RESONANT CIRCUIT, FILTER CIRCUIT, AND ANTENNA DEVICE

• US 20080055181A1
• Filed: 05/21/2007
• Published: 03/06/2008
• Est. Priority Date: 05/24/2006
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Kawaguchi, Tamio, Kayano, Hiroyuki, Aiga, Fumihiko, Shiokawa, Noritsugu, Hashimoto, Tatsunori
• Granted Patent: US 7,825,751 B2
• Time in Patent Office: Days
• US Class Current: 343/850
• CPC Class Codes: H01P 1/203 Strip line filters
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 1/52 Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure absorbing means H01Q17/00
• CPC Class Codes: H01Q 21/065 Patch antenna array

Abstract

In resonant elements 102 to 105 constituting a resonant circuit, an uncontrolled cross coupling which exists between two resonant elements is controlled by using a coupling element 106 which is newly arranged between the resonant elements, whereby it is possible to create a state where two resonant elements are not coupled with each other or a state where the amount of the coupling is reduced, which states are difficult to be realized on a plane. As a result, it is possible to improve characteristics of a planar filter.

Claims

1. A resonant circuit, in which resonant elements of a plurality of orders of at least four or more are arranged by forming a predetermined conductor pattern on a dielectric substrate,

wherein among the resonant elements of the plurality of orders, a first to fourth resonant elements constituting a desired four orders of the resonant elements are arranged to effect electromagnetic field couplings between the first and second resonant elements, between the second and third resonant elements, between the third and fourth resonant elements, and between the fourth and first resonant elements,

comprising at least either a first coupling element which is arranged between the second and the fourth resonant elements, in a region on the dielectric substrate except element forming regions in which the resonant elements are formed, so as to intersect a first line segment formed by removing from a line segment connecting a center of gravity of a first region in which the first resonant element is formed to a center of gravity of a third region in which the third resonant element is formed, parts of the line segment included in the first and third regions in which the first and third resonant elements are formed, or

a second coupling element which is arranged between the first and the third resonant elements, in a region on the dielectric substrate except the element forming regions in which the resonant elements are formed, so as to intersect a second line segment formed by removing from a line segment connecting a center of gravity of a second region in which the second resonant element is formed to a center of gravity of a fourth region in which the fourth resonant element is formed, parts of the line segment included in the second and fourth regions in which the second and fourth resonant elements are formed, and

wherein electrical lengths of the first and second coupling elements are selected from a range except electrical lengths of integer multiples of a half wavelength of a wavelength in a range corresponding to a frequency range determined on the basis of a center frequency and a band width of the resonant circuit.

2. The resonant circuit according to claim 1, wherein each of the first and second coupling elements is constituted by a line which is opened at both ends.

3. The resonant circuit according to claim 1, wherein each of the first and second coupling elements is constituted by a line having a plurality of open ends.

4. The resonant circuit according to claim 1, wherein a ground conductor is formed on the lower face of the dielectric substrate.

5. The resonant circuit according to claim 1, wherein the resonant element is formed by using a superconductor.

6. A filter circuit, in which resonant elements of a plurality of orders of at least four or more, and an input section and an output section which are connectable to the outside, are arranged by forming a predetermined conductor pattern on a dielectric substrate,

wherein among the resonant elements of the plurality of orders, a first to fourth resonant elements constituting a desired four orders of the resonant elements are arranged to effect electromagnetic field coupling between the first and second resonant elements, between the second and third resonant elements, between the third and fourth resonant elements, and between the fourth and first resonant elements,

comprising at least either a first coupling element which is arranged between the second and the fourth resonant elements, in a region on the dielectric substrate except element forming regions in which the resonant elements are formed, so as to intersect a first line segment formed by removing from a line segment connecting a center of gravity of a first region in which the first resonant element is formed to a center of gravity of a third region in which the third resonant element is formed, parts of the line segment included in the first and third regions in which the first and third resonant elements are formed, or

a second coupling element which is arranged between the first and the third resonant elements, in a region on the dielectric substrate except the element forming regions in which the resonant elements are formed, so as to intersect a second line segment formed by removing from a line segment connecting a center of gravity of a second region in which the second resonant element is formed to a center of gravity of a fourth region in which the fourth resonant element is formed, parts of the line segment included in the second and fourth regions in which the second and fourth resonant elements are formed, and

wherein electrical lengths of the first and second coupling elements are selected from a range except electrical lengths of integer multiples of a half wavelength of a wavelength in a range corresponding to a frequency range determined on the basis of a center frequency and a band width of the filter circuit.

7. An antenna device, in which resonant elements of a plurality of orders of at least four or more, and an input section as a feeding line, are arranged by forming a predetermined conductor pattern on a dielectric substrate,

wherein among the resonant elements of the plurality of orders, a first to fourth resonant elements constituting a desired four orders of the resonant elements are arranged to effect electromagnetic field coupling between the first and second resonant elements, between the second and third resonant elements, between the third and fourth resonant elements, and between the fourth and first resonant elements,

comprising at least either a first coupling element which is arranged between the second and the fourth resonant elements, in a region on the dielectric substrate except element forming regions in which the resonant elements are formed, so as to intersect a first line segment formed by removing from a line segment connecting a center of gravity of a first region in which the first resonant element is formed to a center of gravity of a third region in which the third resonant element is formed, parts of the line segment included in the first and third regions in which the first and third resonant elements are formed, or

a second coupling element which is arranged between the first and the third resonant elements, in a region on the dielectric substrate except the element forming regions in which the resonant elements are formed, so as to intersect a second line segment formed by removing from a line segment connecting a center of gravity of a second region in which the second resonant element is formed to a center of gravity of a fourth region in which the fourth resonant element is formed, parts of the line segment included in the second and fourth regions in which the second and fourth resonant elements are formed, and

wherein electrical lengths of the first and second coupling elements are selected from a range except electrical lengths of integer multiples of a half wavelength of a wavelength in a range corresponding to a frequency range determined on the basis of a center frequency and a band width of the antenna circuit.