Integrated frequency comb source based Hilbert transformer for wideband microwave photonic phase analysis

Area of Science:

• Photonics
• Optical Engineering
• Microwave Engineering

Background:

• Integrated photonics offers a platform for advanced signal processing.
• Microwave signal generation requires precise phase control.

Purpose of the Study:

• To demonstrate a photonic RF Hilbert transformer for broadband microwave signal generation.
• To achieve in-phase and quadrature-phase generation using an integrated optical frequency comb.

Main Methods:

• Utilized a nonlinear microring resonator on a CMOS-compatible doped-silica glass platform.
• Generated a high-quality optical frequency comb with large frequency spacing.
• Implemented filters with up to 20 taps for quadrature filtering.

Main Results:

• Achieved a quadrature filter with over a 5-octave (3 dB) bandwidth.
• Demonstrated an almost uniform phase response across the operational bandwidth.
• Leveraged the high quality and large frequency spacing of the optical comb.

Conclusions:

• The integrated photonic RF Hilbert transformer is effective for broadband microwave signal generation.
• The developed platform enables high-performance quadrature filtering with wide bandwidth.
• This technology advances integrated photonic solutions for RF applications.