A new type of compact microstrip patch antenna based on Composite Right/Left-Handed Transmission Lines (CRLH-TLs) combined with Koch-fractal-shape geometry

A new type of microstrip antenna based on Composite Right/Left-Handed Transmission Lines (CRLH-TLs) combined with Koch-fractal-shape geometry is designed in this paper. Matching means of a ring slot is also presented. The dimensions of the implemented antenna is 29.6*28mm
²
, which has been miniaturized by 57% compared with conventional microstrip antenna(44*44mm
²
). Numerical results show that antenna gain of conventional half wavelength resonance mode without ring slot is up to 6 dB which is two times as conventional microstrip antenna. Zeroth order resonance (ZOR) antennas radiate electromagnetic wave omnidirectionally like monopole antennas and simultaneously maintain the inherent advantages of low profile.