Abstract: During installation or maintenance of a phased array antenna system in which the transmission line to each element includes an adjustable phase shift device, it is required that the effective electrical lengths of the lines be adjusted to be equal, or alternatively that the phase errors be determined and stored as correction data for use during normal operation. One way of doing this is to phase modulate by .+-.90.degree. the phase shift device of one element at a time, while applying a test signal to all elements. The signal is radiated by the array, received via a test antenna, and supplied to an envelope detector. If the element is out of tune, the envelope has different amplitudes at +90.degree. and -90.degree. of the modulation. The element is tuned by adjusting the length of its transmission line or the adjustment of its phase shift device to obtain a null at the amplitude detector.In an improved technique, to reduce certain errors, sum tuning is used, in which the .+-.90.degree.

Abstract: A lightweight slot array antenna comprises an array of slotted waveguides and a radome. The radome consists of two or more sheets of fiberglass with a honeycombed dielectric disposed between and bonded to each pair of adjacent sheets. The array of slotted waveguides is disposed inside the radome. Honeycombed dielectric material may be disposed between and bonded to each pair of adjacent waveguides.

Abstract: An add-on system as disclosed for use with an existing multilevel antennae switching matrix of the type having a plurality of input ports, each supplied by a respective input signal source with at least one unused input port being available and a plurality of output ports are connected to receivers. The add-on system uses a plurality of switching devices which are each selectively operable to couple each of the input signal sources to a different one of the unused input ports. This provides that when an attempt to effect an interconnection between a desired one of the input ports and a desired output port is blocked then the input signal source which supplies the desired input port associated with an attempt connection is coupled to any one of the unused input ports for facilitating the connection at that port to the desired output port.

Abstract: A beam waveguide feeder in which a feed horn, a pair of revolvable paraboloidal reflectors, and at least one plane reflector are arranged in the order stated so as to form a path for an electric wave, said pair of paraboloidal reflectors facing each other and being equal in focal distance and off-set angle, their zeniths and focuses being on an identical plane, is characterized in that said feed horn can be fixed in position while its equivalent feed horn, i.e., the image of said feed horn focused by the beam waveguide feeder, can be moved into an arbitrary location and turned in an arbitrary direction.

Abstract: The antenna 10 comprises a line of radiating columns 12 extending transversely to the line and a plurality of conducting rods 14 interspersed among the columns 12. The conducting rods 14 are aligned along two lines 22a, 22b to form two reflecting arrays spaced one behind the other with respect to the look direction 11 of the antenna 10. The spacing is one quarter wavelength at the operating frequency.

Abstract: The directivity as well as the gain of an antenna element associated with a finite length reflector, which includes a feed antenna such as a dipole antenna and a reflector having a finite length of several wavelengths or less, are improved by disposing a non-feed loop element having a peripheral length of about 2 wavelengths along a common imaginary plane with the feed antenna so as to surround the feed antenna. Preferably, the non-feed loop element is disposed in parallel to the reflector, and more preferably it is disposed nearly symmetrically with respect to the center of the feed antenna.

Abstract: The antenna feed includes a waveguide radiator with a conductive flange positioned about the waveguide near its radiating end. A dielectric element is positioned about the waveguide between the flange and the radiating end and establishes the dielectric surface impedance seen by the waveguide. The dielectric element may consist of one or more layers of dielectric material to form a composite dielectric. One of the layers may be an air gap adjacent to the flange. The size and position of the flange and dielectric element will control the radiation pattern of the beam from the feed.

Abstract: First and second annular r.f. radiating structures are mounted for concentric relative rotational motion with their r.f. radiation patterns directed toward one another. The annular r.f. radiating structures may be realized, for example, by cylindrically conformed microstrip antenna radiators which define tuned resonant cavities feeding one or more radiation apertures defined between an edge of a microstrip radiator "patch" and an underlying electrical reference or ground surface. The microstrip radiator "patch" may be either continuous in its circumferential dimensions or it may have occasional circumferential discontinuities formed by axially directed gaps therein. If the total circumferential dimension is greater than one wavelength at the intended operating frequency, then a corporate structured feedline provides plural spaced-apart feedpoints about the circumference so as to achieve a substantially uniform distribution of r.f. field amplitudes and phases about the circumference.

Abstract: The present invention relates to an antenna arrangement comprising a feed producing a predetermined feed aperture illumination and a plurality of sequentially arranged reflectors including a main reflector forming the aperture of the antenna arrangement. The present antenna arrangement also includes filtering means centered on a real focal point between two reflectors of the antenna arrangement. The filtering means is arranged to pass therethrough the central ray of a beam launched by the feed and for smoothing out discontinuities of the image of the feed aperture illumination in the area of the main reflector normally found without filtering. The main reflector is then made slightly oversize to intercept the smoothened-out image of the feed aperture illumination along a line which produces a predetermined level of edge intensity.

