Questions about mixer input impedence

[chunlee]

mixer input impedence

Hi everyone,

as we know, the mixer input impedence is capacitive. is it that means the real input impedence of the mixer is zero? How to match the LNA output to mixer input on wafer?

Thanks.

 

[kevinj]

Re: mixer input impedence

if the mixer is bjt then the input impedance is Rpi and Cpi. So there is a resistor. if the mixer is a mos then the resistance is huge and there is also a cap, Cgate.

 

[biff44]

Re: mixer input impedence

Do you know what impdance means?

 

[kevinj]

Re: mixer input impedence

impedance means the resistance : real plus imaginary. meaning a resistor (real) plus inductor or capacitor (imaginary).