The Design And Research Of High Scanning Rate Dual-Beam Leaky Wave Antenna

With the rapid development of the information technology,communication technique has become a significant technique on the area of the national defense,industry,medical and so on.As the main device for transmitting and receiving signals in the communication system,antenna plays a vital role for the performance of system.Planar leaky wave antenna(LWA),as a type of antenna,is widely applied on radar detecting,satellite navigation,wireless communication and other filed by featuring the excellent directivity,low cost,low profile,simple feeding network and frequency-depended beam direction.Due to the problem of the limited frequency band environment and require of the multibeam scanning,a high scanning rate single beam LWA and high scanning rate asymmetrical dual-beam LWA are proposed in this dissertation.The main research contents are outlined below:1.A high scanning rate single beam LWA working on X-band is designed.Through printing the metal stub on the magnetic wall of half-mode substrate integrated waveguide,obtaining the surface plasmon polaritons unit with the slow-group-velocity dispersion characteristic.Then,based on the sinusoidally modulated reactance surface,the slow-group-velocity part of dispersion diagram is excited to the fast-wave mode of the higher-order harmonics,contribution to a high scanning rate LWA.An additional metal via and modified stub length is applied to suppress the open stopband(OSB)effect.The measurement results show the antenna can scan from-54° to + 54° within the operating band of 9.25-10.25 GHz,obtaining a high scanning rate of 10.5 and the maximum gain of 11.56 d Bi.2.A high scanning rate asymmetrical dual-beam LWA operating on the X-band is designed.Based on the slotted HMSIW-SIW with slow-wave dispersion characteristic,using the technique of sinusoidally modulated reactance superimposing surface,a high scanning rate asymmetrical dual-beam radiation is realized.A series of slots is etched on the bottom of antenna with an offset against the top surface to form an asymmetrical structure.Thus,the OSB effect is eliminated.The two beams can steer from-65° to-2°and form-6° to +51° within the frequency band of 8.65 to 9.5GHz.The dual-beam scanning rate,defined as the sum of the scanning rate of each beam,is obtained up to12.9 for the proposed dual-beam antenna.