Abstract: The present invention is directed to a dual band, omni-directional antenna having a symmetrical radiating structure defined by a pair of conductive portions interconnected by a tuning bridge formed on a printed circuit board. An outer housing holds the circuit board in place. An adhesive layer is used to secure the antenna to a dielectric, such as the rear window of an automobile. The antenna housing incudes an outer surface includes a plurality of surface interruptions in the form of ridges and valleys that render the housing flexible so that it may conform to the shape of different mounting surfaces. The tuning bridge of the antenna permits tuning of the resonant frequency bands for the radiating structure to define two separate and distinct, selectable frequency bands.

Abstract: An improvement is disclosed to an antenna structure that is a pair of coplanar triangular loops with a corner of each triangle at the center and the triangle sides opposite those corners placed parallel to each other to form the outer sides of the structure. The improvement is extra conductors placed between the central point and the center of the outer parallel sides. This improvement not only strengthens the structure, which may be important in the high-frequency spectrum, but it also is convenient for turnstile and log-periodic arrays of such structures.

Abstract: An electric dipole antenna includes a first and a second arm extending along a dipole axis away from a feed gap in substantially opposite directions. A first and a second end body are operatively coupled to opposite ends of the first and the second arms. Each end body has a width dimension which extends perpendicular to the dipole axis. A dipole length dimension extends along the dipole axis through the first and the second arms and the first and the second end bodies. A current conduction circuit provides a radiation field for the electric dipole antenna. The circuit passes along the first and the second arms and around a closed perimeter of the first and the second end bodies. As a result, the electric dipole antenna exhibits a series resonant frequency at a wavelength which is at least eight times the dipole length dimension. In addition, an electric monopole antenna design is used. The monopole is situated over a conducting ground plane which reflects the above-ground plane portion of the antenna.

Abstract: A broad band electrically small antenna comprising opposed wire triangular outline shaped elements connected to a source or receiver at their respective apexes and a second set of wire triangular outline shaped elements connected to the base members of the first set of triangular shaped or "bowtie" elements and extending generally parallel thereto and spaced from the first set. The antenna exhibits a low antenna factor and voltage standing wave ratio at relatively low frequencies in the range of 20 to 200 megahertz, for example. The folded triangular shaped element antenna is connected to a log periodic dipole antenna array to provide broad band reception and transmission characteristics. A second single plane or folded triangular element or bowtie antenna may be mounted on and electrically connected to the array to improve the operating range of the antenna.

Abstract: A television antenna exhibiting a bandwidth including VHF and UHF, a low standing wave ratio, and an essentially omnidirectional radiation pattern. The antenna includes a sheet-like antenna element having a feedpoint, and an electromagnetic characteristic having non-uniform variation with distance from the feedpoint.

Abstract: A single element, multi-frequency dipole antenna including two substantially equal arm sections of conductive material extending co-axially in a straight line in opposite directions from each other, each arm section being a mirror image of the other arm section throughout its entire length, each arm section including at least two contiguous shorter sub-sections of j.sub.1, j.sub.2, . . . j.sub.n lengths, wherein j.sub.1 represents the length of the innermost sub-section, sub-sections terminated by discontinuities wherein j.sub.1 represents the 1/4 wavelength of the highest resonant frequency and each consecutive-integer sequence of j sub-sections represent the 1/4 wavelength of lower resonant frequencies.

Abstract: In a broadband antenna using a semicircular conductor disc, a semicircular cutout is formed in the semicircular radiator concentrically therewith. Alternatively, a semicircular arcwise radiating conductor with a semicircular cutout defined concentrically therewith is bent into a cylindrical shape to form a radiator.

Abstract: A folded crossed grid dipole antenna element includes one or more partially or fully conductive areas in the antenna element. The conductive areas are defined by a group of conductors of the antenna element. In a further configuration, upper and lower tiers of a conventional antenna element are essentially switched and a transmission feed line is provided to the upper tier via an opening in the lower tier.

Abstract: An antenna element comprised of an hollow conductor and a central grounded onductor within the hollow conductor, there being a variation in capacitance between the hollow conductor and the central conductor along their length.

