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: The foreshortened dipoles of the antenna described in U.S. Pat. No. 3,732,572 are further substantially shortened without performance impairment with a new construction in which each radiating element comprises a planar rectangular body electrically connected to the feed line by a stem attached to the body remotely from the feed line and spaced slightly from the plane of the body.

Abstract: A shortened wideband decoupled sleeve dipole antenna is disclosed in which a helically wound upper radiating element and an inductively loaded lower radiating sleeve element reduce the linear size of the antenna. Substantial decoupling is provided by a helically wound feed coaxial transmission line within the sleeve element. A matching network at the antenna feed point provides capacitive reactance above the antenna resonant frequency and inductive reactance below the antenna resonant frequency such that an impedance match between the feed coaxial transmission line is obtained at frequencies above and below the resonant frequency and dual-band performance may be obtained.

Abstract: An electric field probe array including several dipole probes, each including a diode connected between two conductors with the diodes being collectively connected to at least two probe terminals. Also disclosed is a system for heating a target with electromagnetic radiation that includes a central control unit, a source coupled to the control unit with the source generating the electromagnetic energy at a frequency and power in response to the control unit, a radiation apparatus coupled to the source for transferring the electromagnetic energy from the source to the target and input circuitry connected to the control unit for indicating the status of the target whereby the operation of the system is controlled by the control unit as a function of the target's status.

Abstract: The invention relates to a directive broad band antenna element of V-shaped dipole type with bent wire- or strip-shaped dipole antenna (A). The dipole antenna is divided into two sections, a first section (S1) where the radiation is minimized (or prevented) by a small distance between the conductors and a reduced phase velocity, and a second section (S2), where the radiation is enhanced by increasing the phase velocity by means of introduced series capacitances (C1, C2, . . . Cn). The series capacitances have respective values which depend on the local angle between the dipole conductors and a radiation axis (x), and are chosen such that the phase velocity is increased to a value which effects radiation contributions from different parts of the conductors to cooperate in the desired radiation direction.

Abstract: Multiband dipole antennas connected to a coaxial feeder are usually not balanced and are not operated at maximum efficiency. In the present invention pairs of capacitors are connected at the feed point of respective half-wave dipoles, associated with different frequency bands to reduce these deficiencies. A similar technique is useful for single band half-wave dipoles and allows unbalanced multiband ground plane antennas to be constructed.

Abstract: A coaxial dipole antenna includes a first radiator which is approximately one quarter wavelength long. A second radiator exhibits length less than one quarter wave length and is coupled to the feed port by a reactive element which has an electrical reactance which is insufficient to increase the electrical length of the second radiator to one quarter of the wavelength. The length of a dipole antenna is substantially shortened while an effective aperture of one half wavelength is maintained by causing a portion of the transceiver housing to radiate in phase with the antenna.

Abstract: The deviation in operating frequency which antenna system elements can handle without serious transmission line mismatch is increased by constructing the antenna such that the inner portions (40, 42) of its legs (40,48 and 42,50) are formed of coaxial transmission line connected so that the outer conductor serves as part of the radiator, and so that the inner and outer conductor of the line cooperate to form compensation stubs whose impedance varies with frequency in a manner to cancel or oppose the reactance which the antenna legs exhibit with frequency change. The stubs are connected in series or in parallel with the antenna feed point and parasitic elements. Surge impedance is selected so that the antenna driven elements (nearly resistive) and signal source, and parasitic elements that incorporate the invention, are mismatched at band end frequencies and center band frequency in apparoximately like amount.

Abstract: A direction finding antenna for accurate direction finding over broad conuous frequency spectrums, independently of polarization, comprising a phased array of six log-periodic dipole antennas with loaded elements.

Abstract: A broadband antenna of miniature size employs an array of dipole elements whose inner ends are connected to a pair of closely spaced parallel central conductors. Three pairs of dipole elements are disposed in a symmetrical array and extend outwardly from the central conductors. The longest pair of dipole elements are capacitively end loaded and the length of that longest pair is approximately one eighth of a wavelength at the lowest frequency in the broadband. The length of the shortest pair of dipole elements is in the range of a third to a quarter of the wavelength at the highest frequency in the broadband. The third pair of dipole elements is a half wavelength at an intermediate frequency in the broadband. At the points where their inner ends are connected to the central conductors, adjacent pairs of dipole elements are spaced apart by a distance in the range of a half to a quarter of the wavelength at the highest frequency in the broadband.

Abstract: A compact, all channel television antenna system is provided for improved reception within buildings where multiple reflections or ghosting and weak signals are typical operating conditions. The high performance in this environment with a very small antenna is achieved by the antenna's directive gain and pattern nulls, good impedance matching, low acceptance of vertical polarization, band switching, and repeatable orientation of the antenna. The antenna is characterized by a miniature, symmetrically top-loaded dipole and efficient matching circuit at the lower VHF television band. The top-loading elements are reused as parasitic elements in a compact, directive array at the upper VHF channels. Similarly, in the UHF television bands bending and top loading is used to reduce the size of radiators and to provide loading for the VHF bands. A construction of UHF half loops in parallel is used with a system of reflecting and directing elements.

