| 摘要 |
PROBLEM TO BE SOLVED: To provide a frequency detector reducing a circuit scale and curtailing a throughput to a frequency detecting section using an inverted tangent arithmetic operation and realizing the same characteristics as a case when the inverted tangent arithmetic operation is used. SOLUTION: The division type frequency detecting section 17 for a device for leading out an angle of rotation has a delay detecting section 21 and a phase detecting section 23. In the delay detecting section 21, a complex base band signal (an output 16 from an LPF section) is input and delay-detected in a complex region at over-sample intervals, and a d(n) is obtained as a signal 22. The following formula d(n) represents the signal 22 after a delay detection by the delay detecting section 21. d(n)=r(n)*r(n-1)<SP>*</SP>. In the phase detecting section 23, the d(n) for the signal 22 is input, and a phase is detected by the following formula. p(n)=A*Imäd(n)}/Reäd(n)}. Where A represents a constant, and is determined unidivertionally by the intervals of the over-sample intervals and the bit accuracies of an input and an output. COPYRIGHT: (C)2006,JPO&NCIPI
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