radiating member. A second diffracting system corrects the purity of polarization of the waves for some directions at least.

Abstract: A broadband partial fan cone direction finding antenna and array disclosed. The antenna includes a radiator having a partial cone shape. The radiator substantially occupies a spatial area defined by a portion of a cone and the cone is defined by a cone axis, a cone height, and a cone angle. The cone has a base and an apex, and the portion of the cone is defined by a cone sweep angle. The cone sweep angle is determined as the angle subtended by a projection of the portion of the cone projected onto a plane that is perpendicular to the cone axis. The cone sweep angle is less than 360.degree. so that the portion of the cone is bounded on its sides by edges which extend radially from the apex of the cone outward to the base of the cone.

Abstract: An antenna (100) has a low reluctance material (140) positioned to influence radiation pattern. The antenna (100) includes a radiator (110), and the low magnetic reluctance material (140) is positioned in close proximity to a particular side of the radiator (110). The low reluctance material (140) has a primary function of providing a preferred path for the magnetic field generated by the radiator (110), thus confining the magnetic energy and reducing radiation along at least one side of the antenna (100).

Abstract: To an oxide magnetic material consisting essentially of, calculated as oxides, 15-30 mol % of Fe.sub.2 O.sub.3, 6-12 mol % of CuO, and 58-79 mol % of NiO as main ingredients, 1.5-4.5% by weight of PbO, 1.0-3.7% by weight of SiO.sub.2, 0.7-1.0% by weight of CoO, and 0.01-1.0% by weight of ZnO are added as additives. The material is suited to form magnetic cores for operation in high-frequency bands.

Abstract: A system of antennas for conserving space and concealing the separate identity of the individual antennas. The antennas may be a radio antenna and a telecommunications antenna. The antennas may have a common base to eliminate separate wires and holes in the vehicle on which they are mounted. The antennas may be housed within the same casing to protect them from the elements and from other harm.

Abstract: A miniature chip antenna which can be utilized as an antenna for use in a high-frequency region is provided. The chip antenna comprises a substrate, at least one conductor, and at least one feeding terminal. The substrate comprises a dielectric material portion and a magnetic material portion, at least a part of the magnetic material portion being exposed to the exterior of the substrate. The conductor is formed at least either on the surface of the substrate or inside the substrate. The feeding terminal is provided on the surface of the substrate to impress a voltage on the conductor.

Abstract: A downsized chip antenna having a large bandwidth ratio is disclosed. The chip antenna has a rectangular prism-shaped base member providing a mounting surface. A conductor is formed inside the base member in such a manner that it is spirally wound around a winding axis, for example, a winding axis parallel to the mounting surface, i.e., in the longitudinal direction of the base member. One end of the conductor is extended to a surface of the base member to form a feeding section, which is connected to a feeding terminal, disposed over the surfaces of the base member to apply voltage to the conductor. In one embodiment, the other end of the conductor is connected to a midway portion of the conductor within the base member, thereby forming a loop in said conductor.

Abstract: The invention relates to a microwave antenna having at least one tubular portion with a central axis, and magnets which are located within the tubular portion along the central axis. The magnets generate a magnetic field in the vicinity of the antenna, with each end of each magnet facing an end having the same polarity of an immediately adjacent magnet. This type of antenna is used in the manufacture of microtips on large surfaces.

Abstract: A passive electronic marker uses a plurality of ferrite cores to increase locating range, and the cores are attached in such a manner that a slight bend of the marker at a junction between the cores does not significantly affect the markers performance. Stable locating range and tuned frequency are achieved by controlling the air gap between the cores, using specially shaped ends or a sphere which is positioned between the cores. By selecting the appropriate geometry for the core ends and winding interconnections, the first order permeability across the air gap is held constant during bending of the marker.

Abstract: An electronic apparatus has a demodulating section and a strap antenna having a conductor in its inside. Radio waves received by the strap antenna are demodulated by the demodulating section. A receiving-sensitivity adjustment member has at least one through hole for passing the strap antenna in it is slidably placed on the strap antenna, and since a magnetic substance built in the receiving-sensitivity adjustment member changes the electric field generated in the conductor of the strap antenna, receiving sensitivity can be adjusted to the most appropriate state. With an insulator member placed on the strap antenna, a loop antenna can be used as a monopole antenna. When the strap antenna is made detachable, another antenna can be used depending on the use condition.

