Ku-Band Printed Bow-Tie Antenna H-plane Array with Low Mutual Coupling

A simple type of printed bow-tie antenna H-plane array has been designed, implementing low mutual coupling, a stable radiation pattern, and favorable impedance characteristics. To obtain the stable radiation pattern of the printed bow-tie element, a trapezoidal-shaped substrate has been proposed. Mutual coupling has been optimized by suitably adjusting the height and the dielectric constant of the substrate. The diffracted wave at the edge of the substrate is utilized to offset the direct wave coupled to the adjacent dipole elements. Notably, a parameter study and an E-field distribution investigation demonstrate that the mutual coupling diminishes as the dielectric constant increases, while the return loss characteristics degrade at a high dielectric constant. To enhance the impedance characteristics, a row of small via holes was created near the upper edge of the antenna. A 13×1 array was fabricated to validate the proposed model. Simulation and measurement results showed consistency and indicated that the impedance bandwidth covers the Ku-band, and the mutual coupling between two adjacent antennas is less than -15 dB across the same band. Moreover, the active element gain is in the range of 4.5-8 dBi.