Multilayer metal-semiconductor-relaxor microstrip line low-pass filters for communication and wireless electronic applications: Design, materials selection, and characterization.

摘要

ultilayer metal-semiconductor-relaxor microstrip lines have been investigated as packaging amenable low-pass filters for applications in communication and wireless electronics. The investigation begins with the identification of the requirements imposed by the package, and the requirements imposed by the current trends in hybrid integrated electronics. Based on these requirements, it has been found that relaxor ferroelectrics and ferromagnetic materials are the suitable materials for this application.;The complex dielectric permittivity and complex magnetic permeability of the selected materials have been measured between 100 Hz and 10 GHz. Under 500 MHz, the dielectromagnetic properties have been measured using conventional techniques. The measurements above 500 MHz have been carried out with two new techniques that were developed during this study. By modifying the electrodes and selecting samples whose thicknesses were a geometric series, the coaxial probe method has been used in a new manner. These modifications required solving a new set of conditions at the discontinuity coaxial line-material. The open coaxial probe terminated in an electroded sample has been used to measure the complex permittivity of several relaxor ferroelectrics from 500 MHz to 10 GHz at constant and variable temperatures. Using an open coaxial probe terminated in electroded and non-electroded samples, the magnetic properties of the ferrimagnetic materials have been measured between 500 MHz to 3 GHz.;The wave propagation in a multilayer microstrip line has been modeled with the parallel plate waveguide approximation. The new coaxial probe methods were used to collect broadband electromagnetic characteristics of the materials which were needed to fit a relaxation model that would most closely describe their dielectromagnetic behavior. The relaxation models produced analytical expressions for the dielectromagnetic properties that were then replaced in the parallel plate waveguide model. The modeling revealed that the ferrite layer defines the bandwidth, and the relaxor layer defines the frequency sensitivity of the characteristic impedance and harmonic distortion of these filters. Additionally, it has been found that the ferrimagnetic materials used in this application must have a conductivity larger than 2.3 ;Samples were fabricated by gluing the layers of relaxor ferroelectric and ferrite with a non-conducting epoxy resin. The results show that these filters have a bandwidth insertion loss of less than 0.7 dB, and a minimum return loss of