Abstract: The present invention features a broadband radio frequency (RF) device in the form of a power splitter. A broadband spiral transmission line power divider is used to divide power into two powers with a constant phase difference between the two divided powers. The power divider produces large bandwidths.

Abstract: An antenna for passing a cable to a second antenna includes shorts positioned along a circumferential perimeter of the antenna, first and second bicone sections of oppositely directed conductive cone sections energized at respective apices and opening along an antenna axis, first and second dipole sections, where the first dipole section is joined together with and extending from the first conical section to the circumferential perimeter of the antenna, and where the second dipole section is joined together with and extending from the second conical section to the circumferential perimeter of the antenna.

Abstract: The invention as disclosed is a direct fed bifilar helix antenna. The bifilar helix is lengthened as needed to obtain the desired unidirectional pattern. The bifilar helix is employed as an infinite balun to bring a feed cable onto the antenna structure and eventually connect the feed cable to the antenna feed point. The bifilar elements are widened such that the combined width of each element is as wide as practically possible before the elements touch and/or overlap (approximately 98.5% of the available width) so that the practical lowest characteristic impedance value of approximately 50 ohms is obtained so that there is no need for a matching network.

Abstract: A tapered direct fed bifilar helix antenna comprises bifilar antenna elements which helically spiral around an antenna axis to define an outer cylindrical shape of the direct fed bifilar helix antenna. The width of the bifilar antenna elements at the feed end of the antenna is sized to provide the antenna with an approximately fifty ohm characteristic impedance. The individual filar elements taper at a predetermined axial position from a maximum width at the feed end to a minimum width at the end furthest from the feed end. A fifty ohm coaxial cable directly feeds the tapered bifilar antenna elements.

Abstract: A vertically polarized dipole or bicone antenna is positioned cylindrically with in many cylindrical layers of polarizing grids that slowly rotate the incident field to cross 0 degrees, i.e., 90 degrees to the horizon, and to attenuate or minimize the effects of gain nulls from reflections off of the innermost grid layer. Such an antenna is used for detecting both horizontal and vertical polarized signals over a broad bandwidth whereby the response to both polarizations is equal.

Abstract: A broadband power splitter and phase shifter having a plurality of transmission lines, a 3 db, zero degree power splitter for splitting a signal, an open quadrifilar spiral for receiving a first signal and reflecting power, a modified, open quadrifilar spiral for receiving a second output after a delay and for reflecting power, and wherein a difference between the reflected power from the open quadrifilar spiral and the modified, open quadrifilar spiral in conjunction with a delay provides a constant phase shift over a broad range of frequencies.

Abstract: A forty five degree polarized antenna having grid layers wrapped around a vertically polarized dipole, or grids wrapped internally or externally around a vertically polarized bicone antenna, and having grid segments separated by capacitors that can attenuate, remove or minimize circumferential resonances that appear due to the presence of the grids and reduce the nulling effects from reflections from the innermost grid layer.

Abstract: A slotted bifilar or quadrifilar helix antenna has a plurality of helical antenna elements. The antenna elements have an outer planar surface. A slot element is secured to an interior of the outer planar surface. The slot element extends radially inwardly to a slot element edge. At least two radially opposite slot element edges define a tapered slot. At a shorted point on the antenna, at least one radially opposite pair of slot elements are electrically shorted together. A feed point is axially offset from the shorted point along the antenna axis.

Abstract: An open Yaggi antenna array is disclosed wherein the reflector element and parasitic director elements of the antenna array are opened in line with the feed point of the driven element so that the reflector and director elements do not cause a shunting effect on the driven element of the antenna.

Abstract: A quadrifilar helix antenna is provided having a feedpoint for the antenna connecting to individual helical antenna elements. A capacitive network, distributed along the length of the antenna, constitutes a variable frequency shunting network. At each position a first capacitive structure, that may comprise a single capacitor or multiple capacitors in series, interconnects a first pair of opposite antenna elements; a second capacitive structure interconnects the second pair of opposite antenna elements. As an applied frequency increases, the capacitive structures progressively short the opposite antenna elements thereby electrically reducing the antenna length.

Abstract: A quadrifilar helix antenna is provided having a feedpoint for the antenna connecting to individual helical antenna elements. Each antenna element comprises a normal helix element with a plurality of series capacitors inserted along the element length with a maximum capacitor value at a feed end and a minimum capacitor value at a remote or unfed end. Again, the element is not simply a series of connected capacitors-if it were it would not radiate. The element is a normal element, which is inductive, which has had capacitors inserted along its length.

