A broadband non-contact terahertz near-field micro-substance detection device and a detection method

Abstract

This invention discloses a broadband non-contact terahertz near-field trace substance detection device and method. The device includes a vector network analyzer, a terahertz signal transmitter, an extended hemispherical lens, a trace substance detection chip, and a terahertz signal receiver. The terahertz signal transmitter includes a first terahertz S-parameter detection module, a first lens, a second terahertz S-parameter detection module, a second lens, a first frequency selective surface, and a first reflector. The terahertz signal receiver includes a third terahertz S-parameter detection module, a third lens, a fourth terahertz S-parameter detection module, a fourth lens, a second frequency selective surface, and a second reflector. The device and method disclosed in this invention use quasi-optical technology to achieve non-contact connection between the trace substance detection chip and the terahertz S-parameter detection module. Simultaneously, quasi-optical band splicing technology enables detection over a broadband range, which can improve the detection speed of the sample and achieve broadband non-destructive non-contact detection of the sample.

Description

Technical Field

[0001] This invention relates to the field of terahertz technology, and in particular to a broadband non-contact terahertz near-field trace substance detection device and detection method. Background Technology

[0002] Trace substance detection plays a crucial role in scientific research and industrial production. Many substances possess unique characteristics in the terahertz frequency band, making its effective detection crucial for applications. Researchers have developed a trace substance detection technique based on the principle of interference. This technique involves passing the detection signal through both a reference sample and the detection sample. The signal carrying sample information is then combined into an interferometric terahertz signal after passing through a power divider or coupler. The interference frequency depends on the phase difference of the phase shifter. This method enables the effective detection of trace substances.

[0003] Existing trace substance detection technologies based on the principle of interference employ coaxial adapter connections or GSG probe pricking methods. In the terahertz band, due to the very small size of the trace substance detection chip, additional packaging technology introduces extra errors, while GSG probe pricking can damage the detection chip. Furthermore, only one band can be detected at a time, limiting the detection frequency range. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a broadband non-contact terahertz near-field trace substance detection device and method, thereby achieving broadband non-contact detection of trace substances.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] A broadband non-contact terahertz near-field trace substance detection device includes a vector network analyzer, a terahertz signal transmitter, an extended hemispherical lens, a trace substance detection chip, and a terahertz signal receiver. The terahertz signal transmitter includes a terahertz S-parameter detection module one, a lens one, a terahertz S-parameter detection module two, a lens two, a frequency selective surface one, and a reflector one. The terahertz signal receiver includes a terahertz S-parameter detection module three, a lens three, a terahertz S-parameter detection module four, a lens four, a frequency selective surface two, and a reflector two.

[0007] The terahertz S-parameter detection module is used to multiply the signal emitted by the vector network analyzer to the terahertz band.

[0008] The second terahertz S-parameter detection module is used to multiply the signal emitted by the vector network analyzer to the second terahertz band.

[0009] Lens 1, Lens 2, Lens 3 and Lens 4 are used to collimate terahertz signals;

[0010] The frequency selective surface one and frequency selective surface two are used to achieve full transmission of signals in terahertz band one and total reflection of signals in terahertz band two.

[0011] The first reflector is used to reflect the signal passing through the first frequency-selective surface to the extended hemispherical lens;

[0012] The second reflector is used to reflect the signal that has passed through the extended hemispherical lens to the second frequency selective surface;

[0013] The extended hemispherical lens is used to transmit the signal reflected by the first reflector to the trace substance detection chip, and to transmit the signal passed through the trace substance detection chip to the second reflector.

[0014] The trace substance detection chip is based on the principle of interference. It is used to transmit the received terahertz signal in two paths to the detection sample and the reference sample, and to combine the detection signals carrying sample information to form an interferometric terahertz signal, which is then transmitted to the extended hemispherical lens.

[0015] The third terahertz S-parameter detection module is used to downconvert the received signal from the first terahertz band to the microwave band and transmit it to the vector network analyzer.

[0016] The fourth terahertz S-parameter detection module is used to downconvert the received terahertz band II signal to the microwave band and transmit it to the vector network analyzer.

[0017] The vector network analyzer is used to transmit signals, receive signals, and analyze the properties of the substance to be tested.

[0018] In the above scheme, the trace substance detection chip includes a receiving antenna, a power divider I, a phase shifter group, a near-field sensing unit group, a power divider II, and a transmitting antenna arranged sequentially in the signal transmission direction. The phase shifter group includes a phase shifter I and a phase shifter II connected in parallel. The near-field sensing unit group includes a near-field sensing unit I and a near-field sensing unit II connected in parallel. The detection sample and the reference sample are respectively placed on the near-field sensing unit I and the near-field sensing unit II.

[0019] In the above scheme, the transmitting or receiving ends of the terahertz S-parameter detection module one, terahertz S-parameter detection module two, terahertz S-parameter detection module three and terahertz S-parameter detection module four are all equipped with horn antennas.

[0020] In a further technical solution, the first terahertz detection band is 110-170 GHz, and the second terahertz detection band is 170-220 GHz.

