Control of microstrip antenna far field phase with its parameters in phased array applications

In this thesis, a novel technique for generating required inter-element phase shifts in microstrip phased arrays antennas without the use of phase shifter is introduced. It is based on reconfigurable patches and MEMS technology where the array takes advantage of the antenna elements' inherent phase shift obtained due to the frequency shift and slightly different element sizes.; This theory is examined on circular single and staked microstrip antennas. Various analytical solutions such as transmission line and cavity model analysis are considered to determine the phase shift. Then, the numerical analysis is utilized to confirm the results. The variation of single antenna cavity dimension (i.e. patch radius, height, and probe location) leads to achieve about 70 degrees phase shift. For stacked antennas, one parameter (i.e. lower patch radius, upper patch radius, substrate thickness, separation between the patches, and probe location) is not sufficient and both upper and lower patch parameters are required to shift the frequency from one patch to the other, leading up to 180 degrees phase shift.; After observing single and stacked microstrip antennas phase properties, a linear-four element array configuration is utilized and the antennas behaviour in phased arrays are discussed. It is deduced that the proposed method leads to a scan angle of 14 degrees which can be increased by the use of a single digit phase shifter.