A panel antenna, also known as a flat panel antenna, is a type of directional antenna commonly used for wireless communication applications. It consists of a flat, rectangular or square panel that contains multiple elements, such as dipoles or patches, arranged in an array.

Panel antennas are designed to radiate or receive electromagnetic waves in specific direction, providing focused in that direction. They have a narrow beamwidth, which allows for greater gain and better signal strength in the desired direction while reducing interference from other directions.

Panel antennas are often used in point-to-point or point-to-multipoint wireless communication systems, as in Wi-Fi networks, cellular base stations, and wireless backhaul links. They can be mounted on walls, rooftops, or poles and are typically used for medium to long-range communication over distances ranging from a few hundred meters to several kilometers.

The advantages of panel antennas include their directional coverage, high gain, compact size, and ease of installation. They can be easily aimed in a specific direction to optimize the signal strength and minimize interference. However, it's worth noting that panel antennas have a limited coverage area, and their performance can be affected by obstacles such as buildings or trees blocking the line of sight.

Overall, panel antennas are a popular choice for wireless communication systems that require focused coverage in specific directions, offering reliable and efficient signal transmission.