Multiterminal gyrator

The multiterminal-gyrator concept is introduced as an extension of the well known 2-port device. In general, it is treated as having n input and m output terminals plus a reference or earthed terminal, common to both input and output. The (n + m + 1)-terminal device is therefore mathematically described using an (n + m)th-order admittance matrix. Both the mathematical characterisation and impedance-inverting properties of the multigyrator are shown to be directly analogous to those of its 2-port counterpart. An active realisation of the generalised multigyrator is proposed which uses unity-gain voltage and ± unity-gain current amplifiers. The method is quite general and uses n + m terminals. The actual gyrator transconductances are defined by an interconnecting network of resistors. The use of multigyrator capacitor networks to simulate inductor networks is shown to be possible and synthesis examples are given. Finally, the results of two experimental multigyrator filters are given.