Abstract: A television antenna is constructed of a flat plate antenna comprising a plurality of concentric, rectangularly shaped loops formed of conductive material and disposed on a substrate. Each loop forms an antenna for signals in a predefined frequency band within the TV frequency spectrum. An additional loop is disposed within the plurality of concentric loops and is adapted for receiving signals in the FM frequency range. Each of the loops has four sides having an electrical length equivalent to one-quarter wavelength at a center frequency within a frequency band and each side of each antenna loop is connected to a side of another antenna loop and to one of a pair of antenna output terminals. The sides of each loop are formed by conductive strips deposited on a dielectric substrate which is particularly adapted for installation adjacent a dielectric roof panel or the like.

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 first spiral-mode microstrip (SMM) antenna has an antenna element situated over and spaced from a parallel ground plane. The antenna element is a frequency-independent planar structure having a plurality of spiraling arms extending outwardly in a plane from a central portion, the arms having respective feed points to excite the spiral modes. Of particular significance, a shorting mechanism connects one or more arms to the ground plane element for influencing the shape of the electromagnetic radiation pattern. A second embodiment of the SMM antenna is constructed as the first, but has a center feed and an off-center feed, and further comprises shorting mechanisms situated well within the periphery of the antenna element. A third embodiment of the SMM antenna is constructed similar to the first, but has a concentric gap situated within the arms so that there is, in effect, a first antenna element having a first plurality of arms and a second concentric antenna element having a second plurality of arms.

Abstract: An antenna and mounting device assembly fits on opposite sides of an aircraft to handle radio signals during flight. The antenna has a boom and radiating elements extending normal to the boom. The mounting device includes a first clamping bracket that attaches to the exterior of the aircraft, a pair of spaced arms that are twisted relative to the longitudinal axis of the first clamping bracket to orient the antenna relative to the horizontal and a second clamping bracket that attaches to the antenna.

Abstract: The radio antenna arrangement for establishing a radio link with terrestrial radio stations includes a group of antennas (10) mounted on an inclined window pane (1) of a particular electrically conductive motor vehicle body, each of the antennas (10) including an antenna element (3) mounted outside of an interior of the vehicle body (8) and on the window pane perpendicular to it; an antenna counterweight (4) mounted on the inclined window pane, the antennas (10) together forming a group antenna with a group antenna connection point (6); and a network (7) containing the group antenna connection point (6), the antennas being radiatively coupled to each other by high-frequency radiation and at least one antenna (10) having an antenna element connection point (2) connecting it with the network (7).

Abstract: A heated microwave antenna ideal for the direct broadcast satellite service, and heated conversion kits for retrofitting to conventional antennas. Antennas modified in accordance with the invention are highly weather resistant, as the dish is warmed to avoid snow and ice accumulation to prevent signal degradation. The heated microwave antenna mounts upon a mast that is bracketed to a satisfactory support. The dish focuses microwave signals upon a low noise broad band amplifier (LNB). The dish comprises multiple laminations from internal elements that are sandwiched together, and exhibits significant mechanical strength and substantial weather resistance. The preferred dish comprises a metallic reflector, a heated grid, an insulation layer, and a backing plate nested together to form a composite, laminated unit. The grid comprises a resistive heater element activated by a temperature-responsive thermostat. A concentric trim ring surrounding the dish periphery waterproofs the antenna.

Abstract: A rod antenna element is connected at its lower end to one end of a coaxial impedance converter, the other end of which is connected to a feeder. A coil antenna element is capacitively coupled to the rod antenna element to provide a double resonance characteristic. When held at its retracted position, the rod antenna element, inserted in an outer conductor of the coaxial impedance converter, may preferably form an inner conductor larger in diameter than that when the rod antenna element is at its extended-out position, and the rod antenna element is connected to a coil antenna element with a low impedance.

Abstract: A driven element is disposed on an antenna axis for transmission of electromagnetic energy in a transmission direction along the antenna axis. First and second parasitic arrays are disposed on opposite sides of the antenna axis in the transmission direction from the driven element. At least a portion of the antenna axis adjacent to the parasitic arrays is without parasitic elements. Each parasitic array has a plurality of parallel parasitic elements or directors spaced apart along a respective array line that includes a proximal portion adjacent to the driven element that extends in a general direction that is at an acute angle to the transmission direction. The first and second parasitic arrays are sufficiently close to the antenna axis to produce a radiation pattern that has a lobe with greatest magnitude in the transmission direction.

Abstract: A motor vehicle antenna system is disclosed for receiving electromagnetically radiated signals in the FM radio broadcast frequency range. The antenna system includes a magnetic current receiving, conformal, substantially rectangular truncated slot antenna. The slot antenna is defined in part by a substantially horizontal portion of a conductive periphery of a window opening of the motor vehicle. The slot antenna is further defined in part by a conductive trace integral with a glazing panel mounted in the window opening. The conductive trace extends horizontally a distance equal to one-half a wavelength in the FM broadcast frequency band. The ends of the trace are effectively connected to the conductive periphery of the window opening.