Abstract: A linear/circularly polarized antenna system is provided by four conductive elements. The conductive elements are joined in pairs at their ends with the joined ends spaced by a conductive support member from a flat reflector. The lengths of the conductive elements of each dipole element are changed from being equal lengths of approximately a quarter operating frequency wavelength to one slightly longer and the other slightly less than a quarter wavelength to selectively change operation from that of a linearly polarized antenna to that of a circularly polarized antenna.

Abstract: A broadband antenna in the form of a multiple element interlaced dipole array is mounted on a thin elongated strip of dielectric material which is mechanically flexible, light weight and electrically small. Each dipole has a first tapered radiator section with an inductive loading section electrically connected to one end of the tapered radiator section. A capacitive end-loading section is connected to the inductive loading section. Second tapered radiator sections are joined to one another by a second inductive loading section. The inductive loading sections increase the effective electrical length of the first and second tapered radiators, respectively. A UHF gap filling conductor is connected to each of the dipoles to suppress grating lobes at the high-frequency end of the frequency spectrum received by the antenna.

Abstract: An apparatus and method wherein an electrial impulse source transmits a radar-type signal through an antenna into the ground and is reflected by a target. The reflected signal or echo is detected by the antenna and an analog-to-digital converter converts it to a digital form which may be readily operated on, stored and recalled. A memory stores the information until recalled for comparison with a subsequent signal to give an indication of the location of metallic and non-metallic buried targets.

Abstract: A novel antenna is disclosed which provides inherent filtering action by ch the frequency response curve of the antenna can be shaped. In the preferred inventive embodiment, the antenna comprises at least one elongated receiving element, and preferably two such elements in the form of a dipole, both elements being constructed, at least in part, of an electrically resistive material. A detector, such as a diode detector, is directly coupled to the receiving elements. The resistance of the receiving element and the capacitances of the receiving element and the detector form a distributed parameter RC filter, the values of which parameters can be carefully controlled so as to provide the desired frequency response curve shaping. In the preferred inventive embodiment, a conductive strip is disposed along the length of and preferably to both sides of each receiving element, with a layer of dielectric material being sandwiched therebetween, whereby the filtering action is enhanced.

Abstract: A whole wave antenna is placed on an insulating support and has its feed input located a little above its middle. In order to reduce secondary lobes inductive reactances are serially inserted in the antenna on each side of its feed input so as to produce a rapid rotation with inversion of the phase of the currents on each side of the feed input.

Abstract: A directional loop antenna, particularly for television signals, comprising a conductive member shaped into a folded dipole configuration is disclosed. Covering the conductive member is a plastic material which may comprise two coaxial coatings of different dielectric constants. The folded dipole legs are formed into a generally circular configuration with the folded ends brought together and overlapped to form a pair of loops. The two loops thus formed lie in planes which intersect each other at a point beyond the forward side of the antenna. At the opposite side of the loops, the two ends of the conductive member emerge to form terminals for connection to a transmission line. At this side of the antenna the loops are spaced farther apart than at the side where the folded dipole ends overlap. This construction results in a highly directional antenna capable of wide frequency band reception with a good match to a 300 ohm transmission line.

Abstract: An improved gain antenna which is vertically mounted to a horizontal ground plane is disclosed. The gain antenna substantially consists of a radiating conductor having first and second ends and a centrally located feed point, and phasing apparatus electrically connected to the conductor for producing a predetermined current distribution. The phasing apparatus produce shortened out of phase current sections along the length of the conductor. Centrally feeding the gain antenna results in an improvement in the bandwidth and input impedance. The conductor consists of a linear section of coaxial cable which extends vertically from the horizontal ground plane to approximately the central feed point and a solid conductor rod which extends vertically upwardly from the central feed point. Current phasing apparatus having improved bandwidth and reactance characteristics are also described.

Abstract: An elongated, rigid, television frequency antenna of the dipole type, for indoor reception use, including a long, flexible, lead-in or transmission line for connection to a television set, the antenna itself being otherwise physically free, with no supporting structure of its own, so that it may be disposed in innumerable positions, or diverse orientation within a room, for maximum reception. Both of the dipole elements are enclosed within a single plastic, elongated sturdy tube resembling a stick, for facilitating selective and desired orientation of the antenna, and supported in such orientation by the floor, or walls of the room. The transmission line is also so connected to the dipole that it modifies the characteristics of one half of the dipole more than the other, thus providing greater choice of orientation.

Abstract: A center fed dipole with a shortened aperture is described. A first rod-like radiator element approximately a quarter wavelength long at the center operating frequency of the antenna is coupled to the inner conductor of a coaxial transmission line. A second radiator element includes a hollow-conductive cylinder, coaxial with the coaxial transmission line, and a coil. The conductive cylinder is substantially less than a quarter wavelength long at the center operating frequency of the antenna. The conductive cylinder is coupled at one end to the outer conductor of the coaxial transmission line and the end of the cylinder remote from the one end is coupled to the coil.