Abstract: The present invention provides multidimensional stacked photonic band gap crystal structures improving the performance of current planar monolithic antennas and RF filters by forbidding radiation from coupling into the substrate thereby significantly enhancing radiation efficiency and bandwidth. This invention comprises a number of sub-crystals with each having at least two lattices disposed within a host material, each lattice having a plurality of dielectric pieces arranged and spaced from each other in a predetermined manner, the sub-crystals being stacked in a crystal structure to provide a photonic band gap forbidding electromagnetic radiation propagating over a specially designed frequency band gap, or stopband. Both two dimensional and multidimensional crystals are disclosed.

Abstract: An HF antenna comprising a sheet-like, flexible multipart magnet core (16) manufactured of ferromagnetic material is provided with an antenna winding which is made up of a plurality of turns and surrounds the magnet core (16). The turns of the antenna winding are formed by printed wiring (12a and 12b) arranged on a flexible film (10a and 10b) surrounding the magnet core (16).

Abstract: The present invention discloses an electromagnetic device which includes a magnetic flux producing apparatus for producing a magnetic flux path loop. The magnetic flux producing apparatus preferably comprises a magnetic core 20 surrounded by electrical windings 22. A strip of electrically conductive material 24 is disposed such that it passes through the magnetic flux path loop and overlies the windings 22. The strip 24 has a width which is substantially greater than its thickness. The device may further include an antenna 16 which is electrically coupled to the strip 24.

Abstract: Apparatus and method for producing a flexible antenna suitable to be incorporated in a badge or similar object. The antenna comprises electrical windings (28, 38) surrounding a flexible antenna core (26, 36). The antenna core (26, 36) is of a material having a high quality factor formed of a plurality of mutually insulated, longitudinally extending chains of magnetic soft material of high .mu.. According to one embodiment, a powder of small particles of a magnetic soft material of high .mu. is mixed with a synthetic resin so that a high saturation of magnetic material in the mixture is formed in a vacuum. The mixture is cured in a strong magnetic field so that the particles form chains (18A, 18B, 18C) of the particle parallel to the applied magnetic field.

Abstract: Three embodiments of a tunable ferroelectric transmitting system are included. Each embodiment includes a tunable oscillator and a tunable antenna. Two embodiments include a negative resistance diode, the frequency of oscillation being controlled by a single crystal tunable ferroelectric resonator. The third embodiment uses a transistor. The tunable antenna is made of a single crystal tunable ferroeletric resonator. All conducting depositions are made of films of a high Tc superconducting material.

Abstract: An integrated radiating and coupling device (30) for a duplex communication radio (26) is formed using a ferrite body (36) having first and second surfaces. A multi-port circulator (40) is mounted on the first surface. The circulator (40) has at least three ports; a transmitter port (42), a receiver port (44), and an antenna port (38). A patch antenna (32) is mounted on the second surface and connected to the antenna port (38) by, for example, a wire passing through a via hole in the ferrite body (36). The device (30) provides transmitter and receiver isolation, antenna coupling, and filtering in a single integrated structure.

Abstract: A compact broadband microstrip antenna for mounting to one side of a ground plane comprises a closed (usually circular) array of antenna elements positioned to one side of a substrate for spacing the antenna elements a selected distance above the ground plane, the antenna elements being adapted to be electrically driven out of phase from one another to excite one or more spiral modes. In another form, a compact microstrip antenna comprises one or more antenna elements positioned to one side of a magnetic substrate for spacing the antenna elements a selected distance from a ground plane, the magnetic substrate being chosen to have a relative permittivity which is roughly equal to its relative permeability. In a third form, a microstrip antenna is adapted for operating in a single mode and radiation from other modes is suppressed by varying the spacing above the ground plane in the radiation zones so that only radiation in the desired mode is fostered.

Abstract: A magnetic core element for use in a thin antenna. The magnetic core element has a thickness of 25 .mu.m or less and is made of a particular amorphous alloy strip or a particular nano-crystalline alloy strip. A thin antenna having a laminated magnetic core made of the magnetic core elements is highly resistant to deformation and has a high Q-value.

Abstract: A ferrite antenna is disclosed. The antenna includes a board on which a ferrite component is mounted. The board includes a plurality of slots and a conductive pattern extending between two of the slots. First and second metal bands are wound around the ferrite component and inserted into the slots. The metal bands are coupled together by the conductive pattern to form a coil. Thus, the interval between adjacent bands can be more accurately set and the antenna can be more easily fabricated. In another embodiment, a metal band partially encloses the ferrite component and covers an open area between the ferrite component and one end of the metal band. The sensitivity of the antenna is thus increased beyond the upper limit of a regular ferrite antenna. In still another embodiment, conductive patterns are formed on the periphery of the board and coupled to the metal bands to improve the directional sensitivity of the antenna.

