Compact dual-polarisation planar log-periodic antennas with integrated feed circuit

The design and construction of several planar log-periodic antennas are implemented using integrated tapered-microstrip baluns for the feed sections. The dimensions of the balun are determined using a simulation program. The efficiency of the combined balun and antenna has been determined using the Ansoft HFSS simulation package. These studies were performed for four different log-periodic antennas, with different frequency ranges and design characteristics. The measurements are in good agreement with simulation results and present acceptable radiation patterns and VSWR.