Title: Modulator and correction method thereof
Application Number: 200480001156 Application Date: 2004.01.08
Publication Number: 1701505 Publication Date: 2005.11.23
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: H03C1/00;H03L7/08;H03L7/18
Applicant(s) Name: Matsushita Electric Ind Co., Ltd. Address:
Inventor(s) Name: Hirano Shunsuke;Miyahara Yasunori
Attorney & Agent: huang xiaolin wang zhisen
Abstract:
    It is possible to maintain conformance of frequency characteristic and prevent lowering of modulation accuracy in a wide band modulator using a PLL synthesizer even when manufacturing irregularities are present. The division ratio of a divider (2) is modulated by a modulation signal generated by a modulation signal generator (42). In the wide band modulator using a PLL (6) for outputting a modulation carrier signal from a VCO (1), data for first and second calibration from a calibration data generator (15) is input via a selector (40). An amplitude value of an AC component of each modulation signal appearing at the output of a loop filter (5) or an amplitude value of an AC component of each modulation signal modulated by a modulator (18) is converted to a digital value by an A/D converter (11). A difference between the two is detected by error detection means (32). Frequency characteristic correction means (33) generates a control signal FCR for dissolving the difference and corrects the frequency characteristic of the PLL (6) or a pre-distortion filter (8).
Time: 13