Abstract: A waveguide element for an electrically controlled radar antenna comprises a non-resonant waveguide (V) fed from a feed opening (M). The feed opening divides the waveguide longitudinally into a first and a second part, each provided at its outer end with absorbent terminations (A1, A2). Slits (S.sub.11, S.sub.12, S.sub.21, S.sub.22, etc) are formed in the waveguide, and their central points in the longitudinal direction have in the first part a mutual spacing (d.sub.1) which is less than half the wavelength (.lambda.g/2), while their central points in the longitudinal direction in the second half have a mutual spacing (d.sub.2) which is greater than half the wavelength.

Abstract: It is sometimes necessary to reduce the power of microwave transmissions, e.g. to avoid overloading a receiver or to reduce a transmitter's potential to cause interference. The invention reduces the power by inserting radiation absorbent material into the aperture of the antenna. In the preferred embodiment a membrane of absorbent plastics is stretched across the aperture of the dish reflector.

Abstract: Disclosed is an arrangement of two conical radiators that electromagnetically interact with one another to produce circularly polarized radiation in a surface wave transmission system. One of the radiators includes an annular conductive region that coaxially surrounds the surface wave transmission line with a pair of spiral antenna arms extending outwardly along the conical surface of the radiator from oppositely disposed positions on the outer boundary of the annular conductive region. The second radiator, which is spaced apart from the first radiator, includes a circular conductive region to which the end of the surface wave transmission line is joined and further includes a pair of spiral antenna arms that extend outwardly along the surface of the second conical radiator.

Abstract: An antenna system wherein the feed assembly is rotated to provide spatial polarization stabilization with respect to vehicle movement so that orthogonal polarizations can be used simultaneously.

Abstract: A vertically extendible and retractable mast for supporting an antenna and coaxial cable connected thereto to receive and/or broadcast information and is particularly adapted for use by seismograph exploration crews for receiving data from portable transmitter units which may be located at substantial distances from the receiver with the mast being adapted for mounting stationarily or on a mobile vehicle. The mast and antenna is a multiple stage antenna with simultaneous movement of the sections of the mast with the coaxial cable being fed at the same rate that the upper end of the antenna mast moves with the specific arrangement of the extension or lifting cables, retracting cables, winch and coaxial cable producing a novel and unique extendible and retractable antenna mast.

Abstract: An antenna for mounting on a non-conductive surface such as a windshield of an automobile coupled by a capacitor to housing on the inside of the resonant plate. The antenna has a jack for receiving a plug from a car radio and provides for interchangeability of the cable between the radio receiver and the jack. The circuit allows for fine tuning to the resonant frequency of the antenna.

Abstract: An omni-directional aerial, more especially for the reception of domestic television programs in the U.H.F. band, comprises four folded dipole elements (1-4), each formed as a self-supporting open-ended wire loop (1A, 1B, 1C, 1D) integral with twin feeder portions (1E, 1F; 2E, 2F; 3E, 3F; 4E, 4F). The loops are arranged in planes parallel to a common central axis and are regularly angularly displaced about this axis so that opposed pairs of loops lie in parallel planes. The twin feeder portions (1E, 1F; 2E,2F; 3E,3F; 4E,4F) are connected in common to respective terminal means at the central axis, and each pair of feeder portions of each loop extend parallel to one another in a plane radial to the central axis which enables simple matching of the impedance of the aerial to a connecting cable.

Abstract: In a high-frequency antenna comprising a plurality of horns 1, phase differences arising in these horns 1 would need to be corrected. Such phase differences are avoided by providing a planar design of the antenna comprising four adjacent horns 1 fed by T-shaped power divider 6, being linear and symmetrical.

Abstract: A dielectric member may be thin and planar and may have first and second opposite surfaces. An electrically conductive material is disposed on the first surface at one end of the first surface and an electrically conductive material is disposed on the second surface at the opposite end of the second surface. The conductive materials in the first and second surfaces define a first antenna operative at a first frequency. Slots are provided in the conductive material in the first surface. The slots define a second antenna operative at a second frequency greater than the first frequency. The slots include first and second slots extending in a direction transverse to the relative direction of the conductive materials on the first and second surfaces. The first and second slots may have substantially equal lengths and may be aligned with each other. The slots also include third and fourth slots extending in such relative direction and respectively communicating with the first and second slots.

Abstract: An antenna system for mounting on a glass plate with a radiator extending from one side of the glass plate and with an electrical connector and a cable extending from the opposite side of the glass plate whereby energy is transferred through the glass plate. Coupling means for a cable is provided, defining a receptacle for retaining the coupled end of the coaxial cable at an angle of essentially 15 to 60 degrees to said glass plate in said mounted position. Also, the antenna may define a helical base portion which may be attached to the glass plate on the side opposite to the coupling means. The helical base serves to shorten the antenna, and also to simultaneously serve as an electrical phase cancelling coil. Additionally, improvements are disclosed in the design of field cancelling conductors used.

