Novel compact UWB Vivaldi nonuniform slot antenna with enhanced bandwidth

Abstract

A new theory called Vivaldi nonuniform slot profile antenna (VNSPA) is developed based on the nonuniform transmission lines (NTLs) theory and applied to reduce the size of the predesigned compact ultrawide band (UWB) Vivaldi-tapered slot antenna (VTSA) without affecting its performance in terms of matching and bandwidth. Using this theory, 33% of the taper slot length is reduced, resulting in a novel compact UWB Vivaldi nonuniform slot antenna (VNSA). Furthermore, compactness is achieved by performing parametric studies on VNSA with a final 51.94% size reduction. MATLAB optimization codes, CST simulation, and prototype manufacturing and measurement are used to validate the new theory. The proposed antenna provides a measured S11 < -10.89 dB through 2.9-13.55 GHz with 2.91% and 5.8% bandwidth and maximum realized gain enhancement, respectively, as compared with VTSA's results. The effectiveness of VNSPA theory is proven by comparing the simulated and measured findings of VNSA and VTSA.