Wideband Triangular-Cavity-Cascaded Antennas

A triangular-cavity-cascaded antenna is proposed and analyzed for wideband applications. By alternatively and periodically shorting a metallic plate on its edges with small slices, isosceles-triangular field patterns are generated and cascaded for wideband antenna design. Synchronous electric edge fields which contribute to radiation occupy almost all the areas of both sides of the plate. Compared with a typical microstrip antenna with a rectangular cavity, the triangular-cavity-cascaded antenna is a relatively open structure with less shorting boundary around. As a result, the quality factor is smaller, and the impedance bandwidth is wider. In order to prove the design strategy, a 1-D cascaded antenna with 1 × 5 triangular cavities and a 2-D cascaded antenna with 2 × 5 triangular cavities are fabricated and tested. Experimental results show that the impedance bandwidths of 1-D and 2-D antennas are 35.66% and 21.43%, while the peak gains are 13.27 and 16.47 dBi, respectively.