Which of the following represents the best standing wave ratio (SWR)?

The best standing wave ratio (SWR) is 1:1. This value indicates perfect matching of the load impedance to the transmission line impedance, which means that all the power transmitted through the line is delivered to the load without any reflections. A 1:1 SWR signifies no standing waves are present, reflecting that the transmission line is optimally tuned to the load, resulting in efficient power transfer and minimal loss.

In practical terms, an SWR of 1:1 is ideal because it minimizes potential damage to the transmitter that can occur from reflected power and ensures high-quality signal transmission. Higher ratios, such as 2:1, 3:1, or 4:1, denote increasing mismatch conditions, which lead to higher levels of reflected power, potential interference, and higher losses in transmission, negatively impacting performance and efficiency.