Patent Number: 6,798,319

Title: High-frequency filter

Abstract: A high-frequency filter for use in a superhigh frequency band such as of microwaves and millimeter waves has a substrate, a metal conductor disposed on a first main surface of the substrate, a resonator comprising a transmission line of a coplanar structure which is made of the metal conductor, and input and output lines disposed on a second main surface of the substrate transversely across the resonator and electromagnetically coupled to the resonator. The resonator may be a coplanar line resonator (coplanar waveguide resonator) or a slot line resonator. The high-frequency filter has a steep attenuating gradient in filter characteristics. The high-frequency filter may be combined with variable-reactance devices such as variable-capacitance diodes for electronically controlling the filter characteristics.

Inventors: Aikawa; Masayoshi (Yokohama, Kanagawa, JP), Nishiyama; Eisuke (Saga, JP), Kawamura; Yoshifumi (Kanagawa, JP), Asamura; Fumio (Saitama, JP), Oita; Takeo (Saitama, JP)

Assignee: Nihon Dempa Kogyo Co., Ltd.

International Classification: H01P 1/201 (20060101); H01P 1/20 (20060101); H01P 001/20 ()

Expiration Date: 09/22016