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.

Abstract: A multiplexer has a plurality of bandpass filters coupled through E-plane or H-plane T-junctions to a waveguide manifold. Where the multiplexer has four channels and each filter is a six-pole filter, two triple mode cavities make up each filter. Where each filter is a five-pole filter, one triple cavity and one dual mode cavity makes up each filter. Two band edge channel filters are operated to produce an asymmetrical filter function response, thereby causing extra transmission zeros to be created and improving the selectivity of the filter out of the passband. The multiplexer is designed for use in satellite communication systems and can have a reduced volume and weight when compared to previous multiplexers without any sacrifice in electrical performance.

Abstract: In accordance with the present invention there is provided a bandpass T filter and power splitter for electromagnetic energy. It is composed of a plurality of resonant elements serially arranged to form a plurality of forward multi-pole bandpass filters. At least one resonant element is common to both signal paths. The common resonant element transfers energy from the common path to the independent signal paths to effect a power split. The two signal output paths are isolated from one another by a multi-pole bandpass filter. The resonant elements may be composed of either resonant waveguide cavities or dielectric resonators.

Abstract: A frequency multiplier for electromagnetic waves in which multiples of the input frequency propagate, while the input frequency evanesces. A rectangular waveguide or other suitable wave conveying element with a cut-off frequency above the input frequency but below the output frequency contains the multiplying structure. The input frequency is multiplied using a post located in the waveguide or other element adjacent to the source of input waves. The post may define a multiplier gap between one of its surfaces and a wall of the waveguide or other element, in which case the multiplier gap may contain a multipactor between its surfaces which generates multiples of the input frequency. The multiplier gap may alternatively contain a non-linear element responsive to a high electric field, such as a ferroelectric material, which also generates multiples of the input frequency. Alternatively, the post may be surrounded by a non-linear element of ferromagnetic material responsive to a strong magnetic field.

Abstract: A circuit component for separating and/or combining two pairs of high-frequency signal waves lying in different frequency bands, the waves of each pair having the same frequency but mutually orthogonal planes of polarization, comprises two mutually identical and aligned 3dB couplers bracketing a filtering assembly between them. Each 3dB coupler has a central guide of square cross-section surrounded by four collateral guides, each connected with the central guide by a coupling guide letting only the waves polarized in one plane--regardless of frequency--pass therebetween. The filtering assembly has sets of baffles in line with the central and collateral guides of both couplers, these baffles defining slots giving passage to only the waves of one of the two bands while reflecting the others.

Abstract: A system is disclosed for coupling orthogonal polarized microwave signals from a reflector to signal processing circuits. The system includes successively a horn, a bandpass filter, a polarizer, a mode separator, and a housing for containing the circuits. The system is constructed from two half-shells. The horn, bandpass filter and polarizer form a waveguide portion which is coupled to the circuits by the mode separator.

Abstract: A primary source for a space communications antenna requiring a mode extractor means comprises more especially a horn with two types of evenly spaced alternate corrugations whose depth decreases, for each of the types, from the neck to the opening, followed by a band separator of the quasi-optical filter type, followed by a mode extractor means placed in series in the reception channel of the primary source.

Abstract: A combiner for transmitting and receiving co-polarized microwave signals in a selected propagation mode in at least two different frequency bands, the combiner comprising a main waveguide dimensioned to simultaneously propagate signals in the different frequency bands, at least a portion of the main waveguide being overmoded; at first and second junctions spaced along the length of the main waveguide for coupling signals in the different frequency bands in and out of the main waveguide, at least the first junction being located in an overmoded portion of the main waveguide and having side-arm waveguide means associated therewith for propagating signals in one of the different frequency bands; filtering means disposed within the main waveguide and operatively associated with the first and second junctions, the filtering means having (1) a stopband characteristic for coupling signals in a first one of the frequency bands between the main waveguide and the first junction and the side-arm waveguide means associat

Abstract: A waveguide structure carrying microwaves with two mutually orthogonal planes of polarization and in two different frequency bands, transmitted and received by an associated antenna, comprises two orthomode transducers in the form of coaxial cylindrical guide members of different inner diameters, the smaller-diameter transducer terminating in a short-circuiting end wall while the larger-diameter transducer, adjoining same at an annular shoulder, extends to a feed horn confronting a reflector. Each transducer is formed with two elongate peripheral access slots, opening onto respective rectangular-section branches, which are longitudinally bisected by mutually perpendicular axial planes while being relatively offset in axial direction.

