Microwave Integrated Circuits, Spiral Inductors

The topic of this thesis is to develop simple and accurate CAD formulas for spiralinductors in practical microwave integrated circuits (MIC). With "bootstrapping", one canget CAD formulas from simple to more complicated and practical structures, such as fromthe formula of patch capacitor to that of square spiral inductors.In this thesis, we first obtain the simple CAD formula for inductance calculation of atwo-level square spiral inductor, which currents of the two spirals are in the same direction.And then using the CAD formula for inductance calculation of single square spiralinductor obtained by other researchers, we could obtain the mutual inductance between thetwo spirals. And so, the CAD formula for inductance calculation of two-level square spiralinductor, which current directions of the two spirals are different, is easily coming. Andthen we obtained the CAD formulas of patch capacitor, capacitance and inductance ofsingle square spiral inductor in LTCC by synthetic asymptotes. Equivalent circuits oftwo-level square spiral inductor and single square spiral inductor in LTCC are alsoresearched in this thesis.With a few arbitrary constant for every formula, the average errors are less than 3％for all the formulas in this thesis, while the average errors of the |S₁₁| and |S₁₂| calculate bythe equivalent circuits are less than 2％compared with IE3D. Since the formulas arederived and not curve fitted, their range of validity can be large covering whole spans ofalmost all the parameters in the formulas. And the formulas are simple, accurate, and givegood physical insights. The characteristics of these formulas are very useful for the designof practical MIC circuits.