Design of non-balanced cross-coupled oscillators with no matching requirements

Using two-port network transmission parameters we derive the general characteristic equation of a cross-coupled circuit topology which involves two active devices and four or six impedances. The derived equations are generic and apply both to BJT or MOS transistors and even any other active device without any matching constraints. Application to realising novel non-balanced non-matched cross-coupled oscillators is demonstrated. Spice simulations of a MOS oscillator in a 0.25 technology are given as well as experimental results from an oscillator employing discrete Bipolar transistors.