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 FM antenna utilizes a generally rigid conductive element, as a dipole segment, that is connected in electrical communication with a capacitive segment. The capacitive segment can be manufactured from a preselected length of coaxial cable with the central conductor of the coaxial cable being connected in electrical communication with the dipole segment and with the cylindrical conductor, or braided shield, of the coaxial cable being connected to an electrical ground. A variable inductor is connected in electrical communication with the central conductor of the coaxial cable between the capacitive segment and an FM receiver. The central conductor of the capacitive element is connected serially between the dipole segment and the variable inductor. This configuration provides an omnidirectional antenna for use with FM receivers that is relatively small in size and inexpensive to manufacture.

Abstract: A flat antenna particularly suited for mounting to a briefcase as part of a cellular telephone. The antenna has a radiator conductor and ground-plane conductor spaced from each other and mounted at right angles on an insulating support, preferably cardboard. The cardboard also serves as a mounting structure for a cable having two conductors, one soldered to the ground-plane conductor and a second soldered to the radiator. The flat structure is mounted in a panel of a carrying case and the cable is routed to a suitable transceiver.

Abstract: A dipole phase shifter for use in a phased array antenna includes an insulating substrate having first and second sides. A dipole element having first and second conductive dipole arms is formed on the first side of the insulating substrate and a PIN/NIP diode pair is mounted on the second side of the insulating substrate and electrically-connected to the first and second dipole arms, respectively. A coaxial RF transmission line having a center conductor extending through the insulating substrate connects an input signal to the phase shifter. Quarter-wave transformers are connected between the center conductor and the diodes to compensate for the forward and reverse bias reactances thereof. The first and second dipole arms serve as groundplanes for the quarter-wave transformers. The center conductor also serves as a common bias line which allows forward biasing of one diode and, simultaneously, reverse biasing of the other diode.

Abstract: An electromagnetic wave radiator is provided formed by a radiating element and its supply device, both formed from a dielectric plate with median longitudinal axis, metalized on one face along two parallel strips of total width d.sub.2, wherein the supply device is formed by a slot-line placed inside a metal parallelepipedic case. The radiating element may be of the dipole type. Such a wave radiator may be used as an elementary source for an electronic sweep network antenna.

Abstract: An antenna for operating over a broadband of frequencies includes an operating radiating elements for radiating radio frequency energy at a selected band of frequencies and a lower radiating element for providing a counter poise to the upper radiating element. An antenna coupler transforms the load impedance of the upper radiating elements and the lower radiating element to a nominal impedance, such as 50 ohms. The coupler element also electronically couples the lower radiating element to the upper radiating element.

Abstract: The antenna for equipping a portable receiver comprises a metal plate and a metal box containing the receiver components and which is provided with a surface facing the metal plate, the metal box behaving in the manner of a virtual plate positioned half-way up the box.

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 folded dipole antenna system for use in the transmission reception of radio frequency energy by a radio frequency generator capable of continuous operation over an entire extremely broad bandwidth while maintaining an effective radiated power factor and a substantially linear visual standing wave ratio of less than 2 to 1 for each frequency over the entire operational bandwidth. The antenna system exhibits a substantially shortened overall length which is proportional to the entire operational bandwidth.

Abstract: The existence and method of suppression of spurious post mode to improve sidelobe performance of an array of dipole antenna elements together with examples of geometric configuration for suppression of such post mode is described.

Abstract: A circularly polarized antenna has bays stacked at spacings of less than one wavelength in order to have a broadband SWR characteristic and to minimize radiation along a supporting mast axis. Vertical stubs are used to increase the circularity of the horizontal pattern and to improve the axial ratio.

Abstract: A portable antenna construction is provided for high frequency radio transmission and reception. A physically and electrically shortened center-fed dipole, the antenna includes a driven element assembly 62, a center insulator assembly 60, a center loading coil assembly 74, two end loading coil assemblies 70 and 72, two capacity hat assemblies 64 and 68, and a mast assembly 63, each such assembly constructed from parts allowing for easy assembly and disassembly. The antenna further includes a carrying case 78 of sufficient size to hold all disassembled parts, so that such disassembled parts can be easily transported. Center loading coil assembly 74 includes a center loading coil 76 having multiple tap points 77 for transmission line connection, thereby permitted impedance match at any frequency to which the antenna is tuned.

Abstract: A radio antenna having linear radiating elements, a loading coil electrically connected to these linear radiating elements and a tuning disc located within the loading coil and rotatable about a diameter of the loading coil whereby said antenna can be easily and accurately tuned to the exact frequency of operation selected. The disc is preferably electrically conductive such that when its plane is perpendicular to the axis of the coil the coil will have a minimum inductance.

Abstract: An input transformer arrangement includes an unbalanced signal suppress transformer for suppressing unbalanced signal carried in a feeder line extending between a television receiver and an antenna therefor, and an impedance transformer for dropping the impedance. These two transformers are arranged on one core for unifying and simplifying the arrangement.

Abstract: The invention is concerned with the provision of a dipole radiator for feeding a parabolic reflector and provides a half wave dipole arranged at the mouth of a shallow cavity. The cavity is preferably circular with a diameter approximately three times its depth. In an example of linearly polarised radiator a cylindrical cavity is provided having a diameter of 0.72.lambda. and a height of 0.26.lambda. and the half wave dipole element is positioned 0.26.lambda. above the base of the cavity so that the dipole element extends beyond the cavity. In an example of circularly polarised radiator two crossed half wave dipole elements are provided, one of which is arranged to be inductive and the other of which is arranged to be capacitive. The cylindrical cavity has a diameter of 0.66.lambda. and a height of 0.28.lambda. and the crossed dipole elements are positioned 0.22.lambda. above the base of the cavity so as to lie flush with the mouth of the cavity.

Abstract: An antenna configuration in which multiple frequency band coverage is obtained in simple structures. This invention is most useful in the high-frequency spectrum where other techniques of providing multiple frequency operation become physically difficult to implement. The antenna configuration includes a multiplicity of conductor elements, a coaxial cable network for interconnection of the elements and connection to a feedline, and a high permeability core to aid decoupling to the feedline exterior from the antenna proper.

Abstract: A notch fed electric microstrip dipole antenna consisting of a thin electally conducting, rectangular-shaped element formed on one surface of a dielectric substrate, the ground plane being on the opposite surface. The length of the element determines the resonant frequency. The feed point is located in a notch along the centerline of the antenna length and the input impedance can be varied by moving the feed point along the centerline of the antenna without affecting the radiation pattern. Of all the many types of microstrip antennas built to date, this antenna offers the best advantages as far as arraying of the elements are concerned. The notched antenna can be arrayed using microstrip interconnecting transmission lines. The corner losses in the clad material and the width of the notch determines how narrow the element can be made. The purpose of the notch feed system is to interconnect any array of elements at the elements' optimum feed point using microstrip transmission lines.