What does VSWR stand for in RF systems?

What does VSWR stand for in RF systems?

• A. Very Small Wave Ratio.
• B. Vector Standing Wave Ratio.
• C. Voltage Standing Wave Ratio.
• D. Voltage Sine Wave Ratio.

Answer: (C)

The concept being tested is what VSWR communicates about an RF transmission line. VSWR stands for Voltage Standing Wave Ratio. It describes how well the line is matched to its load by looking at the standing wave formed from the incident and reflected waves along the line. When the load matches the line impedance, there are no reflections, the reflection coefficient is zero, and VSWR is 1.0. Any mismatch creates reflected power, building standing waves with voltage peaks and troughs, so VSWR rises above 1. The value is computed from Vmax and Vmin along the line or from the reflection coefficient Γ via VSWR = (1+|Γ|)/(1−|Γ|). In practice, a VSWR near 1 means efficient power transfer; higher values indicate more reflections, less power delivered to the load, and potential stress on the transmitter. The other terms aren’t standard RF terminology: Very Small Wave Ratio isn’t used, Vector Standing Wave Ratio would misstate what’s measured, and Voltage Sine Wave Ratio doesn’t capture the standing-wave concept.

The concept being tested is what VSWR communicates about an RF transmission line. VSWR stands for Voltage Standing Wave Ratio. It describes how well the line is matched to its load by looking at the standing wave formed from the incident and reflected waves along the line. When the load matches the line impedance, there are no reflections, the reflection coefficient is zero, and VSWR is 1.0. Any mismatch creates reflected power, building standing waves with voltage peaks and troughs, so VSWR rises above 1. The value is computed from Vmax and Vmin along the line or from the reflection coefficient Γ via VSWR = (1+|Γ|)/(1−|Γ|). In practice, a VSWR near 1 means efficient power transfer; higher values indicate more reflections, less power delivered to the load, and potential stress on the transmitter. The other terms aren’t standard RF terminology: Very Small Wave Ratio isn’t used, Vector Standing Wave Ratio would misstate what’s measured, and Voltage Sine Wave Ratio doesn’t capture the standing-wave concept.