A circular-shaped time-delay line inspired by CRLH TL unit cell for UWB operation

Abstract

This paper presents the design of a circular-shaped ultra-wideband (UWB) time-delay lines inspired by the use of composite right/left-handed transmission line (CRLH TL) unit cells. A rotated version of a conventional CRLH TL unit cell is used as the basic element to achieve UWB operation. For comparison, time-delay lines using the right-handed transmission line (RH TL) and CRLH TL unit cells are also studied, fabricated and tested. Simulation and measurement results show that our proposed time-delay lines have high return loss, low insertion loss, UWB operation and much longer time delays than that of the time-delay line based on RH TL.