Abstract: A microwave filter has a plurality of resonant cavities with each cavity containing a dielectric resonator. There are self-equalizing probes or self-equalizing apertures located between some of the cavities. A circulator is connected to an output of the filter. The circulator has an input/output which is connected to an equalizer. The equalizer contains a dielectric resonator that is slightly different from the dielectric resonators of the filter to permit the equalizer to be tuned at a slightly different frequency from the filter. The equalizer and self-equalizing probes or apertures are capable of being operated to reduce a dispersive slope of the filter. The filter can operate in a single mode or a dual mode. The electrical performance of the filter is superior to prior art filters, particularly in the wideband versions because the dispersive slope is reduced.

Abstract: The invention relates to a single mode multi-cavity microwave filter that includes a housing formed with a plurality of walls which define at least two rows of side-by-side dielectric loaded cavities, wherein sequential cavities are coupled to one another via slots formed in the walls therebetween and at least one pair of non-sequential adjacent cavities are coupled via a probe. The coupling via the slots is defined mathematically as positive coupling. The probe is selectively configurable to provide positive or negative coupling relative to the sign of the slot coupling. Further, at least one non-adjacent, non-sequential pair of cavities is coupled via a second probe that may be configured to provide either positive or negative coupling relative to the sign of the slot coupling. The filter housing supports a plurality of adjustable fins which extend into the slots, one fin to each slot, to selectively adjust the size of the slot.

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: This invention relates to a modular contiguous channel multiplexer having one or more modules that produce an asymmetric filter function that is combined with responses from other modules to produce an overall symmetrical response. The multiplexer can have channels arranged in any order of relative frequencies and one or more channels can be added or removed from the multiplexer without disturbing the operation of the existing or remaining channels. A method of constructing a multiplexer involves choosing the most downstream channel first, then choosing sequentially the channel immediately upstream from the channel last chosen and choosing filters of each channel to meet certain criteria. The filters of each channel are identical to one another but are not necessarily identical to filters in adjacent channels.

Abstract: Cascaded dual-mode resonance cavities are separated by plates having each a cruciform iris therein, the arms of which have lengths determined by a direct and precise procedure starting from a conventional Butterworth prototype filter. The transfer function parameters are altered to change the filter response and the group delay performance is determined and compared to an ideal flat response for producing a penalty function signal from the difference in order to modify the parameters again in such direction that the penalty function signal is likely to be reduced. The process is repeated until the penalty function signal is minimum, whereby a compact structure is realized which provides an attenuation response having sharp cut-off slopes at the edges of the signal bandwidth together with a close to flat in-band group delay response.

Abstract: A structure comprising a cascade of dual mode resonance cavities wherein each cavity has a pair of tuning screws located at 90.degree. to each other in a sectional plane of the cavity and a coupling screw located at 45.degree. to the tuning screws for coupling the two resonances supported by the cavity. Each cavity is coupled to the adjacent cavity by means of a coupling iris set at a determined angle relative to the angular position of the tuning screws of the cavity and the adjacent cavity is positioned at a determined angle relative to the angular position of the coupling iris which couples said cavity to the former one.

Abstract: An electric transmission structure for implementing a transfer function with finite real-frequency transmission zeros, which comprises a main body comprised of a plurality of resonant cavities placed adjacent to each other with inductive coupling irises between adjacent cavities, the resonant cavities being arranged symmetrically relative to a plane of conjugate symmetry, said main body synthesizing the linear phase part of the filter transfer function, and at least one pair of pole resonant cavities arranged symmetrically relative to said plane of conjugate symmetry, each of said resonant cavity pairs synthesizing a pair of finite real-frequency transmission zeros of the filter transfer function, with the respective pole cavities of each pair being connected across the input and output ends of the main body through phase-shift waveguides having defined phase-shift lengths.