A system for characterizing an oscillator, comprising: an input port that receives an oscillation signal from an oscillator under test; an input port signal splitter that splits the received oscillation signal into a first oscillation signal and a second oscillation signal; a first homodyne photonic signal processing branch circuit that processes the first oscillation signal to produce a first branch output beat signal, the first homodyne photonic signal processing branch circuit comprising a first signal splitter that splits the first oscillation signal into a first photonic branch signal and a first electrical branch signal, a first photonic branch that receives the first photonic branch signal and comprises a first laser that produces a first laser beam, a first optical modulator that modulates the first laser beam in response to the first photonic branch signal to produce a first modulated laser beam that carries the first photonic branch signal, a first optical delay unit that transmits the first modulated laser beam to produce a delay in the first modulated laser beam, and a first optical detector that converts the first modulated laser beam into a first detector signal, a first electrical branch comprising a first voltage controlled phase shifter that receives the first electrical branch signal and changes a phase of the first electrical branch signal to produce a first output signal, and a first signal mixer that mixes the first detector signal and the first output signal to produce the first branch output beat signal; a second homodyne photonic signal processing branch circuit that processes the second oscillation signal to produce a second branch output beat signal; a dual channel signal analyzer that receives the first and second branch output beat signals to measure noise in the received oscillation signal; and a computer controller that controls the first voltage controlled phase shifter of the first photonic signal processing branch circuit, the second photonic signal processing branch circuit, and the dual channel signal analyzer to control measurements of the noise in the received oscillation signal. an input port that receives an oscillation signal from an oscillator under test; an input port signal splitter that splits the received oscillation signal into a first oscillation signal and a second oscillation signal; a first homodyne photonic signal processing branch circuit that processes the first oscillation signal to produce a first branch output beat signal, the first homodyne photonic signal processing branch circuit comprising a first signal splitter that splits the first oscillation signal into a first photonic branch signal and a first electrical branch signal, a first photonic branch that receives the first photonic branch signal and comprises a first laser that produces a first laser beam, a first optical modulator that modulates the first laser beam in response to the first photonic branch signal to produce a first modulated laser beam that carries the first photonic branch signal, a first optical delay unit that transmits the first modulated laser beam to produce a delay in the first modulated laser beam, and a first optical detector that converts the first modulated laser beam into a first detector signal, a first electrical branch comprising a first voltage controlled phase shifter that receives the first electrical branch signal and changes a phase of the first electrical branch signal to produce a first output signal, and a first signal mixer that mixes the first detector signal and the first output signal to produce the first branch output beat signal; a first signal splitter that splits the first oscillation signal into a first photonic branch signal and a first electrical branch signal, a first photonic branch that receives the first photonic branch signal and comprises a first laser that produces a first laser beam, a first optical modulator that modulates the first laser beam in response to the first photonic branch signal to produce a first modulated laser beam that carries the first photonic branch signal, a first optical delay unit that transmits the first modulated laser beam to produce a delay in the first modulated laser beam, and a first optical detector that converts the first modulated laser beam into a first detector signal, a first electrical branch comprising a first voltage controlled phase shifter that receives the first electrical branch signal and changes a phase of the first electrical branch signal to produce a first output signal, and a first signal mixer that mixes the first detector signal and the first output signal to produce the first branch output beat signal; a second homodyne photonic signal processing branch circuit that processes the second oscillation signal to produce a second branch output beat signal; a dual channel signal analyzer that receives the first and second branch output beat signals to measure noise in the received oscillation signal; and a computer controller that controls the first voltage controlled phase shifter of the first photonic signal processing branch circuit, the second photonic signal processing branch circuit, and the dual channel signal analyzer to control measurements of the noise in the received oscillation signal.