New Theoretical Models and Computer Programs for Accurate Design of Microwave Junction Circulators

This paper presents some of the results obtained in a project for optimization and design of microwave junction circulators for stripline and microstrip applications. A new set of expressions for the ferrite permeability parameters has been developed, which is valid and gives accurate results for all magnetizations and internal field intensities. Improved wideband properties of junction circulators are obtained by the use of additional matching elements. Computer programs for accurate design and analysis of circulators with prescribed characteristics have been developed. Comparisons with measurements on experimental models show very good agreement. The program have been used for design of a circulator for operation at two different frequencies.