This paper deals with the passage of

signals along with additive Gaussian noise through a memoryless bandpass nonlinearity. It offers a method for finding the fundamental zone output attributable to any

input signals (including their intermodulation) which at the same time specifies the equivalent new nonlinearity seen by these signals. The fundamental (i.e, bandpass) transfer characteristic of the original nonlinearity is arbitrary and may include AM-to-PM conversion. The approach is a generalization of Blachman\´s treatment of the problem for a signal-plus-noise jnpdt. The analysis is based on the author\´s previously reported stochastic decomposition method for multiple signals feeding a bandpass nonlinearity.