Equivalent Circuit Analysis of RF-Integrated Inductors with/without Ferromagnetic Material

Abstract

In this paper, the X-ray diffraction profiles of multilayer with uncorrelated rough interfaces are directly simulated using kinematic theory of X-ray diffraction. The result shows that the decrease of the reflective intensity caused by the interfacial roughness is more severe than that caused by random fluctuation of period of the same degree, and the decrease of the reflective intensity of high order Bragg deffraction is more rapid than that of low order ones. So it is very important to reduce the interfacial roughness in the deposition and in the annealing of multilayer films.

RF VCO tuning using MEMS piezoelectric actuated variable inductors

“…This model is shown in Fig. 4 and is an adapted version of the equivalent circuit of the magnetic thin-film inductor presented in [14].…”

“…The latter elements model the inductive and resistive contribution of the ferromagnetic core to the whole inductor structure. The inductance, resistance and capacitance of the magnetic film can be neglected because these parameters are very small compared with other parameters [14]. In this model, the parasitic capacitances between the magnetic film and the ground plane and the parasitic capacitances between the magnetic film and the coil are also neglected.…”

“…In this model, the parasitic capacitances between the magnetic film and the ground plane and the parasitic capacitances between the magnetic film and the coil are also neglected. In [14] since the model was used for the sub-gigahertz region, the inductive contribution of the magnetic film is represented by a frequency independent inductance and the loss resistance by a frequency independent resistor, which are in series to the branch of the air-core inductor. In this model, the frequency dependency of the magnetic film is not ignored and is being represented by a parallel L-C-R resonator tank.…”

“…Then since the relationship between the model parameters and the Z-parameters is known (Eqs. [13][14][15][16], it is possible to generate estimated Z-parameter data for a range of parameter estimates. The user enters an estimate for each different parameter and a range of estimates is automatically generated from 1 to 150% of the entered values.…”

Stacked π- type Equivalent Circuit Analysis of Ferromagnetic RF Integrated Inductor

“…Last year we have proposed a stacked-π type equivalent circuit for a ferromagnetic RF spiral inductor with magnetic film on top of the spiral, followed by the low frequency approximation of the proposed equivalent circuit to ease parameter extraction up to 5 GHz [5], [6].…”