Near-field real-time calibration method for human body millimeter wave imaging safety inspection system

Abstract

The invention discloses a near-field real-time calibration method for a human body millimeter wave imaging safety inspection system, and the calibration system comprises a switch array, an antenna array, a metal calibration line, an amplitude and phase consistency calibration module and a relative time delay calibration module. The antenna array is used for measuring a reference signal, the amplitude and phase consistency calibration module is used for calibrating amplitude and phase consistency, and the relative time delay calibration module is used for calibrating relative time delay, thereby completing the near-field real-time calibration method for the human body millimeter wave imaging safety inspection system. In the method, the metal line is adopted for performing near-field calibration on the imaging system, and the disturbance of the structure of the metal calibration line on a radiation field of the antenna array is small, so that the calibration repeatability is good, and the calibration precision can be ensured. The calibration method can complete calibration by only performing measurement on an air target region once, a calibration reflector does not need to be placed, the calibration time is less than imaging measurement time, and real-time calibration can be performed on a working clearance of the system at any time.

Description

technical field [0001] The invention relates to a near-field real-time calibration method, in particular to a near-field real-time calibration method for a human millimeter wave imaging security inspection system. Background technique [0002] The existing active millimeter wave human body imaging security inspection system, referred to as the imaging system, is composed of an image acquisition and processing device, a mechanical scanning and electrical scanning hybrid scanning device, a millimeter wave transmitter and receiver, a linear antenna array and a switch array. The imaging system uses millimeter wave illumination to image the human body. The imaging system transmits a broadband step frequency modulation signal for measurement, and performs two-dimensional scanning in the horizontal and vertical directions to obtain the three-dimensional measurement information of the target. The imaging system adopts a hybrid scanning method of mechanical scanning and electric sca...

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to provide a near-field real-time calibration method for human body millimeter-wave imaging security inspection system, which solves the problems of difficulty in multi-channel calibration, real-time calibration, and poor calibration repeatability in previous methods

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