A compactly integrated bidirectional optical true-time delay network for radio frequency beam steering

A compactly integrated bidirectional Optical True-Time Delay Network (OTTDN) for radio frequency beam steering is proposed by introducing an asymmetrical power splitting scheme. The dual-port network can achieve both time delay tunability and bidirectional tunability through a single heater. A 20-GHz, ∼ ±13-ps bidirectional time delay is experimentally demonstrated.