Band-pass filter comprising series coupled split gap resonators arranged along a circular position line

• US 6,130,591 A
• Filed: 05/27/1998
• Issued: 10/10/2000
• Est. Priority Date: 08/25/1997
• Status: Expired due to Fees

• Current Assignee: Advanced Mobile Telecommunications Technology Incorporated
• Original Assignee: Advanced Mobile Telecommunications Technology Incorporated
• Inventors: Tsuzuki, Genichi
• Primary Examiner(s): LEE, BENNY T
• Application Number:
  US09/084,438
• Time in Patent Office: 867 Days
• Field of Search: 333/99 S, 333/204, 333/219, 505/210, 505/700, 505/701, 505/866
• US Class Current: 333/204
• CPC Class Codes: H01P 1/20381 Special shape resonators
• CPC Class Codes: Y10S 505/701 Coated or thin film device, i.e. active or passive
• CPC Class Codes: Y10S 505/866 Wave transmission line, network, waveguide, or microwave storage device

Abstract

Herein disclosed is a band-pass filter for a radio wave having a wavelength range of a high frequency, such as a microwave and a milliwave. The band-pass filter comprises: a dielectric substrate; input and output terminals; and a plurality of conductive strip line resonators being capable of resonating with a predetermined wavelength. Each of the strip line resonators has two ends and bent line extending from one end to the other end with a predetermined length corresponding to the wavelength. The one end and the other end are placed face to face with each other to provide a gap therebetween. In the band-pass filter, the plurality as arranged on the dielectric substrate in series and spaced apart from each other at predetermined intervals along a predetermined position line and coupled with each other through the inductive and capacitive coupling to transfer the signal between the resonators one after another. Each of the adjoining resonators has a predetermined intensity of the coupling between them in accordance with a relationship between the positions of the gaps of the adjoining resonators. As a result, the band-pass filter can be miniaturized as regulating a desired intensity of coupling between resonators.

Claims

1. A band-pass filter comprising:

a dielectric substrate;

input and output terminals; and

a plurality of conductive strip line resonators being capable of resonating with a predetermined wavelength, each resonator respectively having two ends and bent line extending from one end thereof to the other end thereof with a predetermined length corresponding to said wavelength, said one end and the other end respectively being placed face to face with each other to provide a corresponding gap therebetween,

said plurality of resonators having;

a first resonator coupled with said input terminal, being capable of resonating with said predetermined wavelength;

a second resonator arranged apart from said first resonator at a predetermined interval and coupled with said first resonator through an inductive and capacitive coupling therebetween, being capable of resonating with said predetermined wavelength, and further coupled with said output terminal to output the resonating signal; and

at least a third resonator intervening between said first and second resonators,

said plurality of resonators being arranged on said dielectric substrate in series and spaced apart from each other at predetermined intervals therebetween along substantially a predetermined circular position line encircled around a center of said substrate with a predetermined radius and extending from said first resonator to said second resonator,

said at least a third resonator being coupled with said first and second resonators through the inductive and capacitive coupling to transfer a signal from said first resonator to said second resonator therethrough,

adjoining ones of said plurality of resonators having a predetermined intensity of coupling therebetween in accordance with a respective gap position relationship between the positions of said respective gaps of said adjoining ones of said resonators,

said plurality of resonators being arranged on said substrate so that substantially all of the signal transferred from said first resonator to said second resonator passes in series from said first resonator through said at least a third resonator to said second resonator.

2. A band-pass filter as set forth in claim 1, in which said respective gaps of said corresponding resonators are directed in the same direction with respect to said circular position line, and said gap position relationship of each of said adjoining ones of said resonators is variable in accordance with a centered angle with respect to the center point of said circular position line, so that said band-pass filter can obtain a desired response.

3. A band-pass filter as set forth in claim 1, in which each of said strip line resonators is a respective circular shape having a corresponding opening portion interposed between said one end and said other end.

4. A band-pass filter as set forth in claim 1, in which each of said strip line resonators is a respective U-shaped shape having a corresponding opening portion interposed between said one end and said other end.

5. A band-pass filter as set forth in claim 1 further comprising shielding means interposed between said first and second resonators for shielding against electromagnetic energy to prevent the coupling between said first and second resonators.

6. A band-pass filter as set forth in claim 1 further comprising shielding means placed on a center of said circular position line for shielding against electromagnetic energy to prevent the coupling between said resonators except for said adjoining resonators with each other.

7. A band-pass filter as set forth in claim 1, in which said interval between said first and second resonators along said circular position line is larger than the interval between any other adjoining resonators positioned on said circular position line.