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Variational principles are efficient CAD tools for planar tunable MICs involving lossy gyrotropic layers
Author(s) -
Huynen I.,
Stockbroeckx B.,
Vander Vorst A.
Publication year - 1999
Publication title -
international journal of numerical modelling: electronic networks, devices and fields
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.249
H-Index - 30
eISSN - 1099-1204
pISSN - 0894-3370
DOI - 10.1002/(sici)1099-1204(199909/10)12:5<417::aid-jnm338>3.0.co;2-h
Subject(s) - planar , transmission line , lossy compression , microstrip , biasing , resonator , reciprocity (cultural anthropology) , coupling (piping) , electronic engineering , topology (electrical circuits) , materials science , computer science , optoelectronics , engineering , electrical engineering , voltage , telecommunications , psychology , social psychology , computer graphics (images) , artificial intelligence , metallurgy
The paper presents an efficient design method for frequency‐tunable planar devices using gyrotropic ferrite YIG films. The behaviour of the tunable YIG film is modelled by an equivalent lossy transmission line. Its parameters are the function of the permeability tensor components, which depend on the frequency and magnitude of the DC biasing magnetic field. We propose two analytical variational models for computing these transmission line one‐ or two‐port parameters, depending on their coupling to the planar MIC accesses. Compared with most numerical methods, the two resulting models offer the advantage to be fully analytical and remain valid when losses of the anisotropic material are taken into account. These two models are able to predict the expected and also the unwanted effects, such as non‐reciprocity and losses, with a very limited numerical complexity. The efficiency of the proposed approach is illustrated by comparing theoretical designs using these variational models with measurements carried out on the various topologies of the tunable one‐ and two‐port planar resonators in the microstrip and slotline technology. Copyright © 1999 John Wiley & Sons, Ltd.