Chapter 10 Test Tools; Vswr; Vswr Test Function; Scope Of Vswr Test - Viavi AVX-10K Operation Manual

Chapter 10 Test Tools

VSWR

10.1 VSWR

10.1.1 VSWR Test Function

The VSWR test function provides users with the ability to troubleshoot potential cabling
and / or antenna issues.
• Voltage Standing Wave Ratio (VSWR) is a measurement that represents how well
an antenna's impedance is matched to the radio or transmission line to which it is
connected.
The smaller the VSWR measurement, the better the antenna and transmission line
match, and therefore less loss and better signal strength on the transmission line.
The minimum VSWR is 1.0, which means no power is being reflected
• Return loss (RL) is the ratio of the reflected signal to the transmitted signal. A low
return loss indicates less signal reflection and better signal strength. A high return
loss indicates more signal reflection and less signal strength, indicating an issue
along the transmission line.
When Return Loss is selected, measurements are displayed in dB.

10.1.2 Scope of VSWR Test

This test is used to evaluate how well an antenna's impedance matches the impedance of
the radio or transmission line to which it is connected.

10.1.3 UUT Parameters/Characteristics

The example in this section assumes the following UUT (Unit Under Test) characteristics
and settings. You will need to adjust settings according to the operational capabilities of
the device you are testing. In this case, we will be showing a test of a Transponder
antenna.
Frequency Range Settings: 900 to 1250 MHz

10.1.4 Equipment Needed for VSWR Test

The following equipment is required to perform the procedures defined in this section:
•
Cable or antenna to be tested
• Calibration Kit (short cable with short and load – included with the AVX-10K)
Rev 004
10 - 2
AVX-10K Operation Manual 22135254
January 2024