Dual-frequency dual-polarization antenna of high isolation with embedded mushroom-like EBG cells

Abstract

A dual-frequency dual-polarization (DFDP) antenna of high isolation between two ports with embedded 2 x 1 mushroom-like electromagnetic bandgap (EBG) cells is presented. The equivalent circuit of a suspended microstrip line over 2 x 1 EBG cells is introduced. The numerical analysis from the equivalent circuit and measured results show that the microstrip line with embedded EBG cells has a distinctive and sharp rejection band that provides near 0 dB insertion loss outside the rejection band. By embedding the EBG cells tinder feedlines of a DFDP antenna, the isolation between two ports of the proposed antenna is enhanced by more than 20 dB, when compared with that of a conventional DFDP antenna. The proposed DFDP antenna is fabricated and measured. The simulated and measured results show a good agreement.