5.2: IMPEDANCE SIMULATORS

5.2.1 Impedance Converters

In figure 5.15 a simple CCII-based negative impedance converter has been reported ^[2].

Figure 5.15: Current controlled negative impedance converter

Using a positive CCII, the current injected at X node will flow into Z impedance, so imposing a negative voltage at Y node. This value is also present at X node, where the equivalent impedance is equal to ?Z, as shown in eq. (5.14).

If we consider, as a source, a voltage generator instead of a current generator, the solution presented in figure 5.16 can be employed, where the equivalent impedance at Y node is now considered.

Figure 5.16: Voltage controlled negative impedance converter

The operating principle is exactly the same and the resulting input impedance at input node Y is still equal to ?Z.

The two solutions proposed in figure 5.15 and 5.16 allow the simulation of a grounded negative impedance. In order to implement a floating negative impedance, it is necessary to introduce a second CCII. A possible implementation is reported in figure 5.17. We notice that this topology has been obtained simply doubling that shown in figure 5.16, so the resulting input impedance is still equal to ?Z.

Using CCIIs, it is...