A VSWR of 2:1 or less is often considered acceptable. Which option reflects this statement correctly?

• A. A VSWR of 1:1 is always acceptable
• B. A VSWR of 4:1 or less is acceptable
• C. A VSWR of 2:1 or less is often considered acceptable
• D. VSWR has no practical acceptance criteria

Answer: (C)

Impedance matching in RF systems is about minimizing reflections so most of the power gets to the load. VSWR measures how well the line is matched: lower values mean better matches and less reflected power. A VSWR of 1:1 is a perfect match with zero reflections, while a VSWR of 2:1 indicates only a moderate mismatch—roughly 11% of the power is reflected. In practice, many systems tolerate small reflections, so a VSWR of 2:1 or less is often considered acceptable. If the VSWR were pushed to 4:1, reflections become substantial (around 36%), which is typically not acceptable for most transmitters and cables. VSWR does have practical acceptance criteria, so saying there are no criteria isn’t accurate. Therefore, the statement that a VSWR of 2:1 or less is often considered acceptable best reflects common engineering practice.