Propagation verification of left handed transmission line implemented without series capacitive load

Abstract

This paper presents the verification of left handed propagation in planar left handed transmission lines implemented using only periodic shunt inductive load. In other words, the implemented left handed transmission line was designed with no series capacitive load. The left handed transmission line was designed on a ferrite substrate in coplanar waveguide configuration. The ferrite substrate is horizontally magnetized which has small demagnetization factor and hence it requires small external DC magnetic bias. The equivalent negative permeability was obtained thanks to the ferrite negative permeability according to the ferrite magnetic properties and the applied DC magnetic bias. The design concepts for this kind of transmission lines have been explained theoretically. The left handed transmission propagation verification along the transmission line has been done using both the transmission characteristics and electric field profile. The transmission characteristics results, for different DC magnetic bias values, confirms that the transmission coefficient (S21) gains up to 15 dB increase in its value within the frequency band of ferrite negative permeability. Also, the electric field profile emphasize illustrates the negative phase associated with left-handed propagation