The Design And Optimization About Emergency Communication On Terminl Antenna

The emergency navigation and telecommunication (ENT) terminal system is a kind of first-aid hand-held terminal system used in location, navigation and communications of emergency. It is developed on the basis of the EPIRB which is used in such activities as personal adventure, scientific exploration and so on. This system has two kinds of working modes: one works in 406MHz frequency which carries on relaying through the global miniature search and rescue system (COSPAS- SARSAT); the other one works in 1.6GHz frequency which carries on relaying through the MARSAT marine satellite. In order to satisfy the miniaturization and hand-hold practical application characteristics of this system, the antennas in this terminal system should have some requirements such as light weight and small volume and so on. Therefore, this paper discussed the miniaturized technology of the antenna design and the optimization of the antenna structure parameters united CST and based on the neural network and the genetic algorithm in this terminal system.Firstly, based on the elementary theory of the miniaturized antenna, two kinds of 406MHz antennas (ring antenna and the normal mode helix antenna) are designed, which achieve the antenna technical standards such as the nominal gain, standing-wave ratio, the axial ratio and so on, and realizes the polarization and miniaturization of the antenna. By comparison of the performance analysis between the two kinds of antennas, the antenna design is chosen which is more suitable for the emergency navigation and telecommunication terminal system.Secondly, based on the miniaturization technology of the micro-strip antennas, two kinds of 1.6GHz antennas are designed: the one is a kind of micro-strip antenna loaded with small groove gap and adopting the special structure; the other is a kind of 1.6GHz/2.4GHz dual-frequency miniaturization micro-strip antenna which is designed adopting the special materials and based on the composite right/left-handed transmission line (CRLH) theory. The simulation results show that the two kinds of antennas meet the basic requirements of international standard, and has such advantages as the small structure size, the low section plane, the convenience production, ease of integration and so on. Moreover the latter kind contains the 2.4GHz working frequency, which can carry out the close data and voice communications and provide a new idea for the antenna design of the new emergency navigation and telecommunication terminal system.Finally, the optimized module is designed united CST and based on the neural network and the genetic algorithm, which carries on the structural parameters optimization, the center frequency and the bandwidth characteristic, for the two kinds of 1.6GHz micro-strip antennas to get the more suitable design of meeting the national standard. At first, some structural parameters are listed in the experiment design table using partial orthogonal experiment, and are calculated with CST to output the results. Then establish the NN modal using the former results to map the relation between the structure and the performance. Finally, based on the genetic algorithm optimizes the optimization of the final selected parameters are carried on to get the best parameters. In this paper, the actual attempt to optimize the module provides the accumulation and matting for the future research.