Realizing Wideband Negative Inductor Using Current Feedback Amplifier

Firstly, a compact current feedback amplifier-based negative impedance converter (CFA-based NIC) is designed and its equivalent circuit is proposed. Secondly, to obtain a stable negative inductor, a stabilization network is developed and combined with the CFA-based NIC. Meanwhile, the stability of the combined circuit is analyzed in the time domain by the method of Routh-Hurwitz criterion (R-H criterion). Finally, the prototype of the designed CFA-based NIC with stabilization network is fabricated. The measurement results have a good agreement with simulated results. The measurement results show the negative inductive property of the input impedance over a wideband from 50 MHz to 500 MHz. Especially, the equivalent inductor of the present circuit is -3.4 nH +/- 10 % from 200 MHz to 500 MHz.