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Title:
PHASE DETECTOR
Document Type and Number:
Japanese Patent JPH0392774
Kind Code:
A
Abstract:

PURPOSE: To achieve a higher accuracy by an A/D converter, a branching filter, a multiplier, a cumulative adder, a divider, an inverse tangential circuit and the like.

CONSTITUTION: An analog input signal A is converted into a digital signal B with an A/D converter 1 and separated into a sine wave signal C and a cosine wave signal D with a phase difference branching filters 2 and 3 of a 90° phase difference branching filter 12. An output E of a variable digital sine wave oscillator 4 turns to an output F through a phase difference branching filter 5 to be multiplied by the signal C with a multiplier 6 and an output G is inputted into an cumulative adder 8 to obtain an output J. The output F and the signal D are multiplied with a multiplier 7 and an output H is inputted into a cumulative adder 9 to obtain an output J. The output I is divided by the output J with a divider 10 and the resulting output K is applied to an inverse tangential circuit 11 to obtain a phase L of a selection frequency thereby achieving a higher accuracy with ease.


Inventors:
KOMATSU MASATOSHI
WADA SHIGENORI
Application Number:
JP23011189A
Publication Date:
April 17, 1991
Filing Date:
September 04, 1989
Export Citation:
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Assignee:
NEC CORP
MIYAGI NIPPON DENKI KK
International Classes:
G01R25/00; (IPC1-7): G01R25/00
Attorney, Agent or Firm:
Uchihara Shin



 
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