Atek HP 8753D, User Manual, Page: 416 / 677

Mixer P arameters That Y ou Can Measure
Figure 6-87. Mixer P arameters
Transmission characteristics include conversion loss , conversion compression, group delay ,
and RF feedthru.
Reection characteristics include return loss , SWR and complex impedance .
Characteristics of the signal at the output port include the output power , the spurious or
harmonic content of the signal, and intermodulation distortion.
Other parameters of concern are isolation terms , including LO to RF isolation and LO to IF
isolation.
A ccuracy Considerations
In mixer transmission measurements , you have RF and LO inputs and an IF output. Also
emanating from the IF port are several other mixing products of the RF and LO signals . In
mixer reection measurements , leakage signals from one mixer port propagate and appear
at the other two mixer ports . These unwanted mixing products or leakage signals can cause
distortion by mixing with a harmonic of the analyzer's rst down-conversion stage . T o ensure
that measurement accuracy is not degraded, you must lter certain frequencies or avoid them
by frequency selection. If you place attenuators at all mixer ports , you can reduce mismatch
uncertainties .
6-150 Application and Operation Concepts