This work investigates substrate-coupling effects in mixed IC’s, specially the
perturbations on RF blocks. The design and analysis of fully integrated radiofrequency
Voltage Controlled Oscillators (VCOs) are key points in RF analysis. First of all, the
oscillation frequency sensitivity functions of tuning voltage, bias current and spurious
side-bands due to injected noise are extracted to find out some relation between
substrate noise and spectrum purity.
In the goal to realize quantum nanometric devices, for instance, based on a resonant
tunneling effect through the Si/SiO2 interface, we model SiO2/Si/SiO2 double barriers
embedded between two n-doped Si layers. To study the quantum confinement in Si QW
we have solved a set of coupled Schrödinger–Poisson equations simultaneously.
In the core of the paper, we try to develop quantitative predictions about the phase noise
of such oscillators, and to give some new tracks in this field.
Mixed mode simulations are involved by applying a microscopic Drift Diffusion Model
to the device, while the Kirchhoff’s laws govern the rest of the circuit used.
Another problem field for the designers of complex heterogeneous circuits is to predict
the perturbations coming from commutating logical gates blocks, flowing through the
substrate to reach some sensitive analog blocks. We present an application of a
stochastic process model; the digital switching activity is handled as functions defined
as Markov Chains.
Keywords: Mixed circuits, radiofrequencies, 3D, parasites, noise propagation,
substrate coupling, ground or supply bounces, oscillators, theory, modeling, phase
noise, sensitivity functions, resonant tunnelling, stochastic process.
