Research on the improvement of tightly coupled antipodal Vivaldi antenna array

A method which is the combination of traditional antipodal Vivaldi and tightly coupled approach is proposed in this paper to meet the demands of the application of ultrawideband phased array antenna. Through the improvement of the combination structure, the performance of broadband array has been greatly improved. Firstly, by adding the truncated arms to the edge elements at both ends to compensate the edge elements. Then, by changing the bottom exponential curve of the antipodal Vivaldi to a special curve to obtain better low-frequency performance, the array has a VSWR of less than 2.5 within the band of 2–12 GHz. Finally, by arraying triangle arrays and controlling the number of elements in each row, the grating lobes and lobe-splitting phenomenon won't appear at the array pattern within the band of 2–12 GHz