High-Q inductance circuit using an integrator and its application

In this paper we propose a high-
Q
inductance simulation circuit using an integrator and a voltage-current converter. This is followed by a description of an application of this circuit to realize a high-
Q
bandpass amplifier. The input voltage
E_i
, is integrated and the resulting output
E_0
is converted to a current
I_i
whose magnitude and phase are proportional to those of
E_0
. So the phase angle of
I_0
lags
E_i
by almost 90 degs. The design of the integrator circuit which provides a phase lag of 90 degs is described; analysis of the effect of element tolerances and temperature variations, frequency range over which the effective inductance has nearly constant value, and the maximum value of
Q
attainable by adjusting the circuit parameters are presented. It is also shown that over a frequency range of about 1 Hz-500 kHz, maximum values of
Q
in the range of 500-1500 may be realized stably. Finally, a frequency selective amplifier using an inductance circuit with an unloaded
Q
of 830 is described to illustrate the stability of such high-
Q
circuits.