Continuously tunable photonic true-time-delay device for millimeter-wave beamforming

We present a novel CMOS compatible plasma dispersion modulation scheme for slow wave photonic true-time-delay structure harnessing the frozen mode to enable applications in millimeter-wave (mmWave) beamforming. Leveraging the Soref-Bennett model for the electro-refractive effect in silicon plasma dispersion, continuous tunability of approximately 6.8 ps/V with a peak delay of approximately 11.4 ps is achieved for a low threshold voltage of 0.9 V. This plasma dispersion will enable fast and sophisticated modulation and beamforming in 5G mmWave and 6G terahertz communications.