An EBG enhancement to patch array antenna with integrated optical transducer

In this paper, a circular polarized two-by-two patch array is designed and manufactured with the enhancement of spiral EBG elements. The design procedure of the EBG elements is described, as well as the simulated and measured antenna performance. More compact in size comparing with traditional mushroom structure, the spiral element with via also tackles the circular polarized field. The mutual coupling levels of the array are significantly reduced by more than 5 dB at 5.24 GHz, while the radiating element spacing remains at half wavelength in free space.