A study of the broadband printed rectangular slot antenna with a 3D microstrip-line feed

We propose a new design of a broadband printed rectangular slot antenna with a 3D microstrip-line feed. Such a loaded 3D microstrip-line feed retains low profile and easy fabrication advantages. By introduction of the 3D microstrip-line feed of the rectangular slot, a broadband impedance matching of the rectangular slot over a large frequency band can be achieved. In addition, by adjusting the tuning structure of the microstrip-line feed near the side perpendicular to microstrip line, a very broadband operation of triangular slot antenna can be obtained. In general, the obtained broadband bandwidth can be greater than 2.5 times that of a conventional printed wide rectangular slot antenna (-20%). In the proposed design, the impedance bandwidth of about 55% has been obtained. Antenna designs and typical experimental results of the proposed antenna are shown and discussed.