Radial-line planar antenna with microstrip-feed coupling lines

Radial-line antennas are an excellent choice for efficient design, as they present an easy manufacturing high-gain and efficient design, as they present an easy manufacturing process due to their planar structure. In this paper, a new feeding mechanism, from the transmitting radial waveguide to the radiating elements, is proposed. This coupling structure is based on microstrip lines placed inside the radial waveguide and connected to each radiating patch. By changing the dimensions of the microstrip lines, it is possible to achieve the desired feeding configuration. In order to check the validity of the new feeding mechanism, coupled field measurements are done in the radial waveguide. Likewise, a prototype antenna is manufactured in order to evaluate the behavior of the microstrip coupling lines when the radiating patches are connected to them. The results obtained from this prototype are presented and discussed and future research is proposed. (c) 2005 Wiley Periodicals, Inc.