Investigation on multi-band fractal antennas for satellite applications

Abstract

Remote sensing is a very important application of satellite communication. In remote sensing applications, multiple frequencies are utilized. Use of different antennas for different frequencies is a complex task and so use of single multiband antenna is desirable. Fractal geometries can be utilized to design single multiband antenna operating at various required frequencies which may be widely separated and non-harmonically related. In this thesis fractal geometry concept has been utilized to achieve multiband and compact design. Here multifractal cantor geometry is used due to its simple construction and ease in tuning. In addition to multiband behavior, the antenna must provide sufficient bandwidth. Unfortunately the microstrip antennas are having very narrow bandwidth. There are other techniques to increase bandwidth such as aperture coupled structure or electromagnetically coupled structure. But these solutions result in the complex multilayer structure. To prevent this complexity and to increase bandwidth, monopole structure has been utilized. Usually for satellite communication 28 dB to 32 dB gain is required. To fulfill this requirement, an array using multiband element is also designed.