Application of Integrated Optics and Fiber Optics to Phased-Array Antennas

摘要

Time-delay steering of a 2-5 GHz microwave phased-array antenna is described. This report suggests that the antenna beam can be formed and steered by programmable optical time-delay elements. These delay elements would be part of a fiber-optical feed system for the antenna, a feed that requires microwave-to-optical and optical-to-microwave conversion. One programmable delay elelement is associated with each of the N x M microwave radiating elements in the array. The result is a broadband, agile, electronically steered, computer-controlled antenna. Because the programmable devices are 'fast', the antenna's pointing direction could be updated in less than 1 microsecond. To implement the delay devices, a combination of integrated optics and fiber optics is proposed. Fiber-optic paths of differing lengths would provide the required delays in the 0.1-to-20 nsec range by means of the 5 nsec/m optical propagation time per unit length of fiber. Integrated optical switches would be used to select the desired fiber paths. Keywords include: Integrated optics; Fiber optics; Phased array antennas; Electro-optics; Time-delay beamsteering; and Optical switching Ti:LiNb03.