Continuously tunable true-time delay lines based on a one-dimensional grating waveguide for beam steering in phased...

Area of Science:

• Photonics
• Integrated Optics
• Antenna Technology

Background:

• True-time delay (TTD) lines are crucial for beam steering in phased array antennas.
• Existing TTD solutions, such as photonic crystal waveguides, face challenges with chip size and propagation loss.
• Silicon-on-insulator (SOI) platform offers advantages for integrated photonic devices.

Purpose of the Study:

• To propose and design integrated one-dimensional (1D) grating waveguide-based TTD lines on an SOI platform.
• To optimize the waveguide structure for high time delay and low loss.
• To demonstrate a beam steering module for phased array antenna applications.

Main Methods:

• Optimization of 1D grating waveguide structure for enhanced time delay.
• Design of a novel step taper for efficient coupling between strip and grating waveguides.
• Simulation of a 1x4 beam steering module utilizing the proposed TTD lines.

Main Results:

• Achieved a time delay of 77.23 ps/mm over a broad wavelength tuning range (1540.20 nm to 1558.97 nm).
• The proposed waveguide occupies 70% less chip area and exhibits lower propagation loss compared to 2D photonic crystal devices.
• Demonstrated a wide beam steering angle from -67.84° to 67.84° for an X-band phased array antenna.

Conclusions:

• The proposed 1D grating waveguide TTD lines offer a compact and efficient solution for integrated photonic systems.
• The novel step taper design ensures high coupling efficiency, facilitating practical device integration.
• The demonstrated beam steering module shows significant potential for advanced phased array antenna systems.