Abstract: A transponder system employs a transponder antenna with a distributed inductance and capacitance that exhibit parallel and series resonant frequencies. Transmissions to the transponder circuit are made at one or more parallel resonant frequencies to maximize the excitation of the transponder circuit, while return signals transmitted back from the transponder are modulated at one or more series resonant frequencies to maximize the signal current. The transponder antenna is implemented as a pair of aligned coils on opposite sides of a thin dielectric substrate, with the coils connected together through the substrate at one point and the substrate thickness not more than about 25 microns to obtain a significant mutual inductance between the coils.

Abstract: To reduce strong diffractive fields at the baseline edge of a metal body which is reflective of electromagnetic radiation, a substrate substantially transparent to the radiation is placed contiguous to that edge. Conductive reflective elements are carried on an exposed surface of the substrate, in a pattern such that reflection decreases and transparency increases from the baseline toward the terminal edge of the substrate. Thus the diffractive field is gradually reduced.

Abstract: An electrical antenna assembly includes a rod antenna, and a coil antenna carried by one end of the rod antenna. The coil antenna has a dielectric core carried by the rod antenna and preformed with a helical recess, an electrically-conductive helical coil seated in the recess, an electrical connector connected to one end of the helical coil by a crimped solderless connection, and a dielectric sleeve enclosing the helical coil.

Abstract: A wide-banded mobile antenna enhancing signal transmission by broadening the effective transmission bandwidth. The wide-banded mobile antenna is interchangeable with currently existing mobile antennas as the two use connectors established by industry. An antenna matching network is situated within a protective housing having a metal shield. A toroidal inductor is serially connected with the antenna and creates a parasitic capacitance with the metal shield. The resulting network, including the antenna, is tuned. An antenna compensating network increases the bandwidth of the antenna with a parallel resonance network. The parallel resonance network has a capacitor and an inductor connected in parallel to the antenna and each other. The parallel resonance inductor is oriented so that the fields it generates are perpendicular to those of the antenna and the matching inductor to prevent coupling between the inductors.

Abstract: A transmit and receive loop antenna includes a first loop element coupled to an electrical circuit element for generating near fields and far fields and a shunt loop element surrounding the first loop element such that voltages are induced in the shunt loop element by the fields generated by the first loop element. The shunt loop element is constructed from a continuous loop of conductor to maximize current from the voltages induced in the shunt loop element. The current in the shunt loop element generates fields which largely cancel the fields generated by the first loop element in the far field. Thus, the first loop element and the shunt loop element establish a surveillance zone in an area proximate the loop elements. A second loop element, such as a figure-8 loop element may be placed proximate the first loop element and the shunt loop element for receiving electromagnetic energy radiated by a tag circuit which enters the surveillance zone.

Abstract: A mammography antenna arrangement for magnetic resonance examinations of the female breast has first and second conductor loop pairs, each of which is formed by two saddle-shaped conductor loops lying opposite one another and between which an essentially cylindrical examination space, having a receptacle opening, is located. The two conductor loop pairs are rotationally offset by 90.degree. relative to one another in the circumferential direction. A capacitive element is connected in a part of each conductor loop that faces away from the receptacle opening.

Abstract: A mobile antenna mount structure has a two-piece assembly including an upper chamber adapted to hold a whip-type antenna, and a lower chamber for holding a spring-loaded contact. The upper and lower chambers are separated from one another by a wall which prevents passage of water.

Abstract: A high-power broadband antenna comprises an impedance matching transformer electrically coupled to a radio frequency source generating an input signal having a base wavelength corresponding to the lowest frequency of the input signal. The impedance transformer is electrically coupled to at least two vertical antenna sections. Each antenna section comprises a plurality of substantially collinear electrically conductive radiating elements fixed to an electrical insulator mounted on a horizontal ground plane. Each radiating element has a length appropriate to effect optimum overall efficiency of the high-power broadband antenna over the frequency bandwidth of the input signal. At least two loading elements are each electrically coupled between the radiating elements in each antenna section. Each loading element comprises a parallel combination of a resistor, an inductor, and a capacitor to effect optimum overall efficiency of the high-power broadband antenna over the frequency bandwidth of the input signal.

Abstract: A conical microstrip antenna carried by a frustum of a cone with a half-angle at the apex .alpha., height H.sub.0 and a circular reference line of radius R, includes an annular succession of N radiating patches disposed on the frustum and divided into at least one sub-array of radiating patches connected with equal phase by a respective tree-structure feed array to the same common point, the N radiating patches being made on a dielectric material to resonate in a predetermined frequency band having a center frequency Fo. The tree-structure array is formed of n stages each including dividers of the same order, either the second order or the third order. When developed onto a flat surface, the dividers within the same stage i are made up of an integer number of substantially identical straight line segments with equal angles .gamma.

Abstract: A dual function antenna structure transceives in first and second modes. A first feed (120) feeds a primary antenna element (110) for operation in the first mode. A second feed (140) couples via a coupling element (130) to a portion of the first feed (120) or the primary antenna element (110) to realize a secondary antenna element. In a portable radio, dual function operation is thus possible by a compact structure by the first and second feeds (120, 140).

Abstract: An active repeater assembly for in-vehicle use of personal communication devices is both simple and reliable. The assembly includes an RF amplifier coupled to first and second antennas, and is characterized by the total absence of removable coaxial connectors between the antennas and the amplifier. The outside antenna is an on-glass device, mounted on the opposite side of the same window. Oscillation is prevented by the provision of electromagnetic shielding between the inside and outside antennas.