| With the rapid development of ultra-wideband (UWB) technology, UWB antenna has attracted more and more attention in the industry. UWB antenna not only has a wide operating bandwidth, the stability of the radiation characteristics and high radiation efficiency, but also has a smaller size compared with traditional narrowband antenna. However, althouch a large number of UWB antenna could satisfy the UWB communication requirements, because most of them are not easy integrated, they should not be used for a portable device in ultra-wideband; Meanwhile, the UWB communications band exists other narrowband wireless communication band, such as WiMAX (3.3-3.7GHz), wireless local area network WLAN (5.15-5.825GHz), etc., during communication, UWB signal transmission power is low, the wireless signal of these narrowband systems are susceptible to interference. In response to these problems, this paper on the basis of a detailed analysis of UWB antenna miniaturization technology and notch technology, design miniaturization of ultra-wideband antenna and notch ultra-wideband antenna. Main contents are:First of all, in conclusion, on the basis of a variety of commonly used in antenna miniaturization technology, we designed two miniaturized ultra-wideband microstrip antenna: H-shaped radiation patch ultra-wideband microstrip antenna and ultra-wideband microstrip defected ground structure antenna. H-shaped ultra-wideband microstrip patch antenna radiation improves through the traditional rectangular radiating patch, and combines with ladder-type ground plane structure to improve the antenna sideband effect; ultra-wideband microstrip antenna with defected ground etches L-shaped ground connection surface on the basis of the polygon radiation patches.On the one hand,this method can guarantee the good characteristics of the antenna within the operating band,on the other hand, the size of the antenna is reduced, the size of the antenna is only28mm×18mm×1mm, while the radiation characteristics of the antenna in the E and H-plane are close to the omni-directional radiation. Secondly, in order to suppress the interference for the radio signal of the UWB systems from the narrowband system which coexists in ultra-wideband systems, the commonly used method is introduced notch in the frequency band of the antenna interference, this article uses two common notch methods:Loading parasitic unit and slotted then designed two notch UWB Antenna:single-band notch ultra-wideband antenna and ultra-wideband antenna with dual-band notch, the simulation results demonstrate they effectively suppress WiMAX and WLAN signal interference.Finally, the article is summarized and prospected,at the same time pointed out the direction of efforts in the future. With electronics’ integration and miniaturization, the miniaturization of the antenna volume requirements are also increasing. Therefore, the ultra-wideband antenna miniaturization technology is a direction of future efforts by seeking more ways to solve this problem, in order to meet the rapid development of electronic equipment. UWB wireless communications bands within the narrow band, except WLAN, also include satellite communications band (3.7-4.2GHz), WiMAX frequency band (3.3-3.7GHz) and ITu (8.025-8.4GHz), etc.. Therefore, the design of miniaturized ultra-wideband antenna having a plurality of band-stop frequency bands needs to focus on research; Finally, ultra-broadband antenna applications also focus on the practical significance in the wireless electronic devices, the design of ultra-wideband antenna need has a effective integration with front-end circuit, designing directly ultra-wideband antenna with a low noise amplifier integrated circuit, this direction is also worth considering. |
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