High speed LVDS digital input/output interface circuitries for high resolution imaging sensors /

Soyer, Suhip Tuncer
In communication systems like WiMAX, WLAN, 3G, 4G and LTE, design of wideband and dual polarized antennas are required. It is known that bandwidth of patch antennas can be broaden by using thick air substrates. The bandwidth can be further improved by using three dimensional feed strucutures that are electromagnetically coupled to the patch. In this thesis, microstrip patch antennas that are excited by elevated wide strips are studied. First, a linearly polarized antenna is considered and the effects of antenna and feed parameters on the input impedance characteristics are investigated through EM simulations. Then a dual polarized antenna is considered and the effects of antenna parameters on the radiation performance (i.e. isolation) is explored. In the light of these observations, guidelines for the design of dual polarized wideband patch antennas excited with elevated wide strips is presented. To demonstrate the usage of these guidelines an antenna, which operates in a different frequency band, is designed by following the steps of the proposed design procedure. Finally, the input impedance and radiation pattern measurements of a two element antenna array that was previously designed as a base station antenna are performed. Simulation and measurement results are compared and discussed. The EM simulations are performed by a Finite Element based full-wave analysis software HFSS by Ansys.