Abstract: A multi-port, multi-frequency combiner comprising a main waveguide having a cross-section in the shape of a right-angle parallelogram and dimensioned to simultaneously propagate co-polarized signals in different frequency bands and at least one signal that is orthogonally polarized with respect to the co-polarized signals, at least a portion of the waveguide being overmoded; a plurality of junctions spaced along the length of the main waveguide for coupling selected signals in the different frequency bands in and out of the waveguide, at least one of the junctions being located in an overmoded portion of the waveguide, each of the junctions having an unbalanced or pseudo-balanced feed with only a single side-arm waveguide for transmitting and receiving the signals; and filtering means disposed within the main waveguide and operatively associated with each junction therein for signals in the highest frequency band, the filtering means having (1) a stopband characteristic for coupling signals in the highest fre

Abstract: A waveguide apparatus guides a first pair of horizontally polarized transmit and receive frequency signals independently of and in parallel with a second pair of vertically polarized transmit and receive frequency signals. The waveguide apparatus is constructed to operate across the 3.7 to 6.425 GigaHertz band with a very narrow bandwidth for the transmit frequency and a very narrow bandwidth for the receive frequency and with a single size of rectangular waveguide for separating the transmit and receive frequencies. This construction simplifies frequency separation filtering techniques and provides effective operation over this broad band with an apparatus which is efficient in terms of space, compact and implemented by a simple package.

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 tri-mode coupler (80) for developing from a received signal including three waveguide propagation modes the three tracking signals (i.e. sum signal, elevation signal, and azimuth signal) used in a high-frequency monopulse tracking system and for transmitting a signal at a different frequency, the coupler comprises broadband means such as a two-arm turnstile junction (84) coupling a first circular waveguide section (82) to an E-plane folded hybrid junction (90) for separating out one waveguide mode of the received signal and receiving the signal to be transmitted, and a second circular waveguide section (86) of smaller diameter than the first waveguide section and coupling the latter section to an additional E-plane folded hybrid junction (88) for separating out the two additional waveguide modes of the received signal.

Abstract: A transducer for coupling to an antenna with a first polarizing duplexer for working in a low-frequency band, a between-guide transition element formed from a variable-section guide and a second polarizing duplexer for working in a high-frequency band. In the polarizing openings of the first duplexer are placed dipoles resonating at the mean frequency of the high band which cause a short-circuit for the high frequencies and let the low frequencies pass. A set of quasioptical filters, situated in the body of the first duplexer, between the polarizing openings of this first duplexer and the transition element, causes a short-circuit for the low frequencies and lets the high frequencies pass.

Abstract: The invention provides a mode coupler arrangement comprising a main waveguide coupled via arrays of slots to two sets of subsidiary waveguides over a common length. One set of subsidiary waveguides is such as to support one mode of propagation and the other set another mode of propagation. In a preferred embodiment the slots in one set of subsidiary guides are staggered by (1.lambda./4) relative to the slots in the other set of subsidiary guides and the guides of one set are longer than the guides of the other set.For TE11 communications mode signals, the two sets of subsidiary guides are of different frequency, with each subsidiary guide arranged such that its variation of wavelength with frequency coincides with that of the main waveguide only in the frequency band for which that subsidiary guide is provided.

Abstract: A four-port network for separating signals comprised of two doubly polarized frequency bands for an antenna feeder system in directional or satellite radio operation, wherein a first polarization converter for converting linear polarization to circular polarization, and vice versa, is designed for the lowest inherent ellipticity in the lower frequency band and is connected ahead of a symmetric polarization filter for the lower frequency band, and a second polarization converter which compensates the remaining ellipticity in the upper frequency band is connected between the symmetrical polarization filter and a further polarization filter for the upper frequency band.

Abstract: In the illustrated embodiments a dual branching is coupled to two simple branchings via coupling elements which are rotationally symmetrical so as to accommodate different spacial dispositions of the two simple branchings while maintaining electrically completely symmetrical passageways and consequent phase synchronism therein. When the dual branching is connected with an antenna for directional or satellite broadcasting operations, the sending and receiving frequencies, with respective polarizations at the respective simple branchings, may be separated with the use of a bandpass arrangement and 3-dB directional couplers for the respective separated frequencies.

Abstract: A constant resistance network which exhibits frequency dependent characteristics consists of a cavity resonator having two coupling loops mounted parallel to the walls of the cavity. The resonant frequency of the cavity is primarily determined by the dimensions of a resonator plate whose frequency of resonance can be trimmed by adjusting the size of a slot. The network can be used for combining the different frequencies by arranging that one of the frequencies is at the resonant frequency of the plate. The network can be extended by the provision of additional resonator plates to provide a more complex frequency response.

