A wide-tunable translinear second-order oscillator

This paper describes the design and measurement of a translinear second-order oscillator. The circuit is a direct implementation of a nonlinear second-order differential equation and follows from a recently developed synthesis method for dynamic translinear circuits. It comprises only two capacitors and a handful of bipolar transistors and can be instantaneously controlled over a very wide frequency range by only one control current, which indicates its suitability for spread-spectrum communications. Its total harmonic distortion can be made small by design, which enables fully integrated transmitters. A semicustom test chip, fabricated in a standard 2-µ, 7-GHz, bipolar IC process, operates from a single supply voltage, which can be as low as 2 V and oscillates over 6 decades of frequency with -31 dB total harmonic distortion.