Abstract
Tuneable true time delay device is designed through utilizing the frozen mode at the degenerated band edge (DBE) to allow UWB frequency independent beamforming technique. The frozen light mode out of the DBE mode is obtained through coupled periodic silicon ridge waveguides. Tow perforated silicon coupled waveguides are designed to couple four modes at the bandgap providing a frozen light mode. A 20-unit cell device is constructed to realize the frozen mode at the degenerate band edge. Under external dc biasing, liquid crystal cladding layer is implemented to allow real time tuning of the true time delay device.