Research And Design Of UWB Antenna With Band-notched Characteristics Based On Substrate Integration Waveguide

UWB antenna works at 3.1-10.6GHz whose absolute bandwidth is more than 500MHz and relative bandwidth greater than 20%. Since the UWB technology spread from military to civilian,it has been widely applied in short distance wireless communication system and microwave imaging technology. This paper focus on the UWB antenna which is an important component of the microwave imaging system. High directivity, high gain and low loss are most important design criterions of the antenna which is used in the microwave imaging technology. UWB antennas with low profile, low loss, high directivity, high gain characteristics are proposed in this paper.This paper firstly introduces the realization method and design rules of substrate integrated waveguide and proposes the analysis of the transmission characteristics and dispersion characteristics. After that, a SIW to microstrip and a SIW to grounded coplanar waveguide transition structure are designed. Based on the low loss characteristics of SIW and the high directivity characteristics of taper slot antenna, an UWB antenna which is applied in the microwave imaging system is designed. The working frequency of the antenna is 4.04-10.64GHz. And the relative bandwidth is 90%. The radiation pattens of E-plane and H-plane at the entire bandwidth have good consistency and directivity.According to this, a notched band at WLAN(5.725-5.825GHz) is realized by the method of adding a SRR as a parasitic element. Finaly, in the light of the microwave transmission theory, a novel impedance matching method based on the SIW technology and its equivalent circuit are carried out. The impedance bandwith with the matching structure is 15.3% more than that of without matching structure.