Analysis of a tunable frequency-selective surface on an in-plane biased ferrite substrate

The response characteristic of a frequency-selective surface (FSS) made up of a Jerusalem cross on a in-plane biased ferrite substrate is analyzed with the full-wave moment method. It is shown that the resonant frequency of a FSS can be dynamically adjusted by changing the de bias magnetic field. For normal incidence of the plane electromagnetic wave, a resonant-frequency shift of about 5 GHz can be obtained by tuning the bias de magnetic field. It is further proved that it is easier to get the shift of resonant frequency of a FSS for the case of the Jerusalem cross than for the cross dipole for a given range of bias magnetic field. For an oblique incidence of 45°, about a 3-GHz resonant-frequency shift can be easily achieved.