Abstract: An apparatus for coupling a receiver and a transmitter to a single antenna via a feedhorn so as to allow for the simultaneous transmission and reception of signals. The apparatus is an integrally formed single unit which includes a polarizer, a circular waveguide section, a transmitter waveguide section, and a receiver waveguide section. The polarizer has a first, second and third port and is operative to separate and combine a first and second signal which are orthogonally polarized. The circular waveguide section has a first port formed integral with the first port of the polarizer and a second port for coupling to the antenna via a feedhorn. The circular waveguide section is operative for transmitting or receiving the first and second signals. The transmitter waveguide section has a first port formed integral with the second port of the polarizer, and a second port for coupling to the transmitter.

Abstract: The waveguide multiplexer/demultiplexer includes a rectangular collecting waveguide provided with a short-circuit plane at one end thereof and elements for coupling the collecting waveguide to tunable waveguide filters arranged on opposing sidewalls, which are tunable to different frequency channels. The sidewalls are each provided with at least one pair of coupling openings. The two coupling openings of each pair are arranged side-by-side in a transverse direction relative to the waveguide longitudinal axis.

Abstract: An antenna/filter combiner for connecting a plurality of frequency transmission signals to an antenna having an arrangement with n circulators connected in a waveguide with m transmission channels being supplied thereinto via respective combining networks composed of sub-filters to provide a reactance free combination of n.multidot.m transmission frequency channels.

Abstract: A microwave cavity filter (30, 30A) is formed of a section of waveguide (36, 114) terminated by end walls (38, 40, 44, 166, 168, 176) to form cavities (32, 34, 32A, 34A) wherein ridges (100, 102, 118, 120) are disposed longitudinally within a cavity and extend from the cavity wall partway to a central region (104, 124) of the cavity. In a preferred embodiment of the invention, the ridges are disposed symmetrically about a central plane (144), each ridge having a first component (106, 122) perpendicular to the central plane and a second component (108, 126) parallel to the central plane. A cross-sectional shape of a filter cavity may approximate a semicircle wherein one wall section (88, 130) of the filter cavity is disposed within a diametric plane (216) of the cavity. The end walls of the cavities may be constructed as iris plates with apertures (82, 182, 184, 186, 190) for coupling energy of selected modes of electromagnetic resonance within the respective cavities.

Abstract: A diplexer (14) has a first rectangular waveguide (38) extending from a front port (16) to a back wall (70), the back wall having a rectangular opening (72) therein constituting a section of a second rectangular waveguide (20) and serving as a back port (18) of the diplexer. A first spectral region of electromagnetic power communicates between the front port and a side port (28), and a second spectral region of electromagnetic power communicates between the front port and the back port. A center frequency of the second spectral region is greater than a center frequency of the first spectral region by a factor greater than or equal approximately to two. The side port includes an aperture (126) disposed in a sidewall (42) of the first waveguide, a third waveguide (32), and a coupling element (128) extending from the third waveguide through the aperture into the first waveguide for coupling electromagnetic power at the first spectral region between the first and the third waveguides.

Abstract: A right angle waveguide junction for a microwave multiplexer is provided including a step in one of the waveguides for improved electrical response. A rectangular waveguide manifold (10) is coupled to a filter (12) which includes a coupling iris (14) and a circular cavity resonator (16). The circular cavity resonator is a circular waveguide with two ends closed by a metal wall. The structure of the waveguide multiplexer includes a step change (18) in the rectangular waveguide (10) height which controls the electrical response properties of the junction.

Abstract: A waveguide assembly includes a waveguide having walls defining a cavity; and a frame surrounding the walls of the waveguide. The frame has a coefficient of thermal expansion less than that of the waveguide. First and second connecting spacers are attached to and project away from oppositely located wall portions of the waveguide and are attached to the frame such that forces derived from a difference between a heat expansion of the frame and a heat expansion of the waveguide are transmitted by the first and second connecting spacers to the waveguide walls for deforming the same.

