Design Of W-band Waveguide Slot Array Antenna And Its Application

The waveguide slot antenna has become one of the most popular antennas used in vehicle,airborne and shipborne radar systems,because of its simple and compact structure,high reliability and easy control of the aperture field distribution.Millimeter wave antenna has the advantages of high gain,narrow beam and small size,which meet the needs of modern radar for high sensitivity,high resolution and miniaturization.Therefore,the research of W-band waveguide slot array antenna has important practical value.This paper reports on the design and fabrication of a W-band non-resonance waveguide slot array antenna with 76 slots by using Taylor synthesis method and structure of traveling-wave-fed array.The designed waveguide slot antenna has the characteristics of high gain,narrow beam,low side-lobe and frequency scanning.In the process of antenna design,firstly,based on the theory of Taylor distribution and power transmission method,the MATLAB software is used to calculate the amplitude of gap current excitation and the normalized conductance.Secondly,in order to determine the relationship between conductance and gap size,based on the traditional experimental method,'normalized conductance value-gap angle-cutting depth' function is extracted by using 3D electromagnetic simulation software HFSS.In the process of extraction,this paper analyzes the surface waveguide thickness of the key design parameter of the W band,and illustrates the effect of this variable on antenna efficiency,fabrication and design difficulty.Finally,compared with the theoretical distribution,the field intensity distribution on the antenna aperture is extracted by HFSS,and then the slot size is optimized to obtain the final machining size.In order to meet the requirements of practical engineering application,a tolerance analysis on the key design parameters,such as gap spacing and slot inclination,on the basis of full investigation of the current domestic technology level has been carried out in this paper.The results indicate that the structure of the antenna has good robustness.The four waveguide slot antennas are fabricated and tested.The measured results indicate that the gain of the slotted waveguide antenna is better than 23dBi,the half power beam width of the E-plane is 1.20±0.040,the scanning angle of the 3dB beam is greater than 5?,the side-lobe level is less than-20dB,and the input VSWR is less than 1.3.Finally,an elliptic cylindrical reflector antenna is developed with the developed waveguide slot antenna as feed source to meet the requirement of a practical radar system.The antenna is mechanically scanned on the azimuth plane and the frequency scanning is used in the pitch plane.The measured results indicate that the gain of the reflector antenna is better than 44dBi,and the half power beam width of the E plane and the H plane is 1.2°±0.04°and 0.4°±0.02?,respectively.