Linear VCO with sine wave output

This paper presents a sinusoidal oscillator whose frequency of osculation hears a linear relation with the controlling voilage V
T
. The bask configuration involves a four-quadrant analog multiplier as a mechanism to adjust precisely the gain requirement for sustained oscillation with ultra-low distortion operation. The circuit makes use of a scaled-resistance element R
1
/K
²
to realize the oscillation-frequency f in the form f = kf
0
, where the scaling parameter k is a linear function of V
t
and f
0
is the unsealed frequency. The use of grounded capacitors in the basic structure offers desirable features for IC implementation of the whole oscillator circuit.