BROADBAND MODULATION PLL, AND MODULATION FACTOR ADJUSTING METHOD THEREFOR

Title:

BROADBAND MODULATION PLL, AND MODULATION FACTOR ADJUSTING METHOD THEREFOR

Document Type and Number:

WIPO Patent Application WO/2005/020429

Kind Code:

A1

Abstract:

A broadband modulation PLL having an excellent modulation accuracy is provided at a low cost. A PLL includes a VCO (21), a frequency divider (22), a phase comparator (23), a charge pump (24) and a loop filter (25). The frequency division ratio of the frequency divider (22) and the VCO (21) are controlled for adjustment. The VCO (21) has two control terminals for PLL and for modulation. A control signal producing part (28) produces, based on an input voltage (V_t1) to be applied to the PLL control terminal and a phase modulation data, a control voltage (V_tm) to be applied to the VCO (21). During a modulation factor adjustment, the control voltage (V_tm) to be applied to the modulation control terminal of the VCO (21) is controlled, and the input voltage (V_t1) is measured to calculate the frequency modulation sensitivity of the VCO (21) to the control voltage (V_tm). Then, the modulation factor of the phase modulation data is adjusted based on the modulation sensitivity as calculated.

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Inventors:

OCHI TAKETOSHI
HIRANO SHUNSUKE

Application Number:

PCT/JP2004/010776

Publication Date:

March 03, 2005

Filing Date:

July 22, 2004

Export Citation:

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Assignee:

MATSUSHITA ELECTRIC IND CO LTD (JP)
OCHI TAKETOSHI
HIRANO SHUNSUKE

International Classes:

H03C3/00; H03C3/09; H03L7/099; H03L7/18; H03L7/197; (IPC1-7): H03C3/00; H03L7/18

Foreign References:

JP2003092513A	2003-03-28
JPH1168719A	1999-03-09
JPH01171114U	1989-12-04

Other References: