| Ultra-wideband technology has great perspective in the application of the civil, military and microwave weapons, and the antenna which is as an important part of this system has functions of receiving and radiating radio wave. The antenna applied in the impulse signal radio is different from the traditional broad band antenna and narrow band antenna in signal transmitting process. The fidelity and effect of antenna's radiate impulse signal directly influence the performance of the system.This thesis focuses on the designing of pulse antenna elements and array antenna. The characteristics of frequency domain and time domain are discussed. Some useful conclusions would derived by changing the distances between the neighbors. The contents of this paper are as follows:The first chapter of this paper introduces ultra-wide band antenna technology in the aspects of the background, significance and progress at home and abroad. Several types of UWB antennas are summarized and their time-domain characteristics are analyzed. The antenna applied for pulse radiation is deduced by characteristics of the time domain. This article highlights the development of the bowtie antenna the Vivaldi antenna. Finally, key UWB technologies and development trends of time-domain antenna are discussed.The second chapter introduces several parameters of the time-domain antenna. From the time domain and frequency domain characteristics of UWB pulse antenna, it can be concluded that pulse antenna must be of wideband character. This chapter also analyzes the radiation and transmission principles of pulse antenna, and discussed the causes that lead to its waveform distortion and ringing phenomenon. Finally, comparison between narrow-band radar equation and ultra-wideband radar equation were demonstrated.Elliptical bowtie antenna is designed according to requirement of "XXX" project, and the radiation pulse is introduced to explain the importance of reducing the lower operating frequency. The radiation characters of two same signals with different pulse-widths are compared. According to design requirements, the antenna with size less than 70mm shall be able to operate at frequency from 1.32 to 7.81 GHz, and the antenna with metal ring can reduce the frequency at the lower end. Since the input impedance of SMA is 50Ω, and input impedance of Antenna is 100Ω, a balun with size of 8mm×17mm was designed for impedance matching. Finally, its characteristics of frequency domain and time domain are analyzed. According to the derived peak pulse radiation pattern, the antenna has excellent radiation characteristics. The antenna is manufactured and tested by vector analyzer E5071C. The simulation results and measurement results agree well with each other.In the fourth chapter, Vivaldi antenna used for high-power radiation is designed. Its time domain and frequency domain characteristics of meets the design needs while the lower operating frequency of the antenna is 0.32GHz. The peak pattern indicates the antenna has good directional radiation character. The antenna array is designed based on the design of Vivaldi antenna. Far field of the Array are synthesized and the pulse is 1.7ns. By changing the distance between antenna elements, it can conclude that the effects by changing distances at different directions are different. Finally, the beam scanning simulation is employed on array antenna and the simulation results and theoretical calculations are consistent.The work and innovation of the article are summarized in Chapter V and presented my views on further development of UWB technology. |
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