Design of Planar Microstrip Antenna Arrays and Mutual Coupling Effects

In patch antennas, characteristics such as high gain, beam scanning, or steering capability are possible only when discrete patch elements are combined to form arrays. The elements of an array may be spatially distributed to form a linear, planar, or volume array. Planar arrays have elements distributed on a plane. Planar array configurations are extensively used in both communication and radar systems where a narrow pencil beam is required [51]. Individual elements can be positioned along a rectangular grid to form a planar array for better control of beam shape and position in space. Planar arrays of printed radiating elements are potentially good candidates for low cost scanning array applications [52]. Microstrip patch arrays are versatile as they can be used to synthesize a required pattern that cannot be achieved with a single element. In addition, they are used to increase the directivity and perform various other functions, which would be difficult with any one single element [53].