A novel design of leaky wave antenna based on composite right/left-handed structure

In this paper, a leaky wave antenna based on Composite Right/Left-handed Structure(CRLH) is proposed. The equivalent series capacitance in the CRLH is realized by the ring slot on the microstrip and the metal vias realizes the equivalent shunt inductance. The special structure of CRLH makes the propagation constant in the region of lower frequency negative, showing the left-handed characteristics, and the phase velocity and the group velocity have the opposite direction. In the higher frequency region, the phase velocity and group velocity have the same direction, showing the right-handed characteristics. The structure achieves a frequency scanning angle of -60 degrees to 30 degrees and it achieves high gain in the working band of the antenna.