Design of Microwave Printed Circuit Log - Periodic Antennas

Abstract

<p>The subject presented in this thesis concerns the design and fabrication of microwave printed circuit log - periodic antennas meant for operation at frequencies above 1.0 GHz. The designs has its basis in the work which was presented by Robert L. Carrel as a Ph. D thesis in 1961 and is one of the classic papers in the design of log - periodic dipole arrays.</p> <p>The method is modified to some extent firstly to compensate for planar, instead of cylindrical dipole and the effect of the dielectric loading which the supporting substrate provides.</p> <p>Methods which allow feeding the array from the opposite direction in which the main lobe extends are also discussed, one of which, the mode converter, is found to be immediately successful.</p> <p>A typical antenna is fabricated, its input impedance and radiation pattern measured and the results discussed with some comparison to Carrel's results.</p>