Microwave oscillator with noise degeneration feedback circuit

A microwave oscillator comprising:

• (a) means, responsive to a control signal, for providing an output signal with an output frequency;
• and
• (b) means, responsive to a portion of the output signal, for providing the control signal to reduce variation of the frequency of the output signal, wherein the control signal providing means comprises:
• (i) a modulated laser, having an input and an output, the input coupled to the output signal;
• (ii) a fiber-optic cable having a first end and a second end, the first end connected to the output of the modulated laser;
• and
• (iii) a photo detector having an input and an output, the input connected to the second end of the fiber-optic cable.

A microwave frequency signal source comprising:

• (a) means, responsive to a control signal, for providing a microwave frequency output signal;
• (b) means, responsive to a portion of the microwave frequency output signal, for providing a modulated optical signal, the modulated optical signal time delayed by a predetermined amount of time;
• (c) means, responsive to the time delayed modulated optical signal, for providing a microwave feedback signal;
• (d) means, responsive to the microwave feedback signal and a portion of the microwave frequency output signal, for providing the control signal for the microwave frequency output signal providing means.

A signal source comprising:

• (a) an oscillator having an output and a control port;
• and
• (b) a feedback circuit disposed between the output and the control port of the oscillator, the feedback circuit comprising:
• (i) a first modulated laser, having an input and an output, the input coupled to the output of the oscillator;
• (ii) a second modulated laser, having an input and an output, the input coupled to the output of the oscillator;
• (iii) a first photo detector having an input and an output;
• (iv) a second photo detector having an input and an output;
• (v) a first fiber-optic cable having a first end and a second end, the first end connected to the output of the first modulated laser and the second end connected to the input of the first photo detector;
• and
• (vi) a second fiber-optic cable having a first end and a second end, the first end connected to the output of the second modulated laser and the second end connected to the input of the second photo detector.