ACWWong
|
1. the output termination resistance or load impedance should represent the input impedance of the following stage. Only by doing this does the conversion gain of the mixer mean anything once placed into a system.
2. the OIP3 will only equal the IIP3 (obviously differnec of the conversion gain included) if the output doesn't signal limit. Often, because of the gain and limited output headroom, one find the output clipping at much lower signal levels than one expect from the input stage (gm stage is classical gilbert) linearity alone.
wrt the output impedance capacitive part... this will limit the conversion gain bandwidth... ie the IF bandwidth for which you get the conversion gain will reduce with more load capacitance.
|