| 摘要 |
PROBLEM TO BE SOLVED: To restrict an occupied area of the circuit, improve a gain, and take out the maximum performance of a mixer by feeding a bypass current of constant current power supplies F3, F4 between the amplifying stage 32 and the switch stage, and controlling an operation current independently in a gilbert cell type mixer circuit 31, in which constant current power supplies F1, F2, an amplifying stage 32, a switch stage 33, and an output load 34 are connected in series, for mixing a RF signal and an LO signal and generating an IF signal. SOLUTION: The bypass current is so set that an output 3rd intercept point OIP3 or a difference value between the value of OIP3 and a noise factor becomes a maximum. Then, without lowering an input 3rd intercept point IIP3 greatly, a conversion voltage gain can be improved, and a decrease in noise factor NF can be restricted. The original performance of the mixer can be fully demonstrated, and superior design with efficiency can be carried out. COPYRIGHT: (C)2004,JPO
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