Wideband Design Of Millimeter-wave Slotted Waveguide Array Antenna And Exploration Of Antenna With Air Post-wall Waveguide Structure

Millimeter wave has many characteristics such as large bandwidth,narrow beam and easy device miniaturization.Slotted waveguide array antennas possess advantages such as large power capacity,compact structure and high aperture efficiency and so on.Therefore,wideband,high-gain,easy-to-fabricate millimeter-wave slotted waveguide array antennas have extremely high market demand from the perspective of technology and market potential.This paper mainly studies the design of wideband high-gain millimeter-wave slotted waveguide array antenna,and explores the new structure of light-weight and easy-to-fabricate slotted waveguide array antenna.Firstly,this paper introduces the basic principle of the slotted waveguide array antenna design,which is mainly composed of the outline of the rectangular waveguide and its transmission characteristics,the radiation mechanism of the waveguide slot,the type and the corresponding physical model of the slot units,basic principles,types and applications of slotted waveguide array,the broadband design method of slotted waveguide array antenna.Then a 20×20-element millimeter-wave wideband slotted waveguide array antenna in Q-band is proposed.The wideband design uses standing-wave excitation,divides the whole array into sub-arrays by feeding network,and applies "overloading"technology to the sub-array design,which makes the radiation and coupling sub-arrays have similar double-resonance matching characteristics and greatly improves the antenna matching bandwidth.As the simulation results of the 20×20 element array antenna,the impedance matching bandwidth for the reflection less than-12 dB is 8.46%,and the bandwidth of aperture efficiency higher than 70%is 8.21%,which performs good radiation characteristics.Then,the wideband design of 16x 16-element slotted waveguide with decoupling structure is completed in E-band.Compared with the previous broadband design idea,the design scheme is further strengthened.By considering the decoupling method,air cavity structure is added above the radiation part to suppress the coupling effect of radiation elements,and different size air cavities are tried to optimize the bandwidth.The matching bandwidth of 16×16 element array antenna for the reflection less than-10 dB is 14.01%,and the bandwidth of aperture efficiency higher than 80%is 12.73%,the bandwidth of array antenna is improved significantly.Finally,after analyzing the current manufacturing technology of millimeter wave array antenna,combined with the advantages and characteristics of 3D printing process,a 16×16-element millimeter-wave array antenna based on air post-wall waveguide is designed.The technology uses the model of metal post-wall in the air to replace the traditional metal waveguide wall,and adj usts the local adaptability of each structure's parts.The matching bandwidth of the 16×16-element array antenna for VSWR<-1.5 is 11.72%.The feasibility of the structure design is verified,which provides new ideas of light-weight and easy-to-fabricate millimeter-wave slotted waveguide array antennas.