Phase noise floor suppression of the output carrier from double sideband-carrier suppressed modulation system
A theoretical model of all the influencing factors on the phase noise floor of the output carrier from the double sideband-carrier suppressed (DSB-CS) modulation system is presented. Based on the established DSB-CS modulation system with different cases, the phase noise of the input carrier and the output doubled frequency carrier is measured and calculated using the theoretical model, respectively. The calculation results basically agree with the measurement results. It is shown that the phase noise floor of the output carrier is primarily influenced by the signal-spontaneous beat noise and the relative intensity noise (RIN) of the laser. So the phase noise floor of the output carrier can be minimized by choosing the laser with low RIN and the EDFA with low noise factor.
phase noise double sideband-carrier suppressed modulation microwave photonics