| Widely used in precision guidance,airborne imaging radar and Satellite communications and many other areas,mm-wave antenna has a small structure and wide bandwidth,which can achieve narrow beam,high resolution and inhibit multipath interference.As a novel type of transmission line structure,the ridge gap waveguide is widely used in mm-wave,and this paper mainly research on mm-wave aperture coupled microstrip antenna technology fed by ridged waveguide.By using ridge gap waveguide and compact slot coupling structure,the antenna feed form and transmission efficiency are improved,so that to enhance and the performance of mm-wave antenn.In this paper,we firstly focus on,from the model field and transmission line theory,the general characteristics of the waveguide.According to the periodic lattice structure Brillouin dispersion diagram,combined with the whole structure simulation to complete the periodic structure design,and simplify the process.Based on the equivalent model and electromagnetic simulation,the relationship between the structural parameters and transmission characteristics of the waveguide is analyzed,and the structure at 35 GHz is obtained.On this basis,the power splitter,the waveguide adapter and the T-type end are designed respectively,providing the foundation of the feed network.Based on the ridge gap waveguide structure,this paper presents a compact aperture coupling structure.Firstly,the microstrip-gap coupling structure is designed with single microstrip-gap coupling as the prototype.Then,through the specific analysis of each part of the function,the microstrip-gap coupling is improved to patch-gap coupling by using the monitoring current method combined with the design rule of the traditional coupling structure,which realizes the unity of the three functions of coupling,power division and radiation.This architecture reduces the complexity of the underlying feed network and transmission losses and improves antenna gain and aperture efficiency.Then the parameters of the coupling structure are analyzed,and a general design method is obtained,which can be applied to the antenna design.Finally,on the basis of the above structure,a 2×2 subarray,8×8 parallel feed array and 8×8 parallel series feed array are designed respectively by combining the ridge gap waveguide and the coupling structure.The circular array of 2×2 subarrays is analyzed and the design flow is simplified by the monitoring current method,and a low-side antenna sub-array is obtained.The 8×8 co-feeder array is designed and the reason of its sidelobe change is analyzed.The article also designed 2×8 series feed linear array,and on this basis,composed of 8×8 parallel series feed array.By optimizing the current weights,using the special radiation properties of the coupling structure,the sidelobe is-20 dB and the gain reaches 25.7 dB. |
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