Signal generator, oscillator, and radar device

摘要

A signal generator of an embodiment has an oscillator to generate an oscillation signal controlled in frequency by an analog control signal; a digital phase detector; a first differentiator; and a comparator outputting digital frequency error information. The generator includes a second differentiator differentiating the frequency setting code to generate a gain value and an inverse number of the gain value; a first multiplier multiplying the digital frequency error information by the gain value, a low-pass filter removing a high frequency component in a multiplication result, and a second multiplier multiplying an output of the low-pass filter by the inverse number. The generator includes a D/A converter converting a multiplication result into analog frequency error information, and an integrator converting the analog frequency error information into analog phase error information to output the analog phase error information as the analog control signal.

主权项

1. A signal generator, comprising:
an oscillator configured to generate an oscillation signal controlled in oscillation frequency by an analog control signal; a digital phase detector configured to detect phase information of the oscillation signal and to output digital phase information; a first differentiator configured to differentiate the digital phase information and to output digital frequency information; a comparator configured to compare a frequency setting code used for setting the oscillation frequency with the digital frequency information and to output digital frequency error information; a second differentiator configured to differentiate the frequency setting code and to generate a gain value corresponding to a slope of the frequency setting code and an inverse number of the gain value; a first multiplier configured to multiply the digital frequency error information outputted from the comparator by the gain value; a low-pass filter configured to remove a high frequency component in a result of multiplication by the first multiplier; a second multiplier configured to multiply an output of the low-pass filter unit by the inverse number of the gain value; a D/A converter configured to convert a result of multiplication by the second multiplier into analog frequency error information; and an integrator configured to integrate the analog frequency error information so as to convert the analog frequency error information into analog phase error information and to output the analog phase error information as the analog control signal.