Abstract: A variable slot conductance dielectric wavequide antenna in which the transmission line and radiating aperture is formed in one continuous, integrated and homogeneous material. The radiated antenna beam pattern is controlled by varying the conductance of radiating slots using varied geometries for each of the slots.

Abstract: A scannable antenna array especially suited for aircraft having a common reflector and a plurality of spaced apart end-fired Yagi type elements each comprising a driver and one or more director segments spaced mutually from each other and the driver in the direction of the field pattern for the array. In the preferred embodiment, the driver is a dipole comprised of two laterally extending hooked-back radiating segments so dimensioned and spaced from the director elements so as to minimize the mutual electromagnetic coupling among elements of the array. In other embodiments, the driver may comprise a slot.

Abstract: A one-piece array antenna dipole radiating element is formed from a wide, thin conductor. This element is suitable for attachment to a microstrip or other feed circuit. The radiation element includes a dipole portion, a balanced transmission line portion and a balun portion. These various portions are formed by providing an appropriately shaped slot in the thin conductor.

Abstract: There is disclosed herein an antenna, particularly for use at high frequencies such as approximately one gigahertz and above, which is frequency selective. The antenna design allows signals at a given frequency to be preferentially received, as distinguished from broadband reception. The antenna design can be modified for reception of signals of different given frequencies. The antenna comprises a plurality of parabolic sections in the form of concentric rings or segments with each segment being offset axially from the next adjoining segment to thereby provide an antenna which is relatively flat, or having a low profile, as compared to a standard parabolic antenna. The surface of each segment is a segment of a different focal length parabola, but with each parabolic surface being a function of the signal wavelength (or frequency) to be received by the antenna. The antenna may be round, rectangular or have other shapes. Also disclosed are feed and pick-up arrangements for the antenna.

Abstract: Each radiating slot having a length L in the vicinity of the operating wavelength .lambda. of a direct-radiation slotted rectangular waveguide is placed on one side of the waveguide so as to be parallel to the lines of current flow and is provided with a transverse stepped section formed at the center of the slot at right angles to the current lines.

Abstract: An imbalance equilibrating system for an airborne radar system in which the rotation about its axis, in a clockwise or counterclockwise direction, of a pivoting element placed in cantilever relationship with respect to its axis of rotation, causes cables to wind about a pulley which is integral with and has the same axis of rotation as the pivoting element, whereby the cables transfer the rotational movement of the pivoting element to an antagonistic movement of a remotely located equilibrating mass.

Abstract: A high current low impedance antenna having an electrically short monopole radiation pattern is provided by shielding at least one of the segments or legs of a loop antenna so that the shielded leg has no cancelation effects and thereby produces the uniform radiation pattern of a short monopole antenna.

Abstract: A horn-reflector microwave antenna comprises the combination of a paraboloidal reflector for transmitting and receiving microwave signals; a tapered feed horn extending downwardly from the reflector for guiding microwave signals to and from the reflector; a waveguide connected to the lower end of the feed horn; and a dielectric membrane extending across the interior of the feed horn for collecting any debris that falls down into the feed horn. In the preferred embodiment of the invention, the outer periphery of the dielectric membrane is secured to the interior walls of the feed horn, and the central portion of the membrane is elevated above the periphery thereof so that debris collected on the membrane slides to the walls of the feed horn.

Abstract: An antenna for CP signals uses a reflector, such as a truncated pyramid. Feed tubes, which act as a balun extend from the pyramid. Four truncated square loops are coupled to the feed means. The truncation results in a smaller radome being used and hence smaller wind resistance. A feed strap has a capacitance hat for a better match.

Abstract: A lightweight mounting structure combination for small dish antennae is provided. The structure includes an upright mast for supporting the dish antennae. The mast has an upper end for attachment to said dish and a lower end for anchoring to a rigid-type structure. The structure also has a bent strut having a lower end for anchoring to a rigid-type structure and an upper end for attachment to said mast. In addition, a second strut is provided having a lower end for anchoring to a rigid-type structure and an upper end for attachment to said mast. Further included is means for anchoring the respective lower ends of the mast, bent strut and second strut to the rigid-type structure and for attaching the respective upper ends of the bent and second struts to the mast. The means includes a bracket, a threaded bolt having a shank portion for extending through the bracket and respective end, and a nut threaded on said bolt for drawing the bracket and respective end tightly together.

Abstract: In an antenna device for a direction finder including an electrically conductive antenna plate of a configuration symmetrical around its center and disposed in parallel with a base plate with a predetermined distance maintained therebetween, a plurality of pairs of connecting portions are provided around the antenna plate so that one in each pair is provided opposite to the other with respect to the center. An electronic switch provided in the device transfers the connection in order that one in a pair thus transferred is grounded through a resistor having the characteristic impedance of the antenna plate while the other in the pair is connected to the receiver of the direction finder through a cable having the characteristic impedance.