Abstract: A microwave crossover by which an electromagnetic wave can crossover from one waveguide to another waveguide is formed completely within a planar structure having two hybrid couplers arranged in tandem with output ports of the first coupler connected to input ports of the second coupler. Each coupler is formed of an electrically conductive housing and two electrically conducting bars disposed therein and insulated therefrom. The bars are disposed in a common plane and are equally spaced from top and bottom walls of the housing. A central portion of each bar is angled relative to end portions of the bars to permit a crossing over of the bars at the central portions thereof. Each of the central portions is formed with a notch which engages with the notch of the other bar while maintaining a gap therefrom, the notches permitting the crossover to occur in the foregoing plane. Ends of the bars protrude through openings in the housing in the form of coaxial transmission lines.

Abstract: An adjustable phase-shifting apparatus for use in shifting the phase of a microwave signal transmitted along a TEM transmission line, such as coaxial line whose inner and outer conductors have square cross-sections. The apparatus includes a body with an elongated cavity therein which forms part of the outer conductor, and a cover attached to the body which forms at least part of the outer conductor. The cover has at least one pair of elongated openings that provide access to a portion of the cavity. The apparatus also includes a movable member provided with at least one pair of elongated, tapered, dielectric-loaded projections that slidably pass through the elongated openings and are positionable about either side of the center conductor to provide an adjustable phase lag.

Abstract: A launcher of cross-polarized electromagnetic radiation is provided with increased bandwidth by inserting a set of axially directed ridges on the interior surfaces of waveguide walls of the launcher for concentrating electric fields of radiations of the different polarizations. A first radiation radiated by a probe in a back section of the launcher waveguide propagates forward into a front section of the launcher waveguide. A second radiation is radiated into the front section by a probe therein, there being a vane disposed in the front section for inhibiting the propagation of the second radiation into the back section. The front section is flared to provide a larger exit aperture at a front end of the front section. A second and a fourth of the ridges are tapered towards the back section to permit a smooth transition in the propagation of the first radiation into the front section.

Abstract: Apparatus for catching fluid leaking from underneath a vehicle is provided. The invention includes means for supporting a receptacle relative to a vehicle which is leaking fluid in a position whereby the fluid flows into the receptacle. In a preferred embodiment, the means for supporting the receptacle is a magnet which is bonded to the receptacle. A specific embodiment includes material for absorbing the fluid after it has flowed into the receptacle. In the illustrated embodiment, the material is a foam. The specification sets forth other aspects of the invention designed to reduce weight, reduce cost, improve strength and improve overall performance.

Abstract: A waveguide switch operable at microwave frequencies is formed of two waveguides of rectangular cross section with a longer wall and a shorter wall, the two waveguides sharing a common shorter wall. Two coupling windows are disposed within the common wall for coupling electromagnetic energy between the two waveguides, each coupling window introducing a 90.degree. phase shift. Each window couples one-half the power of an electromagnetic wave from a first of the guides to a second of the guides. The common wall is parallel to the electric field of the coupled wave, with each wave being a TE wave. A 90.degree. phase shift is introduced by each coupling with the result that utilization of both windows produces a summation of the two waves in the second of the waveguides and a cancellation of the two waves in the first of the waveguides.

Abstract: A phase compensated waveguide hybrid coupler is formed with a pair of waveguides of rectangular cross section and sharing a common short wall. An aperture in the short wall provides for the coupling of electromagnetic energy between a first of the waveguides and a second of the waveguides. Such coupling introduces a 90.degree. phase shift. An input terminal is located at an end of the first waveguide. Phase compensation is introduced by a set of capacitive irises located in the first waveguide and by a set of inductive irises located in the second waveguide. The capacitive and inductive irises are located on a side of said coupling aperture away from said input terminal.

Abstract: A waveguide hybrid coupler is formed with a pair of waveguides of rectangular cross section and sharing a common sidewall. An aperture in the sidewall provides for the coupling of electromagnetic energy between a first of the waveguides and a second of the waveguides. An input terminal is located at an end of the first waveguide. A pair of stepped, multi-tiered abutments are disposed on the outer sidewalls of the waveguides opposite the coupling aperture. The dimensions of the abutment steps are selected to stagger-tune the frequency response of the coupler to achieve wideband operation.

