4957D/E/F Microwave Analyzer Quick Start Guide
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3.6 Measuring Average Power in the UBS-PM Mode
The USB Power Meter (USB Power Meter) mode of 4957D/E/F adopts a USB interface
to for connecting an external USB power probe via an UBS cable for power test. With the
8723X series USB power probes provided by China Electronics Technology Instruments
Co., Ltd., it can test radio frequency / microwave signals up to 40 GHz and can measure
real average power in a high dynamic range of-60 dBm to +20 dBm. The measurement
reading is displayed on the display interface of the USB Power Meter mode of 4957D/E/F.
The test block diagram is shown in Figure 3.11, and attenuators can be added as
required.
The test steps are shown as follows:
1. Mode selection
After startup, press [Mode], select the "
USB Power Meter
" mode, and press [OK] to
complete.
Figure 3.11 Test interface of USB Power Meter mode
2. Connecting power probes
1) As shown in the figure, connect the small end of the USB cable to 8723X series USB
power probe.
2) Then connect the large end of the USB cable to the USB interface of the analyzer,
and the green indicator light of the power probe will be on later.
3) If the power is turned off, remove the USB cable to turn off the power of the USB
power probe, and then the green LED indicator will go out.
3. Connecting the tested signal
1) Connect the power probe with the signal to be measured, and connect an attenuator
or gain between the signal to be measured and the power probe as necessary to
ensure that the signal power of the input probe is within the power range marked on
the probe.
2) If an attenuator or gain is connected, the offset function can be used to set the offset
value to cancel the attenuation value or gain value so as to read the actual power
