Photonic Calibration of Sweeping Oscillator and Its Application to RF Measurement

A photonic system is proposed to calibrate the instantaneous frequency and glitches of a fast frequency sweeping oscillator using a pseudo random bit sequence (PRBS) frequency comb. Its performance is demonstrated by simulations and experiments. A vector signal generator (Agilent E8257D), whose frequency ranges from 0.5 to 2.5 GHz and from 2.5 to 5 GHz, respectively, is calibrated. The deviation from linearity of frequency sweeping is measured to be less than 0.02%. As an extension of the calibrating system, the characterized sweeping oscillator is applied to multi-tone radio frequency (RF) measurement with an accuracy of 5 kHz and a resolution of 1 MHz. This technique will find applications in the field of electronic warfare and communication systems.