Synthetic Transformer Design Using Commercially Available Active Components

In this study, a novel synthetic transformer (ST), namely mutually coupled circuit, using commercially available active components such as current feedback operational amplifiers (CFOAs) is proposed. The proposed ST uses four CFOAs, two grounded capacitors and five resistors. It possesses only resistors but no capacitors attached in series to W/X terminals of the CFOAs; consequently, its high-frequency performance is well. Nevertheless, it needs a single matching condition for symmetrical coupling. As an application example, a double-tuned band-pass filter is given. The validity of the proposed circuit is demonstrated through several SPICE simulations and experiments.