Design and implementation of an analog complex correlator for passive millimeter wave imaging system

In this paper the design of an Analog Complex Correlator has been described. The correlator is intended to be used with a Passive Millimeter Wave Imaging System. The correlator performs complex multiplication of the signals received by each antenna pair of the Interferrometric Array to compute the so called Visibility function. Instead of conventional multipliers, the correlator has been realized using "add and square" detection scheme using power combiners and detectors for reduced complexity and improved dynamic range.