Abstract: RF communication through an RF barrier is facilitated by an RF field concentrating core that is lodged within an opening through the barrier and extends out from at least one side of the barrier. An antenna coil is wound around the core, with a capacitor connected across the coil to establish a parallel resonant circuit at the exciting frequency. The core/coil combination provides a bidirectional RF coupler for transmitting signals between opposite sides of the barrier. It is particularly useful for transponder systems in which a transponder is located within an RF-blocking enclosure, and is interrogated by an exciter/reader outside the enclosure.

Abstract: A lightweight search-coil antenna or sensor assembly for detecting magnetic fields and including a multi-turn electromagnetic induction coil wound on a spool type coil form through which is inserted an elongated coil loading member comprised of metallic glass material wrapped around a dielectric rod. The dielectric rod consists of a plastic or a wooden dowel having a length which is relatively larger than its thickness so as to provide a large length-to-diameter ratio. A tri-axial configuration includes a housing in which is located three substantially identical mutually orthogonal electromagnetic induction coil assemblies of the type described above wherein each of the assemblies include an electromagnetic coil wound on a dielectric spool with an elongated metallic glass coil loading member projecting therethrough.

Abstract: An array antenna includes a ferrite substrate having a two-dimensional planar array of antenna elements disposed over a first surface thereof and means for applying an external magnetic field having a magnitude and direction which can be varied at least in a plane in which the antenna elements lie. The amplitude and direction of the external magnetic biasing field is varied to control the relative phases between each of the plurality of antenna elements and to steer the direction of a main antenna beam in two dimensions.

Abstract: A microstrip patch antenna with radiation polarization that can be magnetically varied via the application of the in-plane magnetic field. The antenna comprises a retangular metallic patch which is deposited on a ferrite film, which itself has been deposisted on a dielectric substrate. The patch is fed via an SMA connector which is grounded to the back of the substrate. The center pin of the connector passes through a hole drilled in the substrate. The patch radiates first and second perpendicular polarizations. The first polarization is broadband in frequency, and does not tune with an applied magnetic field. The second polarization is narrowband in frequency, and its center frequency increases as an in-plane bias field is applied. As bias is applied, the narrowband radiation tunes across the frequency bandwidth of the more broadband, perpendicularly polarized radiation. The phase relationship between the two polarizations is thus changed at frequencies at which power is radiated by both polarizations.

Abstract: A compact parametric antenna (CPA) employs the principle of stimulating an electric field E and a magnetic field H for synthesis of an electromagnetic wavefront according to the Poynting vector theory S=E .times.H. The CPA includes a dielectric, magnetically-active, open circuit mass core, ampere windings around the mass core and an RF source for driving the windings to produce an electromagnetic wavefront. The principle behind the synthesis of a electromagnetic wavefront is that the RF current source provides a sinusoidal RF current I.sub.0 which drives the ampere windings to stimulate an external electric field E and, through the induction of gyromagnetic, gyroscopic and Faraday effects in the dielectric, magnetically-active, open circuit mass core, an external magnetic field H having an internal magnetic flux density B.

Abstract: The ferroelectric scanning RF antenna includes a ferroelectric material having conductors deposited thereon that are connected to an adjustable d.c. or a.c. voltage source. The scanning antenna is placed in an RF transmission line that includes appropriate input and output impedance matching devices such as quarter-wave transformers. The scanning section of the RF scanning antenna is constructed of two prismatic structures of a ferroelectric material. When the two prismatic structures are at the same zero bias voltage, then the RF energy passing through the antenna is not deflected and a boresight radiation pattern is obtained. Application of a bias voltage reduces the permittivity and the refractive index of the outer prismatic structure. The RF energy is refracted away from the normal at the interface between the prismatic surfaces and the radiation pattern is scanned in one direction. Application of a bias voltage reduces the permittivity and the refractive index of the inner prismatic structure.

Abstract: Apparatus and method for producing a flexible antenna suitable to be incorporated in a badge or similar object. The antenna comprises electrical windings (28, 38) surrounding a flexible antenna core (26, 36). The antenna core (26, 36) is of a material having a high quality factor formed of a plurality of mutually insulated, longitudinally extending chains of magnetic soft material of high .mu.. According to one embodiment, a powder of small particles of a magnetic soft material of high .mu. is mixed with a synthetic resin so that a high saturation of magnetic material in the mixture is formed in a vacuum. The mixture is cured in a strong magnetic field so that the particles form chains (18A, 18B, 18C) of the particle parallel to the applied magnetic field.

