Fundamental-Mode Leaky-Wave Antenna (LWA) Using Slotline and Split-Ring-Resonator (SRR)-Based Metamaterials

A new composite right/left-handed (CRLH) slotline leaky-wave antenna (LWA) is proposed. The antenna, implemented by loading a slotline with split-ring resonators (SRRs), is designed to exhibit a balanced dispersion relation, with a continuous transition between the left-handed and the right-handed bands at 2.5 GHz. Since the periodicity of the structure is much less than a wavelength, the proposed LWA belongs to the family of quasi-uniform LWAs, and it radiates from the fundamental mode (contrary to periodic LWAs). Measured and simulated radiation patterns, gain, and scanning angle are reported for a 17-cell LWA. The experimental results demonstrate the potential of the LWA to continuously radiate from backward (- 50°) to forward (+60°) scanning angles, with maximum gains of 7.1 and 11.3 dB in the left- and right-handed bands, respectively, and specular radiation patterns.