Abstract: A two port dual bandpass microwave filter consisting of "n" resonant cavities. Each cavity resonates in two independent modes at displaced frequencies so that the filter has two passbands in a desired frequency band. By orienting an incoming waveguide at an angle with respect to the filter, both TE and TM modes can be excited to produce two separate passbands. The passbands may have either equal or unequal characteristics. Fine tuning of the TE and TM modes is accomplished using tuning plungers or tuning screws. The dual bandpass response of the new filter is achieved by utilizing the TE.sub.1,1,1 and TM.sub.0,1,0 modes in right circular cylindrical cavities, or equivalent modes in rectangular, or other cavities. These modes are orthogonal so they do not couple to each other. The cavity loaded Qs are independently adjustable, so the two passbands can have the same or different bandwidths, the same or different amplitude ripples and the same or different phase responses.

Abstract: This invention provides for separating undesired signals from spectra of desired signals in a communication system. Specifically, a communication system for transmitting and receiving spectra of signals having undesired signals and desired signals comprising: a transceiver system; a TEE-junction coupled to the transceiver system and having first and second ports, the undesired and desired signals being separated at the TEE-junction; an Off-line signal interference reduction device coupled to the first port, the Off-line signal interference reduction device receiving the undesired signals from the first port; and an In-line signal interference reduction device coupled to the second port and an antenna system.

Abstract: Disclosed is a method and apparatus for combining a plurality of television signal channels which are immediately adjacent in frequency to each other. A main transmission line transmits a plurality of television signals therethrough in a predetermined direction of transmission. The visual signal of a first of the television channels is inserted into the main transmission line in the predetermined direction. The visual signal of a second, immediately adjacent television channel is then inserted into the main transmission line in the predetermined direction, using a frequency band otherwise occupied by the aural signal of the first television channel as a guard band to separate the combined visual signals of the first and second television channels.

Abstract: A device for the filtering of electromagnetic waves propagating in a main rotational symmetrical waveguide element comprising at least one filtering section constituted of a rectangular waveguide section inserted in being spliced into the main waveguide element, each transition between said main waveguide element and each of said filtering sections being made by metal walls which are substantially perpendicular to said axis of symmetry, the number and the geometrical and dimensional characteristics of the filtering sections being chosen so as to constitute a filter with a pre-determined filtering profile. The device can be applied especially in dual band filtering, for example for the making of dual band or bi-polarization duplexers.

Abstract: An antenna feed having a common circular waveguide with a longitudinally extending rectangular slot in a wall thereof and defining a receive port. An iris is rotatably connected adjacent the receive port permitting selective relative polarization of the transmit and receive signals. The relative polarization may be readily selected by a technician in the field without the need for changing antenna feeds when, for example, changing from co-polarization to cross-polarization. The iris includes a rectangular opening therein permitting the passage therethrough of the transmit signal while blocking the passage of a signal of the same frequency as the receive signal. The iris is positioned adjacent the receive port to enhance coupling of the receive signal into the receive port. The antenna feed provides high isolation between transmit and receive ports without the need for a filter on the transmit port.

Abstract: The disclosed waveguide branch separating filter can be modularly constructed of a basic frequency separating filter and of a filter expansion unit. Both the basic frequency separating filter as well as the filter expansion unit are composed of a reactively terminated (including short circuit) feeder waveguide to which the separating filters are coupled. The expansion of the basic frequency separating filter occurs in largely disturbance-free fashion during operation in that the reactive termination (including short circuit) thereof is mechanically replaced by the filter expansion unit and is electrically simulated during the refitting by a short-circuit plate or by short-circuit pins.

Abstract: A multiplexing system combines a plurality of electromagnetic signals to propagate along a common path, preferably a square waveguide which can be connected to an antenna feed horn of square cross section which can support both circularly and linearly polarized electromagnetic waves. The system is operative with a plurality of sets of signal channels including a first set of A-channel signals and a second set of B-channel signals. A circular polarizer connects with a first end of the waveguide. All of the A-channel signals are fed into an input port of the polarizer. The B-channel signals are coupled into the waveguide by a plurality of couplers located at positions arranged serially along the waveguide, individual one of the couplers operating at different ones of the B-channel frequencies for selectively coupling respective ones of said B-channel signals into the waveguide to propagate toward the second end of the waveguide.

