Modified antipodal Fermi antenna with piecewise-linear approximation and shaped-comb corrugation for ranging applications

The authors propose the dual-tapered structure consisting of piecewise-linear inner taper and outer shaped-comb corrugation and the antipodal feeding section to present a modified antipodal Fermi antenna. This antenna exhibits the performance with wider band (3.6–15 GHz) in return loss responses, moderately high gain (5.1–14.5 dBi), high front-to-back ratio (24.8–38.9 dB) and available end-fire (29.8° beamwidth and −18.7 dB side lobe level) in radiation patterns. The current distributions demonstrate the characteristics of leakage, transverse waves among dual-taper and transition on balun. The proposed antenna presents the longitudinal conformation for mounting application and evaluate the pulse responses with linearity test for ultra-wideband (UWB) ranging and imaging applications.