RF beam steering using a 5-bit, 4-channel reconfigurable optical true time delay chip on a 3 µm SOI platform

We demonstrate an optical true-time-delay (OTTD)–based RF beamforming system using a 5-bit, 4-channel OTTD chip fabricated on VTT’s low-loss 3-μm SOI platform. Operating in the C-band, the device offers 32 delay states (0 – 100 ps), enabling full 2π phase control at 10 GHz. The platform’s ~0.1 dB/cm loss supports long delay lines. At the same time, OTTD-based beamforming provides advantages in power efficiency, bandwidth, footprint, cost, and EMI immunity, positioning it as a promising technology for future 6G systems.