Beam scanning annular slot-ring antenna array with via-fence for wireless power transfer

Abstract

Wireless power transfer has been the field of research for many decades, and with technological advancement and increase in wireless mobile devices, the future of wireless power transfer technology is very promising. The major requirement of wireless power transfer is an efficient and compact antenna array with high gain and flawless scanning performance. In this article, a 4 x 8 element array is proposed with a gain of 18 dB and scanning capability of +/- 45 degrees in azimuth and elevation plane at 5.8 GHz. The overall size of the array is 100 mm x 200 mm. The element separation in the array is only 0.48 lambda. There was strong mutual coupling due to smaller separation, which has been minimized with the application of via-fence around the antenna element. A dual feed circularly polarized annular slot-ring antenna is proposed and analyzed with via-fence to develop an array of 4 x 8 elements. The antenna array reflection coefficient obtained is less than 20 dB for different scan angles and the gain of the array obtained is also within 2 dB for +/- 45 degrees scan angles.