| As the rapid development of ultra-wideband communication, the wide band and ultra-wideband antenna technology have entered a new development stage. Conventional three-dimensional UWB antennas are already beyond the need. Therefore, planar, small sized and easy integrated UWB antennas have become the focus of the design. Faced with this change, breaking through in the theory and key technology has become a hot and focal point in UWB antenna research.This thesis commits itself to the research of the high performance UWB slot antennas. On the basis of plentiful theoretical analysis and experimental research, several variants novel UWB slot antennas with high performance were designed which include tapered slot antenna with new slot profile, radiation performance optimized tapered slot antenna, compact UWB open slot antenna, band-notched UWB open slot antenna and multiband UWB slot antenna. The innovative achievements are follows:1. The theory of tapered slot antenna is studied and the novel tapered slot antenna with Klopfenstein tapered slot profile is present. Experiments show that this tapered slot antenna can effectively meet UWB impedance matching. On the basis of this antenna, a corrugated edge of the antenna is designed to increasing radiate performance. The new tapered slot antenna with corrugated edge reduce the side-lobe level by about lOdB and hold gain steady at 9.3dBi-13.4dBi, furthermore, the 3dB beam-width of E-plane are kept in about 300 on a wide bandwidth. Therefore, the tapered slot antenna has good radiate performance and satisfies the detection and measurement applications.2. The theory and design of the compact UWB open slot antenna with steeped feeding strip are present. The largest electrical length of this antenna is 0.26?0, which is the smallest UWB slot antenna reported. The steeped feeding strip can match the several resonance points in the band and makes the measured bandwidth extend to 2.9-12GHz. Measured results show that the radiation patterns are nearly omnidirectional; the gain and the time domain characteristics are relative stable.3. According to the quarter guide wavelength resonance characteristic, the theory and design method of the band-botched UWB open slot antenna are presented. The designed antenna can suppress the interference with the existing wireless local area network (WLAN) for IEEE 802.11a operating in 5.15-5.825GHz bands. Based on the same principle, a dual band notched UWB antenna is also presented.4. The multiband technology which can add mobile communication band on UWB antenna is presented on the premise of no increase in the antenna size, furthermore, a multiband UWB antenna with 1.87GHz-2.17GHz and 3.1GHz-15GHz is designed. The design approach which is add a resonance stub is obtained by analysis of the electric field and surface current distribution on the antenna. The measured results establish that the additional stub has no effect on the frequency and time domain performance on the UWB band of the antenna. Therefore, the multiband UWB antenna proposed is a type of antenna which can fill the requirements of both UWB and mobile communication applications. |
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