Abstract: The present invention is directed to reducing the number of components required to minimize intermodulation distortion within the wide transmission frequency band used by a satellite communications repeater system. In particular, at least two TM.sub.010 mode cavity is cascaded to a plurality of TE.sub.113 mode cavities to form a narrow band-pass, wide band-stop filter for receiving and outputting channel signals to the multiplexer manifold of a satellite repeater. The filter thus constructed realizes the narrow band-pass response required in microwave communications, while eliminating the spurious resonance frequencies normally eliminated by additional filter components. In this manner, the size and weight considerations of the satellite system are improved without loss in performance.

Abstract: A multiple-frequency feed assembly for an antenna system having two coaxial cavities, with a smaller, high-frequency cavity mounted coaxially within a larger, low-frequency cavity. A separate rotatable probe is mounted within each cavity. The smaller cavity is mounted within the larger cavity by any of several structures, such as a ring-shaped spider, a ring-shaped spacer in the form of a planar washer, or a harp extending rearwardly in the larger cavity. In all of the embodiments, a continuous, uninterrupted signal path is provided within the low-frequency cavity, around the high-frequency cavity, for conveying incident electromagnetic signals to the low-frequency probe mounted at the rear of the low-frequency cavity. In other embodiments, the feed assembly is adapted to detect incident electromagnetic signals in a third band of frequencies, lower than the low-frequency band, using a third probe located within the low-frequency cavity, immediately adjacent to the high-frequency cavity.

Abstract: In a branching filter, a transmit filter (14) is divided into first and second transmit filter parts (17, 18). A waveguide branching filter (15) is divided into first and second branching filter parts (19, 20). A receive filter (16) is divided into first and second receive filter parts (21, 22). The first transmit filter part is assembled with the second branching filter part and the second receive filter part. The second branching filter part is assembled with the second receive filter part. The first branching filter part is assembled with the first receive filter part. Alternative assembly is possible. As a further alternative, an installation hole may be formed in the branching filter for removable installation of a cable and be covered with a cover with a packing interposed for hermetic seal and waterproofing.

Abstract: A radio frequency multiplexer provides a desired channelization plan by directionally coupling high quality linearly polarized filters to a waveguide manifold. The multiplexer includes a waveguide manifold for transmitting signals in a plurality of different frequency channels, a polarization translating coupling aperture arrangement, a circular polarizer, and filter for each channel. Wide band signals traveling along the waveguide manifold exit the waveguide through the coupling aperture arrangement. The linearly polarized signal from the waveguide manifold translates to a circularly polarized signal through the coupling aperture arrangement and these circularly polarized signals are translated back to linearly polarized signals by the circular polarizer. The linearly polarized wide band signals from the circular polarizer are then filtered with the filter device which allows only signals in a channel to be separated to pass.

Abstract: Numerous high frequency signals are combined in a system of cavity band-pass filters. Each filter has a bottle shape so that adjacent filters may be fitted together into a compact system. Bridges connect the adjacent filters.

Abstract: A dual band feed arrangement for a microwave antenna provides microwave communication in a lower band and in a substantially widened upper band to provide simultaneous microwave communication for three signals. One signal in the lower band propagates between the outer and inner conductors of a coaxial waveguide in the TE.sub.11 coaxial mode, and two signals in the upper band propagate in the inner conductor in TE.sub.11 circular waveguide mode. A combiner, having a conically shaped section with a plurality of irises through its sidewall, is coupled to the coaxial waveguide to provide a transformation from the TE.sub.11 modes to the HE.sub.11 waveguide modes for each of the three signals. A dielectric rod extends from within the inner conductor and into the horn antenna for propagating the second signal out of and into the antenna.

Abstract: A dual frequency feed assembly for an antenna system having two coaxial cavities, with a smaller, high-frequency cavity mounted coaxially within a larger, low-frequency cavity. A separately rotatable probe is mounted within each cavity. The smaller cavity is mounted within the larger cavity by any of several structures, such as a ring-shaped spider, a ring-shaped spacer in the form of a planar washer, or a harp extending rearwardly in the larger cavity.

