Design Of Miniature Printed UWB Antenna And Research On Its Property Of Slot Loaded

As newly wireless communication technology, UWB(ultra Wide Band) has recently attracted much attention, short distance about 10meters high speed date communication is its mainly application. UWB communication not only requires antennas be of good property in the domain of frequency and time, but also requires small size, simple structure, light weight and low cost antennas. The printed monopole antennas not only have these above merits but also have the properties of wideband, low profile, and easily connecting to feeding network. Therefore, printed monopole antennas satisfy the miniature and broadband requirement of UWB communication terminal, so it attracts more and more attention. In order to get smaller size antennas, further enlarge the bandwidth and realize band-notched at special band, this thesis conducts many works on the analysis of the existing references about printed monopole antennas. Two new kinds of printed monopole antennas are proposed, fabricated, and measured. The measured results are in well agreement with the simulated results. The creative works and research results are:1. Improve the printed monopole antenna feeding by CPW(co-planar waveguide). The bandwidth is effectly expanded and the size of antenna is obviously reduced via adopting partial ground, tapered feeding, beveled in the ground plane, cut rectangles at upper end of patch, and so on. Otherwise, the characteristic of band-notched at WLAN band (5-6GHz) is obtained by introducing different kinds of resonant slot. The performances of the antennas without slot loaded and with different kinds of slot loaded are analyzed by using 3D EM emulator in the domain of frequency and time domain.2. Due to WLAN 802.11b/g(2.4-2.5GHz) and UWB (ultra-wideband) is becoming increasing background compatible, a dual-band monopole printed antenna, which supports both for WLAN and UWB applications is proposed. In order to match the FCC spectrum mask, different kinds of resonant slot loading is been introduced, and realized its band-notched at 2.6-3.1 GHz. The performances of the antennas with different kinds of slot loading are analyzed by using 3D EM emulator in the domain of frequency and time domain.3. The influences of antenna on the design of pulse waveform in UWB system are analyzed. The studies have found that the radiation pulse will be broadened after passing through the UWB antenna, and the spectrum will shift entirely to the lower frequency band. Therefore, it is intensity required that unite the pulse design with antenna, so that the spectrum of radiation pulse which radiation by antenna will meet the requirement of FCC mask.The proposed antennas are fabricated and measured. The theoretical broadband characteristics and notch-filter property are evidenced by the experimental results. The results also show via adopting partial ground, tapered feeding, beveled in the ground plane, cut rectangles at upper end of patch and other technologies can effectly expanded the bandwidth and reduced the size of antenna. Otherwise, by introducing different kinds of slot loading can realize the band-notched characteristic of designed antennas.