The dimensions of antennas used for RF transmission are directly related to which factor?

The dimensions of antennas used for RF transmission are primarily determined by the carrier frequency. This is because the wavelength associated with the carrier frequency plays a critical role in the physical size and design of the antenna.

Antennas are typically designed to be a specific fraction of the wavelength of the frequency they are intended to transmit or receive. For example, a common design principle is to make antennas about one-half or one-quarter of the wavelength. As the carrier frequency increases, the wavelength decreases, leading to a smaller antenna size; conversely, lower frequencies produce longer wavelengths which require larger antennas.

While output power, signal modulation, and environmental conditions can influence antenna performance and design choices, they do not directly dictate the physical dimensions of the antenna in the same way that carrier frequency does. Hence, the correlation between antenna size and carrier frequency is fundamental to understanding RF transmission.