A realization of high‐frequency active RC bandpass filters using voltage followers

Abstract

AbstractUsing voltage followers as active elements in the synthesis of active RC immittances, no impedances could be realized which become zero at dc and no admittances which become infinite with the 2nd order or more at infinite frequencies. A realization method which simulates arbitrary LC filters impedance‐scaled by (1 ρ/s) has been proposed by the authors. This paper presents a realization of high‐frequency active RC bandpass filters simulating impedance‐scaled LC filters by using voltage followers and a passive RC circuit. The frequency characteristics of the simulated filters are damaged mainly by the input capacitances of voltage followers. The effect of the input capacitors is compensated by simulating a circuit consisting of L, C, and ‐R. A transformation of resistively doubly terminated LC bandpass filters is also shown to apply this compensation. Sensitivity analysis and experimental results confirm the effectiveness of the proposed realization method.