Abstract: A cellular telephone system has a special cellular telephone antenna that can be hidden from view so as to deter thieves and vandals as well as prevent damage to the antenna during car washes. In the preferred form, the cellular telephone antenna comprises a rear view mirror-mounted antenna. The cellular telephone antenna can also comprise a sun visor mounted antenna, side view mirror-mounted antenna, glove compartment-mounted antenna, or dashboard-mounted antenna.

Abstract: The antenna array element provides an active element input impedance with a practical tuning frequency range of 3.6:1 (almost two octaves) and a wide instantaneous bandwidth. The balanced feed inputs to the element may be phased to produce any desired polarization. The antenna element is formed from two stacked crossed grid dipole elements with carefully optimized dimensions. The interelement array spacing is the maximum possible for/grating lobe free operation using a rectangular array lattice.

Abstract: A biconical antenna is used to measure the intensity of incident RF electrical fields. The antenna comprises a pair of aligned rods with wires distributed around the rods to define conical cavities around each of the rods. A ferrite choke surrounds each of the rods within the conical cavities to choke off residence within the cavities.

Abstract: A wide bandwidth, wide scan, antenna array element provides an active element impedance close to 350 ohms over a bandwidth approaching one octave in a periodic equilateral triangular array lattice. The two balanced feed inputs to each element may be phased to produce any desired polarization. The interelement spacing is the maximum possible for grating lobe free operation. This antenna element combines features of a crossed grid dipole with a folded dipole. The antenna structure consists of conductors lying in two planes which are parallel to a ground plane. These are joined by a limited number of perpendicular conductors. The VSWR remains below 2:1 in a 300 or 350 ohm system for scan in any direction out to 30 degrees off of broadside over a bandwidth approaching one octave.

Abstract: A small volume, broad beam antenna is disclosed. The antenna has four cavity backed elements. Each of the elements is triangular shaped and is mounted such that the narrow portions of the triangular elements are over the center of the cavity.

Abstract: The antenna system includes a complementary "bowtie" dipole-slot antenna, the antenna having symmetrical halves about a plane of symmetry. The two halves of the antenna are slanted at the plane of symmetry such that the total included angle between the halves is between 70 degrees and 120 degrees. A ground plane is positioned between the halves of the antenna extending through the plane of symmetry. A circuit is included for independently exciting the halves of the antenna. In a second embodiment the ground plane incorporates a pair of notch antennas. Thus, both vertical and horizontal polarization can be achieved independent of each other.

Abstract: A discontinuous panel shaped element forms one of the radiating dipole members of a radio frequency mobile antenna fed by a coaxial cable. The discontinuous element decouples antenna currents in the coaxial cable placed at short to medium distances from the element, while maintaining matched element performance as a long distance transmitter. The radiating elements are surrounded by an insulating material which serves as a dielectric, further improving antenna performance and also serving as environmental protection. The radiating elements are made from readily available sheet stock materials aligned in a generally planar configuration. The discontinuous dipole member is attached to the shield and the other dipole member is connected to the center lead of the coaxial cable. A small section of the central cable conductor is stripped of insulation and shielding, to serve as a miniature loading coil for loading the first plate-type conductive element.

Abstract: A secondary radar transponder on a mobile target has an antenna arrangement which can receive interrogation signals from all directions and radiate reply signals. The antenna arrangement includes several individual antennas, each of which, with its primary lobe, covers a specific sector of the entire 360.degree. range and is connected to a receiver, so that through receiving level comparison, that particular sector from which the interrogation signal incides can be ascertained. The reply signal is then radiated only by the individual antenna covering that particular sector. The transponder is particularly suited for identification friend-foe (IFF) purposes.

Abstract: A foreshortened log-periodic antenna which includes variously configured dipole elements and a tapered feedline is disclosed. The dipole elements are arranged in four regions. A first region, located nearest to a feed end of the antenna, includes solid triangular dipoles having constant base-to-height ratios. A second region, adjacent to the first region, includes solid triangular dipoles having decreasing base-to-height ratios. A third region, located adjacent to the second region, includes a single linear dipole. A fourth region, located adjacent to the third region and nearest to a low frequency end of the antenna, includes foreshortened dipoles. The feedline may be implemented either in coaxial or microstrip form so that a lower characteristic impedance is pressed at the feed end of the antenna than at the low frequency end of the antenna.

