The Design and Analysis of a Novel Optical Delay line Based on Ring Resonators and Microcomb laser Source for Beamforming in a Phased Array Radar

The phased array radars are a favourable type in the group of radars due to their agility inscanning the space and their highly flexible radiation patterns. However, due to theirdependence on the phase to frequency shifters, these radars suffer from “beam squint”, whichlimits the radar bandwidth. Using the true time delay (TTD) technique is one of the suggestedsolutions to this problem. Due to their unique features, the optical circuits have been widelyused for the implementation of the TTD method but these circuits have problems such as highcomplexity, high cost, and the large size of structures. For example, fiber delay lines can onlygenerate a certain and limited amount of delay, they are difficult to maintain, and they take up alot of space. Conversely, the delay lines based on ring resonators create continuous delay andoccupy little volume. However, because of the very small size of the rings, these lines face thechallenge of complexity in construction. In this paper, a delay line based on ring resonators andmicrocomb laser source, with a new structure is presented that while enjoying the conventionaladvantages of these rings, is simpler in structure and requires fewer rings than otherconventional configurations.