Dual-band cavity-backed slot antenna using series resonator

A dual-band technique for a cavity-backed crossed-slot antenna is presented. A conventional cavity-backed slot antenna shows the single resonance characteristic which is determined by the lateral length of the cavity and the length of the slot. In this paper, dual-band cavity-backed slot antenna is proposed using the series resonator across the slot aperture. As the resonance of the series resonator makes the shorting path across the slot, second resonance can be introduced. The inductance and the capacitance of the series resonator which are implemented by using a straight line and a gap between two lines can be implemented using a standard printed circuit board process. The proposed technique is applied to design the dual-band cavity-backed slot antenna around 2.4 GHz for the demonstration. The simulated antenna showed the dual-band characteristics without increasing the size of the cavity.