| This paper studies circularly-polarized focused microstrip antenna array. In order to focus the energy of the antenna array to a target point, a circularly-polarized testing antenna is introduced and placed at the target point as the receiving antenna. The distribution of excitations for the antenna array can be obtained by maximizing the power transmission efficiency between the antenna array and the testing antenna. In order to make the focusing and circularly-polarized performance better, the parameters of the antenna element can be optimized based on the proposed optimization technique. The design, simulation, manufacturing and testing of several focused arrays are investigated.The main research includes:1. Two 4×4 microstrip focused antenna arrays with different feeding way have been designed and have realized a low side lobe field pattern in the Fresnel region and circularly-polarized performance.2. In order to improve the focusing and the circularly-polarized performances of the antenna array, this paper proposes a new ring topology to design the circularly-polarized antenna array. In order to design circularly-polarized antenna, this paper proposes both linear-polarized and circularly-polarized antenna as antenna elements. The new design can enhance the focusing effect and circularly-polarized performance at the same time. Both simulated and measured results are presented to demonstrate the focusing and the circularly-polarized performances.A summary is given at the end of this thesis. Future research topics are also discussed. |
