Abstract

The paper introduces a novel approach to broadband nonlinear oscillator optimisation, making use of the harmonic-balance (HB) technique as the basic circuit analysis algorithm. The key idea is give the optimizer direct control of the magnitude of one harmonic (usually the output fundamental), and to replace the latter by a circuit parameter in the inner analysis loop. In this way the degenerate solution(s) of the HB system are suppressed, and the number of iterations required to achieve a prescribed performance is drastically reduced. The resulting CAD tool is particularly well-suited for systematically tackling complex problems such as broadband multiple-varactor VCO design.