Tdk Corporation

Other

Arun Chandra Kundu

Kenji Endou

Ikuo Awai

A filter comprises a band pass filter that may have a first resonator, a second resonator and a coupling between the first resonator and the second resonator. The coupling may be controlled by at least one of (i) a spacing between the first resonator and the second resonator, and (ii) a shunt inductance coupled to the coupling.

Multilayer band pass filter

A highly compact bandpass filter that has excellent mechanical strength is disclosed. A bandpass filter according to the present invention employs a dielectric block of substantially rectangular prismatic shape constituted of a first portion lying between a first cross-section of the dielectric block and a second cross-section of the dielectric block substantially parallel to the first cross-section and second and third portions divided by the first portion and metal plates formed on surfaces of the dielectric block. The first portion of the dielectric block and the metal plates formed thereon are enabled to act as an evanescent waveguide. The second portion of the dielectric block and the metal plates formed thereon are enabled to act as a first resonator. The third portion of the dielectric block and the metal plates formed thereon are enabled to act as a second resonator. The metal plates include an inductive stub formed on the surface of the first portion of the dielectric block.

Bandpass filter

A highly compact band pass filter that has excellent mechanical strength is disclosed. A band pass filter according to the present invention employs a dielectric block of substantially rectangular prismatic shape constituted of a first portion lying between a first cross-section of the dielectric block and a second cross-section of the dielectric block substantially parallel to the first cross-section and second and third portions divided by the first portion and metal plates formed on surfaces of the dielectric block. The first portion of the dielectric block and the metal plates formed thereon are enabled to act as an evanescent waveguide. The second portion of the dielectric block and the metal plates formed thereon are enabled to act as a first resonator. The third portion of the dielectric block and the metal plates formed thereon are enabled to act as a second resonator. The metal plates include at least one exciting electrode formed on a first surface of the dielectric block which has the widest area. Thus a wide band characteristics can be obtained whereas the very thin dielectric block is used. Further, a high unloaded quality factor (Q ) can be obtained because the radiation loss is lowered when the thickness of the dielectric block is reduced.

TEM dual-mode rectangular dielectric waveguide bandpass filter

A highly compact and easily fabricated band pass filter is disclosed. A band pass filter according to the present invention employs a first half-wave (&lgr;/2) resonator having a first open end on which an input terminal is formed and a second open end opposite to the first open end, a second half-wave (&lgr;/2) resonator having a third open end on which an output terminal is formed and a fourth open end opposite to the third open end, and an evanescent waveguide interposed between the second open end of the first resonator and the fourth open end of the second resonator. The first half-wave (&lgr;/2) resonator, the second half-wave (&lgr;/2) resonator, and the evanescent waveguide being single-unit. An air gap does not have to be formed by mounting components on a printed circuit board. Therefore, the overall size of the band pass filter can be miniaturized and fabrication of the band pass filter is simplified.

TEM band pass filter having an evanescent waveguide

A highly compact band pass filter that has excellent mechanical strength is disclosed. A band pass filter according to the present invention employs a dielectric block of substantially rectangular prismatic shape constituted of a first portion lying between a first cross-section of the dielectric block and a second cross-section of the dielectric block substantially parallel to the first cross-section and second and third portions divided by the first portion and metal plates formed on the surfaces of the dielectric block. The first portion of the dielectric block and the metal plates formed thereon are enabled to act as an evanescent waveguide. The second portion of the dielectric block and the metal plates formed thereon are enabled to act as a first resonator. The third portion of the dielectric block and the metal plates formed thereon are enabled to act as a second resonator. The metal plates include a capacitive stub formed on a first surface of the dielectric block which is substantially perpendicular to the cross-sections.

Dielectric band pass filter having an evanescent waveguide

A TEM mode &lgr;/4 dielectric resonator includes a rectangular dielectric block having a top planar surface, a bottom planar surface and four side surfaces, a first metal layer coated on the top planar surface, a second metal layer coated on the bottom planar surface, and a third metal layer coated on one of the four side surfaces.

TEM-mode dielectric resonator and bandpass filter using the resonator

A highly compact band pass filter that reliably achieves desired characteristic is disclosed. A band pass filter according to the present invention employs first and second disk resonators having exciting electrodes formed on one side surface thereof, an evanescent waveguide interposed between the first and second disk resonators, and a capacitive stub formed on other side surfaces of the first and second disk resonators. The capacitive stub reduces the size of the band pass filter because a resonant frequency of the disk resonators is lowered by the capacitive stub. Further, the capacitive stub enhances the mechanical strength of the band pass filter because a coupling constant k between the disk resonators is lowered by the capacitive stub.

Band pass filter

In a dual-mode filter, this invention is capable of optionally setting an attenuation pole frequency with maintaining a passbandwidth of the filter by selecting a combination of an angle between input/output ports and a size of a stub perturbation. The dual-mode filter includes a circular resonator formed on a dielectric substrate, a pair of input/output ports connected to the circular resonator through a capacitance formed on the substrate at a symmetrical position with respect to a symmetry plane passing through a center of the circular shape of the circular resonator, and stub poles are formed on the substrate radially extending along the symmetry plane from opposite positions of the circular resonator in the diametrical direction with each other. The pair of input/output ports are formed with defining an angle different from a right angle therebetween. When the angle between the pair of input/output ports is smaller or greater than 90&deg;, an attenuation pole frequency can optionally be set by this angle and the size of the stub perturbation.

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Tokyo, Japan

Arun Chandra Kundu