Com Dev Limited

Van Dokas

Raafat R Mansour

Wai-Cheung Tang

Ming Yu

Richard J Cameron

Soeren F Peik

The invention provides a method and apparatus for a adaptively predistorted filter which has a transfer function that satisfies performance criteria specified for at (east one property of the filter. The transfer function is obtained by adaptively predistorting the transfer function poles to meet the performance criteria such that at least one of the poles is shifted by a unique amount.

Microwave filter with adaptive predistortion

A dielectric resonator is provided having a cavity, a dielectric half disk resonator structure structure, and a support for the half disk resonator structure. The support isolates the dielectric half disk resonator structure from walls of the cavity. A straight edge wall of the dielectric half disk resonator structure couples to a dielectric/air interface within the cavity and forms an approximate magnetic wall. The approximate magnetic wall images the electric field perpendicular to the straight edge wall and supports a single-mode electric field within the half disk resonator structure. Multiple half disk resonator structures may be oriented within the cavity to support other, orthogonal electric fields. Multiple cavities may be coupled to each other through irises formed on the cavity walls.

Quasi dual-mode resonator

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.

Folded single mode dielectric resonator filter with cross couplings

Microwave bandpass filters contain dielectric resonators mounted in dielectric blocks, which are in turn mounted in cavities. There can be more than one dielectric resonator per cavity. Significant size reduction has been achieved over prior art filters. The filters can be operated at cryogenic temperatures and since the results attainable at cryogenic temperatures are repeatable, the filters can be tuned at cryogenic temperatures and returned to room temperature before being returned to cryogenic temperatures for operating purposes. When operated at cryogenic temperatures, the filters contain shorting plates having high temperature superconducting material thereon. The filters can be constructed with various configurations and can be operated in either a single mode or a dual-mode. Previous single mode or dual-mode dielectric resonator filters are larger in size and mass than the filters of the present application.

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Cambridge, Canada

Van Dokas