Towards a microstrip antenna on synthetic high-dielectric constant substrates

This work is an investigation into the dielectric properties of multilayered substrates. We focus on slow-wave polarization modes, known to occur in some layered substrates. We envisage exploiting the high resonant dielectric constant to obtain increased directivity of patch antennas. Issues such as reduced electrical efficiency due to a greater number of back-lobes, directed into the substrate, are also discussed. Simulated results indicate that relative effective dielectric constants exceeding values of 100 are possible at relatively low loss tangents even with very conductive substrates. The main effect of substrate conductivity is the definition of a frequency band in which the enhanced directivity is observed. Furthermore, reflecting schemes are proposed to further enhance antenna efficiency.