Matsushita Electric Industrial Co., Ltd.

Other

Ikuo Awai

Toshio Ishizaki

Toru Yamada

Shoichi Kitazawa

Arun Chandra Kundu

Hideyuki Miyake

Kouji Wada

A notch filter made up from laminated dielectric, which attenuates a specific frequency of a signal to be transmitted, comprises two terminals for input or output a signal to be transmitted, a line connected between those terminals, two resonators each having one end connected to ground and an other end, two first coupling capacitors, and a second coupling capacitor. Each end of the line is connected to the other end of the resonator through the first capacitor. The second capacitor couples said two resonators each other.

Laminated notch filter and cellular phone using the same

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.

Dual-mode filter and design method therefor

A half-wavelength resonator type high frequency filter has N half-wavelength resonators (where N is an integer not smaller than 2); an input terminal; an output terminal; first matching part for matching the first of the resonators to the input terminal; second matching part for matching the N-th of the resonators to the output terminal; and (N&minus;1) interstage coupling part for coupling the resonators with one another, and wherein excitation positions of the first of the resonators and the N-th of the resonators are displaced from the center positions of the respective resonators toward an end thereof, and at least one of the interstage coupling part is electrically connected to its associated resonators at positions other than both ends thereof.

Half-wavelength resonator type high frequency filter

Growing community of inventors

Ube, Japan

Ikuo Awai