Abstract: A dual band signal receiver is provided with inner and outer relatively coaxial cylindrical waveguides electromagnetically coupled to respective upper and lower band rectangular waveguides and ports through suitable polarization switching probe assemblies. The rectangular waveguides are mounted adjacent one end of the outer cylindrical waveguide. The rotatable probe assembly of the inner cylindrical waveguide is electromagnetically coupled to the high band rectangular waveguide by a suitable transmission line extending substantially along the longitudinal axis or centerline of the outer cylindrical waveguide.

Abstract: A diplexing radiating element comprising at least a first radiating element in which two radiating electrical currents flow which are spaced apart from each other, and at least one second element in which two radiating magnetic currents flow which are spaced apart from each other. The invention is particularly applicable to space telecommunications.

Abstract: A dual band integrated feedhorn includes a housing having a rotatable support for a C band coaxial waveguide, a clamp for a Ku band waveguide, a Ku band waveguide slideably mounted in the clamp for focus adjustment, and a pair of low noise blocks connected to the waveguide output probes for downconverting their incoming modulated carrier C and Ku band signals to modulated IF signals. A servo drives the support member to position the waveguides energy output coupling probes to match the polarization of the incoming RF energy; thus, eliminating the need for polarizers and reducing insertion loss significantly. The reduced insertion loss enables defocusing of the Ku band waveguide to widen the half power beamwidth to improve aiming accuracy without decreasing the gain and degrading performance. A position adjustable scalar and a pair of power modules are attached exteriorly of the housing. The scalar is positioned adjacent the end of the C band waveguide for focusing the C band waveguide.

Abstract: A dual frequency feed for use with an antenna permits reception of signals in both a low frequency band and a high frequency band and is comprised of a single feed through which both signals are propagated, a high frequency probe which extends concentrically within the throat of the feed for receiving the high frequency signal, a wave guide connected to the throat of the feed including a pair of turnstile junctions with four wave guides interconnecting the turnstile junctions, and a single output port with a polarization rotation device for receiving the low frequency signal. The four interconnecting wave guides may be either co-axial cables or generally rectangular wave guides.

Abstract: The present invention relates to a two-frequency radiating device comprising a waveguide radiating in a first frequency range opening out into a radiating element operating in a lower, second frequency range. The invention is particularly applicable to antennas.

Abstract: The coaxial-waveguide phase shifter consists of a coaxial waveguide section, comprising an external cylindrical conductor and an internal cylindrical conductor, both hollow. Between them a number of irises are provided parallel to one another. The irises can be differently shaped and can be fixed to the external or to the internal conductor. By replacing the internal cylindrical conductor with a rectangular conductor, the irises can be unnecessary.

Abstract: A diplexer for electromagnetic signals of higher and lower frequency is formed of a common waveguide channel for both signals, the common channel branching into a through waveguide channel and a side waveguide channel. The through channel includes a filter having a pass band for propagation of the lower frequency signal and inhibiting propagation of the higher frequency signal. The side channel is formed as a waveguide below cut-off frequency with respect to the lower frequency signal for inhibiting propagation of the lower frequency signal while permitting propagation of the higher frequency signal. A coupling aperture formed as a slot resonant at the higher frequency is located in a waveguide wall at an integral number of quarter guide wavelengths in front of the filter for coupling the higher frequency signal between the common and the side channels.

Abstract: A diplexer for processing polarized energy at separate transmit and receive frequencies. The nature of the polarization may be circular, linear or elliptical depending upon the phasing associated therewith. The diplexer comprises a waveguide having first and second ports disposed at opposite ends thereof. A symmetrical bandpass resonator arrangement is disposed around the periphery of the waveguide and couples energy at the receive frequency out of the waveguide. A symmetrical bandstop resonator arrangement is also disposed around the periphery of the waveguide and filters energy at the receive frequency to prevent coupling of received energy to the second port. The bandpass resonators of each of the resonator arrangements generally include tuning members that control the amount of energy coupled from the waveguide and that adjust and balance the polarization components of the energy to maintain the polarization state thereof.

