Theoretical Design of Symmetrical Junction Stripline Circulators

The results of detailed calculations based on Bosma's theory of 3-port stripline circulators are presented. The analysis has been modified to enable the scattering matrix, and therefore the circulator bandwidth, to be found. The equations of the 4-port junction have been derived and an expression for the scattering matrix of the general m-port junction is given. A comparison of experimental and theoretical results for the 3-port junction shows good agreement for circulators designed in the frequency band 2-3 Gc. ,