| 摘要 |
<p>There is provided a variable gain mixer capable of controlling a gain at a low source voltage in a wide range without additional current consumption. The mixer includes: mixers constructed with variable gain amplifiers having two transistor pairs Qp+/Qp- and Qn+/Qn- to have a predetermined gain by using LO+ and LO- signals; and LO bias circuits connected to have bias voltages different from each other with respect to the LO+ and LO signals of the mixers and share an input signal. Accordingly, by integrating the variable gain amplifiers into the mixers, a gain change can be obtained at a low source voltage in a wide range without connecting a number of variable gain amplifiers. In addition, by properly applying the LO signals used in the mixers, the gain change can have a linearity in dB characteristic</p> |