Abstract: An apparatus for the coupling of laser radiation into a microwave waveguide, in which the laser radiation and the microwave enter the waveguide perpendicular to one another and, after the microwave is deflected, exit the waveguide colinearly. To enlarge the cross section of the laser beam to be coupled and to be able to adjust it to the microwave waveguide, the invention provides that the entry aperture for the laser beam incorporates a corrugated bandstop filter, and that the entry aperture for the microwave is configured in the manner of an orthomode coupler.

Abstract: A microwave transmit/receive terminal having an antenna and associated feed for receiving vertically and horizontally polarized signals and for transmitting a horizontally polarized signal employs a diplexer to be inserted between the feed and an orthomode coupler. The diplexer is formed of a cylindrical waveguide main body, a first port of which is coupled to the feed for receiving the orthogonally polarized receive signals and for coupling thereto the (horizontally polarized) transmit signal. A second port of the main body is coupled to the orthomode coupler for receiving the horizontally polarized signal to be transmitted and for coupling thereto the vertically polarized receive signals. A rectangular waveguide section is coupled to the cylindrical waveguide main body and forms a third port for coupling the horizontally polarized received signal away from said cylindrical waveguide main body.

Abstract: A diplexer for communicating signals in two different frequency bands with separate polarizations in each band may, for example, concurrently separate low frequency received signals of orthogonal polarizations from high frequency transmitted signals, also of orthogonal polarizations. To this end a common square waveguide leads to serially disposed, axially displaced, orthogonal mode transitions at which branches are made to closely coupled lowpass filters that communicate with separate ports for low frequency signal bands. A smaller square waveguide coupled to the second of the orthogonal mode transitions communicates with another orthogonal mode transition at which axially displaced branches communicate with other ports for high frequency signal bands.

Abstract: A dual frequency feed assembly for antenna systems employing a pair of rotatably mounted probes each in respective coaxial cavities. The smaller cavity is supported by the rotating means for the larger probe and the smaller probe rotates with the larger probe driven by a common motor. The higher frequency signal is taken from the side wall of the lower frequency cavity. In an alternate embodiment, the smaller cavity is supported by a spider which rotates the smaller probe by means of external gearing and a separate motor. Other embodiments show coaxial lines which enter from the front face of the assembly and allow rotation of the smaller probe.

Abstract: A two, three or four channel multiplexer can be operated in the TE.sub.01.delta. or HE.sub.11.delta. modes, each channel of the multiplexer has one bandpass filter, with each filter usually having a plurality of cavities. One cavity of each filter is a common cavity with all of the other filters of the multiplexer. The common cavity contains one independent dielectric quarter-cut or half-cut image resonator for each filter representing a channel of the multiplexer. Each resonator is mounted on a suitable support the common cavity provides a common junction and contains a loop coupling to couple electromagnetic energy between the various channels. The multiplexer has at least one input and at least one output. Previous microwave multiplexers have a plurality of bandpass filters arranged on a coaxial manifold. With the multiplexer of the present invention, the manifold can be eliminated.

Abstract: A multiband feed system for a reflector antenna, capable of operating simultaneously at a plurality of separate bands of wide bandwidths and of having both frequency and polarization diversity, comprises a common tapered waveguide for carrying the frequency multiplexed bands and orthomode junctions spaced along the length of the waveguide for coupling signals in a single frequency band in and out of the waveguide. 90.degree. and 180.degree. narrowband polarization devices between the orthomode junctions and the orthomode transducers provide polarization diversity. A dual-depth corrugated flared horn operating in a beamwidth saturation mode with the feed system gives a radiation pattern with low cross-polarization content and nearly equalized subreflector illumination at all bands of operation.

Abstract: A multiplexer/demultiplexer for combining/separating a large number of contiguous frequency channels in microwave bands while incurring low insertion loss. The invention, in a demultiplexer mode, includes a power divider, to form a multiplicity of samples of an input signal; delay lines to non-dispersively differentially delay the samples in accordance with a first arithmetic progression; phase shifters to add fixed phase shifts to samples in accordance with a second arithmetic progression; and a Butler matrix to coherently combine the samples selectively at different output ports for different input signal frequencies. In a multiplexer mode, input signals are applied to the Butler matrix. The Butler matrix, phase shifters, delay lines, and power divider perform in reverse of the demultiplexer mode (the power divider thus performing as a power combiner). The present invention minimizes insertion loss by eliminating any requirement for resonators and any means for isolating resonators.

