Front-to-Back Ratio Improved 60 GHz Substrate Integrated Coaxial Line Balanced Antipodal Vivaldi Antenna

A new front-to-back ratio (FBR) improved Balanced Antipodal Vivaldi Antenna (BAVA) is presented, with optimized microstrip (MS) to Substrate Integrated Coaxial Line (SICL) feed, that operates in the frequency range of 57 GHz to 67 GHz. The MS-SICL transition facilitates unimodal wideband operation and improves the FBR by a maximum of 7.14 dB at 62 GHz and a minimum of 1.01 dB at 57 GHz. With the dimensions of
$\mathbf{45\times 19\times 0.26}$
mm3, it is compact in size and a significant enhancement of gain is observed by selective positioning of metallic vias with a maximum peak gain of 11.36 dB at 58 GHz. S11 is observed to be less than -10 dB throughout the band of operation. Stable electric field distribution along with consistent radiation patterns are achieved in the E-Plane. The proposed structure maintains a good impedance bandwidth centered around 62 GHz and maintains stable gains throughout the working frequency range.