A Novel Calculation Method to Design Parasitic Decoupling Technique for Two Antennas

In this paper, a systematic and calculation-based parasitic decoupling technique (PDT) is proposed to mitigate the mutual coupling between two closely coupled antennas. The adopted parasitic decoupling structure consists of two transmission lines connected to the feed lines of antennas and a parasitic element connected with a transmission line and terminated by a reactive load. Rigorous decoupling theory and systematic design procedures are presented. The lengths of transmission lines and value of reactive load can be precisely calculated to increase antenna isolation. The superiority of the proposed PDT is verified by four decoupling examples. The simulated and measured results show that high isolations over 24 dB, efficiencies above 70%, and envelop correlation coefficients below 0.05 are achieved simultaneously. The results indicate the proposed PDT a promising decoupling method for MIMO systems.