Com Dev Limited

David Siu

Wai-Cheung Tang

Joseph Sferrazza

Bruce C Beggs

Joseph Frenna

A quadruple mode bandpass filter has at least one cavity resonating in four independent orthogonal modes simultaneously. Preferably, the filter has two cavities, one cavity being a quadruple mode cavity and the remaining cavity being either a single mode, dual mode, triple mode or quadruple mode cavity. By introducing a resonant feedback coupling into filters of the present invention, the number of transmission zeros produced by the filter is equal to the order of the filter. Previous filters have cavities resonating in either a single, dual or triple mode and the maximum number of transmission zeros is equal to the order of the filter minus two.

Quadruple mode filter

A triple mode dielectric loaded bandpass filter has at least one cavity resonating in three independent orthogonal modes. A triple mode cavity can be mounted adjacent to either single, dual or triple mode cavities. Inter-cavity coupling is achieved through the iris having two separate apertures that together form a T-shape. The cavities can be planar mounted. The filter is designed for use in the satellite communication industry and results in substantial savings in weight and size when compared to previous filters.

Triple mode dielectric loaded bandpass filter

A bandpass filter has a plurality of cascade cavities that operate in a dual-mode and are mounted in a planar relationship to one another. Each cavity contains a dielectric resonator and resonates at its resonant frequency in two HE.sub.11.delta. modes. An iris is located between adjacent cavities and contains an aperture that can independently control inter-cavity coupling. The dielectric resonator is cylindrical in shape and an adjustable metallic plunger is located in a wall of each cavity so that the cavity can be tuned over a relatively broad range. The filter has good mechanical and thermal stability as well as being extremely flexible in the arrangement of cavities.

Planar dual-mode cavity filters including dielectric resonators

An odd order bandpass filter has at least one cavity resonating at its resonant frequency in three independent orthogonal modes. The filter has at least one feedback coupling that is made to resonate and change sign at a center frequency. When the filter has two cavities, one being a triple cavity and the other being a dual mode cavity, the filter can be operated to achieve an elliptic function response. Also, the filter of the present invention can achieve a weight and volume reduction when compared to six-pole dual mode filters.

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Hamilton, Canada

David Siu