Abstract: A filter utilizes a frequency selective, non-conductive, dielectric structure for filtering electromagnetic energy in the millimeter to far infrared frequency bands. The filter includes a non-conductive, high-dielectric, background material positioned to receive incident electromagnetic energy. A lattice structure comprised of a plurality of elongated elements formed of a non-conductive, high-dielectric material are disposed in a two-dimensional, periodic arrangement in the background material. The elements extend in parallel to one another through the background material for providing a range of frequencies over a band gap in which incident electromagnetic energy within the frequency range of the band gap is substantially prevented from propagating through the lattice structure. The dielectric structure can be adapted to operate as a band stop filter or a low pass filter.

Abstract: A microstrip antenna includes a ferrite loaded substrate having a ground plane conductor disposed over a first surface thereof and having a strip conductor disposed over a second surface thereof. A DC magnetic field biasing circuit provides a directed DC magnetic field to the ferrite substrate such that the strip conductor radiates electromagnetic energy having circular polarization. In one embodiment, a ferrite material is disposed over the strip conductor to reduce the radar cross section of the antenna.

Abstract: A one piece millimeter wave phase shifter/antenna, wherein magnetic flux is imported into a ferrite rod body through a plated metallic film helix, driven by a pulse generator to change the amount of remnant flux, and therefore the relative microwave phase shift from one aperture port to its neighbor.

Abstract: An antenna element comprising a hollow pipe made of a magnetic material said hollow pipe having an axial bore extending therethrough; a solid or hollow metal bar made of at least one metal selected from the group consisting of aluminum, titanium, copper and alloys thereof, said metal bar being inserted into the axial bore; an insulating material existing between the hollow pipe and the metal bar; and an electrically conductive wire being wound on at least a part of an outer surface of the hollow pipe, said electrically conductive wire having been coated with an insulating material.

Abstract: An antenna element characterized that the core thereof is made of an amorphous metal and at least a part of its surface is wound with an electric conductive material, and an antenna comprising of at least one said antenna element.

Abstract: Microscopic strips of high permeability magnetic conductor are arrayed in a proximate relation to an electrical conductor to form paths for magnetic circuits about the electrical conductor. The strips may take various forms including filaments, such as one hundred micron microwire, and deposited submicron-sized layers of amorphorous magnetic material. The magnetic circuits may be closed with the strips forming a plurality of bands around the electrical conductor, and the magnetic circuits may be open, such as with the strips arrayed linearly adjacent to the electrical conductor. The magnetic circuits have numerous applications, including a variety of antennas, inductive wires, antenna ground planes, inductive surfaces, magnetic sensors, and direction finding arrays.

Abstract: A magnetic corrugated horn antenna system is disclosed. This system includes a magnetic hybrid-mode horn antenna composed of a circular waveguide and a corrugated horn antenna which has a thin magnetic coating on its inner wall. The corrugation of the conical horn helps it to produce equal E-plane and H-plane patterns with low sidelobes. The magnetic coating can enhance or duplicate the beneficial effects of the corrugation, while avoiding the high gain loss and poor patterns reported in prior art systems that relay only on corrugated horns.

Abstract: An antenna arrangement for receiving television signals from a satellite comprises a parabolic dish which collects the signals and feeds them through a feedhorn, then through a polarization switch and to a low noise block to the receiver. The polarization switch comprises a ferrite rod supported in a dielectric holder within a circular waveguide. The ferrite rod is surrounded by a solenoid coil which is energizable to rotate the plane of polarization of the signals passed along the waveguide, so as to enable the switch to select either horizontally or vertically polarized signals. The current in the coil is switchable between two values, one having a predetermined magnitude in one direction through the coil and the other having the same predetermined magnitude but in the opposite direction through the coil. The current levels are seleced such that the corresponding angular positions for the plane of polarization are +45.degree. relative to the datum position for the polarization plane and -45.degree.

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: A magnetostatic wave device comprises a ferrimagnetic base material such as a thin film of YIG (yttrium iron garnet). The ferrimagnetic base material is formed on a supporting plate, for example, a GGG (gadolinium gallium garnet) substrate. On one principal surface of the thin ferrimagnetic base material, a first coupling antenna is formed. Furthermore, on one principal surface of the ferrimagnetic base material, second coupling antennas are formed on both sides of the first coupling antenna. In this magnetostatic wave device, the magnetostatic wave propagated from the first coupling antenna toward both sides of the first coupling antenna is received by the second coupling antennas on both sides of the first coupling antenna.

Abstract: A coplanar antenna system having a single-coil loop antenna provides both transmit and receive functions. The antenna operates in a tuned mode during transmitting and an untuned mode during receiving. Dead zone and transformer effect problems are virtually eliminated. The transmitter is highly efficient and the receiver is impulse noise immune.