Research And Design Of Ultra-wideband Notch Antenna Based On HMSIW

With the development of science and technology,people's production and life rely more and more on wireless communication technology.The technological innovation of the wireless communication system puts forward higher requirements on the antenna,such as ultra-wideband and multi-passband.Ultra-wideband antenna is high data transmission rates,high spectral efficiency,resistance to multipath fading.Notch antenna can effectively solve compatibility between the ultra-wideband and narrowband communication in the passband.Half-mode substrate integrated waveguide(HMSIW)structure with high power capacity,low loss advantages is proposed based on the substrate integrated waveguide(SIW).Besides,HMSIW has a wider dominant mode bandwidth.When it is used to design the antenna,the bandwidth and efficiency will be improved.Yagi antenna is low profile,high gain and good directionality.In this paper,HMSIW and microstrip Yagi antenna structure are combined to study and design ultra-wideband,multi-pass band and adjustable notch antenna.The main content can be summarized as follows:1.An ultra-wideband Yagi antenna based on HMSIW structure is designed.Theoretical analysis of HMSIW structure is showed.The gaps are added to HMSIW structure,and the number,size and position of the gaps are determined by analysis and simulation.The active element of Yagi antenna is a dipole antenna which is placed separately.The reflector is replaced by ground,so the balun structure is omitted.The director is composed of a number of microstrip lines with one gap on the first director to improve the performance of antenna.An ultra-wideband antenna with bandwidth greater than 60%is realized.Relevant research result has been published in the 2017 National Conference of microwave and millimeter wave.2.On the basis of the design 1,considering the compatibility between the ultra-wideband and the narrowband communication in the passband,two notch structures are introduced to filter out the unwanted narrowband.It makes the UWB antenna to be a multiband antenna.The working principle of the varactor diode and the transmission characteristics of the notch structure are analyzed.Two sets of varactor diodes are designed on each notch node.By controlling the reverse bias voltage of the varactor diode,the length of the equivalent trapezoid branch line changes and the resonance frequency of the trap branch line also changes accordingly,so that the antenna notch position and bandwith are adjusted.