| 摘要 |
<p>A mixer is described having a Gilbert cell structure including a first input and a second input for inputting an RF signal, a third input and a fourth input for inputting a local oscillator signal, a first output and a second output for outputting an IF signal, switches to convert the RF input to the IF output, and a dynamic bleed circuit for dynamically reducing the de-current of the switches at the switching-point. As the de-current of the switches is reduced at the point of commutation the 1/f-noise is also strongly reduced without degrading the linearity. The switching happens at twice the Local oscillator frequency. The DBC makes the circuit superior to static bleed current(SBC). When using static bleed current the dc current in the switches is continuously lower, leading to worse linearity The mixer also includes a common mode feedback circuit that feeds the common mode signal, optionally amplified to a common mode feedback control device that is in series between the dynamic bleed circuit and the supply voltage.</p> |
