 Hi, I'm Mr. T with R-Valence. Antennas are all around us these days, but what's an antenna array? Before we answer this question, if you enjoy our videos, consider subscribing to our channel, or let us know in the comments what topics you'd like to learn about. In cases when the radiation pattern of a single antenna is too wide, or if its gain is too low, antenna arrays come handy. Antenna array is typically a setup of two or more identical antennas working as one by being fed the same signal simultaneously. Forming an antenna array has two main effects. Compared to a single antenna by itself, an array has radiation pattern with one main lobe and the side lobes and higher resulting gain of the main lobe. This gives antenna engineers the freedom to tweak the gain and the radiation pattern as needed. How does it work? This is how the electromagnetic fields of a single patch antenna look like. Looking at the fields of an array of two patch antennas, there's a clear difference. They are directions where the fields are strong and in other directions they are weak. This is caused by the wave interference. The maxima come from constructive interference when the waves from both patches have the same phase, adding together resulting in a stronger wave. The minima come from the destructive interference, where the waves have an opposite phase, cancelling each other out. The maxima and minima correspond to the lobes and nulls in the far field radiation pattern. The more antennas in an array, the higher the resulting gain of the main lobe. At the same time, the beam width of the main lobe is decreasing. The weaker beams in different directions than the main lobe are called side lobes and are generally undesired and shrink with the growing size of the array. This principle is universal, regardless of what is the basic radiating element. Using patch antenna, parabolic dish or a horn antenna will result in a radiation pattern with similar main features, the main beam and the side lobes. The spacing between the array elements determines the beam width of the main lobe. The further apart they are, the larger the physical size of the array effectively decreasing the beam width. Also the angles and the size of the side lobes change with the element spacing because the fields add up differently for different antenna spacing. Patch arrays can be linear, resulting in a changing radiation pattern along the array axis, surface resulting in changing radiation pattern along both axes or conformal to fit various surfaces of devices or larger systems. Most common example of an antenna array is a patch array antenna where a number of patches is etched on a printed circuit board and fed through a symmetrical feeding network. Patch arrays are used in many applications such as cellular network coverage, radars or airplanes, due to the flexibility and affordability of the technology. If you find our videos useful, consider subscribing to our channel. Give it thumbs up or leave a comment.