Allen Telecom Group, Inc.

Chia-Sam Wey

Douglas R Jachowski

Erik W Lilieholm

John M Stronks

David P Halley

A dual-band filter providing a bandpass characteristic over a first predetermined range of frequencies, and a notch, or band-reject characteristic over a second predetermined range of frequencies. In one embodiment, the notch characteristic occurs within the bandpass characteristic, yielding a filter frequency response with two asymmetric passbands separated by a reject band. This is particularly suited to cellular Band A receive filter applications, but the design is easily adapted to other uses. Appropriate tuning can restore symmetry to the passbands.

Asymmetric dual-band combine filter

A multichannel combiner includes a plurality of input ports for connection to associated transmitters, narrow bandpass filters associated with each port, and an output port for connection to an antenna system. The output impedance of the filters is selected to be substantially lower than that used in conventional combiners, such that undesired reactance produced in the combiner over its operating range is much reduced. The combiner further includes an impedance transformer to match the low output impedance of the filters to the design impedance of the antenna system.

Multichannel transmitter combiners employing cavities having low output

An RF filter having a housing defining a cavity with plural elongated resonators and plural resonator decouplers adjacent each of plural pairs of the resonators in the housing. The decouplers are grounded adjacent each of their ends only to the housing to provide an enhanced resonator decoupling effect. The filter may instead comprise a dielectric block with resonator holes and resonator decoupler holes each appropriately metalized with the decoupler holes being grounded at each end at external metalized block surfaces.

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Reno, NV, United States of America

Chia-Sam Wey