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Patent Searching and Data


Title:
SWITCHING DEVICE
Document Type and Number:
Japanese Patent JP3221789
Kind Code:
B2
Abstract:

PURPOSE: To prevent the leakage of the sprious signal from other routes by synthesizing an input signal after the signal is detected in a frequency discriminator by switching a desired route after a frequency modulation is performed for the signal or outputting the signal after it is detected in the frequency discriminator after it is synthesized.
CONSTITUTION: After a frequency modulation is performed for the input signals of the frequencies f1 and f2 from input ports 1 and 2 by each frequency modulator 101 of carrier wave signals f10 and f20, the signals are switched by each switch 102 by the control of a control circuit 5. The switched signals are detected by each frequency discriminator 30 to 33 of a detection part 7, the signals are reproduced into original input signals, these signals are synthesized by synthesizers 20 and 21 and they are outputted to output ports 1 and 2. Because large noise is in the output of each discriminator when the signals are not inputted in the input port, the circuit 5 controls the discriminators 30 to 33 and prevents the outputs of sprious signals. Thus, the leak signal can be eliminated from other routes and an excellent isolation characteristic can be obtained.


Inventors:
Ogasawara, Mamoru
Ichikawa, Takaaki
Morita, Kozo
Application Number:
JP1993000286361
Publication Date:
October 22, 2001
Filing Date:
November 16, 1993
Export Citation:
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Assignee:
NIPPON TELEGR & TELEPH CORP <NTT>
International Classes:
H04B15/00; (IPC1-7): H04B15/00
Attorney, Agent or Firm:
本間 崇