Analysis and size reduction of various printed monopoles with different shapes

Abstract

A simple analysis based on the transmission line model applied to printed dipole antennas, and the Babinet principle allows different shapes of printed monopole antennas to be easily optimised. A shortening ratio (ρ) of 48% (respectively 30%, 40%) is achieved for the monopole antenna by using a step change in line width (respectively a triangular monopole, and a line with a triangular cap). Theoretical input impedance of these various monopoles compare closely with experimental results.