Title:
FILTER CIRCUIT AND FREQUENCY SWITCHING METHOD
Document Type and Number:
WIPO Patent Application WO/2017/126452
Kind Code:
A1
Abstract:
The objective of the present invention is to provide a filter circuit by which radio wave interference can be avoided through a simple configuration and a frequency band can be effectively used. In order to achieve the objective, the filter circuit according to the present invention is provided with: a first transmission line and a third transmission line each having a predetermined electrical length; a second transmission line opposed to the first transmission line; an input terminal connected to the first transmission line; a fourth transmission line opposed to the third transmission line; a first output terminal and a second output terminal each connected to the fourth transmission line; a first open end connected to the second transmission line; a second open end connected to the third transmission line; a fifth transmission line connected to the second transmission line; a sixth transmission line opposed to the fifth transmission line; a first switch that connects or opens between the fifth transmission line and the ground; and a second switch that connects or opens between the sixth transmission line and the ground. The electrical length of a transmission line composed of the first open end, the second transmission line, and the fifth transmission line, and the electrical length of a transmission line composed of the second open end, the third transmission line, and the sixth transmission line are each three quarters of a second wavelength corresponding to a second frequency which is higher than a first frequency.
Inventors:
MOTOI KEIICHI (JP)
Application Number:
PCT/JP2017/001148
Publication Date:
July 27, 2017
Filing Date:
January 16, 2017
Export Citation:
Assignee:
NEC CORP (JP)
International Classes:
H01P1/203; H01P1/205; H01P5/10
Domestic Patent References:
| WO2016167190A1 | 2016-10-20 |
Foreign References:
| JP2001119257A | 2001-04-27 | |||
| US20090115555A1 | 2009-05-07 |
Attorney, Agent or Firm:
SHIMOSAKA Naoki (JP)
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