What does the antenna front-to-back ratio measure?

The antenna front-to-back ratio measures how much of the antenna's power is directed toward the intended direction compared to the amount of power that is radiated in the opposite direction. Specifically, it is a comparison of the gain of the antenna in the direction of the desired signal (the front lobe) to the gain in the opposite direction (the back lobe). A higher front-to-back ratio indicates that more power is concentrated in the forward direction, making the antenna more effective at rejecting signals coming from the rear. This characteristic is particularly important for antennas used in communications, as it can help reduce interference and improve overall signal clarity.

Understanding the front-to-back ratio is crucial for selecting an antenna based on its operational needs, especially in situations where minimizing noise from behind the antenna is desired. The other options describe different aspects of antennas, such as total power levels, efficiency, and gain, but they do not specifically define what the front-to-back ratio represents.