Millimeter-wave negative group delay network

This paper describes a negative differential-phase group delay network operating at millimeter-wave frequencies, which can be used to compensate for frequency variations in group delay that may otherwise cause signal distortion. This approach utilizes a defect waveguide with a high Q-factor defect cavity resonator, realized with a high-resistivity silicon-based 2D photonic crystal with engineered waveguide dispersion characteristics. We demonstrate a group delay of -151.8 ns at 99.74 GHz, with a correspondingly high figure of merit value of 3.34.