Ultra-wideband planar focusing lens antenna and design and imaging method thereof

Abstract

The invention relates to an ultra-wideband planar focusing lens antenna and a design and imaging method thereof, and belongs to the field of lens antennas and optical imaging. The method comprises the following steps: performing quasi-conformal transformation on a ball luneberg lens, performing reasonable discretization on a transformed non-uniform dielectric constant, analyzing the influence of different discretization conditions on a focal spot and an angular resolution in a broadband, determining the optimal discretization of the dielectric constant, and realizing high-resolution imaging on a focal plane in the broadband. The system has high imaging resolution of real-time imaging in a wide-angle range, when plane waves in different directions are incident in an imaging range of + / -30 degrees, the size consistency of 3dB focal spots imaged on a focal plane is good, and a real-time imaging structure is simple.

Description

technical field [0001] The invention belongs to the field of lens antenna and optical imaging, in particular to a lens antenna with ultra-broadband and planar focus and its ultra-broadband high-resolution imaging method. The focal spot characteristics and angular resolution of the lens antenna when incoming waves from different directions are incident. The results show that the lens antenna has a focal spot of 36.8 mm to 4.6 mm and an angular resolution of 20 degrees to 2.5 degrees in the ultra-wideband. Background technique [0002] The near-field focusing antenna is the main component of the microwave imaging system. High-quality passive imaging requires the focusing antenna to have narrow beam, high gain, high efficiency and low sidelobe characteristics. At the same time, it is required that the beams can be densely arranged and maintain good beam uniformity. . In the imaging system, focal spot and angular resolution are two important index parameters: when a plane wave ...

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Problems solved by technology

[0007] In the field of ultra-wideband microwave imaging, in order to overcome the problems of narrow frequency band of the focusing array antenna, complex data processing, large volume and poor plane integration caused by the focal surface of the spherical Lunberg lens antenna, the present invention proposes an ultra-wideband planar Focusing lens antenna and its imaging method, through the quasi-conformal transformation of the spherical Lunberg lens, reasonable discretization of the transformed inhomogeneous dielectric constant, and analysis of the impact of different discretization on the focal spot and angular resolution in a wide frequency band The effect of determining the optimal discretization of the permittivity to achieve high-resolution imaging on the intrinsic focal plane over a wide frequency band

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