Abstract
We propose a wideband and dual polarized open-ended waveguide for planar array antennas. The proposal forms most of the antenna structures including waveguide and feeding networks in the dielectric substrates. This yields two advantages. First, it reduces the antenna dimensions because the waveguide is filled with dielectric; this yields 30% bandwidth and short element spacing without grating lobes. Second, it simplifies the machining process, especially for the case of large scale arrays consisting of several hundred elements. We design antenna elements and a four-element array, and then fabricate the four-element array using a 7-layer board of PTFE. Though the calculated and measured reflection characteristics diverge slightly, the radiation patterns well match.
