| Ultra-wide band (UWB) technology based on transmitting short pulse is one of the research focuses in resent years. This technology has special advantage in the application of radar and communication, such as improving the resolvation of the radar system, and improving the rate of data transmitting in short distance communication. As a crucial component of UWB application systems, UWB pulse antenna need to be greatly improved to radiate GHz UWB signals. Antennas performance has significantly impact on the performance of application system, therefore, it is of great significance to research UWB technology.Firstly, this paper expatiates the concept of ultra-wide band technology, and introduces the resent application of UWB in the area of radar, communication, and biology medicine engineering; and particularly, the paper summarizes the recent development of the UWB pulse antennas with the conclusion that the pulse antenna characteristic is almost analyzed in the time domain, and the loaded antenna technology is a method of improving the performance of antennas, high efficiency and small size is one of the research focuses on high power UWB antenna, the communication application of short distance and high rate of data communication is one of the research focuses on the UWB planar antenna.Secondly, this paper discusses the technology of broadband antenna, introduces the broadband vibrator antenna, the traveling wave antenna, and the active receiveing antenna. Moreover, this paper discusses the transient characteristic of pulse antenna and the particularity to reseaching it .Thirdly, the paper introduces the Method of Moment which is based on RWG base function, The RWG base function is corresponding with the planar triangular pairs in antenna surface. Each triangles pair is equivalent with a short dipole. In part 4 and part 5, the pulse radiation characteristic and the parameter in bandwidth of the planar Equiangular Spiral antennas, conical spiral antenna, and V-shaped bow-tie antenna are researched by the Method of Moment and the Matlab procedure. The research found that the antenna parameter of spiral antennas is stable in a wide bandwidth , which proved that the antennas is a kind of frequency-independent antennas, therefore the planar spiral antennas is more suitable to be used in radiating pulse than the conical spiral antennas. For the V-shaped bow-tie antennas, the big arm angle antenna is more suited to radiating lower frequency when the antenna arm length is equal and the parameter of planar bow-tie antennas is more stable in the wide band.The pulse radiation characteristic of Wu-King loaded antenna is studied by the Method of Moment. The research found that when the antenna is loaded by the Wu-King theory value, the radiation is very weak and have no practicality. When the antennas is loaded by smaller resistance under the rule of Wu-King, the radiation is stronger and the pulse distortion is also little. So it is useful in practice.Finally, the author designs a volcano smoke planar ultra-wide band antenna, in which co-planar waveguide voltage feed is employed. And the substructure is 0.8mm thick. The HFSS data analysis and the experiment examination show that there is 0.8GHz--9GHz wide band with the structure size of 75mm×75mm. The lower cut-off frequency of the antenna can be lowered down to 0.5GHz in order to radiate pulse signal more effectively, decrease lower cut-off frequency radiation of pulse signal, and to form combining electric-magnetic vibrator antenna by increase resistance loop circuits to the antenna. The wide-band lower cut-off frequency of the antenna can be decreased to 0.5GHz. The other UWB antenna under-investigated is funnel antenna in which there is 1.1GHz—9GHz wide-band when it is 50mm×50mm in size. And the lower cut-off frequency side can decrease to 0.8GHz after loaded. |
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