Design and implementation of an S‐band near‐field focused array with high E‐field strength

An S‐band near‐field focused array is designed and implemented. Consisting of 4 × 4 metallic Vivaldi elements, the array is designed for focusing the E‐field of several kilovolts per metre within its near‐field region. To minimise the power loss and enhance the synthesis effectiveness, elements are arranged on a sphere surface and oriented towards the sphere centre. When exciting the elements, the waves will be focused to a specific area on the observation plane. By adjusting the excitation phase, the focus position can be tuned. A systematic analysis has been carried out to illustrate the focus scanning process across the entire observation plane. Near‐field two‐dimensional scanning is performed to measure the E‐field distribution of the array. While scanning the focus, the diameter of 3 dB focal area is about 0.3 m, and the maximum field strength in the focus ranges from 1184 to 2129 V/m, which can be used for the radiated susceptibility testing.