Test-and-Measurement » Reasons for High VSWR in 4G/5G Networks and its resolution techniques

Reasons for High VSWR in 4G/5G Networks and its resolution techniques

rf measurements vswr

High VSWR (Voltage Standing Wave Ratio) in 4G and 5G networks indicates poor impedance matching between the transmitter and antenna system. This leads to signal reflections, loss of power and potential damage to RF components.

Why high VSWR in cellular networks ?

Following are some of the common reasons of having high vswr in 4G/5G cellular networks.

CategorySpecific Issues
Antenna Faultsdamaged or broken antenna elements, water ingress or corrosion in outdoor antennas
Cables and connectors problemsLoose, corroded or poor connections, damaged cable, use of low quality cables
Impedance mismatchAntenna or cable not matched to 50 Ohm system, use of incompatible impedance
Installation issuesImproper grounding, short or open at cable ends, incorrect antenna orientation or placement
Hardware issuesDamaged combiners, filters, diplexers, faulty amplifier
Environmental factorsSnow accumulation on antennas, movement due to wind, proximity to trees or metal structures

Resolutions to address high VSWR issues

ResolutionAction
Antenna Inspection & ReplacementInspect and replace damaged antennas (if found)
Connector & Cable ChecksTighten and replace (if worn or rusted)
Impedance matchingEnsure all components are 50 Ohm , Use impedance matching networks if required
Environmental protectionUse weather proof components and install radome or heater to prevent ice or snow build up
proper grounding and mountingEnsure antennas are grounded properly, Install antennas such that they are not blocked by obstacles or metal structures
Monitoring and alarmsInstall VSWR monitoring sensors and integrate alarms into NMS
Routine maintenanceSchedule regular PIM and VSWR testing, keep maintenance logs for analysis

Tools Commonly Used

Following tools are very useful to measure VSWR and other RF parameters.

  • Site Master/Cable & Antenna Analyzer
  • PIM tester
  • RF Power Meter
  • OTDR