Research On Substrate Integrated Waveguide Leaky-wave Antenna

As a kind of travelling-wave antennas,Leaky-Wave antenna has been widely used in engineering applications and It has high gain and beam scanning.In the past design,the leaky wave antennas are restricted due to the disadvantages of the closed waveguide structure(such as large volume,high cost and difficulty to be integrated)and open-planar waveguide structure(such as parasitic and surface-wave modes).The substrated integrated waveguide not only inherits the superior transmission performances of the conventional waveguide,but also has a huge odds in the fabrication process of the planar structure.In this paper,the radiation mechanism of leaky wave antenna are expounded.Leaky wave antenna based on fast wave and slow wave have carried on design and simulation.Based on the basis of the basic structure,the U-shaped dual-beam antenna is proposed in order to miniaturize the length of leaky wave antenna.Buttery space harmonic leaky wave antenna is designed to improve the low frequency gain.The main work and creative points of this thesis can be summarized as follows:1.A U-shaped dual-beam substrate integrated waveguide(SIW)leak-wave antenna(LWA)using periodic slots is proposed in this paper.By folding the waveguide from one dimensional structure to 2D,he length of the U-shaped LWA has reduced by 33%,By this configuration,the U-shaped LWA is capable of steering two symmetrical beams with angel of beam scanning 100%added.In Millimeter wave band a cascade of two U-shaped SIW leaky-wave antenna is also presented for the better performance and the length of cascaded U-shaped LWA has reduced by64%.2.A novel type of leaky wave antenna with slow wave band radiation based on space harmonic wave has been designed.This kind of antenna can change the work band by modified the distance of slots and the highest gain of antenna can achieved 15 dB.3.A novel type of buttery space harmonic leaky wave antenna with slots length periodic gradient has been designed.Buttery leaky wave antenna can solve the problem that the simple space harmonic leaky wave antenna has a low radiation gain in the low-frequency stage.This design increases the radiation in the low-frequency stage from 4dBi to 10 dBi,and at the same time,achieves wider beam-scanning angel with smaller frequency bandwidth.