Research On The Microstrip UWB Antenna With Band Rejections Based On The Half-wavelength Impedance Resonator

With its high transmission rate, strong anti-multipath fading capability and low cost, the ultra-wideband (UWB) system is widely used in fields like military communication, automotive radar and digital communication. As an important part of the wireless communication system, the UWB antenna directly restricts the performance of the UWB system. Since the UWB microstrip antenna is known for its simple structure, low power and easy integration, it has been extensively used in the a hot research. At present, in order to solve the problem of mutual interference between UWB system and existing narrowband communication system, the notched-band UWB antenna has become a hot research topic.In this paper, we first introduce the structure and advantages of the UWB and then we make a brief review of the research progress of the UWB antenna and notched-band UWB antenna. In order to suppress interference between UWB communication system and existing narrowband communication system, for example WLAN and WiMax, we make a deep research of the notched-band UWB antenna.It is difficult to control the notched bandwidth of the ultra-wideband (UWB) antennas. A type of UWB monopole antenna with controllable notched bandwidth is presented. Firstly, ultra-wideband characteristics covering 3.1GHz-10.6GHz band is produced by using the circular-ring monopole antenna. Then, a pair of asymmetric half-wavelength second-order impedance resonators are added to realize the notched function. The notched bandwidth can be easily achieved by adjusting the width, the position and the gap of the asymmetric half-wavelength second-order impedance resonators. Finally, an UWB antenna with rejection band at 5.1-6.0GFIz is designed and fabricated, which effectively limits the interference from WLAN. Experiment results are consistent with simulation that verifies the validity of the simulation.A Novel planar ultra-wideband (UWB) antenna with double band-notched characteristics is designed to effectively minimize the interference of existing narrow-band communication system. The bell-shaped radiation patch and the fed line are loaded with Complementary Split-ring Resonator (CSRR) and asymmetric U-shaped half wavelength impedance resonators, respectively, to achieve the double band-notched characteristics within the frequency rank between 3.4-3.6GHz and 5.1-5.9 GHz. The mechanism of band-notch is discussed and the influence of antenna configuration is analyzed. This antenna was fabricated and tested. The results show that this antenna has good radiation patterns and gain curve and is capable of restraining the interference of both the WiMax and WLAN. it and can be used widely.Finally, we will summarize the work above and make the prospect in the development of the notched-band UWB antenna.