Research And Engineering Application Of Waveguide-fed High-efficiency Antenna Array

In order to realize long-distance detection,modem radar systems have put forward high-gain requirements for antennas.Antenna efficiency is an important determinant of antenna gain.The adoption of waveguide feeding network can effectively reduce losses and improve the efficiency of antenna arrays.Therefore,the research on high-efficiency antenna arrays with waveguide feeding network are of great importance for modern radar systems.The main research contents are as follows:1.Research on high-efficiency planar waveguide slot antenna array:Based on the theories of waveguide slot antenna,the design method of waveguide slot antenna array is discussed.The 15-element waveguide slot array and the planar waveguide slot array with 16×16 elements are designed,which have achieved high efficiency,high gain and low sidelobe level,verify the feasibility of the design method.2.Design of antenna array with "cosecant squared" beamforming:A high-efficiency antenna array working in Ku-band with "cosecant squared" beamforming in the vertical dimension and low sidelobe level in the horizontal dimension is designed for space detection.For antenna array in the vertical dimension,printed dipole antennas are used as elements,and a feeding network based on Wilkinson power divider is designed according to the amplitude-phase weight values calculated by the "cosecant squared" beamforming.In the horizontal dimension,a one-divided-thirty-two waveguide divider is adopted to reduce network loss.The measured results show that the designed antenna array has met the requirements of beamforming and low sidelobe level,and high efficiency is achieved.3.Research on high-efficiency dual-polarized antenna arrays with common aperture:A dual-polarized 2×2 antenna subarray excited by the high order mode substrate integrated cavity is proposed,which reduces the transmission loss by simplifying the feeding network.Furthermore,independent horizontal and vertical polarization feeding layers are designed,by using the substrate integrated waveguide(SIW)as feeding networks.Asymmetric T-dividers are applied to solve the problem of reversed magnetic field in coupling apertures.With the combination of antenna subarrays and SIW feeding network,a high-efficiency dual-polarization 8×8 antenna array in Ka band with common aperture is realized.