Abstract: This specification discloses a microwave circular polarizer for converting a linearly polarized microwave signal to a circularly polarized microwave signal and vice versa. A transducer, such as an Orthomode junction is used to obtain a power split or a power recombination of two orthogonal linear polarizations. To obtain the phase delay required to generate a circularly polarized signal from two linearly polarized signals, the polarizer includes a phase compensator with a pair of waveguides which have appropriate width and length so that signals passing therethrough develop a phase difference therebetween and a composite circularly polarized signal results. The amount of phase shift occurring in each of the waveguides varies with the frequency of the signal in such a way as to produce a high purity circular polarization over a broad frequency band. A phase shift of 90.degree.

Abstract: The cavity of a rotatable cylindrical waveguide supports the TE.sub.11 mode of propagation of a received wave and a transmitted wave. The proximal and distal ends of the cylindrical waveguide are adjacent and axially aligned with one end of a rectangular flexible waveguide and a fixedly disposed horn aperture, respectively. The transmitted wave propagates in the TE.sub.10 mode through the rectangular waveguide to the cylindrical waveguide. Additionally, the rectangular waveguide prevents propagation therethrough of the received wave. The cylindrical waveguide couples the transmitted wave to the horn. Rotation of the end of the rectangular waveguide rotates the polarization of the transmitted wave. A pair of slots in the cylindrical waveguide form passageways between the cavity thereof and a pair of filters that pass the received wave whereby the received wave propagates through the filters.

Abstract: A microwave diplexer apparatus for handling simultaneously two independent polarized transmitted signals at one frequency and two independent polarized received signals at a lower frequency. In the transmit mode of operation, a pair of input signals are applied to a first orthogonal mode transducer wherein the electric fields of the signals are established at right angles to each other. The orthogonal, linearly-polarizer signals are then transformed by a pin/ridge-loaded circular polarizer device to oppositely-rotating circularly-polarized signals and coupled via an antenna port of a second orthogonal mode transducer to an antenna for transmission to a desired target.

Abstract: Apparatus for separating electrical signals of different frequencies comprising two adjoining waveguides wherein both of the signals to be separated exist in one waveguide and only the higher frequency signal exists in the second waveguide including a radial circuit supressor attached to the first waveguide and with an extending center conductor extending through an opening formed in the first waveguide at a spacing of approximately one-quarter wavelength of the lower frequency band and wherein the center conductor of the radial circuit suppressor extends into the first waveguide a distance of approximately one-quarter wavelength for the center frequency of the higher frequency signal. A modification of the invention provides for a resonant cavity attached to the first waveguide with a longitudinal slot formed between the first waveguide and the resonant cavity and a third modification utilizes an inductive diaphragm rather than a slot formed between the resonant cavity and the first waveguide.

Abstract: A microwave diplexer apparatus for handling simultaneously two independent polarized transmitted signals at one frequency and two independent polarized received signals at a lower frequency. In the transmit mode of operation of the diplexer apparatus, a pair of input signals to be transmitted to a target are applied to a first orthogonal mode transducer wherein the electric fields of the signals are established at right angles to each other. The orthogonal linearly-polarized signals are then transformed by a pin/ridge-loaded circular polarizer device to oppositely-rotating circularly-polarized signals and coupled via an antenna port of a second orthogonal mode transducer to an antenna for transmission to the desired target.

Abstract: A series connection of n diplexers is used as a multiplexer for separating a hyperfrequency band into n + 1 sub-bands (or vice-versa). Each diplexer comprises a semi-circular inlet coupler followed by a semi-circular high-pass filter and by a semi-circular outlet coupler, the filter at each stage is dimensioned to reflect only the lowest of the sub-bands which it receives from the previous stage. The creation of unwanted parasitic modes in the reflected sub-band is avoided by so choosing the radius of the inlet coupler that the reflected sub-band lies between the frequencies at which the parasitic TE.sub.12 and TE.sub.22 modes occur. This is achieved by use of the relationship ##EQU1## WHERE V IS THE SPEED OF LIGHT, FMAX AND FMIN ARE THE UPPER AND LOWER LIMIT FREQUENCIES OF THE REFLECTED SUB-BAND AND P'.sub.12 and P'.sub.22 are the second zeros of the first and second order Bessel functions characterising the respective semi-circular TE.sub.12 and TE.sub.22 modes.