Fig. 1. Structure of antenna element

Fig. 2. Electric field distribution

Fig. 3. Simulation results of the antenna element

Fig. 4. Impedance matching structure

Fig. 5. Model of series feed network

Fig. 6. Feed network

Fig. 7. Surface current distribution on the antenna array

Fig. 8. Chebyshev planar array

Fig. 9. Photographs of the proposed antenna

Fig. 10. Simulated and measured S-parameter

Fig. 11. Simulated and measured radiation patterns at E-plane and H-plane