Novel electrical squaring circuit with an output bandwidth from DC to 2·6 GHz

The author has proposed a novel squaring circuit consisting of two double-balanced mixers, with the first mixer serving as an upconverter and the second mixer performing the squaring function. Using commercially available mixers, an experimental squaring circuit was demonstrated with an output bandwidth from DC to 2·6 GHz and with over 30 dB suppression of the unsquared signal power relative to the squared signal power, for input signal powers from -5 to +3 dBm. This circuit is promising for electrical signal processing applications which require a DC-coupled squaring operation with bandwidths in excess of 1 GHz. One such application is in coherent optical phase diversity receivers