An Efficient Procedure for the Time-Domain Sensitivity Analysis

Standard tools for CAD have limited modes of the sensitivity analysis: PSPICE only contains a static mode and SPECTRE includes frequency-domain and static modes. However, many RF systems use symmetrical structures for enhancing the circuit properties. For such systems, the static sensitivities are zero on principle and hence the time-domain sensitivity analysis should be used. In the paper, a novel recurrent formula for the time-domain sensitivity analysis is derived which uses by-products of an efficient implicit integration algorithm. As the selected integration algorithm is more flexible than the Gear’s one that is ordinarily used, the sensitivity analysis is more efficient in comparison with the standard CAD tools. An implementation of the method is demonstrated using the analysis of a low-voltage fourquadrant RF multiplier. Nonstandard temperature sensitivity analyses are also tested in the static and dynamic modes.