Broadband Negative Capacitors Based on NIC with the Darlington Transistors

Broadband non-Foster negative capacitors for the megahertz and gigahertz ranges based on a negative impedance converter (NIC) with composite transistors are presented. A modified Darlington transistor which features a high-impedance RLC-circuit to supply additional current to emitters is employed. A significant extension of the operating bandwidth of the negative capacitors is demonstrated when using NIC with the modified Darlington transistors.