MIXER CIRCUIT

PROBLEM TO BE SOLVED: To enable the conversion of signal frequency band while a prescribed frequency band is attenuated. SOLUTION: Diodes D1-D4 are arranged in ring with their contact points being node N1 to node N4. An RF input terminal is connected to the node N1 and the node N3 through a first transformer 50, and local signal 204 is inputted to the middle point of a second winding 58 of the first transformer 50. An IF output terminal is connected to the node N2 and the node N4 through a second transformer 54 with the middle point of a first winding 60 of the second transformer 54 being grounded. Further, between the node N1 and the node N4 as well as between the node N2 and the node N3, band reject filters F1 and F2 are provided which represent the same attenuation characteristics at a specified frequency band. COPYRIGHT: (C)2005,JPO&NCIPI