Broadband differentially fed tapered slot antenna array for radio astronomy applications

This paper describes the preliminary design results of a differentially fed tapered slot antenna. Traditional unbalanced tapered slot antennas often employ a bilateral strip line feed, or a separate feed board, in combination with a potentially lossy radial stub and microstrip line (balun). In order to reduce the associated transmission line losses, a differentially fed tapered slot antenna is considered. Main focus is on the measurement procedure and the determination of the active reflection coefficient. The properties of the (undesired) common modes are also discussed. Finally, the effective area for broadside is determined and turned out to be larger than 80% of the physical aperture area of the array.