Wideband random phased arrays: theory and design

Wideband antennas may be used to decrease the number of antennas needed on platforms that require operation over a large instantaneous frequency band. Some typical examples of wideband antennas include TEM horns and Vivaldi tapered slot antennas. Although these antennas offer wideband operation, they are often not suitable for certain applications due to large thickness, weight, and complicated feed networks. On the other hand, typical planar phased arrays have limited frequency bandwidth and scan angles. There is a need to mitigate this issue by using a smaller random array as a subarray, resulting in a hybrid array whose pattern has some of the characteristics of both periodic and aperiodic arrays. One possible alternative to these kinds of antennas is the wideband random phased array. In addition to the design of the array topology, another challenge is to develop a low profile, electrically large element that maintains a broadside radiation pattern over the operating band. In this paper, the authors developed a wideband element design of a canted, tapered sector antenna that delivers consistent broadside performance over a 2.8:1 frequency band. The authors conclude with a brief discussion of future work in this area.