New, high frequency transformer topologies

摘要

Flat topologies for inductive devices at high frequencies are limited in performance by both materials and geometric constraints. This research develops design equations and explains the fabrication process in building thick film, high frequency transformers and inductors using single and multilayer spiral windings, where the coils are embedded in the thick film magnetic material. The design frequencies range from 100 MHz to 300 MHz. Core materials were of the Ni/Zn ferrite variety of powders made into thick film pastes. A number of different thick film methodologies, ranging from polymeric to ceramic, on alumina, aluminum nitride, and beryllia were used. The effects of encapsulation and thick film modality are discussed. Measurements on the completed devices using network analysis techniques are explained. Results and future directions for research are discussed.