Analog coherent detection in application to high-sensitivity nonlinear junction detectors

A coherent detection technique has been utilized for the design of a high-sensitivity signal detector for the purpose of detecting nonlinear junctions. The theoretical analysis of signal reception in the presence of noise are shown. Two different approaches to the design of a NLJD are presented, and schematic diagrams of the developed detectors are shown as well as the results of measurements of received signals. High-sensitivity has been achieved and confirmed via adequate measurements shown in the paper. The developed system has been tested and proved its usefulness for the detection of nonlinear junctions embedded in common electronic devices.