Planar nested square fractal patch antenna for multi-band wireless applications

In this paper, a nested square ring-shaped antenna is presented for multi-band operation. The proposed patch antenna consists of a center square with outer rings shaped geometry as a radiating part and an entire ground plane. The nested square rings in the geometry help to operate the antenna for multi-frequency operation. The antenna occupies a small size of \(24 \times 24\) mm\(^2\). The proposed geometry evolution, as well as the circuit model of the antenna, have been studied. The proposed patch is resonated in C-band, X-band, lower Ku-band as well as upper Ku-band. The antenna gives a maximum gain and radiation efficiency of 7.41 dBi and \(60\%\), respectively. Furthermore, the patch provides low side-lobe levels and low cross-polarization for all bands. It also has an excellent front-to-back ratio (FBR) and perfect impedance matching over the bands. A good agreement between simulated and measured results was accomplished, confirming that the proposed patch antenna can multi-frequency operation.