Motorola Corporation

Mark H Ballance

David R Heine

Raymond L Sokola

Keith Ronald Manssen

Michael A Newell

Robert J Munn

Glenn Rice

Protap Pramanick

A ceramic filter (100) with integrated harmonic response suppression has a ceramic monolithic block filter having a predetermined passband defined by tuned resonators located between an input and an output (116); and at least one of a harmonic trap filter, a lowpass filter and a lowpass microstrip filter, each having an inductive and a capacitive component. This is achievable with a design which incorporates an integrated harmonic response suppression filter directly in or on the dielectric ceramic monolithic block. This can result in a substantial savings in space, cost, and part count in an electronic telecommunications device.

Ceramic filter with integrated harmonic response suppression using

A ceramic waveguide filter made from a monolithic block of dielectric ceramic material which has longitudinally spaced resonators is described. Resonant structures having a grounded portion and ungrounded portion, each of the resonant structures being inductively coupled at the ungrounded portion describe the electrical schematic which corresponds to the waveguide filter. The positioning of the input and output on the block of dielectric ceramic material define a passband and also create a shunt resonant section. The shunt resonant section is associated with a shunt zero in the electrical schematic of the waveguide filter. Finally, the dielectric block of ceramic is mostly coated with an electrically conductive coating material with the exception of an uncoated area immediately surrounding the input and output. An extracted pole in the form of a shunt zero can provide a frequency response with a high side zero, low side zero, or both, and two extracted poles in the form of two shunt zeros can provide two high side zeros, two low side zeros, or one zero on each side of the passband. These features together provide a ceramic filter with a extracted pole.

Ceramic waveguide filter with extracted pole

A bandstop filter module (200) with a shunt zero is provided. The module (200) contains a circuit substrate (202) with input and output pads and transmission lines (208). The module (200) also contains at least one dielectric monolithic block (210) mounted to the circuit substrate (202) having a plurality of metallized through holes defining resonators (224) and guard holes (226). All surfaces of the dielectric monolithic block (210) are substantially covered with a conductive material with the exception that the top surface (212) is selectively metallized providing an unshorted metallization pattern (228) relative to a ground plane in proximity to the guard holes (226). The guard holes (226) and the unshorted metallization pattern (228) provide a shunt zero in a frequency response curve of the module (200). The module also contains means for coupling each of the resonators (224) with the transmission lines (208) on the circuit substrate (202). Other module components include at least one inductor coil (230) mounted on the circuit substrate (202) and a shield (232) having tuning windows.

Bandstop filter module with shunt zero

A ceramic filter (100) is disclosed. The filter (100) has a filter body comprising a dielectric material having a plurality of surfaces with each surface having a plurality of metallized through holes extending through the dielectric material defining a first series of resonators (102) in a first plane and a plurality of second metallized through holes in a different plane and extending transversely with relation to the first, defining a second series of resonators (104). The filter (100) also has a metallization layer substantially coating all surfaces of the filter (100) with the exception that a portion of the surface surrounding each resonator is left unmetallized, and a coupling structure (108) for coupling electrical signals into and out of filter (100).

Multi-frequency ceramic block filter with resonators in different planes

A multi-filter device comprising a ceramic block (10) having at least two filters A and B. Both filters A and B include a notch (11 and 13, respectively) formed on one side of the ceramic block (10), such that these notches are flanked by ceramic block material extensions (32). So configured, coarse tuning of the ceramic block (10) can be accomplished through use of existing double-sided lap techniques, yet constant parameter alteration for both filters will be maintained during the milling process.

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Albuquerque, NM, United States of America

Mark H Ballance