Abstract: A three-access polarization and frequency duplexing device has in series a common circular waveguide for passing two polarizations of a wave within a low-frequency band and one polarizations of a wave within a high-frequency band, a first access waveguide which opens into the common waveguide and a transition, a secondary rectangular waveguide. The narrow sides of the secondary waveguide are parallel to one polarization of the low-frequency band and the broad sides are parallel to the polarization of the high-frequency band. A second access waveguide is connected to the secondary waveguide at right angles and coupled by a resonant slot. A short-circuit plate performs a short-circuiting function for the high-frequency portion of the wave of the high-frequency band aligned with the second access waveguide. The free end of the secondary waveguide being forms a third access waveguide. The first access waveguide has a filter for selecting a polarization of the wave from the low-frequency band.

Abstract: A duplexer for use in a feed network for a satellite communications antenna is made in waveguide form and comprises two plate halves each with a pattern of channels on one surface, the pattern on one half being the mirror image of the pattern on the other. When the two halves are assembled with the patterned faces juxtaposed, a receive filter and a transmit filter with receive, transmit and common ports are obtained. Each filter has a main waveguide and several short-circuited half wavelength stubs in serial connection to the main waveguide. The joint between the two halves bisects the waveguide broadwall and is, therefore, of no electrical significance. The simplicity of the design lends itself to fabrication as part of a bigger integral assembly consisting of duplexers and other feed components. After manufacture, no further tuning is necessary.

Abstract: A wideband balanced diplexer splits an incoming wideband microwave frequency signal into separate upper and lower frequency outputs and possesses a sharp band cut-off to increase effective bandwidth. The diplexer includes a pair of waveguide assemblies for separating the upper frequency band from the incoming signal. Each waveguide assembly includes a tuneable, ridged waveguide phase shifter for shifting the phase of the lower frequency band, a reference waveguide for inserting a delay onto the upper frequency signal in order to compensate for the effects of the phase shifter in the other waveguide assembly, and a high pass filter. The high pass filter includes a ridged waveguide having tapered ends of a shape comprising an exponential function raised to a cosine squared power to increase the bandwidth of the upper frequencies and to provide a sharper frequency cut-off.

Abstract: A wideband microwave diplexer is provided which includes a waveguide section characterized by a longitudinal dimension, and defining first and second longitudinally spaced ports, for propagating microwave power substantially within a first lower frequency band between said first port and said second port; coupling resonator means for coupling microwave power substantially within a second higher frequency band between said waveguide section and a coaxial transmission line; and band stop filter means for substantially preventing microwave power substantially within the second frequency band from propagating to said second port.

Abstract: A probe coupled waveguide multiplexer is provided including a first waveguide which serves as a multiplexing manifold; a second waveguide, having a cavity, typically a filter, which is probe coupled to the first waveguide; and a third waveguide which has a cavity and is probe coupled to the first waveguide such that the probe of said third waveguide is diametrically opposed to the probe of said second waveguide and the second and third waveguides are mounted in the same transverse plane in co-planar relation. The probe coupling method and apparatus disclosed herein allows the waveguide filters to be mounted on the manifold in a close physical relation thereby minimizing the length of the manifold and associated costs.

Abstract: A microwave multiplexer has a set of independently tuneable signal channels coupled to a common waveguide. Each of the channels has input and output 3 dB couplers which are joined by cylindrical radiators carrying circularly polarized waves. Both TE and TM waves are propagated within a plurality of resonant cavities within each of the filters. Coupling between the cavities is provided by an array of slots and an array of probes wherein the slots couple TE waves and the probes couple TM waves. Adjustment of the slots and the probes provides for independent coupling coefficients for the two propagation modes. A set of coaxial line probe structures connect between the input and output couplers to end cavities of a filter for the launching of TM waves, there being discs in the end cavities adjacent the probes for converting energy of a TM wave to a TE wave, thereby providing both the TM and the TE wave propagation.

