Large-signal oscillator design procedure utilizing analytical $X$-parameters closed-form expressions

Abstract

New analytical behavioral model formulations based on the polyharmonic distortion (PHD) model have been successfully used to describe the nonlinear behavior of transistors and circuits. In this paper, the PHD model and its associated analytical X -parameters formulation will be utilized to provide an analytical design procedure for use in nonlinear microwave circuit design. For RF oscillator design, the negative-resistance method based on the analytical manipulation of scattering parameters is very popular due to its high rate of success in oscillation frequency prediction. However, it cannot be used to accurately predict the oscillator performance because it is based on linear parameters. To overcome this limitation, new analytical expressions based on large-signal X -parameters have been developed for use in transistor-based oscillator circuit design. The robustness of this new approach has been validated by designing and manufacturing a 5-GHz microwave oscillator.