Analogue multiplier for multiplying 2 difference signals e.g. for mobile radio receiver - uses MOSFET input stage and 2 cross-coupled common-emitter transistor pairs connected in series with respective input stage MOSFET's

摘要

The multiplier has an input stage with a pair of MOSFET's (T1,T1') coupled together at their gates, supplied with a first difference signal (MI,MI') and 2 pairs of cross-coupled common-emitter transistor pairs (T2,T2'; T3,T3'), receiving a second difference signal (LO,LO'), each pair connected in series with one of the input stage MOSFET's. The latter may each be coupled to earth via a resistor (R1,R1'), their gates connected to earth via a common capacitor (C1), with 2 further transistors (T4,T4') connected between the MOSFET's and the associated transistor pairs, for providing a cascade circuit.