Abstract: A fin line circuit card containing a fin line slot feeds a dipole antenna ich extends a quarterwave outside the waveguide and provides an energy beam focal point at or near the open end of the waveguide. The dipole antenna thus maintains a wide and nearly constant beamwidth, low VSWR and a circular symmetric radiation pattern for use in electronic warfare direction finding and surveillance applications.

Abstract: A TV receiving antenna with broad band and capable of connecting with a coaxial cable comprising a sheet of electrically non-conductive synthetic plastic material; a pair of antenna elements of metallic foil in the shape of substantially a triangle or a combination of a triangle and a rectangle being superimposed on one side of said sheet, a pair of frequency compensating members of snake-shaped strip line of metallic foil connected to said antenna elements respectively being superimposed on the one side of said sheet; a pair of antenna elements of metallic foil in the shape of a trapezoid or a combination of a trapezoid and a rectangle being superimposed on the opposite side of said sheet; a pair of frequency compensating members of snake-shaped strip line of metallic foil connected to said antenna elements respectively being superimposed on the opposite side of said sheet; and impedance transformers of microstrip lines of metallic foil on each side of said sheet also superimposed for matching the antenna el

Abstract: A biconical antenna for ultra broad-band linear polarization operation in which capacitive sleeve VSWR tuning is effected between the apex regions of the two cones and zig-zag substantially V-shaped spokes are provided conically diverging from the cone base peripheries.

Abstract: In a log-periodic monopole antenna array of the type described in U.S. Pat. No. 3,286,268, each antenna of the array having active elements spaced over the top surface of a ground structure and grounded parasitic elements interspersed between the active elements, the improvement of means for mechanically and electrically connecting the parasitic elements to a non-solderable ground structure comprising an elongated block compressed into a correspondingly shaped groove in the structure. Screw means threadedly engage the ground structure in a direction transversely of the top surface thereof and abut against the block. The lower strip portion of the parasitic elements is disposed in the groove between the block and a groove side wall and is compressed therebetween when the screw means is tightened into the structure and against the block.

Abstract: A foreshortened log periodic antenna includes variously configured dipole elements which are arranged in four regions along the axis of the array. The first region includes a series of solid, triangular dipoles characterized by substantially constant base/height ratios. The second region similarly includes a series of solid, triangular dipoles. However, these elements are characterized by decreasing base/height ratios so as to afford a gradual transition into the third region, which includes a single linear dipole. The fourth region includes a series of solid or hollow rectangular elements connected by respective stems to the antenna feedline. In a manner set forth in U.S. Pat. No. 3,732,572, entitled "Log Periodic Antenna with Foreshortened Dipoles", the rectangular elements effect a reduction in the width of the array without a substantial affect on electrical performance.

Abstract: Two or mutually nonparallel dipoles for operation over a common frequency band. Each of the dipoles has a central feed port and an inner end connected to a junction box with conductive walls. Each feed port is connected through a junction in the box to a receiver for the common frequency band. For diversity, two receivers for the common frequency band are connected to the two feed ports. For pseudodiversity, the dipoles are connected to a common receiver and are positioned to have noncoincident phase centers separated by more than one-quarter wavelength over some part of the common frequency band.

Abstract: An antenna arrangement consists of a dipole radiator which is fed via a Triplate three-layer transmission line. The dipole is arranged to radiate and receive plane polarized electro-magnetic radiation having a plane of polarization which is determined by the orientation of an elongate slot in the dipole radiator. The Triplate is coupled to the dipole so as to maintain a substantially constant impedance over a reasonably wide bandwidth. A large number of similar dipole radiators can be mounted side by side and fed from a common Triplate structure and in this latter case a common reflector is used for all dipoles and is mounted on the Triplate structure itself.

