Design routine for realizing miniaturized planar antennas

This paper presents a design routine enabling the implementation of small and efficient radiators. The routine is based on studying the wave characteristics of a composite left handed/right handed medium. Through this study, a transmission line is easily matched to such medium. The phase properties at the line edges can then be controlled. This means that in-phase (or out of phase) edges are easily achieved. In-phase edges are used to produce a monopole like radiation pattern. Using the outlined concept, an antenna, with a length of about 0.07 of the free space wavelength, was implemented and matched to a 50 Ohm line. End-fire gain is about 4 dBi. It is also shown that by using an even number of composite cells, a broadside gain of about 2.5 dBi is achieved.