Method for synthesizing vortex electromagnetic field with high orbital angular momentum mode number

Abstract

The invention relates to a method for synthesizing a vortex electromagnetic field with a high orbital angular momentum mode number. The method for synthesizing the vortex electromagnetic field comprises the following steps: N antenna units form a circular antenna array, and by rotating the circular antenna array and regulating and controlling the phase of each antenna unit, the vortex electromagnetic field is synthesized, wherein N is an integer larger than or equal to 1. By utilizing the method provided by the invention, the synthesized vortex electromagnetic field with the target mode numbercan be generated as required, and the vortex electromagnetic field with the high mode number is directly synthesized by rotating the antenna array and regulating and controlling the phase of each antenna unit under the condition of a small number of antennas, so that the resolution of the imaging system in the azimuth direction is increased. The vortex electromagnetic field synthesized by using the method disclosed by the invention not only is beneficial to realizing super-resolution imaging, but also has remarkably improved modal purity, and has a very good application prospect in the fieldsof super-resolution biomedical imaging, radar imaging, wireless communication and the like.

Description

technical field [0001] The invention belongs to the field of microwave (electromagnetic wave) imaging new technology, in particular to a method for synthesizing a vortex electromagnetic field with a high orbital angular momentum mode number. Background technique [0002] Orbital Angular Momentum (OAM) is an important physical quantity of the vortex electromagnetic field. Studies have found that the vortex electromagnetic fields in different modes are orthogonal to each other, and more information can be modulated on it. The application of vortex electromagnetic wave (Vortex Electromagnetic Wave, VEW) with orbital angular momentum in the field of communication has been extensively studied. The radiation field of the vortex electromagnetic wave carrying the orbital angular momentum has a differential distribution in the beam, and the phase of the vortex electromagnetic wave presents a regular distribution feature, and its phase front has a spatial spiral structure around the b...

AI Technical Summary

Problems solved by technology

However, the method of this patent cannot directly obtain the independent vortex electromagnetic field with the mode number m, but only contains the vortex electromagnetic field component with the mode number m

In fact, any vortex electromagnetic field obtained directly can obtain a higher modal vortex electromagnetic field through Fourier expansion, so it is of little significance in practical applications

In addition, the method for generating multi-mode vortex electromagnetic waves disclosed in this patent is directly related to time t, and the obtained radiation electric field of the mth harmonic is also limited by time t

[0006] In addition to the fields of wireless communication and radar imaging, vortex electromagnetic fields are also expected to be applied in the field of biomedical imaging, providing new ideas for the diagnosis and treatment of diseases. However, there is no report on the application of vortex electromagnetic fields to biomedical imaging.

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