Broadband microwave signal generation with programmable chirp shapes via low-speed electronics-controlled...

Area of Science:

• Photonics and Optics
• Signal Processing
• Microwave Engineering

Background:

• Photonic solutions offer superior bandwidth for microwave signal generation compared to electronic methods.
• Flexible and rapid manipulation of chirp shape and frequency remains a challenge in photonic approaches.
• Existing methods face limitations due to laser buildup time from spontaneous emission.

Purpose of the Study:

• To demonstrate a novel concept for generating broadband microwave signals with programmable chirp shapes.
• To overcome the limitations of laser buildup time for ultrafast frequency manipulation.
• To enable reconfigurable signal parameters like bandwidth, center frequency, and temporal duration.

Main Methods:

• Utilizing a recirculating phase-modulated optical loop for ultrafast laser frequency manipulation.
• Employing heterodyne beating between frequency-agile lasers and a continuous-wave laser.
• Achieving programmable chirp shape generation with a time resolution of 649 ps.

Main Results:

• Successfully generated highly coherent broadband microwave signals with customized chirp shapes.
• Demonstrated ultrafast and programmable control over signal chirp characteristics.
• Validated the reconfigurability of signal bandwidth, center frequency, and temporal duration.

Conclusions:

• The proposed photonic approach enables flexible and ultrafast manipulation of microwave signal chirp shapes.
• This technology holds significant promise for applications in LiDAR, broadband radar, and spectroscopy.
• The method overcomes previous limitations, paving the way for advanced signal generation techniques.