Standing wave ratio is a figure of merit for a transmission line or waveguide, expressing transmission efficiency by accounting for the mismatch between source, line, and load.
Standing wave ratio, often abbreviated SWR, is a figure of merit used in a transmission line, waveguide, or similar system to express how efficiently the system transfers power, taking into account the impedance mismatch between source, line, and load. When some power is reflected back due to a mismatch, the forward and reflected waves combine to form standing waves along the line, with maxima and minima. The standing wave ratio is the ratio of the maximum to the minimum voltage, or current, along the line.
In a perfectly matched system, no power is reflected, the standing wave ratio equals one, and only a traveling wave is present. As more power is reflected, the ratio rises toward infinity, indicating a poor match and reduced efficiency. A low standing wave ratio is therefore desirable for efficient power transfer.
In commercial and industrial high-frequency systems, the standing wave ratio indicates how well a cable, antenna, and equipment are matched. Recognizing the measure helps in understanding the importance of impedance matching.
Because a low standing wave ratio is desirable for efficient power transfer, the measure indicates how well a cable, antenna, and equipment are matched, with cable engineered for stable impedance helping preserve efficient power transfer across high-frequency communication systems.
At Windy City Wire, the focus on coaxial and signal cable with consistent impedance supports a low standing wave ratio in high-frequency systems. Supplying cable engineered for stable impedance helps preserve efficient power transfer across commercial communication systems.
SWR (standing wave ratio)