| 摘要 |
An ultra-linear chirp generator includes a voltage controlled oscillator (VCO) having a tuning characteristic which is naturally nonlinear, a linear ramp generator which generates a linearly ramping output signal having a linear slope characteristic with respect to time, a polynomial correction waveform generator which generates a polynomial correction signal, and a summer which is responsive to and sums the linearly ramping output signal and the polynomial correction signal. The summer generates a VCO tuning signal for tuning the VCO. The tuning signal corresponds to the linearly ramping output signal predistorted with a nonlinearity opposite to the natural nonlinearity of the VCO tuning characteristic. The linear chirp generator also includes a phase locked loop which is responsive to the output signal of the VCO and which has a reference frequency which is related to the repetition rate of the output signal of the VCO.
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