Dielectric filter having coupling amount adjusting patterns

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(11)

EP 0 442 418 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	16.09.1992 Bulletin 1992/38

(43)	Date of publication A2:
	21.08.1991 Bulletin 1991/34

(21)	Application number: 91101871.1

(22)	Date of filing: 11.02.1991

(51)	International Patent Classification (IPC)⁵: H01P 1/205

(84)	Designated Contracting States:
	DE FR GB

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Priority:

14.02.1990 JP 31575/90

(71)	Applicant: Oki Electric Industry Company, Limited
	Tokyo 105 (JP)

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Inventors:

Komazaki, Tomokazu, c/o Oki Electric Ind. Co. Ltd.
Minato-ku, Tokyo (JP)
Gunji, Katsuhiko, c/o Oki Electric Ind. Co., Ltd.
Minato-ku, Tokyo (JP)
Onishi, Norio, c/o Oki Electric Ind. Co., Ltd.
Minato-ku, Tokyo (JP)
Yamato, Osamu, c/o Oki Electric Ind. Co., Ltd.
Minato-ku, Tokyo (JP)
Mashimo, Akira, c/o Oki Business Co., Ltd.
Minato-ku, Tokyo (JP)
Ichikawa, Kouichi, c/o Oki Business Co., Ltd.
Minato-ku, Tokyo (JP)

(74)	Representative: Betten & Resch
	Reichenbachstrasse 19 80469 München 80469 München (DE)

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References cited: :

(54)	Dielectric filter having coupling amount adjusting patterns

(57) A dielectric filter having a dielectric block (11) made of a uniform, single dielectric material, dielectric resonators (15-1 - 15-4) each of which includes a central conductor formed in the dielectric block (11) in an approximately parallel fashion, and one or more coupling amount adjusting patterns (13-1 - 13-3) each of which is formed between the two adjacent dielectric resonators and is grounded so that the dielectric resonators are coupled through inductive impedance. The coupling adjusting patterns are formed on the top surface of the dielectric block in thin patterns. This makes the filter smaller in size and the trimming of the pattern more easily than those of the conventional filters in the manufacturing process. Control of the characteristics of the filter can be carried out easily.

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