Planar sleeve antenna with left-handed choke structure

A planar composite right/left-handed (CRLH) transmission line (TL) is applied to a choke structure of a sleeve antenna. The dispersion relation of the CRLH TL is designed as the left-handed (LH) branch at around 600 MHz. |S₁₁| characteristic and radiation patterns are calculated and compared with those of the conventional sleeve antennas. The length of the LH choke structure is 0.06 wavelength at 636 MHz.