Abstract: A broad band dipole antenna of short length is formed by two tubular linear radiators which are spaced apart at their adjacent inner ends. Each of the radiators is encased in an electrically insulative sleeve and the antenna is liquid loaded along its length by a jacket of conductive fluid disposed between the insulative sleeve and an insulative tubular housing surrounding the radiators. The dipole is center-fed and each of the radiators, at its outer end, terminates in a connection to one end of a lumped resistive load whose other end is connected to a conductive disk that is in contact with the conductive liquid.

Abstract: The plate-type antenna is constituted by two tangent circular rings lying in a common plane and interconnected by a slit which is narrow and oriented in the direction of an axis which joins the centers of the rings. The slit extends from the internal edge or circumference of one ring to the internal edge or circumference of the other ring. The tangency zone has a given width which is small as possible in the direction which is perpendicular to the axis of the two rings. One edge of the slit is excited or energized in the immediate neighborhood of the center of symmetry of the antenna. Ground is connected to the middle point of at least one ring located on the axis on the other side of the center. The antennas may be assembled into networks. They may be constructed as double-faced printed circuits.

Abstract: T.V. reception from transmitting stations located beyond the range commonly covered by T.V. receivers using conventional antennas is achieved by means of a highly directional bi-conical antenna structure that accommodates both VHF and UHF signals. Two truncated conductive cone antenna elements are mechanically connected at their apexes to the ends of an r.f. coil to provide the bi-conical antenna structure. The structure is horizontally positioned and rotatable for alignment with a desired station for optimum reception. A monopole antenna element is center tapped to the r.f. coil and the television UHF antenna lead is connected to the r.f. coil. The VHF antenna lead is connected to the bi-conical antenna structure.

Abstract: A dipole antenna consisting of a number of sub-elements, each sub-element comprising a plurality of thin electric conductors or strips of wires arranged on the surface of an insulating cylinder. The conductors in each sub-element have the same length and are distributed around the circumference of the cylinder, so that each such sub-element forms a so-called "thick" dipole element. The lengths of the conductors in different sub-elements are different, so that the sub-elements together will cover a broad frequency band. At least each conductor in the group having the longest conductors are provided with inductive reactances, to prevent excitation of said longer conductors in higher modes at resonance frequencies of the shorter conductors.

Abstract: A folded back doublet antenna including two symmetrical half-plates separd at their one ends by a cut, a long, continuous plate separated from one side of each of the half-plates by a gap, linking sections joining the other external ends of the half-plates to respective ends of the continuous plate, and a line feeding the antenna in the vicinity of the cut and extending along the axis of symmetry of the half-plates. The half-plates have a common width, which is much larger than the width of the continuous plate. The half-plates constitute an input side and the continuous plate constitutes a folded back side.

Abstract: A thick folded doublet antenna, the diameter of the current-receiving wire of which is on the order of ten times greater than that of the folded wire, the current-receiving wire comprising two half-wires of exterior symmetrical cylindrical form terminating at the center in two opposed frusto-conical portions, the small bases of which are close to each other, a coaxial conductor having an impedance of approximately 50 ohms extending axially through one of the half-wires, characterized in that the central conductor of the coaxial line is extended across the space between the bases of the frusto-conical portions and penetrates coaxially into a bore in the other half-wire, the central conductor being insulated from the other half-wire, the length of penetration of the central conductor being very short, and the coaxial line being supplied with signals at frequencies whose wavelengths are approximately six times the total height of said doublet antenna.

Abstract: A thick folded dipole having an operating frequency which is far less than he first resonance frequency. The dipole includes a folded strand and a thick fed strand having a diameter which is about ten times greater than the diameter of the folded strand. The fed strand comprises two spaced apart cylindrical half strands having ends in the form of conical frustums and coaxial bore holes. A center conductor of a coaxial cable extends through the folded strand, the bore hole of one half strand, the space between the half strands and into the bore hole of the other half strand. Symmetrical spaced apart short circuits for matching the radiation impedance of the dipole by varying the distance between the short circuits are provided between the fed strand and the folded strand. In another embodiment there is disclosed a thick folded half dipole including a folded half strand and a thick fed cylindrical half strand.