US 7,307,045 B2Granted

Signal switching device

AssigneeNtt Docomo, Inc.

InventorsKunihiro Kawai, Daisuke Koizumi, Kei Satoh, Shoichi Narahashi, Tetsuo Hirota

Life of this patent

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Abstract

A signal switching device is disclosed that is capable of transmitting signals with less signal loss while securing a good isolation characteristic. The signal switching device includes a first section formed from a superconducting material connected to a first transmission path. The first section has a smaller cross section at the input end than at the output end or, the signal switching device may include a first section formed from a superconducting material connected to a first transmission path in series, and a second section formed from a superconducting material connected to a second transmission path in parallel. The cross section of the second section is smaller than that of the second transmission path. The length of the second transmission path is determined in such a way that an input impedance of the second transmission path is sufficiently large when the second section is in a superconducting state.

Claims12

Dependent claims

A signal switching device including a plurality of transmission paths to an input path, said signal switching device outputting a signal from the input path through one of the transmission paths, comprising:

a first variable impedance unit connected to a first transmission path in series, said first variable impedance unit including a first section formed from a superconducting material;
and
a second variable impedance unit provided on a second transmission path in parallel to a signal line of the second transmission path, said second variable impedance unit including a second section formed from a superconducting material, an area of a cross section of said second section being less than an area of a cross section of the signal line of the second transmission path, a length of the signal line of the second transmission path being determined in such a way that an input impedance of the second transmission path is greater than a predetermined value when the second section is in a superconducting state.

Dependencies are inferred from the claim text.

Facts

Application: 10/702,573Filed 7 Nov 2003
Priority: JP 2002-3244227 Nov 2002
Published: US 2004/0097379 A120 May 2004
Granted: 11 Dec 2007
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H01P 1/127
By mechanical chopper: strip line switches
H01P 1/15
For switching or interrupting: by semiconductor devices
Y10S 505/701
High TC, above 30 k, superconducting device, article, or structured stock: coated or thin film device, i.e. active or passive
Y10S 505/703
Coated or thin film device, i.e. active or passive: microelectronic device with superconducting conduction line