Microwave component miniaturization by local embedding high-permittivity dielectric materials in low-permittivity substrates

Local embedding of high-permittivity dielectric materials has been used for decreasing size and monitoring parameters of microstrip resonators and filters with low-permittivity substrates. Capacitive loads utilizing high permittivity dielectric inclusions or superstrate layers are placed in the structures at the locations defined from the analysis of electromagnetic field distribution at resonant frequencies. Full-wave electromagnetic simulations have been performed by the Finite Difference Time Domain (FDTD) method. The designs of compact microstrip resonators and filters have been developed and the prototypes fabricated by using the Low Temperature Cofired Ceramic (LTCC) technology. The proposed approach demonstrates a new way for microwave component miniaturization and parameter optimization.