Cylindrical Conformal Microstrip Antenna Array

With the rapid development of modern wireless communication technology, the communication system has higher requirements for the antenna. In various antennas, microstrip antenna has many favorable properties, such as low profile, small volume, light weight, and so forth. The microstrip antenna is also easily conformal to other object and integrated with the feed network. Therefore, the mcirostrip antenna becomes increasingly popular. However, it is difficult for the traditional microstrip antenna to realize miniaturization, circular polarization and narrow beam. To solve these problems, we focus on the research of miniaturized and circularly polarized microstrip antenna, and its arrays. The main contents are as follows:1. We first introduce the basic theory of microstrip antenna including the principle of radiation and the technology of antenna array technology. Then, we elaborate the technology on realizing the miniaturization and circular polarized microstrip antenna, which provides basic theory for the following chapters.2. We designed a microstrip antenna array with three elements, which works in s-band. Each element is fed by a cross coupling aperture which makes the antenna have good circular polarization radiation properties. To realize the miniaturization of antenna, slots with gradient depth are symmetrically decorated on each side of patch. On the other hand, we design a slot on ground plate between two adjacent patches to decrease the destructive electromagnetic mutual coupling. A simple multistage T-shape feed network is used to feed the electromagnetic energies.With the help of commercial software(CST), we simulate the S11 parameters and the radiation properties of the designed antenna. At the same time, we test the properties of the antenna. The simulated and tested results show that the S11 parameters are less than-10 d B in the frequency range from 2.3GHz to 2.5GHz. Furthermore, the antenna has good radiation performance, such as high gain(13.58 d B), narrow beam angle(29.14°). The axial ration bandwidth of circular polarization is 70MHz(2.35GHz-2.42GHz)3. We also design a Cylindrical conformal microstrip array based on the proposed microstrip antenna. As an example, we analyze the radiation of the conformal antenna on the surface of a cylindrical. By optimizing the performance of the antenna, we obtain the optimal element spacing and the number of array element. The simulation results demonstrate the good performance of the conformal antenna.