Microstrip Antenna Elements And Dual-Polarized Arrays For Active Integration

In this dissertation, both theoretical and experimental studies on several microstrip antenna elements and dual-polarized antenna arrays suitable for active integration are presented. The research work includes the full-wave analysis and parametric study on the aperture-coupled rectangular patch antenna, the aperture-coupled gridded patch antenna and the microstrip slot antenna with arbitrarily inclined slot; the analysis and design of several dual-polarized microstrip antenna arrays with high isolations, and the microstrip array for polarization-agile applications, etc.At first, using the spectral-domain integral equation method, the aperture-coupled rectangular patch antenna, the aperture-coupled gridded patch antenna and the microstrip slot antenna with inclined slot are numerically analyzed respectively. The integral equations for these antennas are founded, and the numerical results illustrate the effects of various parameters on the input impedances and the resonant frequencies of these antennas. Many conclusions are drawn, which are useful for practical design applications.Next, two kinds of 2 x 2 dual-polarized microstrip antenna arrays are successfully designed. Two novel ways of realizing dual-polarized antennas are proposed, i.e.,the square patch with dual serial-corner feeding and that with dual parallel-corner feeding. New coplanar feedline networks for the dual-polarized arrays are also proposed. By combining the multiport network model, the cavity model, the segmentation and desegmentation techniques, a theoretical method,named as EMNM (the extended multiport network method), is developed, which is used for the analysis and design of dual-polarized arrays. Two kinds of 2 x 2 dual-polarized microstrip arrays are fabricated and measured. The measured results of both arrays demonstrate high isolation between two input ports, as predicted by the theory.Then, this method of design is applied to larger dual-polarized microstrip antenna arrays with high isolation. Two 16-element dual-polarized microstrip antenna arrays are designed, manufactured and measured, showing high isolation and low cross-polarization. Both theoretical and experimental results are presented.Finally, a 16-element microstrip antenna array is developed, which is for realizing the polarization-agile array controlled by one phase-switching circuit. A configuration is proposed for the 16-element dual-polarized microstrip antenna array, which can be used to realize polarization agility after being integrated with the phase-switching circuit. Based on the EMNM, the array is analyzed and designed. The measured results of the 4 x 4 dual-polarized array at 6.0GHz validate the theory. This array is demonstrated to achieve high isolation between two input ports.