An improved composite right/left-handed (CRLH) unit cell optimized for a leaky-wave (LW) antenna is presented. This CRLH cell consists of a series of one transmission line, an interdigital capacitor, another transmission line and a shunt shorted stub. Introducing the transmission lines, the parasitic self-resonances of the capacitor are shifted outside the operational band, the radiation range is extended and the transition frequency at which the balanced cell condition is achieved can be chosen in the design process from a broader range of frequencies. The characteristics and performances of the proposed cell are verified by simulation and by measuring two artificial transmission lines.
2. Lai, A., C. Caloz, and T. Itoh, "Dominant mode leaky-wave antenna with backfire-to-endfire scanning capability," Electronics Letters, Vol. 38, No. 23, 1414-1416, Nov. 2002.
3. Caloz, C. and T. Itoh, "Transmission line approach of left-handed (LH) materials and microstrip implementation of an artificial LH transmission line," IEEE Transactions on Antennas and Propagation, Vol. 52, No. 5, 1159-1166, May 2004.
doi:10.1109/TAP.2004.827249
4. Sanchez-Martinez, J., J., E. Marquez-Segura, P. Otero, and C. Camacho-Penalosa, "Artifial transmission line with left/right-handed behavior based on wire bonded interdigital capacitors," Progress In Electromagnetics Research B, Vol. 11, 245-264, 2009.
doi:10.2528/PIERB08120804
5. Liu, C. Y., Q. X. Chu, and J. Q. Huang, "Double-side radiating leaky-wave antenna based on composite right/left-handed coplanar-waveguide," Progress In Electromagnetics Research Letters, Vol. 14, 11-19, 2010.
6. Monti, G., R. de Paolis, and L. Tarricone, "Design of a 3-state reconfigurable CRLH transmission line based on MEMS switches," Progress In Electromagnetics Research, Vol. 95, 283-297, 2009.
doi:10.2528/PIER09071109
7. Abdelaziz, A., F., T. M. Abuelfadl, and O. L. Elsayed, "Leaky wave antenna realization by composite right/left-handed transmission line," Progress In Electromagnetics Research Letters, Vol. 11, 39-46, 2009.
doi:10.2528/PIERL09080901
8. Casares-Miranda, F. P., P. Otero, E. Marquez-Segura, and C. Camacho-Penalosa, "Wire bonded interdigital capacitor," IEEE Microwave and Wireless Components Letters, Vol. 15, No. 10, 700-702, Oct. 2005.
doi:10.1109/LMWC.2005.856835
9. Pozar, D. M., Microwave Engineering, John Wiley & Sons, New York, 1998.