To provide a signal generator circuit and a radar apparatus capable of providing a low-noise and highly linear FMCW signal of highly accurate frequency.

A signal generator circuit of one embodiment includes an oscillator whose frequency is controlled by an analog control signal. The circuit also includes a digital phase detector, a first differentiator, and a comparator which outputs digital frequency error information. Further, the circuit includes: a second differentiator that differentiates a frequency setting code to produce a gain value, which corresponds to the slope of the frequency setting code, and the inverse thereof; a first multiplier for multiplying the digital frequency error information and the gain value; a low pass filter for removing high frequency components from the multiplication result; a second multiplier for multiplying the low pass filter output and the inverse of the gain value; a D/A converter for converting the multiplication result into analog frequency error information; and an integrator for integrating the analog frequency error information to convert the same into analog phase error information and outputting the same as an analog control signal.