Design of High Directive Planar Antenna using Schelkunoff Polynomial

Abstract

The words broadcasting, unicasting and multicasting are the well familiar terms in the field of communications and are very important in describing various parameters in designing the system. In the field of communications, the applications which involve broadcasting needs an antenna of high directivity and should use the power effectively (low side lobes). Where in applications that needs unicast-reception mainly needs high directivity (Zone of reception) and low interference (low side lobes) antennas. There are some special applications like tracking radars, surveillance antennas demand patterns with special characteristics (Beam widths). Due to the non complexity in implementation and ability to produce symmetrical-high directive beams, generally planar array antennas are used in above mentioned applications. Planar antennas, with compromise in increased number of elements and size, produces high directive beams. Other way of generating desired beam pattern is by synthesizing the antenna radiation pattern. Schelkunoff polynomial synthesis method is one being used in linear array design for suppressing radiation in undesired directions, there by increases the directivity. In order to produce the desired beam with high directivity this paper proposes a planar array design method and also extends the schelkunoff polynomial method (confined as linear array synthesismethod) to planar array design to produce cost effective high directive antennas. The radiation pattern characteristics Directivity, 3dB beam width, Null-Null beam width and side lobe levels are used to analyse the performance of proposed design and algorithm.