Miniaturized antenna design & Radiation pattern corrections in Fresnel region

In this thesis, two research problems have been addressed. Electronic devices require an ever increasing reduction of size and hence the important communication component i.e., the antenna needs to be miniaturized as well to cope up with other technologies. Addressing this problem, in first part of the thesis, a miniaturized antenna was designed and fabricated after analysis for its proper positioning on the PCB. Also, an analysis was done to see the effect on the resonance of the radiating element due to the proximity of other components present on the same PCB. In in this part of the thesis, the analysis and the optimization for size and positioning, of a miniaturized antenna, along with the effects of the proximity to other components has been performed, and a compact antenna has been designed, realized and tested. The measured results were found to be in good agreement with the simulated ones. The second part of the thesis consists of the analysis of the radiation pattern of microwave antennas. The test ranges for Far Field radiation pattern need a certain separation distance between antenna under test and the test probe; this separation requirement increases with frequency and if this separation requirement is not met then some corrections need to be performed on the measured radiation pattern, in particular for the error induced in side lobe level. When far field test site minimum distance requirements between antenna under test and, test probe are not fulfilled. This problem was analyzed for microwave aperture antennas. The side lobe level error due to this problem and its correction has been discussed. On the basis of above analysis Far Field side lobe level corrections factors were obtained in the form of graphs and a closed form formula was suggested on the basis of analysis performed.