Electronic device in which integrated antenna and filter both have balanced terminals

• US 6,351,239 B1
• Filed: 05/16/2000
• Issued: 02/26/2002
• Est. Priority Date: 02/03/2000
• Status: Expired due to Term

• Current Assignee: Hiroyuki Arai, NGK Insulators Limited
• Original Assignee: Hiroyuki Arai, NGK Insulators Limited
• Inventors: Arai, Hiroyuki, Mizutani, Yasuhiko, Hirai, Takami, Mizuno, Kazuyuki
• Primary Examiner(s): Ho, Tan
• Application Number:
  US09/572,033
• Time in Patent Office: 651 Days
• Field of Search: 343/700.MS, 343/850, 343/795, 343/756, 343/909, 343/741, 343/866, 343/806
• US Class Current: 343/700.0MS
• CPC Class Codes: H01P 1/20345 Multilayer filters
• CPC Class Codes: H01Q 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence
• 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 23/00 Antennas with active circuits or circuit elements integrated within them or attached to them
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

An antenna device is provided with a dielectric substrate comprising a large number of stacked dielectric layers and having at least an input/output terminal and a ground electrode formed on its outer circumferential surface. A plurality of ½ wavelength resonator elements of the both ends-open type are arranged in parallel to one another in the dielectric substrate respectively to construct a filter section. An antenna section is formed and constructed on the surface of the dielectric substrate. Two input/output electrodes are formed in the dielectric substrate, which are arranged at positions of point symmetry with respect to a center in the length direction of at least the resonator element disposed on the output side, of the plurality of ½ wavelength resonator elements. The two input/output electrodes are connected to balanced input/output terminals of the antenna section respectively.

Claims

1. An antenna device comprising:

an antenna section comprising an antenna having a balanced input/output including balanced antenna terminals; and

a filter section comprising a filter having a balanced input/output portion including filter terminals, wherein said input/output portion is electrically connected to said antenna terminals.

2. The antenna device according to claim 1, further comprising a ground electrode for constructing a capacitance together with an open end of said antenna section.

3. The antenna device according to claim 1, wherein said antenna section and said filter section are integrated into one unit.

4. The antenna device according to claim 3, including:

a dielectric substrate which includes a large number of stacked dielectric layers and which has at least an input/output terminal and a ground electrode formed on its outer circumferential surface, wherein;

said filter section includes a plurality of ½

wavelength resonators of a both ends-open type arranged in parallel to one another in said dielectric substrate respectively; and

said antenna section is formed on said dielectric substrate.

5. The antenna device according to claim 4, wherein said antenna section and said filter section are formed in regions which are two-dimensionally separated from each other on said dielectric substrate.

6. The antenna device according to claim 4, wherein:

said filter terminals include two input/output electrodes, which are arranged at positions of linear symmetry with respect to a center in a length direction of said ½

wavelength resonator disposed on a side of said antenna section, of said plurality of ½

wavelength resonators, and are provided in said dielectric substrate; and

said two input/output electrodes are connected to said balanced terminals of said antenna section.

7. The antenna device according to claim 6, wherein said two input/output electrodes are capacitively coupled to said ½

wavelength resonator disposed on said side of said antenna section respectively.

8. The antenna device according to claim 6, wherein said two input/output electrodes are directly connected to said ½

wavelength resonator disposed on said side of said antenna section respectively.

9. The antenna device according to claim 4, wherein said filter section includes a coupling-adjusting electrode which is overlapped with said adjoining ½

wavelength resonators with said dielectric layer interposed therebetween in said dielectric substrate and which effects capacitive coupling for said adjoining ½

wavelength resonators.

10. The antenna device according to claim 9, wherein:

a plurality of coupling-adjusting electrodes as defined above are formed; and

said plurality of coupling-adjusting electrodes are formed at positions of linear symmetry with respect to a center in a length direction of said ½

wavelength resonator.

11. The antenna device according to claim 4, wherein said filter section includes inner layer ground electrodes which are arranged to overlap both open ends of each of said ½

wavelength resonators with said dielectric layer interposed therebetween.

12. The antenna device according to claim 4, wherein said dielectric substrate is formed such that a dielectric constant of said dielectric layer on which said antenna section is formed is different from a dielectric constant of said dielectric layer on which said filter section is formed.

13. The antenna device according to claim 12, wherein said dielectric constant of said dielectric layer on which said antenna section is formed is lower than said dielectric constant of said dielectric layer on which said filter section is formed.