High frequency oscillator design using the technique of negative resistance

An alternative method of analysing an oscillator, based upon the technique of modelling it as a one-port network exhibiting negative resistance, is used to design an oscillator for use in the 915 MHz ISM band. CAD software is used to optimize an active network for a suitable value of negative resistance before an external resonator is used to set the frequency of oscillation. The oscillator is constructed and simulated results are compared with measured results, showing that the procedure is both valid and practical.