Devices out of Scope of the BPM Technique (ring resonator)

The last category covers all those circuits, where analysis by means of the BPM technique alone is impossible. The representative of this group may be the ring resonator (see Figure 2) as was already mentioned in the introductory part of the paper. We may also try to reconsider some special omnidirectional devices under the circumstances yielded by the scattering data tools. The next section introduces the mathematical description.