Improvement of Transmit-Receive Array Antenna Isolation by Employing Multilayer EBG Structure

A novel multilayer electromagnetic band-gap (EBG) structure for reducing transmit-receive (T/R) isolation of two X- band antenna arrays is presented. The proposed configuration is a combination of two EBG-mushroom structure which are placed on the top and bottom layer of a dielectric substrate. To verify its efficiency this structure is applied for isolation improvement in two cases of two single patch antenna and the two antenna arrays working in X band. The obtained results using this isolator demonstrate a drastic decrease in the mutual coupling level (28 dB) while it improves the radiation performance. This EBG structure could be a good candidate for radar applications which require closely packed transmit/receive arrays.