Abstract: A directional coupler is provided which has an appropriately dimensioned principle waveguide with a frequency dependent reactive boundary interior surface such that the principle waveguide is suitable to simultaneously: (i) support, without depolarization, effective propagation of first signals in a high frequency band at a HE11 mode with greater concentration of energy near the axis of the principle waveguide than near the interior surface and no effective propagation of first signals at any unwanted mode, and (ii) support, without depolarization, effective propagation of second signals in a lower frequency band at a EH11 mode having a greater concentration of energy near the interior surface of the principle waveguide than near the axis and no effective propagation of second signals at any unwanted mode.

Abstract: An antenna exciter for two different frequency bands which consists of two polarization switches (3, 4) arranged axially one behind the other and of a feed horn (5). The polarization switches (3, 4) are circular tubes of different inside diameters, the diameters being the same over the entire length. To each polarization switch (3, 4) there can be connected, spaced axially from each other, two wave guides (6, 7, 8, 9) 90.degree. apart from each other. Opposite the wave guide (9) adjacent the feed horn (5) a stop closed by a short-circuit plate (12) is arranged in the corresponding polarization switch (4). Between the feed horn (5) and the adjacent wave guide (9) and between the points of connection of the two wave guides (8, 9) of the larger polarization switch (4), two axially extending webs lying diametrically opposite each other and of a predetermined dimension are arranged therein.

Abstract: The invention relates to a rotary microwave joint device comprising a main circular waveguide constituted by two portions (10, 11) situated as extensions to each other and rotatable relative to one another about their axis of symmetry, each of said two portions (10, 11) being provided with at least one access which is orthogonal thereto, and mechanical means enabling a circularly polarized wave to be obtained in the main waveguide. The invention is applicable to space telecommunications.

Abstract: A wavelength separator for separating various electromagnetic signals in such a manner that the separated signals are not seriously attenuated or altered. Ideally, the separator functions best when the ratio of long-wavelength and short-wavelength is greater than 100.

Abstract: A differential phase shifting structure is disclosed, employing corrugated ridges in square or round waveguides or in coaxial lines operating in the TE.sub.11 mode. The structure provides a substantially constant differential phase shift between two waves polarized orthoganally to each other. The corrugations in the ridge provide a series inductance which can be optimized with the shunt capacitance of the ridge to provide a characteristic impedance matching that of the unloaded structure. The corrugated ridges provide increased differential phase shift per unit length. The differential phase shifting structure is particularly well suited to such applications as circular polarizers, quarter wave plates or polarization rotating half-wave plates.

Abstract: A four-port network which is connected to a microwave antenna feed horn for separating four signal paths associated, in pairs, with two polarizations and two frequency bands, and with the network also being utilized for the derivation of antenna tracking signals according to the monopulse principle. A conductor is disposed along the longitudinal axis of the waveguide connecting the antenna feed horn with the four-port network, with this conductor extending, on the one hand, to the region of the antenna feed horn throat and, on the other hand, into the four-port network so as to couple in signals of a higher order mode for the derivation of the antenna deviation signals.

Abstract: A television broadcasting system uses an antenna diplexer to combine signals generated from visual and aural power amplifiers. The diplexer comprises first and second hybrids coupled together by transmission lines which have aural-frequency cavities for reflecting aural energy from an aural input port to an antenna output port of the second hybrid. In the event that the visual power amplifier fails, it is desirable to revert to multiplexed operation, in which the aural power amplifier amplifies a combined visual and aural signal. This mode of operation is accomplished by combining the low-level aural signal with the low-level visual signal, by putting the combined visual-with-aural multiplexed signal through the aural power amplifier, and by simultaneously shorting the transmission lines between the second hybrid and the aural cavities.

Abstract: A dual band polarization filter can be produced at low expense includes two hollow waveguide sections arranged one behind the other. A fin-type conductor structure is provided in each hollow waveguide section. The fin-type conductor structures produce polarization and frequency band separation of the signals fed into the hollow waveguide sections, these signals being associated with two different frequency bands and two polarization directions.