# Z (Impedance)

Model complex impedance

**Libraries:**

RF Blockset /
Circuit Envelope /
Elements

## Description

The Impedance block implements the relation, *v*_{k}(*t*) =
*Z*(*f*_{k})**i*_{k}(*t*), for each simulation frequency, *f*_{k}, where:

*Z*(*f*_{k}) represents complex-valued impedance at a specified simulation frequency.*v*_{k}(*t*) represents the voltage across the terminals of the element at time*t*.*i*_{k}(*t*) represents the current through the element at time*t*.

Circuit envelope current and voltage signals comprise in-phase,
*I _{k}*, and quadrature,

*Q*, components at each frequency,

_{k}*f*.

_{k}Frequency-dependent impedance typically cannot be realized as a physical network such as an RLC chain. You can, however, use the Impedance block to model nonphysical behavior, such as frequency-independent negative capacitance or negative inductance. You can also use this block to specify resonant frequency offsets in filter networks.

## Parameters

## Version History

**Introduced in R2010b**