Analysis of inhomogeneous broadband circulators by means of a mixed numerical method

Broadband stripline circulators are studied by means of a mixed numerical technique which employs both Boundary Integral and Segmentation methods; this technique allows to analyze planar circuits where the substrate is constituted by several regions with arbitrary shape and different electrical properties. The method of study here presented allows to determine the overall impedance matrix of a 3-port circulator constituted by a non-reciprocal disk with sections of striplines going outside each port; in this way the discontinuities between reciprocal and non-reciprocal medium are included in characterization of the overall device.