Conversion Loss Using The Frequency Offset Mode - Agilent Technologies 8753ET Manual Supplement

Conversion Loss Using the Frequency Offset Mode

Conversion loss is the measure of efficiency of a mixer. It is the ratio of side-band IF power
to RF signal power, and is usually expressed in dB. The mixer translates the incoming
signal, (RF), to a replica, (IF), displaced in frequency by the local oscillator, (LO).
Frequency translation is characterized by a loss in signal amplitude and the generation of
additional sidebands. For a given translation, two equal output signals are expected, a
lower sideband and an upper sideband.
Figure 1-14 An Example Spectrum of RF, LO, and IF Signals Present in a
Conversion Loss Measurement
The following procedure describes the R channel swept IF frequency conversion loss
measurement of a broadband component mixer with power meter calibration. For this
example, we will use an LO frequency of 1 GHz (1000 MHz), an IF start frequency of
100 MHz, and an IF stop frequency of 350 MHz.
1. Set the LO source to the desired CW frequency of 1000 MHz and power level to 13 dBm.
2. Connect the measurement equipment as shown in Step 1 of
Figure 1-16).
3. Set the desired analyzer RF power to the value which will provide −10 dBm or less to
the R channel input.
For 8753ET/ES, press
For 8753ES with Option 011, press
CAUTION To prevent connector damage, use an adapter (part number 1250-1462) as a
connector saver for R CHANNEL IN.
Supplement for the User's Guide (Firmware Version 7.66)
Conversion Loss Using the Frequency Offset Mode
PWR RANGE MAN
Power
Power
Figure 1-15
.
0 x1
.
0 x1
(or Step 1 of
1-23