High Scanning Rate Leaky-Wave Antenna Design

With the development of electromagnetic wave technology and the continuous upgrading of communication technology,high frequency beam steering antennas are required gradually in more and more situation,like automobile millimeter wave radar,base station communica-tion,millimeter wave detection,millimeter wave imaging and so on.In many different kinds of antennas,leaky-wave antenna(LWA)based on dielectric integrated waveguide has become a research hotspot,for its advantage of low profile,low loss,high energy tolerance,easy inte-gration,and simple structure.It's easy to realize beam steering by change input frequency for leaky-wave antennas.So,leaky-wave antennas have been widely used in various industries and practical production.First,this paper introduces the research background of leaky-wave antennas.The current research status of leaky-wave antennas is discussed next.Several focus problems of leaky-wave antennas and solutions of these problems are discussed.This paper has introduced the principle of leaky-wave antennas.The classification of leaky-wave antennas and the features of different kind of leaky-wave antennas are discussed next.The way of increase the scanning rate(SR)of leaky-wave antennas is summarized.Two different kind of high SR leaky-wave antennas are proposed.The first one is the slow-wave structure antenna.A leaky-wave antenna based on spoof surface plasmon polaritons is proposed.Two corrugated metallic strips are etched on the surface of the substrate integrated waveguide(SIW).Sinusoidal modulation is used for infinite space harmonics.A total scanning range of 13 ° to 61 ° is realized.The frequency bandwidth is from 16.3 GHz to 17 GHz.The SR of the proposed leaky-wave antennas is 11.42.Base on this structure,period metal vias are used for bidirectional scanning range.The metal vias are shorter than substrate integrated waveguide,and is connect to the bottom surface.This kind of structure could steering from-47 ° to 22°.The second structure is meander line structure antenna.A leaky-wave antenna based on the double-layer substrate integrated waveguide that has a wide scanning range within a narrow bandwidth is proposed.The LWA consists of two layers,each of which consists of multiple elemental SIWs arranged in parallel at each layer while the direction of the SIWs in the two layers are at an oblique angle to each other.The elemental top layer SIWs are connected to those in the bottom layer though parallelogram-shaped slots,so that the two layers together form a double-layer SIW.Thin slots etched on the upper surface of each elemental SIW of the top layer act as radiating structures.As the phase difference between the radiating slots of adjacent elemental SIWs can be enlarged by the waveguide length,wide-angle beam scanning is achieved within a specific frequency bandwidth.The proposed LWA has a scanning range from-58 ° to 49° in a relative bandwidth of 6.45%,from 12.75 GHz to 13.6 GHz.The scanning rate(SR),is up to 16.5.