Reducing the height of a monopole antenna by using magneto dielectric material

This paper presents the use of a high permittivity and high permeability magneto-dielectric material to reduce the height of a monopole antenna without sacrificing the desired bandwidth. A magneto-dielectric material of high permittivity and high permeability has been used as a loading element on a standard quarter wavelength monopole antenna. In our design, the magneto-dielectric material is placed on the top and the bottom of the antenna to achieve reduction in the resonant frequency. It is shown that a monopole designed at a frequency of 1.12GHz can have its resonance frequency shifted to 0.89GHz. Most of the known magneto-dielectric materials tend to be lossy. The radiation efficiency of loaded antenna is better than 60% over the matched impedance bandwidth.