URSI 2007, XXII Simposium Nacional de la Unión Científica Internacional de Radio, La Laguna
A systematic procedure for the design of N-push oscillators, using auxiliary generators in combination with harmonic balance, is presented. The Nth-harmonic output power is maximized through a parametric sweep or load-pull optimization of the sub-oscillator circuit. Two variants of the latter technique are considered: the use of ideal harmonic terminations, defined by their reflection coefficients, and the use of a substitution generator at the output frequency. The latter enables a direct control of the output amplitude at the Nth-harmonic component. A further global optimization of the entire N-push configuration is performed, connecting one auxiliary generator to each sub-oscillator to impose the required phase shift and preventing undesired oscillation modes. A statistical analysis of the design sensitivity to discrepancies between the sub-oscillator elements is also presented. The proposed techniques have been applied to the design of a push-push oscillator at 18 GHz and a quadruple-push oscillator operating at 20 GHz.
