EP0596721A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Noise filter
Assignee: NSC Co Ltd
•
Filing: 1993-11-03
•
Granted: —
•
Expires: 2013-11-03
Abstract
Abstract A noise filter for use in digital electronic equipment is formed on an insulating substrate (1) and comprises a first spiral electrode (3a), a dielectric layer (5), and a second spiral electrode (6a) in at least partial overlapping relationship with the first electrode (3a). The noise filter operates in a normal mode with one end of one of the electrodes (3a,6a) grounded and both ends of the other electrode connected in series with a signal transmission circuit. The noise filter operates in a common mode with both ends of each electrode (3a,6a) connected in series with a signal transmission circuit.
Inventors
- 👤 Takeshi Ikeda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 20:02
CPC Classifications
H; H05; H05K; H05K1/00; H05K1/16; H03; H03H; H03H1/00; H03H1/0007; H03H7/00; H03H7/01; H03H7/0115; H05K1/165; H03H2001/0021; H03H2001/0064; H03H2001/0078; H05K1/02; H05K1/0213; H05K1/0216; H05K2201/00; H05K2201/10; H05K2201/10007; H05K2201/1006; H05K3/00; H05K3/46; H05K3/4644; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12528; Y10T428/24; Y10T428/24802; Y10T428/24917; Y10T428/24926
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
38 words
A noise filter characterized in that a first spiral electrode (3a) is formed on an insulating substrate (1) and a second spiral electrode (6a) is formed on said first spiral electrode by way of a dielectric layer (5).
Claim 2
Dependent Claim
54 words
A noise filter characterized in that a first spiral electrode (3a) is formed on an insulating substrate (1), a dielectric layer (5) is formed on said first spiral electrode and said insulating substrate, and a second spiral electrode (6a) is formed on said dielectric layer at least partially overlapping with said first spiral electrode.
Claim 3
Dependent Claim
49 words
A noise filter as claimed in claim 1 or 2, characterized in that at least one end of one of said spiral electrodes (3a,6a) is grounded and both ends of the other spiral electrode are connected in series with a signal transmission circuit to operate in a normal mode.
Claim 4
Dependent Claim
37 words
A noise filter as claimed in claim 1 or 2, characterized in that both ends of each of said spiral electrodes (3a,6a) are connected in series with a signal transmission circuit to operate in a common mode.
Claim 5
Dependent Claim
27 words
A noise filter as claimed in any one of claims 1 to 4, characterized in that a pure semiconductor substrate is used as said insulating substrate (1).
Claim 6
Dependent Claim
27 words
A noise filter as claimed in any one of claims 1 to 4, characterized in that a magnetic insulating substrate is used as said insulating substrate (1).
Claim 7
Dependent Claim
32 words
A noise filter as claimed in any one of claims 1 to 5, characterized in that a plurality of noise filters are formed as an integral part on an insulating substrate (1).
Claim 8
Dependent Claim
21 words
A noise filter as claimed in any one of the preceding claims, fabricated on a substrate having IC circuits fabricated thereon.
Claim 9
Independent Claim
67 words
A method of making a noise filter characterized by preparing an insulating substrate (1) forming a first spiral electrode (3a) on said substrate by photolithography, depositing a dielectric layer (5) on said first spiral electrode (3a) and said substrate (1), and forming a second spiral electrode (6a) on said dielectric layer by photolithography so that said second spiral electrode at least partially overlaps said first spiral electrode.
References Cited (Backward Citations)
WO1987007074A1
Cited
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.