High Power Measurements; Signal Level Characteristics - HP 8510 User Manual

High Power Measurements

Signal Level Characteristics

Use Figure 10-1 to examine the maximum power ratings and normal signal levels present
in the test set. The signal levels are approximate, with signal path loss increasing with
frequency. Note the following characteristics:
Typically, the RF input is about 9 dBm and the loss to the selected test port is about 9 dB.
With the step attenuators set to zero dB, the loss from the RF input to the a1 or the a2
mixer, and the loss from Port 1 or Port 2 to the b1 or the b2 mixer, are approximately
equal at about 26 dB.
Since each mixer includes a 20 MHz preampli er to o set its conversion loss, measurement
of the User Parameters will show the IF level to be about 22 dB less than the RF input or
the signal level at the test port.
For speci ed performance, the maximum IF signal level as measured by the user parameters
is 10 dBm. Higher signal levels cause errors due to compression, and lower signal levels
produce greater uncertainty due to noise.
Components in the test set will be be damaged at certain signal levels. To
Caution
avoid damage, observe the following operating precautions:
Use the PORT 1 and PORT 2 attenuators (Stimulus Power menu) to
protect the mixer input
Install appropriate components in the rear panel extension links to protect
the test set Forward/Reverse switch
at any input or output. This means that if the device output is greater than
+20 dBm, the switch can be damaged by +20 dBm present at either LOW
POWER OUT connector.
If the device output is greater than +43 dBm, use appropriate components
to protect the test set ports (and the Forward/Reverse switch)
damage level is +43 dBm (20 watts) applied at PORT 1 or PORT 2 for the
HP 85110A, and +47 dBm (50 watts) for the HP 85110L.
the mixer damage level is +20 dBm.
the damage level is +20 dBm applied
High Power Measurements 10-1
10
the