Voltage Standing-Wave Ratio (Vswr) Tests - Fluke 6080A Service Manual

VOLTAGE STANDING-WAVE RATIO (VSWR) TESTS

The Voltage Standing-Wave ratio (VSWR) tests use a VSWR bridge and a spectrum
analyzer to verify VSWR of the UUT.
REQUIREMENTS:
The output VSWR is less than 1.5:1 for output levels < -10 dBm; < 2.5:1 elsewhere.
EQUIPMENT REQUIRED:
• VSWR bridge
• RF spectrum analyzer
• High-frequency synthesized signal generator (FSSG)
REMARKS:
The UUT settings in this procedure are chosen to provide confidence in the VSWR
performance of the UUT throughout its range. However, performance also may be
checked at other levels.
VSWR problems are most likely to involve the A8 Output PCA or the A21 Attenuator
PCA.
The following procedures must be done in sequential order to ensure that
the proper equipment is connected and appropriate programs are
enabled.
PROCEDURE:
1. Low-Level Test
a. With the UUT on, program the UUT to SPCL 909.
b. Program the UUT to 640 MHz at -10 dBm.
c. Select the fixed range special function on the UUT by pressing
d. Using the EDIT function on the UUT, edit the amplitude to -30 dBm. Verify
that the UNCAL annunciator illuminates.
This procedure leaves the output attenuators set as they would be for a -10
dBm output level, but uses the electronic control to turn down the RF
level coming out of the UUT.
e. Connect the UUT to the Device Under Test port of the VSWR bridge.
f. Connect the RF spectrum analyzer to the RF OUT port of the VSWR bridge.
NOTE
NOTE
PERFORMANCE TESTS
4-15.
4-23