Mixer circuit output port

[Hetfield]

hello everyone
i took the example circuit from RF Electronics Design and Simulation by Cornelis J. Kikkert and i want to know why did he use output buffer what is the advantage of the buffer is there any relation about DC voltage level i mean is it used for the voltage shifting? if so how do we determine shifting voltage levels.
thanks in advance.

 

[danadakk]

Basically an output buffer allows interface of a low Z load to
high Z circuitry, and/or raises the amount of power to a load,
its V swing, etc..

Regards, Dana.

 

[Hetfield]

Basically an output buffer allows interface of a low Z load to
high Z circuitry, and/or raises the amount of power to a load,
its V swing, etc..

Regards, Dana.

Could you explain V swing

 

[danadakk]

Voltage swing, can output supply enough current to the load
to get desired amplitude.

Regards, Dana.

 

[BigBoss]

If the next IF stage has a low impedance-generally so- a buffer driver is used to prevent from "loading effect" of the next stage.
If the Mixer Output has directly been connected to IF stage, Voltage Swing of the Mixer will be lower due to loading effect.