Design And Research On Absorbing Structure Of Planar Wave Antenna Based On Substrate Integrated Waveguide

As the role of antennas in military,commercial,and production fields becomes more and more significant,people require the performance indicators of antennas improving.Although the traditional horn antenna has high gain and directivity,it has some limitations in the modern communication system due to its large size and difficulty in integration.Substrate Integrated Waveguide(SIW)antennas have been proposed to figure out these defects.The SIW combines high power capacity,high quality factor of rectangular waveguides,and low cost,small size,ease of integration of microstrip lines.It also has the ability of strong anti-interference.Thus,the SIW is used instead of traditional waveguides to design the pyramidal horn antenna,which is of great theoretical and practical significance,and also promotes the miniaturization of the antenna,making it widely used in the field of wireless communication.The proposed SIW antennas have promoted the miniaturization of horn antennas developing.However,as the size of antennas being smaller,the aperture of antennas become narrower,which easily leads to shortcomings such as uneven phases distribution,poor FTBR,and weak radiation characteristics.Therefore,a lens with adjusting phases is designed at the aperture of the SIW horn antenna,so that it has good beam directivity.At present,most of the dielectric lenses are loaded outside the horn apertures and extend to free space.Although the directivity of antennas become better,it also brings the limitation of increasing the size of the devices.Therefore,using the technology of the phases superposition of electromagnetic wave,this paper designs a SIW plane wave antenna with absorbing structures working at X waveband(8-12 GHz).A series of metal patch lenses are loaded on the aperture,which thickness is less than 0.004 mm and width is along a diminishing quadratic curve distribution.The spacing of each metal patches is derived from the quadratic curve developed by Fourier transform.Thus,it improves the directivity and gain of the antenna,and also achieves long-distance transmission while minimizing the size of lens.The results show that,the SIW plane wave antenna has high selection to the specific frequency in the range of 8-12 GHz,and both H-plane HPBW and E-plane HPBW are less than 71.5 degrees,and gain reaches more than 26 dB.The performance has been improved.At the same time,for avoiding the interference of external electromagneticwave and anti-detection,absorbing structures with thin layers are adhered to the surface of metal patches,so as to achieve independent and normal work between the devices.The results show that,H-plane HPBW reaches 18.14 degrees,while E-plane HPBW is less than 66.06 degrees.