Patent ID: 9057775
Filing Date: 2015-06-16
Classification: G01S

Abstract:
1. A signal generator, comprising: an oscillator to produce an oscillation signal controlled in an oscillating frequency by an analog control signal; a digital phase detector to detect phase information of the oscillation signal and output digital phase information; a first differentiator to differentiate the digital phase information and output digital frequency information; a comparator to compare a frequency setting code setting the oscillating frequency with the digital frequency information and output digital frequency error information; a low-pass filter to remove a high-frequency component of the digital frequency error information; a D/A converter to convert the digital frequency error information of which the high-frequency component is removed into analog frequency error information; an integrator to integrate the analog frequency error information, convert into analog phase error information, and output the analog phase error information as the analog control signal; a second differentiator to differentiate the frequency setting code; a gain calculator to calculate a ratio between information input to the D/A converter and a differential value information of the frequency setting code differentiated by the second differentiator; and a multiplier to multiply the digital frequency error information of which the high-frequency component is removed, by a calculation result of the gain calculator.