Beam scanning range expansion of liquid crystal based leaky wave antennas
In this paper, an effective and general method to expand the electronic beam scanning range of liquid crystal based composite right/left handed leaky wave antennas (LC-CRLH-LWAs) is proposed based on dispersion sensitivity enhancement (DSE). The proposed method does not need to modify the cell structure of the LC-CRLH-LWA, and the balanced condition and impedance matching property of the original LC-CRLH-LWA can be completely kept. For demonstration, a LC-CRLH-LWA is designed. It is shown that, by adding the DSE elements, the electronic beam scanning range of the LC-CRLH-LWA is extended by more than 56% in the frequency region from 12.1 GHz to 12.75 GHz, where the good impedance matching and balanced condition are kept for both extreme tuning states of LC. Finally, prototypes of the designed LC-CRLH-LWA are fabricated. The final simulated results are in perfect agreement with the experimental results.