Out-of-band and adjacent-channel interference reduction by analog nonlinear filters

In a utopian world, our communication technology would have “brick wall” filters, nodistortion amplifiers and mixers, and well-coordinated spectrum operations. In the real world, communications are prone to various types of unintentional and intentional interference of technogenic (man-made) origin that can disrupt critical defense communication systems, with the impacts ranging from slight reduction in the channel capacity to the channel failure. In this paper, we introduce a methodology for mitigation of technogenic interference in communication channels by particular analog nonlinear filters, Nonlinear Differential Limiters, with a specific example of reducing the out-of-band and/or adjacent-channel interference.