Mutual coupling suppression in microstrip lines using metamaterial on Low Temperature Co-fire Ceramic (LTCC) substrate

With the current demands on electronic systems being miniaturization and diverse functionality, electromagnetic interference (EMI) between the RF signals critically affects the system performance. A major limitation in realizing high-density microwave hybrid integrated circuits and SIP (system-in-package) is the parasitic coupling that arises between neighboring transmission lines. So far in literature there have been several studies aimed toward alleviating these problems. One approach involves thinning the substrate under signal lines to facilitate quasi-TEM mode propagation, but this requires an involved etching process [1]. Another method to effectively reduce this coupling is to use Electromagnetic Band-Gap structures (EBGs) [2]. Different types of EBGs have been reported in literature along with methods to evaluate their suitability to a particular application and performance [3]-[5]. But both plane EBGs and vertical EBGs are very difficult in manufacturing together with other circuit sections, which restricts the application of EBGs.