Adjoint Sensitivity Analysis of Nonlinear Distortion in Radio Frequency Circuits

Measuring the effects of nonlinear intermodulation distortion is one of the main requirements in the design of radio frequency circuits. The third-order intercept point (IP3) is one of the main figures of merit that is used to characterize this distortion and is expensive to compute due to the presence of multi-tone inputs. Recently, an efficient method for computing the third order intercept point, using moments analysis, was presented. However, this approach does not provide any sensitivity information. In this paper, we propose an efficient and robust method for computing the sensitivity of IP3 using adjoint moments with minimal additional computational cost.