Research Of Miniature And Broadband Loading Antenna

With the development of communication technology, the miniature and broadband of electrical devices become more significant than ever, and the original narrowband antennas could not meet the requirement of the modern communication technology, such as multi-frequency, jump-frequency, the broadband and miniature devices. The broadband and miniature antennas which have the characteristics with large communication capacity and good anti-interference capability not only make full use of limited space, but also could not cause considerable influence the quality of communication. Monopole antennas have been widely used in many applications due to their instrinsic advantage like simple structure, and omnidirectional radiation pattern. However based on the performance guarantee of the antennas, further reducing the size and improving the bandwidth of the antennas are the research hotspot in recent years.This paper summarizes the development of the broadband and miniaturization of antennas, and explores the realization of broadband and miniaturization and the crucial technology of the antennas. At last the paper obtains some important conclusions about increasing broadband of antennas, like increasing the width of vibrators, using the structure of cone or sleeve, feeding the antennas asymmetrically. Using the fractal structure could effectively lower the resonance frequency of the antennas. According to some of wire antennas can use the loading method cooperating the proper matching network for realizing the performance of ultra-wideband and miniaturization. These conclusions for broadband and miniaturization which is studied in this paper provides important theory and basis.This paper introduces a broadband matching network for Real Frequency Method of designing and optimizing it which only needs some measured impedance of antennas in discrete frequency in detail. It has more applications in engineering, simpler theory and does not ignore the optimization results. It is the ideal method of designing broadband matching network.This paper presents a new optimization method about wire antennas load and matching network on the basis of previous work, which uses the FEKO script commands for antennas modeling and computing input impedance, gain, efficiency, and then applies ADS invoking the input impedance files, that is real frequency impedance, in order to compute the matching network. The Genetic Algorithm programmed by MATLAB calls the two software for the purpose of realizing electromagnetic field and circuit integration automatically simulating and optimizing. According to that method, the paper improving the stability performance of two monopole antennas which work at 50-1000MHz and 100-2000MHz, and then manufacture the two antennas for testing and verifying the optimized results in order to prove the above-mentioned method valid. And more, this paper designs an omnidirectional radiation and broadband folded monopole shortwave antenna, and consequentially analyses the lumped components error performance of the shortwave antenna, using CST for verifying the results. This method is simple, reliable, but it has certain significance on load antennas and matching network integrated design and optimization.