Abstract: An electromagnetic transmitter arrangement includes an antenna line array or subarray defining at least first and second ends, and including first, second, third, fourth, and fifth antenna elements, arranged with the first antenna element at the first end, the fifth element at the second end, the third element at the center, the second element between the first and third elements, and the fourth element between the third and fifth elements. Multiple (N) corresponding radio frequency sources are provided, each source communicating with a respective antenna element along a given radio-frequency signal path extending from the given signal source to the given antenna element, and where a first signal source generates signals at frequency f0, and each of the N?1 additional sources generate signals at frequencies of f0±(N?1)?f, where N is an integer greater than or equal to 5.

Abstract: A method for making a dielectric-slot polarizer includes affixing plural dielectric sheets in a stack with those sheets having the greatest dielectric constant toward the center of the stack. The dielectric sheets may be fused or joined to each other by heat, pressure, or both. A dielectric support sheet is affixed by adhesive to a first side of the stack to form a partially supported stack. Slots are defined through the partially supported stack down to the adhesive. A second dielectric support sheet is adhesively affixed over the slots of the stack to define the polarizer.

Abstract: A dielectric-slot polarizer arrangement includes a first dielectric polarizer plate with first elongated aperture arrangement, and second and third dielectric polarizer plates, also defining elongated aperture arrangements parallel to or registered with the first aperture arrangement. The second and third dielectric plates sandwich the first plate. The bulk dielectric constant of the first plate exceeds that of the second and third plates. The effective perpendicular and parallel dielectric constants of the first plate exceed those of the second and third plates. Ideally, the dielectric plates are free of metal.

Abstract: A radar system comprises an electromagnetic transmitter and an array of antenna elements connected in Multiple-Input Multiple-Output manner for routing signals reflected from the target to a plurality of receive beam rotation processors. The receive beam rotation processing for each antenna element includes application of rotation frequency offsets to the received signals and summation in summing and differencing adders to generate I and Q components of the rotating beams. The I and Q components for each element are summed to generate received signals including angle-or-arrival (AOA) information. The AOA information is further processed by correlating with reference replica AOA signals and by averaging to determine the actual AOA. The transmitter may have multiple contrarotating beams generated by application of frequency offsets. The transmit and receive beam rotations may be synchronized.

Abstract: In various embodiments, the present invention provides electrically conductive and radio frequency (RF) transparent films that include a graphene layer and a substrate associated with the graphene layer. In some embodiments, the graphene layer has a thickness of less than about 100 nm. In some embodiments, the graphene layer of the film is adhesively associated with the substrate. In more specific embodiments, the graphene layer includes graphene nanoribbons that are in a disordered network. Further embodiments of the present invention pertain to methods of making the aforementioned electrically conductive and RF transparent films. Such methods generally include associating a graphene composition with a substrate to form a graphene layer on a surface of the substrate.

Abstract: An antenna element includes a ground plane, a first conductive disk lying parallel with the ground plane and spaced therefrom, and a second conductive disk, larger than the first disk, more remote from the ground plane than the first disk. A electrical and thermal conducing element may make electrical and thermal contact with the ground plane and the first and second disks. A radome extends over the element and in thermal communication with the thermal element. A conductive or high-dielectric-constant planar wing is supported by the ground plane outside of the projection of the disks, with a central axis of the element lying in the plane of the wing. If two wings are present, one may be electrically conductive or dielectric and the other conductive or dielectric. The wings, when the element is arrayed, lie part-way between the centers of adjacent array elements.

Abstract: An antenna element for use with an array includes an elongated slot fed from a waveguide for exciting a patch radiator. An elongated thermally conductive strip lies between the slot and the patch, and is parallel with the direction of elongation of the slot. A radome extends above the patch. In one embodiment, a thermal conductor rod extends from the thermally conductive strip to the patch, and coaxially above the patch to the radome. In a preferred embodiment, the slot is ridged and (inter) digitated near its ends. The slot is excited from stripline by means of an elongated conductive strip orthogonal to the elongation of the slot. Through vias extend through and between thin electrically conductive layers to define the waveguide and provide heat sinking.