Abstract: A phase shifter for microwave electromagnetic energy propagating through a waveguide has a composite structure of a series of capacitive phase shifting posts positioned within the waveguide diametrically across from a symmetrically tapered ridge. The series of posts introduce a nominal value of phase shift with an incremental value which increases with increasing frequency of the electromagnetic energy. The tapered ridge introduces a nominal value of phase shift plus an incremental value which decreases with increasing frequency of the electromagnetic energy. The rates of increase and decrease of the incremental values of phase shift cancel so as to provide a resultant phase shift which is substantially invariant with frequency.

Abstract: A coaxial phase shifter for shifting the phase of a signal being transmitted along a transverse electromagnetic transmission line. The phase shifter is in line with the transmission line's inner conductor, such that it is very compact and such that the transmission line's outer conductor need not be modified. The phase shifter includes electrically-conductive fingers arranged in spaced, confronting relationship with each other, to capacitively couple the signal from one segment of the transmission line's inner conductor to another. In addition, the phase shifter is configured to provide an input impedance at both of its ends that matches the characteristic impedance of the transmission line.

Abstract: A compact power coupler comprises a first waveguide short-circuited at one end, a resonant cavity slot-coupled to the shorted end of the first waveguide, and a coaxial transmission line coupled to the resonant cavity. Power at 6 gigahertz is coupled from the waveguide to the transmission line in a unit that is 3.5 inches long. Alternatively, a second waveguide can be slot-coupled to a narrow-wall of the first waveguide (a quarter-wavelength from the short-circuit) to couple 4 gigahertz power, thereby forming a compact diplexer.

Abstract: A single in-plane orthogonal mode launcher for generating circularly polarized waves having both right and left hand senses is disclosed. A 90.degree. hybrid provides first and second signals to respective input ports of the launcher. First and second coplanar sets of probes are orthogonally disposed in a cylindrical housing and connected to the first and second ports, respectively. The first set of probes generates a first vector signal. The second set of probes generates a second vector signal which is 90.degree. to the first vector signal. Since the input signals to the first and second sets of probes are 90.degree. out of phase, circularly polarized waves are thus generated.

Abstract: A horn antenna is disclosed having a built-in circular polarizer and a cross polarization attenuator. A square-apertured horn antenna has a plurality of pairs of conductive fins disposed along opposite edges of the horn interior. The individual fins are separated from each other by approximately one-fourth wavelength. The fins are at a 45 degree angle to that linear wave and react with that linear wave by imparting a circular rotation to that wave as the wave propagates past each pair of fins. A stepped attenuator is mounted in the input section to the horn antenna perpendicular to the linear input wave. The attenuator substantially absorbs cross-polarized signals whether reflected from the aperture of the horn or provided by the incoming signal.

Abstract: A conical horn antenna is disclosed having dual dielectric bands mounted therein for improving the rotational symmetry or elipticity of the radiated beam as well as the efficiency. The first and second dielectric bands are coaxially mounted to each other and to the conical horn. The lengths of the bands are determined by the frequencies being propagated. A circularly polarized dominant wave such as TE.sub.11 mode is applied to the antenna and excites a series of higher order waves such as the TM.sub.11 mode. The circularly polarized dominant and the higher order modes are propagated toward the aperture where they are in phase and therefore add vectorially. The dual dielectric band acts as a slow wave structure and higher order waves which in turn provide an improved phasing between the dominant modes.

Abstract: A multisided horn antenna such as a square horn is disclosed having an improved axial ratio circular polarization or ellipticity. Ellipticity of a square horn antenna is improved by placing a conical section or ring of conductive material at the aperture of a horn antenna. The conical ring causes a relatively directive beam having a low axial ratio to be produced throughout most of the pattern generated similar to that of a conical horn antenna. Yet, the square horn antenna provides increased power over a conical horn.