Abstract: A two-frequency planar antenna incorporates a resonant antenna and a slot antenna which are arranged in a superposed manner on the same dielectric substrate so as to be operable independently without interfering with each other. The two-frequency planar antenna includes a front conductor plate arranged on one surface of a dielectric substrate to serve as a radiation conductor plate of a resonant antenna and a slotted conductor of a slot antenna, a back conductor plate arranged on the other surface of the dielectric substrate to serve as a grounding conductor of the resonant antenna and a reflector of the slot antenna, and a slot antenna feed line embedded in the dielectric substrate. The slot antenna feed line is arranged along an axis where an electric field in an excitation mode of the resonant antenna is reduced to zero and at least one slot is formed in the front conductor plate along the feed line.

Abstract: A towable broadband submarine antenna system for deployment in the ocean ing operation comprises an antenna element including a metallic termination tip and a length of single conductor buoyant cable. A broadband amplifier connects to the antenna element and provides separate paths for the VLF/LF and the HF/VHF signals with amplification provided only to the HF/VHF signals. The signal from the broadband amplifier is further transmitted on a coaxial cable.

Abstract: The invention relates to a device for wind bracing of the vertical members of a lattice mast. It is characterized in that it is provided at its ends (5, 6) with detachable means (8, 9) for joining it to its vertical members, which in turn are provided with complementary means (10).

Abstract: The aerostat-supported antenna/tether cable of a communication system is protected from destructive corona discharges by a dual corona ring assembly which attaches the feed cable of the transmitter to the antenna. The voltage divider assembly includes upper and lower corona rings which have a space between them which is an isolated and corona-free attachment point for the feed cable. By attaching the voltage divider assembly to the antenna/tether cable at about 12 to 15 feet above the ground, the base of the antenna/tether cable distributes the feed voltage along its length to levels below those voltage levels in which destructive ionization may occur.

Abstract: An FM antenna for a vehicle with a ground plane comprising a horizontal roof having supporting pillars at the front and rear corners comprises a side fed, looped, annular slot antenna in the roof of loop length substantially one wavelength in the commercial FM broadcasting band, the slot antenna being displaced from the center of the roof toward one of the front and rear of the roof.

Abstract: An antenna for a wrist transmitter or receiver carried in a wrist instrument is made of a wire mesh enclosed in an elastic fabric sleeve. The antenna wire is composed of a tubular mesh of individual copper conductors which are loosely woven, twisted, or braided in such a way as to permit lateral expansion and also to assume a flat configuration. In a preferred form of the invention, the wire is woven in a manner similar to that of a coaxial cable outer shield conductor. The method of making the expansion band antenna consists of inserting an unexpanded wire mesh within a stretchable elastic fabric sleeve, expanding the mesh within the sleeve, and then flattening the sleeve and wire mesh. The wire mesh may be expanded within the sleeve by allowing a stretched sleeve to relax while holding the unexpanded mesh within it, or it may be expanded laterally within the sleeve by a mechanical or pneumatic tool.

Abstract: A probe-fed slot antenna is provided having an inner conductor, a cylindrical outer conductor coaxial with the inner conductor, and a plurality of slots in the outer conductor. A plurality of probes extend from the cylindrical outer conductor into the interior, each probe adjacent to one of the slots. A coupling ring is mounted coaxially between the outer and inner conductors to allow efficient transfer of RF energy to and from the slots.

Abstract: A microstrip antenna is formed of a 3.times.2 group of elements, with adjacent H-feeds. The outer pairs of elements are responsive to opposite senses of polarisation respectively and the inner pair of elements is responsive to both sense of polarisation. The appropriate phase for the respective element orientations are obtained by making S=r+.lambda./4 and q=p+.lambda./2 where .lambda. is the wavelength of radiation. The element spacing lies between 0.5.lambda. and 1.0.lambda., typically 0.85.lambda..Larger arrays are formed both by increasing the number of pairs of elements responsive to both senses of polarisation, but leaving the two outer pairs responsive only to respective opposite senses of polarisation, and by increasing the number of rows of pairs.

Abstract: A passive marker device including a tuned circuit enclosed in a housing which includes a base member with an upstanding rim with a cover member bonded to the rim and to a central portion of the base member. An opening is provided that extends through the housing at the central portion of the housing. A boss extends from the central portion of the base member to the cover member. The boss is recessed on the side of the base member that is away from the cover.

Abstract: The antenna is adapted to be connected to a coaxial cable and includes a dielectric carrier board and a radiating element undulating longitudinally of the carrier board. The carrier board and radiating element are disposed in a conductive channel which has side walls adjacent the side edges of the carrier board. An input transition means is provided between the center conductor of the coaxial connector and the undulating track to provide a transition from the impedance of the coaxial cable to the impedance of the radiating element of the sandwich-wire antenna. When the antenna may, or may not, be connected to a coaxial cable, the side walls extend above the carrier board for such a height that the radiating aperture, which comprises the gap between the top edges of the side walls, presents a resistive load in the plane of the radiating element.