Abstract: An antenna to be mounted on a vehicle. The antenna includes a ground plate with an L-shaped radiator plate and an L-shaped sub-radiator plate. One leg of the radiator plate and sub-radiator plate are parallel to the ground plate. The parallel legs are spaced from the ground plate. The other leg is perpendicular to the ground plate. The perpendicular leg is separated from the ground plate by a small gap. The two legs are opposed to each other with a gap between the legs parallel to the ground plate. In some embodiments, filler is placed between the plates.

Abstract: In view of the introduction of cellular radio, there is a requirement for an antenna of simple construction which can be sold in a consumer market. While the invention meets this need it also has application to the problem of providing TM.sub.01 to TE.sub.01 made converters. The invention employs radial conductors printed on a dielectric substrate and aligned with the transverse electric field in a waveguide supporting the TM.sub.01 mode. Circumferential conductors, each coupled to one of the radial conductors, act as monopoles radiating the required field in an antenna where the radial conductors project through apertures in the waveguide. For the mode converter, both radial and circumferential conductors are inside the waveguide, with the radial conductors aligned with the transverse electric field of the TM.sub.01 mode. Arrangements for maximizing the field at the position of the radial and circumferential conductors are described as are means for preventing the propagation of unwanted modes.

Abstract: A compact, wideband antenna system is provided by an open-sleeve, meander dual zigzag monopole consisting of a driven element configured from two symmetrically-oriented meander wires fed from a common feed point and one or two closely-spaced parasitic elements (open sleeves), also configured from two meander wires and shorted to ground plane. The meander monopole has a low silhouette and provides approximately 50% reduction in height as compared to a conventional monopole. By varying the size, geometry, and location of the open sleeves, antennas are synthesized to achieve specific frequency response characteristics. Measurements have demonstrated that the meander monopole is capable of providing the desired radiation pattern characteristics over a 3:1 frequency band.

Abstract: The antenna of the invention is suitable for use with an aircraft and is capable of receiving a plurality of frequency ranges in the communication band and provides a directional antenna. To this end there is provided an upper wing element from which extend vertically two outer leg elements and a central leg element. The central leg element extends into a fairing disposed below and substantially coextensive with the wing element. Two symmetrical slots are disposed in the wing element symmetrically disposed about the central axis. Another slot extends through the central leg element and the fairing. The slots are provided with capacitors to provide antiresonant circuits at predetermined frequency ranges.

Abstract: An antenna structure includes a radiator element secured at one end to a ground plane. Two conducting plates separated by an axial spacer are secured to the opposite end of the radiator element.

Abstract: An antenna comprising a plurality of axially extending, radially spaced, electrically conductive coaxial cylinders and mechanism electrically coupling opposite ends of said cylinders to the adjacent opposite ends of alternate adjacent cylinders.

Abstract: A VHF monopole antenna unit, particularly adapted for operation in the 30 MHz frequency range, yet capable of embodiment in a compact structure only approximately 11/2 feet in height is described. Coarse tuning is accomplished in a number of switched bands, for each of which is provided a specially designed matching network comprised of inexpensive L-networks of inductors and capacitors. Tuning is accomplished through adjustment of inductor elements. The simple, inexpensive design of the matching circuits eliminates need for intricate mechanisms typically used for automatic impedance matching over a wide band and also for a broadband impedance matching transformer. The compactness made available by the unique top-load structure design is further made possible by provision of a specially designed dielectric filled vertical antenna element, accomplishing the same range and efficiency in an even more compact antenna.

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: An antenna comprising a collinear array of "thick" and "thin" elements selected to produce a given current distribution so that when the antenna is vertically polarized a circular horizontal plane pattern and a highly directional vertical plane pattern are produced which has a single principal lobe directed generally at the horizon.

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: The invention relates to an antenna structure comprising a number of parallel conductors having dimensions and spacings which are small against operating wavelength, and positioned perpendicular to a conducting ground plane; the upper ends of the conductors are terminated by metal plates acting as capacitors against the ground plane, and interconnected by inductive elements, the lower ends of some of said conductors are electrically connected to said ground plane, while another one of these conductors is connected to a power source to impress a voltage between the lower end of said other conductor and said ground plane.