Abstract: An antenna is provided that can switch from generating a low radiation angle to a high radiation angle. The antenna comprises a quadrifilar helix antenna in which the helical antenna elements have a first pitch at one end of the antenna and a second pitch at the other end of the antenna. Controlling the phase of a driving signal and isolating one section of the antenna are steps that facilitate switching the antenna from generating a pattern with a low elevation angle or high elevation angle.

Abstract: A quadrifilar helical antenna is provided having a feedpoint for the antenna connecting to individual helical antenna elements. Each antenna element tapers from a maximum width at the feedpoint to a minimum width. The tapered antenna elements provide impedance transformation. The antenna produces a cardioid pattern that corresponds to antennas with constant width antenna elements.

Abstract: A bicone antenna that facilitates the passage of cables for at least one other radiating antenna. The bicone antenna has a plurality of inductive shorts spaced approximately one-quarter wavelength (at the cut-in frequency) from the antenna axis. Each inductive short provides a pathway for a cable for another antenna. Consequently, an antenna cable from each of one or more other antennas can be led to a center point on the bicone antenna, directed radially along a cone to an inductive short, led through the inductive short and directed along the surface of the other cone to the center line. The outer conductor of each antenna cable attaches to an antenna surface.

Abstract: A helix antenna includes a base portion for containing a feed network including a power input, a 90 degree power splitter in communication with the power inlet, and first and second 180 degree power splitters in communication with the 90 degree power splitter. A support tube is mounted on the base portion, and a plurality of disk separators are mounted on the tube. Four elongated elements are wound around the tube and are spaced therefrom by the disk separators. The elements are connected to end-most lower and upper ones of the disk separators, the elements extending toward a center feed point of the upper disk separator. First and second radially opposite pairs of feed cables are wound around the support tube, extending from the lower disk separator to the upper disk separator, and are in communication, respectively, with the first and second 180 degree power splitters.

Abstract: A quadrifilar helical antenna is provided having feed points connected to e individual helical antenna elements through a spiral coupling path. The spiral coupling path additionally is wound contrarily to the winding of the helix. Moreover, each path has variable dimensions to provide impedance matching.

Abstract: A wideband, low-profile, towable submarine antenna is provided. The antenna is formed with a metal cylinder having a longitudinal slot. The entire enna may be encapsulated in a tow body and towed horizontally on the surface of the water. The longitudinal slot is open at one end and closed, or shorted, at the opposite end. The location of the antenna feedpoint is placed along the slot so as to set up two sets of frequency resonances. This configuration provides two voltage standing wave ratio minimums, thereby extending the effective reception and transmission range over the entire military UHF frequency range (225-400 MHz).

Abstract: A broadband phased antenna is comprised of multiple patches which are dirly feed. The multiple patches provide the broadband patch antenna having overlapping narrow frequency bands and comprise a ground-plane element, multiple antenna elements, multiple dielectric layers, an RF feed line, and a feed arrangement. The ground-plane element has predetermined length and width dimensions and an aperture therein at a predetermined location near its center. The multiple antenna elements have an uppermost antenna element. The multiple dielectric layers are respectively interposed between and separate the multiple antenna elements into a stacked arrangement having odd and even numbered antenna elements.

Abstract: A broad passband pressure barrier arrangement is provided for insertion in circular waveguide between a source and a receiver of radio frequency (RF) energy with a spatially circumferential electric field characteristic of the TE.sub.01 mode. At least two cylindrical barrier regions are coaxially aligned and arranged symmetrically in mirror image fashion about a radial plane of the circular waveguide. The cylindrical barrier regions include at least one solid cylindrical plug region sealed in a cross-section of the circular waveguide and having a longitudinal thickness sufficient to withstand a predetermined pressure load. Each of the cylindrical barrier regions are defined by a characteristic impedance at opposing end faces thereof and a by characteristic impedance between the opposing end faces. A region-by-region impedance analysis process begins with an end face of the arrangement that is furthest from the source and is completed with an end face of the arrangement that is nearest the source.

Abstract: A quadrifilar helix antenna is provided having a feedpoint for the antenna connecting to individual helical antenna elements. A capacitive network, distributed along the length of the antenna, constitutes a variable frequency shunting network. At each position a first capacitive structure, that may comprise a single capacitor or multiple capacitors in series, interconnects a first pair of opposite antenna elements; a second capacitive structure interconnects the second pair of opposite antenna elements. As an applied frequency increases, the capacitive structures progressively short the opposite antenna elements thereby electrically reducing the antenna length.