Evolution of Antenna Technology: Arrays, linear, planar, and circular.

Arrays are the most versatile antenna configurations whose geometrical arrangement and number of elements, including spacing, amplitude and phase excitation between the elements, can be used to control the overall radiation characteristics, including directivity, beamwidth and side lobe level. While arraying dates back to near 1900, modern antenna designs and advancements, including some classic designs, were initiated in the 1920s. Few of these designs, including some of their radiation characteristics, will be highlighted in this paper; others are discussed and found in the references.