In
this manuscript, to the best of our knowledge, we proposed the first
optoelectronic oscillator (OEO) that can generate arbitrary microwave
waveforms. A reconfigurable optical waveform generator is constructed via
optical carrier-suppressed single-sideband modulation. The optical waveform
from the generator can be seen as a series of frequency-scanning optical
wavelengths in the frequency domain, and at any instant, the number of
wavelengths can be from 0 to infinite. When the optical waveform serves as the
optical source for an OEO based on the phase-modulation-to-intensity modulation
conversion using a phase modulator cascaded with a phase-shifted fiber Bragg grating,
a frequency-scanning microwave photonic filter with scanning characteristics
according to the optical waveform is realized. By setting the period of the
optical waveform or its multiple equal to the cavity round-trip time, a Fourier
domain mode-locked (FDML) OEO that can generate arbitrary microwave waveform is
realized. The key contribution of the work is that the concept of FDML OEO is
further analyzed and extended to generate an arbitrary microwave waveform.
Based on the proposed system, in addition to the single-frequency microwave
signal and linearly-chirped microwave waveforms, low phase noise arbitrary
microwave waveforms can be generated utilizing the low phase noise merit of an
OEO.
Costas-coded linear frequency modulation waveform generation based on a VCO-controlled Fourier domain mode locking optoelectronic oscillator
