CN-116380787-B - Broadband non-contact terahertz near-field trace substance detection device and detection method

CN116380787BCN 116380787 BCN116380787 BCN 116380787BCN-116380787-B

Abstract

The invention discloses a broadband non-contact terahertz near-field trace substance detection device and a detection method, wherein the device comprises a vector network analyzer, a terahertz signal transmitting end, an expanded hemispherical lens, a trace substance detection chip and a terahertz signal receiving end, the terahertz signal transmitting end comprises a terahertz S parameter detection module I, a lens I, a terahertz S parameter detection module II, a lens II, a frequency selection surface I and a reflecting mirror I, the terahertz signal receiving end comprises a terahertz S parameter detection module III, a lens III, a terahertz S parameter detection module IV, a lens IV, a frequency selection surface II and a reflecting mirror II, the device and the method disclosed by the invention adopt a quasi-optical technology to realize the non-contact connection of the trace substance detection chip and the terahertz S parameter detection module, and simultaneously adopt a quasi-optical band splicing technology to realize the detection within a broadband range, so that the detection speed of a sample to be detected can be improved, and the broadband non-destructive detection of the sample to be detected can be realized.

Inventors

YANG JINPENG
HAN SHUNLI
YANG YAOHUI
ZHANG TING
ZHANG WENZHENG

Assignees

中国电子科技集团公司第四十一研究所

Dates

Publication Date: 20260505
Application Date: 20221230

Claims (5)

1. The broadband non-contact terahertz near-field trace substance detection device is characterized by comprising a vector network analyzer, a terahertz signal transmitting end, an extended hemispherical lens, a trace substance detection chip and a terahertz signal receiving end, wherein the terahertz signal transmitting end comprises a terahertz S parameter detection module I, a terahertz S parameter detection module II, a terahertz S parameter detection lens II, a frequency selection surface I and a reflection mirror I; The terahertz S parameter detection module I is used for doubling the frequency of a signal sent by the vector network analyzer to a terahertz wave band I; the terahertz S parameter detection module II is used for doubling the frequency of the signal sent by the vector network analyzer to a terahertz wave band II; the first lens, the second lens, the third lens and the fourth lens are used for collimating terahertz signals; the first frequency selection surface and the second frequency selection surface are used for realizing total transmission of signals of the first terahertz wave band and total reflection of signals of the second terahertz wave band; The first reflecting mirror is used for reflecting the signal passing through the first frequency selection surface to the extended hemispherical lens; the second reflecting mirror is used for reflecting the signal passing through the extended hemispherical lens to the second frequency selection surface; The extended hemispherical lens is used for transmitting the signal reflected by the first reflecting mirror to the trace substance detection chip and transmitting the signal passing through the trace substance detection chip to the second reflecting mirror; the trace substance detection chip is based on an interference principle and is used for transmitting received terahertz signals to a detection sample and a reference sample on the trace substance detection chip in two ways, combining the detection signals carrying sample information to form an interfered terahertz signal and transmitting the interfered terahertz signal to the extended hemispherical lens; the terahertz S parameter detection module III is used for down-converting the received signals of the terahertz wave band I to a microwave frequency band and transmitting the signals to the vector network analyzer; The terahertz S parameter detection module is used for down-converting the received signals of the terahertz wave band II to a microwave frequency band and transmitting the signals to the vector network analyzer; the vector network analyzer is used for transmitting signals, receiving signals and analyzing the characteristics of the substances to be detected; The trace substance detection chip comprises a receiving antenna, a first power divider, a phase shifter group, a near field sensing unit group, a second power divider and a transmitting antenna which are sequentially arranged in a signal transmission direction, wherein the phase shifter group comprises a first phase shifter and a second phase shifter which are connected in parallel, the near field sensing unit group comprises a first near field sensing unit and a second near field sensing unit which are connected in parallel, and a detection sample and a reference sample are respectively placed on the first near field sensing unit and the second near field sensing unit; the terahertz detection wave band I is 110-170GHz, and the terahertz detection wave Duan Er is 170-220GHz.
2. The broadband non-contact terahertz near-field trace substance detection apparatus according to claim 1, wherein the transmitting end or the receiving end of the first terahertz S parameter detection module, the second terahertz S parameter detection module, the third terahertz S parameter detection module, and the fourth terahertz S parameter detection module are respectively provided with a horn antenna.
3. The broadband non-contact terahertz near-field trace substance detection method adopting the broadband non-contact terahertz near-field trace substance detection device as set forth in claim 1, is characterized by comprising the following steps: The method comprises the steps that a signal sent by a vector network analyzer is subjected to frequency multiplication to a terahertz detection wave band I through a terahertz S parameter detection module I, is collimated through a lens I, irradiates onto a frequency selection surface I and is transmitted through the frequency selection surface I, is subjected to optical path turning through a reflector I, irradiates onto an extended hemispherical lens, the extended hemispherical lens converges the collimated terahertz signal to a trace substance detection chip, the terahertz signal carrying sample information is transmitted to a frequency selection surface II through the extended hemispherical lens and a reflector II, finally reaches a terahertz S parameter detection module III through a lens III, and is subjected to down-conversion to a microwave frequency band through the terahertz S parameter detection module III, and then the characteristics of a detected sample are analyzed by the vector network analyzer; The signal sent by the vector network analyzer is subjected to frequency doubling to a terahertz detection wave band II through a terahertz S parameter detection module, is collimated through a lens II after being transmitted, irradiates onto a frequency selection surface I and is reflected to a reflecting mirror I, then is subjected to light path turning through the reflecting mirror I and irradiates onto an extended hemispherical lens, the collimated terahertz signal is converged to a trace substance detection chip through the extended hemispherical lens, the terahertz signal carrying sample information is transmitted to the frequency selection surface II and is finally subjected to reflection through a lens IV to reach a terahertz S parameter detection module IV, the detection signal is subjected to frequency down conversion to a microwave frequency band through the terahertz S parameter detection module IV, and then the characteristics of a detected sample are analyzed through the vector network analyzer.
4. The broadband non-contact terahertz near-field trace substance detection method as claimed in claim 3, wherein the receiving antenna of the trace substance detection chip receives terahertz signals, the terahertz signals are divided into two paths of signals with equal amplitude and same phase after being divided by the power divider I, the two paths of signals respectively pass through the phase shifter I and the phase shifter II, the two paths of signals subjected to phase shifting are respectively transmitted through the near-field sensing unit I and the near-field sensing unit II, the near-field sensing unit I and the near-field sensing unit II are respectively provided with a detection sample and a reference sample, after the signals interact with the detection sample and the reference sample, the two paths of terahertz signals carrying sample information are combined into one path of terahertz signals forming interference after passing through the power divider II, and the signals are transmitted to the extended hemispherical lens by the transmitting antenna.
5. The broadband non-contact terahertz near field trace substance detection method according to claim 3, wherein the detection of the terahertz detection band one and the detection of the terahertz detection band two are performed separately.

