A modified compact antipodal Vivaldi antenna is proposed with good performance for different applications including microwave and millimeter wave imaging. A step-bystep procedure is applied in this design including conventional antipodal Vivaldi antenna (AVA), AVA with a periodic slit edge and AVA with a trapezoid-shaped dielectric lens to feature performances including wide bandwidth, small size, high gain, front-to-back ratio and directivity, modification on E-plane beam tilt, and small side lobe levels. By adding periodic slit edge at the outer brim of the antenna radiators, lower end limitation of the conventional AVA extended twice without changing the overall dimensions of the antenna. The optimized antenna is fabricated and tested and the results show that S 11 < -10 dB frequency band is from 3.4 GHz-40 GHz and it is in good agreement with simulation one. Gain of the antenna has been elevated by the periodic slit edge and the trapezoid dielectric lens at lower frequencies up to 8 dB and at higher frequencies up to 15 dB, respectively. The E-plane beam tilts and side lobe levels are reduced by the lens.Index Terms-Antipodal Vivaldi antenna (AVA), tapered slot antenna (TSA), compact wideband antenna, dielectric lens.
High‐quality microwave and millimetre wave imaging of construction materials and structures requires ultra‐wideband (UWB) techniques to provide high‐range resolution as well as a reasonable penetration depth. A modified compact microwave and millimetre wave UWB antipodal Vivaldi antenna is designed and presented in this study. First, the conventional antipodal Vivaldi antenna is designed as a reference antenna. Then, to provide the desired frequency range (3.4–40 GHz) with increased gain at its lower frequencies, the slit edge technique is applied, thus creating a periodic slit edge antipodal Vivaldi antenna (PSEAVA). Finally, a trapezoid‐shaped dielectric lens (TDL) as an extension of the substrate is added and optimised to increase gain and directivity at higher frequencies of the frequency range, creating PSEAVA with a TDL (PSEAVA‐TDL). The results show that the PSEAVA‐TDL has the highest gain (up to 16 dB) and front‐to‐back ratio (up to 37.5 dB), and the narrowest half power beamwidth (down to 11.7°). A prototype of the proposed PSEAVA‐TDL with compact size of 40 × 90 × 0.508 mm3 is fabricated and applied for the imaging of samples made of construction materials. High‐range resolution images of the samples are obtained with this antenna by using synthetic aperture radar algorithm.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.