| 摘要 |
A mixer circuit is provided which achieves substantially reduced intermodulation distortion products as compared with conventional mixers. The present mixer circuit includes first and second mixers situated in first and second signal paths, respectively. A small portion of the signals incident upon the input of the first mixer are coupled to the input of the second mixer via a first coupler. The first coupler effectively substantially attenuates signals incident upon the first mixer before providing said signals to the input of the second mixer. Intermodulation products as well as desired signals are generated at the outputs of both the first and second mixer. The output of the second mixer is coupled to the output of the first mixer via a second coupler. The second coupler exhibits an appropriate amount of attenuation, such that the intermodulation products which are coupled from the output of the second mixer to the output of the first mixer exhibit an amplitude equal to the first mixer intermodulation products. Thus, the intermodulation products from the first and second mixers meet at the circuit output in such a manner as to destructively interfere with each other resulting in substantial intermodulation product cancellation while the remaining desired signals are provided to the circuit output.
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