Description

Broadband non-contact terahertz near-field trace substance detection device and detection method Technical Field The invention relates to the technical field of terahertz, in particular to a broadband non-contact terahertz near-field trace substance detection device and a detection method. Background The trace substance detection has important roles in activities such as scientific research and industrial production, and meanwhile, a plurality of substances have unique characteristics in the terahertz frequency band, and the trace substance detection method has important application in realizing effective detection of trace substances in the terahertz frequency band. Researchers have developed techniques for detecting trace substances based on the principle of interference. The technology synthesizes the detection signals respectively passing through a reference sample and a detection sample and carrying sample information into terahertz signals with interference after passing through a power divider or a coupler, wherein the interference frequency depends on the phase difference of a phase shifter. By the method, effective detection of trace substances is realized. The existing trace substance detection technology based on the interference principle adopts a detection method of coaxial adapter connection or GSG probe needle insertion. In the terahertz frequency band, because the size of the trace substance detection chip is small, an extra error can be introduced by adopting an extra packaging detection technology, and the detection chip can be damaged by adopting GSG probe needle insertion detection. And, can only detect a wave band once, limited its detection frequency range. Disclosure of Invention In order to solve the technical problems, the invention provides a broadband non-contact terahertz near-field trace substance detection device and a detection method, so as to achieve the purpose of broadband non-contact detection of trace substances. In order to achieve the above purpose, the technical scheme of the invention is as follows: The broadband non-contact terahertz near-field trace substance detection device comprises a vector network analyzer, a terahertz signal transmitting end, an expanded hemispherical lens, a trace substance detection chip and a terahertz signal receiving end, wherein the terahertz signal transmitting end comprises a terahertz S parameter detection module I, a terahertz S parameter detection module II, a terahertz S parameter detection lens II, a frequency selection surface I and a reflection mirror I; The terahertz S parameter detection module I is used for doubling the frequency of a signal sent by the vector network analyzer to a terahertz wave band I; the terahertz S parameter detection module II is used for doubling the frequency of the signal sent by the vector network analyzer to a terahertz wave band II; the first lens, the second lens, the third lens and the fourth lens are used for collimating terahertz signals; the first frequency selection surface and the second frequency selection surface are used for realizing total transmission of signals of the first terahertz wave band and total reflection of signals of the second terahertz wave band; The first reflecting mirror is used for reflecting the signal passing through the first frequency selection surface to the extended hemispherical lens; the second reflecting mirror is used for reflecting the signal passing through the extended hemispherical lens to the second frequency selection surface; The extended hemispherical lens is used for transmitting the signal reflected by the first reflecting mirror to the trace substance detection chip and transmitting the signal passing through the trace substance detection chip to the second reflecting mirror; the trace substance detection chip is based on an interference principle and is used for transmitting received terahertz signals to a detection sample and a reference sample on the trace substance detection chip in two ways, combining the detection signals carrying sample information to form an interfered terahertz signal and transmitting the interfered terahertz signal to the extended hemispherical lens; the terahertz S parameter detection module III is used for down-converting the received signals of the terahertz wave band I to a microwave frequency band and transmitting the signals to the vector network analyzer; The terahertz S parameter detection module is used for down-converting the received signals of the terahertz wave band II to a microwave frequency band and transmitting the signals to the vector network analyzer; the vector network analyzer is used for transmitting signals, receiving signals and analyzing the characteristics of the substance to be detected. In the above scheme, the trace substance detection chip comprises a receiving antenna, a first power divider, a phase shifter group, a near field sensing unit group, a second power divider and a transmitting