Abstract:
A suspended microstrip filtering device comprises a printed circuit board that includes a substrate having at least one resonator thereon, a ground plate, and an insulating separator interposed between the printed circuit board and the ground plate, the insulating separator having a plurality of air-filled openings.
Abstract:
The present invention provides filter assemblies, tuning elements and a method of tuning a filter. A filter assembly includes a housing having a top cover, a bottom cover and at least one sidewall, the top cover, the bottom cover and the at least one sidewall defining an internal cavity, the housing configured to receive first through third radio frequency ("RF") transmission lines; a top metal sheet mounted within the internal cavity that has a plurality of openings that form a first hole pattern; and a bottom metal sheet mounted within the internal cavity that has a plurality of openings that form a second hole pattern. The top and bottom metal sheets are vertically spaced-apart from each other in a vertically stacked relationship within the internal cavity. The top metal sheet and the bottom metal sheet each include at least one resonator.
Abstract:
A metallized dielectric waveguide filter includes an upper metallized dielectric waveguide having a plurality of upper resonant cavities, the upper metallized dielectric waveguide comprising an upper dielectric block having metallized outer walls, and a lower metallized dielectric waveguide having a plurality of lower resonant cavities, the lower metallized dielectric waveguide comprising a lower dielectric block having metallized outer walls. A first of the upper resonant cavities is operatively connected to a first of the lower resonant cavities via at least one coupling window. A first slot having metallized walls is provided in a portion of the upper dielectric block that is part of the first of the upper resonant cavities.
Abstract:
A resonant cavity filter has a housing having a resonator mounted therein, a tuning screw that comprises a head portion, a metallic tuning element and a dielectric spacer interposed between the head portion and the metallic tuning element. The tuning screw is mounted for coaxial insertion into an interior of the resonator to adjust a frequency response of the resonant cavity filter.
Abstract:
A bandpass filter has a combline structure having a plurality of cascaded nodes (503, 504, 506, 508 ). A plurality of nodes in the filter are connected both to resonant elements ( 514, 517 ) (a.k.a. resonators) and non-resonant elements ( 601, 604 ) (including elements having inductances and/or capacitances that do not resonate in a predetermined frequency band of interest). The resonant frequencies of the resonant elements may be adjusted, in order to adjust the location of the center frequency and/or the width of the passband of the filter. The characteristics of the resonant and non-resonant elements are selected such that the poles of the filter, when plotted on the complex plane, move substantially along the imaginary axis when the resonant frequencies are adjusted, without substantial movement along the real axis. The resulting bandpass filter has substantially constant losses and substantially constant absolute selectivity over a relatively wide range of bandwidths.
Abstract:
An in-line resonator filter has a linear array of three or more conductors. A first pair of adjacent conductors has inductive main coupling and oppositely signed capacitive main coupling, while a second pair of non-adjacent conductors has inductive cross-coupling. The first and second pairs have one conductor in common. Between the second pair of non-adjacent conductors, there is no direct ohmic connection that provides the corresponding inductive cross-coupling. The oppositely signed capacitive main coupling compensates for at least a portion of the inductive main coupling between the first pair of adjacent conductors. The in-line resonator filter is able to provide one or more transmission zeros without requiring any discrete bypass connectors that provide direct ohmic connection between pairs of non-adjacent conductors. As such, the in-line resonator filters can be smaller, less complex, and less susceptible to damage.
Abstract:
Resonant cavity filters include a conductive housing having a floor. A dielectric resonator is mounted to extend upwardly from the floor. The dielectric resonator has a cylindrical body with a longitudinal bore that defines an inner sidewall. The longitudinal bore has a variable transverse cross-sectional area. A threaded dielectric fastener is at least partially inserted within the longitudinal bore of the cylindrical body. The dielectric resonator may have a protrusion that extends inwardly from the inner sidewall.
Abstract:
A metallized dielectric waveguide filter includes first and second input/output ports and a dielectric block that has metallized top and bottom surfaces and metallized sidewalls. The dielectric block further includes a plurality of metallized openings that extend into the interior of the dielectric block, and these metallized openings divide the dielectric block into a plurality of resonator cavities. A first of the metallized openings extends at an oblique angle with respect to a first of the metallized outer sidewalls.
Abstract:
Provided an in-line resonator filter (400) comprising a linear array of three or more conductors (410), the linear array comprising: a first pair of adjacent conductors (410(1), 410(2)) having inductive main coupling and oppositely signed capacitive main coupling; a second pair of non-adjacent conductors (410(1) and 410(3)) having inductive cross-coupling, it is an objective of the present application to further allow the altering of the coupling within the resonator filter, and thereby tune the overall transfer function of the resonator filter to be different from the filter's inherent transfer function. The object is achieved by a first tuning element (422(3) and (4)) that extends from a bottom of the ground plane (402) of the in-line resonator filter; and a second tuning element (420) that extends from a top of the ground plane (404) of the in-line resonator filter; wherein: the first and second pairs have one conductor (410(1)) in common; and at least a portion of the oppositely signed capacitive main coupling compensates for at least a portion of the inductive main coupling between the first pair of adjacent conductors (410(1), 410(2)).
Abstract:
An in-line resonator filter (400) comprising a linear array of three or more conductors (410), the linear array comprising: a first pair of adjacent conductors (410(1), 410(2)) having inductive main coupling and oppositely signed capacitive main coupling; a second pair of non-adjacent conductors (410(1), 410(3)) having inductive cross-coupling; and one or more tuning elements (422), each extending from a ground plane of the in-line resonator filter, wherein: the first and second pairs have one conductor (410(1)) in common; between the second pair of non-adjacent conductors, there is no direct ohmic connection that provides the corresponding inductive cross-coupling; and at least a portion of the oppositely signed capacitive main coupling compensates for at least a portion of the inductive main coupling between the first pair of adjacent conductors.