Title:
MODEM CIRCUIT
Document Type and Number:
Japanese Patent JP3497069
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To enable modulation on a carrier wave 1/2 frequency of a transmission frequency by impressing a 1st carrier wave to one input of the logic XOR circuit of two inputs and one output and impressing a 2nd carrier wave at the same frequency as that of the 1st carrier wave with a phase different at 90° to the other input.
SOLUTION: A 1st carrier wave C0 is inputted to one input terminal of a logic XOR circuit 10, a 2nd carrier wave C90 having the phase different from that of the 1st carrier wave C0 at 90° is inputted to the other input terminal of the logic XOR circuit 10, a transmission signal B is sent to the base of a transistor Q1, and the output signal of an inverter 22 is given to the base of a transistor Q2. When XOR is operated concerning the carrier waves C0 and C90, a rectangular wave of double the frequency of carrier waves C0 and C90 is provided. Since the output signal of the logic XOR circuit 10 is synthesized with the transmission signal by a Gilbert mixer 20, a modulated output having the double frequency of the frequency of carrier waves C0 and C90 can be provided.
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Inventors:
Hiroto Matsuoka
Tsuneo Tsukahara
Tsuneo Tsukahara
Application Number:
JP29634797A
Publication Date:
February 16, 2004
Filing Date:
October 14, 1997
Export Citation:
Assignee:
Nippon Telegraph and Telephone Corporation
International Classes:
H04L27/20; (IPC1-7): H04L27/20
Domestic Patent References:
| JP7226782A | ||||
| JP9135277A |
Attorney, Agent or Firm:
Shinichi Kawakubo
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