Abstract: An antenna, which may be used as an element in an array, includes an elongated curved dielectric member having a high dielectric constant. One end of the dielectric member is in physical contact with the “center” conductor of an unbalanced transmission line, and projects above a ground plane. The dielectric member is roughly vertical at the feed point and horizontal at the distal end. The dielectric constant is greater than 10, preferably greater than about 80, and most preferably 120 or more.

Abstract: A broadband mesh antenna and a phased array broadband mesh antenna are provided. The antenna of the present invention is a mesh antenna system that may be implemented with printed circuit board technology and wired technology that operates with increased bandwidth. The mesh antenna system provides for a single mesh antenna to operate at a wide range of frequencies. The antenna may be employed as a high efficient broadband antenna for rockets, space vehicles and ships when placed inside a metallic open box.

Abstract: A high gain dual port antenna and antenna array provide enhanced isolation between a receiver and a transmitter. The antenna includes a helical element connected to one port and a dipole element positioned within the helical element and connected to a second port. The helical element can have a uniform diameter or varying diameters, while the dipole element is preferably a Z-shape for accommodation within the helical element.

Abstract: A high gain dual port antenna and antenna array provide enhanced isolation between a receiver and a transmitter. The antenna includes a helical element connected to one port and a dipole element positioned within the helical element and connected to a second port. The helical element can have a uniform diameter or varying diameters, while the dipole element is preferably a Z-shape for accommodation within the helical element.

Abstract: A broadband mesh antenna and a phased array broadband mesh antenna are provided. The antenna of the present invention is a mesh antenna system that may be implemented with printed circuit board technology and wired technology that operates with increased bandwidth. The mesh antenna system provides for a single mesh antenna to operate at a wide range of frequencies. The antenna may be employed as a high efficient broadband antenna for rockets, space vehicles and ships when place inside a metallic open box.

Abstract: A means and method to increase the beam traffic capacity, especially in high user density regions, of a multi-beam antenna communication system with multiple signals at any frequency transmitted (received) when in a transmit (receive) mode by canceling interference with neighboring signals. An interference cancellation network is provided for canceling the interference caused by the sidelobe(s) of at least one signal with one or more of the other signals in the network. Each power divider divides its input signal into one reference fractional signal and at least one non-reference fractional signal. Phase shifters/attenuators shift the phase and attenuate the amplitude of at least one of the non-reference fractional signals. Each power combiner combines its input reference fractional signal with at least one non-reference fractional signal into a composite signal emerging from the combiner. The phase/attenuation settings are selected to optimize the signal to interference ratio for each communications link.

Abstract: A coupler couples signal by way of a cluster of four square waveguide ports at a high frequency band, or by way of a two ridged waveguide ports at a lower frequency band, to a common square port. The coupling path includes a branch coupler for combining the TE2,0 and TE0,2 high-band signals from the square ports with the TE1,0 low-band signals from the two ridged ports. The branch coupler is coupled to a mode converter or transformer, which allows the TE2,0 and TE0,2 mode signals to pass through unchanged, and which converts the TE1,0 mode signals from the two ridged ports to TE1,0, TE0,1 in a square port. A ridged square waveguide section couples the square port of the mode converter to the common square port. The ridged square waveguide section includes ridges and phase shifters which delay components of the high-band modes to produce TE1,0 and TE0,1 modes at the common port in both bands.

