Compact Elliptically Tapered Slot Antenna with Non-uniform Corrugations for Ultra-wideband Applications

A small size elliptically tapered slot antenna (ETSA) fed by coplanar waveguide (CPW) for ultra-wideband (UWB) applications is proposed. It is printed on an FR4 substrate and occupies a size of 37×34×0.8 mm3. A pair of quarter circular shapes is etched on the radiator to reduce the size. To overcome the limitation of uniform corrugation, non-uniform corrugation is utilized to reduce the cross-polarization level. A parametric study is carried out to investigate the effects of circular cut and corrugations. In order to validate the design, a prototype is fabricated and measured. Both simulated and measured results confirm that the proposed antenna achieves a good performance of a reflection coefficient below -10 dB from 3.1 GHz to 10.6 GHz, including a maximum antenna gain of 8.1dBi, directional patterns in the end-fire direction, low cross-polarization level below -20 dB and linear phase response. The antenna is promising for applications in UWB impulse radar imaging.