アナログRF回路のシミュレーション(シミュレーションの世界)  [in Japanese] Analog RF Circuit Simulation  [in Japanese]

This paper describes circuit simulation methods for analog RF circuits It reviews the small signal analysis and noise analysis methods for periodically operating nonlinear circuits, such as mixer circuits and oscillators. Time-invariant circuit simulators, such as SPICE, cannot simulate small signal responses and noises of these circuits Periodic nonlinear circuits are modeled as periodic linear time-varying circuits for small inputs. These small signal responses and noises can be calculated using periodic time-varying transfer functions from an input to an output For the case of oscillators, calculation of the transfer functions has a serious numerical problem The method to solve this problem is described The periodic linear time-varying circuit can be obtained by applying the perturbation technique to the periodic steady-state solution of the nonlinear circuit. Hence, it is necessary first to find a periodic steady-state solution The periodic steady-state analysis method to compute the periodic responses directly is also presented