What happens to the Standing Wave Ratio (SWR) when ice accumulates on the antennas?

• A. It decreases
• B. It increases
• C. It remains stable
• D. It fluctuates

Answer: (B)

When ice accumulates on antennas, it typically alters the physical characteristics of the antenna system, including its impedance. The Standing Wave Ratio (SWR) is a measure of how effectively radio frequency power is transmitted through a transmission line and into the antenna.

An increase in ice accumulation can change the dimensions or loading of the antenna, which can lead to a mismatch between the transmission line and the antenna's impedance. This mismatch results in a higher SWR, as more reflected power occurs when the impedance between the line and antenna does not match. High SWR values indicate that less of the transmitted power is radiated by the antenna and more is reflected back towards the transmitter, which can potentially cause damage to the transmitter if the SWR gets too high.

Thus, the correct choice highlights that increased ice accumulation negatively affects the antenna's performance, leading to an increase in the Standing Wave Ratio.