Abstract: The present invention is a tunable bandpass filter to provide a constant absolute bandwidth across a tuning range, comprising of a pair of resonators to determine a filter center frequency, each said resonator has a rectangular waveguide cavity, wherein said filter center frequency depends on the dimensions of said rectangular waveguide cavity; a pair of side walls attached to said pair of resonators to form a filter housing; a tuning element movably attached to at least one of said pair of side walls and extending in said filter housing and movable orthogonally to said pair of resonators, and wherein said dimensions of said rectangular waveguide cavity change by moving said tuning element, thereby said filter center frequency is changed.

Abstract: The present invention is a high Q tunable co-axial filter, which maintains a constant absolute bandwidth and a constant Q over the tuning range. The present filter can be tuned by a single rotational mechanism irrespective of the filter order. A plurality of tunable resonators is aligned on a common filter axis. Each resonator has a casing having an inner wall and a cavity. The resonators are coupled by an iris opening. A pair of end plates completes the filter casing. A rotating rod placed on the common axis of the resonated, that has a tuning post attached to it, and each post located in each resonator, is used to tune the filter.

Abstract: The present invention is a high Q tunable co-axial filter, which maintains a constant absolute bandwidth and a constant Q over the tuning range. The present filter can be tuned by a single rotational mechanism irrespective of the filter order. A plurality of tunable resonators is aligned on a common filter axis. Each resonator has a casing having an inner wall and a cavity. The resonators are coupled by an iris opening. A pair of end plates completes the filter casing. A rotating rod placed on the common axis of the resonated, that has a tuning post attached to it, and each post located in each resonator, is used to tune the filter.

Abstract: The present invention is a tunable bandpass filter to provide a constant absolute bandwidth across a tuning range, comprising of a pair of resonators to determine a filter center frequency, each said resonator has a rectangular waveguide cavity, wherein said filter center frequency depends on the dimensions of said rectangular waveguide cavity; a pair of side walls attached to said pair of resonators to form a filter housing; a tuning element movably attached to at least one of said pair of side walls and extending in said filter housing and movable orthogonally to said pair of resonators, and wherein said dimensions of said rectangular waveguide cavity change by moving said tuning element, thereby said filter center frequency is changed.