Research On Short Millimeter Wave Beamforming And High Gain Horn Array Antenn

With the rapid development of wireless communication,low frequency spectrum resources are increasingly scarce,and the short millimeter wave(W-band and above)has received lots of attention.The short millimeter wave antenna which located at the front of the wireless communication link has great research significance.Based on the current problems faced in the research of short millimeter wave antennas,this thesis will focus on the research of the beamforming and high-gain horn array antennas in combination with current mainstream CNC and MEMS processes.The main contents are as follows:The H-plane horn antenna is selected to form 1×4 array in W-band(75 GHz-110 GHz).The method of maximum power transmission theory(MMPTE)is used to realize the tilted-beam of antenna.Based on the calculated excitation distribution,the corresponding broadband waveguide feed network is designed.The feed network and antenna are machined by the computer numerical control(CNC)milling machines technology.The simulated and measured results show that the feed network can output the stable amplitude and phase,and the antenna beam can maintain the stable tilted-angle within 80 GHz-100 GHz.Secondly,based on the array and feed network structure,the Taylor distribution is applied to the 1×4array and the low side-lobe beam of the array is realized.The corresponding broadband feed network based on the excitation is designed.The simulation results show that the side-lobe levels of the antenna are below-21 dB in the full W-band,which has the great characteristics of broadband and low side-lobe level.According to the simulated and measured results,The design of this part is a low-cost,high-efficiency,broadband,and flexible design of short millimeter wave beamforming scheme for horn array antenna.The array methods of two-dimensional horn array antenna are researched in this section.The diagonal horn antenna is selected as the radiation element to design the 64-element array antenna at 220 GHz after considering the gain,side-lobe level,grating lobe level and bandwidth.The array method of antenna reduces the side-lobe level and the grating lobe level effectively.To drive the array element in same amplitude and phase,the feed network is designed.All the design of antenna and feed network are based on the available silicon micro-mechanical system(MEMS)technology.Finally,the antenna is fabricated and measured.According to the measured results,the reflection coefficient of the antenna is below-10 dB,the antenna gain fluctuations between 28 dBi and 30.9 dBi,the sidelobe level are all less than-25 dB in the range of ±40 degrees near the main beam of E and H-plane and the grating lobe level is below-16 dB in the 190 GHz-250 GHz frequency band.The measured results are in great agree with simulated and it verifies the feasibility of processing THz horn array antenna by MEMS technology.