Dual-Band Circularly Polarized Dual-Slot Antenna With a Dielectric Cover

A new circularly-polarized (CP) dual-slot antenna fed by a single L-probe is proposed for dual-band applications. The antenna consists of a zonal slot and an annular slot, both of them being cut onto a square conducting cavity with a protective dielectric cover. It is observed that the resonance frequencies of the lower and upper bands are controlled by the zonal and annular slots, respectively, making designs of the dual-band antenna very easy. To demonstrate the idea, the proposed antenna was designed at 2.4/5.8 GHz for two IMS bands. The reflection coefficient, axial ratio, radiation pattern and gain of the dual-band antenna were studied, and reasonable agreement between the simulated and measured results was obtained. A parametric study was carried out to characterize the proposed antenna.