Design of a Microstrip Near-Field Focusing Antenna Array with Back-Fed Network

With the continuous progress of antenna technology, near-field focusing antenna has gradually become a research hotspot. This antenna has a wide range of applications in microwave imaging, microwave hyperthermia, access control systems and other fields. However, the traditional focusing antenna design usually requires the installation of a lens, which leads to a large volume of the antenna and is not conducive to practical applications. To address this problem, a microstrip near-field focusing antenna array with a 16×16 structure is designed in this paper. The array adopts the design of back feed network. After modeling and simulation analysis, it is concluded that the antenna array is able to achieve focusing at 50 mm, an approximately circular focal spot was formed with a short-axis length of 4.28 mm and a long-axis length of 4.48 mm. The experimental results show that the designed antenna array has good focusing performance.