Experimental study of CPW-fed printed UWB antenna with radiation improvement for ground coupling GPR application

A compact (35x30x0.8 mm(3)) coplanar waveguide-fed circular disk monopole antenna with gain enhancement using dual frequency-selective surface (FSS) layers, each of dimension 44x44x1.6 mm(3) is proposed in this letter. The proposed antenna added with FSS provides a maximum gain improvement of nearly 5 dBi in the impedance band from 3 to more than 20GHz. Radiation in the broadside direction is also improved due to the addition of FSS layers. The proposed antenna is also experimentally tested in close proximity of sand and wood made test beds of varying thicknesses with aluminum sheet at the bottom of it. Antenna can cover the 3.1-10.6 GHz unlicensed band with linear transfer function and nonvarying group delay response in this ground coupling experimental test.