A real-time calibration method for active terahertz fast security detector based on internal target

Abstract

The invention discloses an active terahertz rapid security inspection instrument real-time correction method based on an inner object, comprising: obtaining corresponding simple-frequency signals according to the distance between an inner object and a transmit-receive channel, and the distance between a measuring object and the transmit-receive channel; and converting each corresponding simple-frequency signal to obtain a correction signal and an object signal so as to realize correction. The method can correct the nonlinearity of different emission channels i and receiving channels j, complete real-time correction on each pulse, not require complex array calibration networks, and realize network terahertz front end design.

Description

technical field [0001] The invention relates to terahertz MIMO synthetic aperture radar imaging, in particular to a real-time correction method for an active terahertz fast security detector based on an internal target. Background technique [0002] Active terahertz fast security detectors are an important application field of terahertz waves, generally based on short-range terahertz MIMO (Multiple-Input Multiple-Output) synthetic aperture radar technology: using the characteristics of short wavelength and easy access to large bandwidth in terahertz frequency band , higher resolution can be obtained; and the use of array electronic scanning can effectively improve the system frame rate; thus it has received extensive attention and research. However, since the technology of directly generating terahertz sources is relatively immature, the technology of indirect generation of terahertz sources after multiple frequency doubling and amplification is generally used at present. A...

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Problems solved by technology

[0016] 1) The nonlinearity of different transmission channels cannot be corrected: due to the relatively large inconsistency of the terahertz transmission array, it cannot be equivalent to simply using a terahertz correction source; so for the same reception channel j, different transmission channels i of the array correction network method The non-linear correction effect of the general

[0017] 2) The array calibration network method cannot achieve real-time calibration. Once the working status (such as temperature, etc.) changes, the calibration signal needs to be collected again

[0018] 3) The noise of the correction source can enter the terahertz receiving front end through the coupler, which increases the input noise of the receiver and reduces the signal-to-noise ratio of the system

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