Gyrator implementation from commercially available transimpedance operational amplifiers

A new configuration for a gyrator which is implemented from two commercially available transimpedance operational amplifiers (opamps) and uses only three passive components is described. A filter exhibiting simultaneously two transfer functions, bandpass and highpass (or lowpass), has been implemented from this gyrator. It is characterised by a Qfactor value which is adjustable from a passive component, without modifying coo. Experimental results which confirm the theoretical analysis are given and discussed. They have been obtained using the AD 844 AN transimpedance opamp from Analog Devices.