New microwave / millimeter wave true time delay device utilizing photonic approaches

A new method is presented for establishing variable microwave / millimetre wave true time delay utilizing photonic approaches. In many applications there is a need for a significant time delay which cannot be established by microwave methods. The optical fiber can offer a substantial time delay which can be utilized by converting the microwave signal into the optical domain and after the proper delay it is converted back to microwave. The main contribution is the variation of the delay. That is achieved by applying a dispersive fiber and a tunable laser. That new approach is very advantageous for beam steering of phased array antennas because a common delay line can control several radiating elements. This way a more comprehensive delay structure is obtained.