Design And Analysis Of Ultra-wideband Antenna With Notch Bands

Ultra-wideband(UWB)system,characterized by high data rate,low power,low cost and strong multi-path resolution,is one of the sensational developments in recent years.UWB antenna,an integral part of that,has also drawn wide attention.UWB antennas with various structures have been proposed.The frequency spectrum of communication devices such as WLAN?WiMAX is included in that of UWB.Mutual interference between the spectrums is inescapability.It is of realistic significance in implement research on UWB antenna with frequency notched band.Narrow-band interference occurs in UWB band,in accordance with this problem,the paper mainly designs and analyses UWB antenna with frequency notched band.Three kinds adjustable UWB antenna with dual-notched band?triple-notched band and quadruple-notched band are designed.The band of these antennas covers the frequency range from 3.1 to 10.6GHz which meets the requirements that VSWR>2 within the rejection bands,the rejection bands are adjustable and the antennas have omni-directional radiation characteristics.The entire design process and the main parameters of the antennas are analyzed and discussed at last.The dual-notched band UWB antenna uses an arc-shaped stub and a pair of parallel coupled lines to realize the dual rejection bands characteristics.It operates well in the UWB bandwidth stipulated by Federal Communications Commission regulations,and it inhibits WiMAX system(3.4GHz ~ 3.69GHz)and WLAN system(5.15 GHz ~ 5.825GHz)signal effectively.UWB antenna with triple-notched band which has the characteristics of that of dual-notched band UWB antenna inhibits X-band(7.25 GHz ~ 8.4GHz)signal effectively.It is employed an arc-shaped stub and two reverse stepped impedance resonator(SIR).The results show that the antenna could suppress band in 3.4GHz ~ 3.69GHz?5.15 GHz ~ 5.825GHz?7.25 GHz ~ 8.4GHz effectively.UWB antenna with quadruple-notched band coupled with inhibitionn of onboard band(3.9GHz ~ 4.2GHz)based on UWB antenna with three rejection bands.We add the detour line structure and double SIR structure in the same direction and etch arc "L" shaped slot on the ground plane to suppress band in 3.4GHz ~ 3.69GHz?5.15 GHz ~ 5.825GHz?7.25 GHz ~8.4GHz.The notch bands of that can be independently adjusted separately,which increases flexibility and application range.