High-directivity microstrip antenna with Mandelbrot fractal boundary

High-directivity is a needed feature for small base station antennas in order to provide coverage to a certain geographic area. For wireless communications, arrays of microstrip antennas are frequently used as radiating elements due to their thin profile. In this study, a single microstrip element is proposed to achieve the same directivity as an array with a similar area but without using the complex feeding network usually required. A microstrip antenna inspired by the Mandelbrot fractal is designed achieving a narrow beamwidth in the vertical plane and a wide beamwidth in the horizontal plane, which is especially suitable for hot-spots.