Abstract: A coupler couples signal by way of a cluster of four square waveguide ports at a high frequency band, or by way of a two ridged waveguide ports at a lower frequency band, to a common square port. The coupling path includes a branch coupler for combining the TE2,0 and TE2,0 high-band signals from the square ports with the TE1,0 low-band signals from the two ridged ports. The branch coupler is coupled to a mode converter or transformer, which allows the TE2,0 and TE0,2 mode signals to pass through unchanged, and which converts the TE1,0 mode signals from the two ridged ports to TE1,0, TE0,1 in a square port. A ridged square waveguide section couples the square port of the mode converter to the common square port. The ridged square waveguide section includes ridges and phase shifters which delay components of the high-band modes to produce TE1,0 and TE0,1 modes at the common port in both bands.

Abstract: A means and method to increase the beam traffic capacity, especially in high user density regions, of a multi-beam antenna communication system with multiple signals at any frequency transmitted (received) when in a transmit (receive) mode by canceling interference with neighboring signals. An interference cancellation network is provided for canceling the interference caused by the sidelobe(s) of at least one signal with one or more of the other signals in the network. Each power divider divides its input signal into one reference fractional signal and at least one non-reference fractional signal. Phase shifters/attenuators shift the phase and attenuate the amplitude of at least one of the non-reference fractional signals. Each power combiner combines its input reference fractional signal with at least one non-reference fractional signal into a composite signal emerging from the combiner. The phase/attenuation settings are selected to optimize the signal to interference ratio for each communications link.

Abstract: A conical horn antenna that yields performance substantially equivalent to, or even greater than, that of a corresponding corrugated horn antenna while being simple and inexpensive to manufacture and light in weight. The body portion of the conical horn antenna is a conical horn antenna with a flare break positioned with respect to a central axis. At the output aperture of the body portion, a structure is located. The structure is a series of parallel rings, concentric to the common central axis, that are made of an electrically conductive material, and that are spaced at intervals to form a dielectric region between each ring. The dielectric region may be vacuum, air, free space or may contain a dielectric material. Alternatively, the structure is a helical winding, made of electrically conductive material, that spirals outwardly away from the central axis and forms a dielectric region between the turns of the winding. In a variation, the helical coil winding is surrounded by a jacket of dielectric material.

Abstract: An antenna, or in the context of an array an antenna element, includes a feed and a separate polarization converting director. The polarization converting director includes a helically disposed conductor defining a pitch, a projected diameter, and a longitudinal axis. The feed propagates electromagnetic radiation (in transmit mode) toward the director, parallel its axis. The director intercepts part of the radiation, focuses or directs the radiation, and also converts circular polarization to linear, or linear polarization to circular. The feed may thus be linearly or circularly polarized. Various feeds include waveguides or horns, slots, dipoles, and planar or nonplanar spirals.

Abstract: A short axial-mode helical antenna (10) includes a winding (12) including a conductor (20) helically wound about an axis (8). A first portion (22) of the winding is wound with a first pitch (&agr;) on a segment of a cone (41) having a smaller diameter (D1) at a plane (31) adjacent a ground plane (14), and a larger diameter (D2) at a second plane (32) parallel with the ground plane and remote therefrom. A second portion (24) of the winding (12) is wound with a second pitch (&bgr;) on a segment of a second cone (42) coaxial with the first cone, and having its smaller diameter (D3) at a third plane (33) parallel with the first and second planes. The antenna provides higher gain than a straight uniform, tapered-end, continuous taped, or nonuniform-diameter helical antenna of equal length, and consequently has less mutual coupling when mounted in an array.

Abstract: A near-field calibration arrangement for a phased-array antenna determines the phase shifts or attenuation of the elemental control elements of the array. The calibration system includes a probe located in the near field, and a calibration tone generator. The tone generator is coupled to the probe in the case of calibration of a receive antenna, and to the signal port of the array in the case of calibration of a transmit antenna. A code generator generates sets of values, with each set being orthogonal to the others. The codes are applied to the control input port of the array antenna, so that the codes encode the tone passing through the antenna. The encoded tones are applied to a decoder and processor, which processes the signals to determine the phase shift or attenuation associated with each bit of the control signal.