Broadband design of the printed triangular slot antenna

We propose a new design of a broadband printed triangular slot antenna. By introducing a small rectangular slot protruding from the triangular slot, a new resonant mode in the vicinity of the fundamental resonant mode of the triangular slot can be excited. Also, good impedance matching of both the fundamental and the new mode can be obtained, which leads to the antenna having a much enhanced operating frequency bandwidth. In addition, by adjusting the structure of the microstrip-line feed near the side perpendicular to the microstrip line, a very broadband operation can be obtained. In general, the obtained broadband bandwidth can be more than four times that of a conventional printed wide rectangular slot antenna (∼20%). In the proposed design, an impedance bandwidth of about 84% has been obtained. Antenna designs and typical experimental results of the proposed antenna are shown and discussed.