Analysis And Design Of Miniature Ultra-Wideband Antenna

With the development of the indoor high-speed wireless communication technology, ultra-wideband (UWB) short-range wireless communications has aroused great concern in the field of wireless communications. As an important part of UWB communication systems, UWB antenna has been a research focus in recent years. According to the present study on UWB antenna, in addition to meet the system technical requirements, the antennas need to achieve miniaturization and low cost. A band-notch UWB antenna is required to avoid the interference from WLAN (5.15 GHz - 5.825 GHz) and WiMax (3.3 GHz - 3.6 GHz). The research work presented in this paper focuses on the miniaturized UWB antenna used in UWB wireless communication systems. Several microstrip line-fed and coplanar waveguide-fed UWB monopole antennas were studied. The slotted notch performance and notch functionality of the band-notch UWB antenna were discussed. The primary work is concluded as follows:Firstly, with reading and studying mass of references, this paper sums up development of traditional UWB antenna, study hotspot and its applications. The basic theory of microstrip antennas and the UWB antenna technical performance requirements were comprehensive discussion. Based on traditional a microstrip line-fed circular patch UWB Coplanar Monopole Antenna was proposed and fabricated, The measured results shown good agreements with the simulated results which prove the feasibility of this antenna structure and practicability of the proposed methods.Secondly, in order to further reduce the antenna size, a cup-shaped patch microstrip line-fed UWB antenna was proposed, the antenna has a compact structure. This paper study and research the impact of the reflection coefficient caused by the changes of patch parameters and structural parameters of the floor step. After processing test, the -10 dB bandwidth of the antenna is: 3.1 GHz - 12 GHz. In order to facilitate systems integration, two kinds of CPW-fed UWB antenna were proposed and the sensitivity parameters had been analyzed. The small ladder structure of coplanar waveguide UWB antenna with a working frequency of 3.1 GHz - 14 GHz was obtained And in the H surface it had a good omni-directional pattern. Finally, based on the coplanar waveguide antenna several band-notch UWB antennas was proposed. U-shaped and L-shaped slots were opened on the antenna patch and the simulation distribution of current show the principle of notch function. Through the gap parameters analysis we obtained that the notched frequency band was controlled by the slot length. The width and location of the slots affect the width of notched band. The new structure antenna proposed to achieve the function of band-notched to one or two frequency bands, and it has a practical value.