US 8,299,876 B2Granted

Filter

AssigneeASUSTeK COMPUTER INC.

InventorsPei-Yang Lin, Chih-Chung Lin, Wen-Lin Yang

Life of this patent

Estimating the term…

Loading patent…

Abstract

A filter for filtering noise generated by a differential signal having a specific wavelength transmitted by a first transmission line and a second transmission line is disclosed. The filter includes a multi-layer substrate, a first microstrip line and a second microstrip line. The first and the second transmission lines and the first and the second microstrip lines are disposed at the multi-layer substrate. In addition, one end of the first microstrip line and one end of the second microstrip line are electrically connected to the first and the second transmission lines, respectively, by passing through the vias, and the other end is in a floating state. The impedances of the first and the second microstrip lines match the impedances of the first and the second transmission lines, respectively. Thus, the first and the second microstrip lines may filter the noise generated by the differential signal having the specific wavelength.

Claims8

Dependent claims

A filter for filtering noise generated by a differential signal having a specific wavelength transmitted by a first transmission line and a second transmission line together, the filter comprising:

a multi-layer substrate for carrying the first transmission line and the second transmission line;
a first microstrip line disposed at the multi-layer substrate, one end of the first microstrip line is electrically connected to the first transmission line through a first via;
and
a second microstrip line disposed at the multi-layer substrate, one end of the second microstrip line is electrically connected to the second transmission line through a second via;
wherein the impedances of the first microstrip line and the second microstrip line match the impedances of the first transmission line and the second transmission line, respectively, the maximum length of the first microstrip line is a quarter of the specific wavelength, and the maximum length of the second microstrip line is a quarter of the specific wavelength.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/704,529Filed 12 Feb 2010
Priority: TW 98105655 A23 Feb 2009
Published: US 2010/0214039 A126 Aug 2010
Granted: 30 Oct 2012
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

H01P 1/20345
Comb or interdigital filters: multilayer filters
H05K 1/0216
Electrical arrangements not otherwise provided for: reduction of cross-talk, noise or electromagnetic interference
H05K 1/0245
High frequency adaptations: lay-out of balanced signal pairs, e.g. differential lines or twisted lines
H05K 1/0251
Impedance arrangements, e.g. impedance matching, reduction of parasitic impedance: related to vias or transitions between vias and transmission lines