An antenna, when individually can radiate an amount of energy, in a particular direction, resulting in better transmission, how it would be if few more elements are added it, to produce more efficient output. It is exactly this idea, which led to the invention of Antenna arrays.
An antenna array can be better understood by observing the following images. Observe how the antenna arrays are connected.
An antenna array is a radiating system, which consists of individual radiators and elements. Each of this radiator, while functioning has its own induction field. The elements are placed so closely that each one lies in the neighbouring one’s induction field. Therefore, the radiation pattern produced by them, would be the vector sum of the individual ones. The following image shows another example of an antenna array.
The spacing between the elements and the length of the elements according to the wavelength are also to be kept in mind while designing these antennas.
The antennas radiate individually and while in array, the radiation of all the elements sum up, to form the radiation beam, which has high gain, high directivity and better performance, with minimum losses.
The following are the advantages of using antenna arrays −
The following are the disadvantages of array antennas −
The following are the applications of array antennas −
The basic types of arrays are −
We will discuss these arrays in the coming chapters.