A patch antenna is a type of antenna that consists of a flat rectangular or circular metal patch mounted on a dielectric substrate. It is commonly used in wireless communication systems due to its low profile and lightweight design. Patch antennas are typically easy to manufacture and can be integrated into various devices, making them popular in applications like mobile phones and GPS systems. These antennas operate by radiating electromagnetic waves when an alternating current is applied. They are known for their directional radiation patterns, which means they can focus energy in specific directions, enhancing signal strength and reducing interference. Patch antennas are often used in arrays to improve performance and gain.