20 GHz arbitrary radio-frequency waveform generator based on incoherent pulse shaping

Area of Science:

• Photonics
• Radio-Frequency Engineering
• Signal Processing

Background:

• Generating broad bandwidth radio-frequency (RF) signals is crucial for advanced communication systems.
• Existing methods often face limitations in bandwidth, control, or complexity.
• Photonically assisted signal generation offers a promising avenue for overcoming these challenges.

Purpose of the Study:

• To demonstrate a new approach for photonically assisted RF waveform generation.
• To utilize a spectrally incoherent light source for RF signal synthesis.
• To achieve broad bandwidth electrical signals with controllable repetition rates.

Main Methods:

• Employing a generalized frequency-to-time mapping operation.
• Utilizing external modulation with two electro-optic Mach-Zehnder modulators for short pulse gating.
• Implementing spectral shaping prior to optical-to-electrical (O/E) conversion.
• Leveraging an amplitude filter for noise reduction.

Main Results:

• Successful generation of electrical signals with up to 20 GHz bandwidth.
• Demonstration of repetition rate control for the generated RF waveforms.
• Preservation of the frequency-to-time mapping despite spectral shaping before O/E conversion.
• Significant noise level reduction due to the amplitude filter's function.

Conclusions:

• The proposed photonically assisted method effectively generates broad bandwidth RF waveforms from an incoherent light source.
• The system offers precise control over the generated signal's repetition rate.
• This technique provides a viable and efficient approach for advanced RF signal generation using standard telecommunication equipment.