Active Electronically-Controlled Circulator Based on Mem-OTAs

The circuit idea of an electronically-controlled three-port active circulator is proposed. Since its topology enables independent programming of characteristic port impedances, the circulator provides impedance matching for arbitrary non-symmetrical loads. The core of the circulator consists of three gm stages operating as non-volatile programmable transmemductors. Additional memristive RF switches can be used for modifying the conventional circulating scheme.