An Elliptical Slot Loaded Planar Monopole Antenna with Tapered Feed Line and Spline Cut Ground Plane for Super-Wideband Applications

In this paper, a super-wideband (SWB) planar antenna that is using the elliptical shape as a patch is presented. The elliptical patch is loaded with an elliptical slot and fed by $\pmb{50}\ \Omega$ tapered feed line. A spline cut ground plane is also implemented to get the SWB response. The proposed antenna has been studied and optimized at 1–50 GHz with return loss $\leq-\pmb{10}\ \mathbf{dB}$. The optimized size of the antenna is 44.45 mm x 46.69 mm x 1.57 mm, and it can maintain the specified return loss starting from 1.576 GHz to above 50 GHz. The gains are simulated in 5 frequencies, i.e., 5 GHz, 16.25 GHz, 27.5 GHz, 38.75 GHz, and 50 GHz. In sequence, the gain of the antenna is 2.37 dBi, 4.72 dBi, 5.89 dBi, 7.68 dBi, and 7.94 dBi. Then, the observation of the bandwidth is extended up to 140 GHz. As the results, this antenna still works on the specified return loss, and it has a bandwidth ratio higher than 88.8:1, a bandwidth percentage greater than 195.6%, and the BDR index greater than 3566.