Part 1 of the series covered beam direction and working with a uniformly spaced linear array of antennas. In part 2, we’ll cover antenna gain, directivity, and aperture, as well as array factors.
Antenna Gain, Directivity, and Aperture
Before we go too far, it’s helpful to define antenna gain, directivity, and aperture. Let’s start with a clarification on gain vs. directivity, as the two are often interchanged. Antenna gain and directivity are in comparison to an isotropic antenna, which is an ideal antenna that radiates evenly in all directions. Directivity compares the maximum power measured, Pmax, in a specific direction to the average power radiated across all directions.