SYSTEM AND METHOD FOR THz AMPLIFICATION BY WAVELENGTH INJECTION OF RESONANT TUNNELING DIODE OSCILLATOR

A method for injection locking a waveguide RTD and characterizing absolute phase noise of the resulting THz radiation, the method comprising:

• injecting a waveguide RTD with a first reference THz radiation signal;
• applying a DC bias voltage to the RTD to tune an oscillation frequency of the RTD and to establish injection locking with the first reference THz signal;
• mixing an amplified RTD output signal from the RTD with a second THz reference signal to form an intermediate frequency (IF) output signal in response to a mixture of the amplified RTD output signal and the second THz reference signal;
• and
• measuring an absolute phase noise of the first reference THz radiation signal.

A method for injection locking a waveguide RTD and characterizing residual phase noise of the waveguide RTD, the method comprising:

• generating a THz reference signal;
• splitting the THz reference signal into a first portion and a second portion;
• applying a frequency shift to the second portion using a frequency synthesizer;
• injecting a waveguide RTD with the first portion of the THz reference signal;
• mixing an amplified RTD output signal from the waveguide RTD with the frequency-shifted second portion in a waveguide mixer;
• and
• analyzing a resulting IF signal from the waveguide mixer using a phase noise analyzer synchronized to the frequency synthesizer to determine a residual phase noise introduced by injecting the waveguide RTD with the first portion of the THz reference signal.