The SWR standing wave ratio, or Standing Wave Ratio (SWR), measures how effectively radiofrequency power is transferred from a source through a transmission line to a load. It is the ratio of the amplitude of the maximum voltage to the amplitude of the minimum voltage in the standing wave pattern along the transmission line. A high SWR indicates poor impedance matching and significant reflected power, while a low SWR indicates better impedance matching and efficient power transfer.

### What does standing wave ratio mean?

The standing wave ratio (SWR) represents the ratio of the amplitude of the maximum voltage to the amplitude of the minimum voltage in a standing wave pattern along a transmission line. It provides a measure of how well the impedance of the load matches the impedance of the transmission line. A low SWR indicates good impedance matching and efficient power transfer, while a high SWR suggests a mismatch and more reflected power.

Which of the following cannot be the standing wave ratio SWR? Standing wave ratios (SWR) cannot be less than 1:1. An SWR of 1:1 represents perfect impedance matching with no reflected power. Any value above 1:1 is acceptable, but an SWR of 0:1 or negative values are not physically possible.

The term standing wave refers to the pattern of waves that remain in a fixed position on a transmission line due to interference between the forward and reflected waves. This pattern creates nodes (points of minimum voltage) and antinodes (points of maximum voltage) along the line. Standing waves are a result of impedance mismatches and can lead to inefficiencies in power transfer.

### What should be the VSWR value?

The ideal VSWR value should be as close to 1:1 as possible, indicating perfect impedance matching with minimal reflected power. In practical scenarios, a VSWR of 1.5:1 or lower is often considered acceptable. Higher values suggest a significant impedance mismatch, which can lead to reduced performance and increased power loss.