User`s guide

2-46
Making Mixer Measurements
Isolation Example Measurements
Figure 2-35 Example Mixer LO to RF Isolation Measurement
RF Feedthrough
The procedure and equipment configuration necessary for this measurement are very
similar to those of the previous LO to RF Isolation procedure, with the addition of an
external source to drive the mixer’s LO port as we measure the mixer’s RF feedthrough.
RF feedthrough measurements do not use the frequency offset mode.
1. Select the CW LO frequency and source power from the front panel of the external
source.
CW frequency = 300 MHz
Power = 10 dBm
2. Initialize the analyzer by pressing .
3. To select the analyzer frequency range and source power, press:
This source stimulates the mixer’s LO port.
4. To select a ratio B/R measurement, press:
NOTE Isolation is dependent on LO power level and frequency. To ensure good test
results, you should choose these parameters as close to actual operating
conditions as possible.
Preset
Start 10 M/µ
Stop 3000 M/µ
Power 0
PWR RANGE MAN
x1
Meas
INPUT PORTS
B/R