[0021] A broadband non-contact terahertz near-field trace substance detection method includes the following steps:

[0022] The signal emitted by the vector network analyzer is frequency-doubled to the first terahertz detection band by the first terahertz S-parameter detection module. After transmission, it is collimated by the first lens, illuminates the first frequency-selective surface, and passes through. After the optical path is deflected by the first reflector, it illuminates the extended hemispherical lens. The extended hemispherical lens focuses the collimated terahertz signal onto the trace substance detection chip. The terahertz signal carrying the sample information is then transmitted through the extended hemispherical lens and the second reflector to the second frequency-selective surface, and finally reaches the third terahertz S-parameter detection module by the third lens. The third terahertz S-parameter detection module downconverts the detection signal to the microwave band, and then the vector network analyzer analyzes the characteristics of the detected sample.

[0023] The signal emitted by the vector network analyzer is frequency-doubled to terahertz detection band two by the terahertz S-parameter detection module. After transmission, it is collimated by lens two, illuminates frequency selective surface one, and reflected to mirror one. After optical path deflection by mirror one, it illuminates the extended hemispherical lens. The extended hemispherical lens focuses the collimated terahertz signal onto the trace substance detection chip. The terahertz signal carrying sample information is then transmitted through the extended hemispherical lens and mirror two, reflected by frequency selective surface two, and finally reaches terahertz S-parameter detection module four through lens four. Terahertz S-parameter detection module four downconverts the detection signal to the microwave band, and then the vector network analyzer analyzes the characteristics of the detected sample.

[0024] In the above scheme, the receiving antenna of the trace substance detection chip receives the terahertz signal, which is divided into two signals of equal amplitude and phase by a power divider. The two signals pass through a phase shifter and a phase shifter, respectively. The two phase-shifted signals are transmitted through a near-field sensing unit and a near-field sensing unit, respectively. A detection sample and a reference sample are placed on the near-field sensing unit and the near-field sensing unit, respectively. After the signal interacts with the detection sample and the reference sample, the two terahertz signals carrying the sample information are combined into one terahertz signal after passing through a power divider, forming an interference terahertz signal. This signal is transmitted to the extended hemispherical lens by the transmitting antenna.

[0025] In the above scheme, the detection of terahertz detection band one and terahertz detection band two are carried out separately.

[0026] Through the above technical solution, the broadband non-contact terahertz near-field trace substance detection device and method provided by the present invention have the following beneficial effects:

[0027] This invention introduces a non-contact detection method into trace substance detection technology. It achieves the detection of trace substances through terahertz near-field detection technology based on the interference principle, and uses quasi-optical technology to realize non-contact connection between the trace substance detection chip and the terahertz S-parameter detection module. At the same time, it uses quasi-optical band splicing technology to achieve detection in a wide range, which can improve the detection speed of the sample and realize broadband non-destructive non-contact detection of the sample. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0029] Figure 1 This is a schematic diagram of a broadband non-contact terahertz near-field trace substance detection device disclosed in an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of the internal structure of the trace substance detection chip disclosed in the embodiments of the present invention.

[0031] In the diagram, 1. Vector network analyzer; 2. Extended hemispherical lens; 3. Trace substance detection chip; 4. Terahertz S-parameter detection module one; 5. Lens one; 6. Terahertz S-parameter detection module two; 7. Lens two; 8. Frequency selective surface one; 9. Mirror one; 10. Terahertz S-parameter detection module three; 11. Lens three; 12. Terahertz S-parameter detection module four; 13. Lens four; 14. Frequency selective surface two; 15. Mirror two. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0033] This invention provides a broadband non-contact terahertz near-field trace substance detection device, such as... Figure 1 As shown, it includes a vector network analyzer 1, a terahertz signal transmitter, an extended hemispherical lens 2, a trace substance detection chip 3, and a terahertz signal receiver.

[0034] The terahertz signal transmitter includes a terahertz S-parameter detection module 1 (4), a lens 1 (5), a terahertz S-parameter detection module 2 (6), a lens 2 (7), a frequency selective surface 1 (8), and a reflector 1 (9); the terahertz signal receiver includes a terahertz S-parameter detection module 3 (10), a lens 3 (11), a terahertz S-parameter detection module 4 (12), a lens 4 (13), a frequency selective surface 2 (14), and a reflector 2 (15).

[0035] Terahertz S-parameter detection module 4 is used to multiply the signal emitted by vector network analyzer 1 to the terahertz band.

[0036] Terahertz S-parameter detection module 26 is used to multiply the signal emitted by vector network analyzer 1 to the terahertz band 2;

[0037] Lens 1 (5), Lens 2 (7), Lens 3 (11), and Lens 4 (13) are used to collimate terahertz signals;

[0038] Frequency selective surface 1 (8) and frequency selective surface 2 (14) are used to achieve total signal transmission in terahertz band 1 and total signal reflection in terahertz band 2.

[0039] Reflector 9 is used to reflect the signal passing through frequency selective surface 8 to extended hemispherical lens 2;

[0040] Reflector 2 15 is used to reflect the signal that has passed through the extended hemispherical lens 2 to the frequency selective surface 2 14;

[0041] The extended hemispherical lens 2 is used to transmit the signal reflected by the reflector 9 to the trace substance detection chip 3, and to transmit the signal passed through the trace substance detection chip 3 to the reflector 15.

[0042] The trace substance detection chip 3 is based on the principle of interference. It is used to transmit the received terahertz signal in two paths to the detection sample and the reference sample on it, and to combine the detection signals carrying sample information to form an interference terahertz signal, which is then transmitted to the extended hemispherical lens 2.

[0043] Terahertz S-parameter detection module 310 is used to downconvert the received terahertz band 1 signal to the microwave band and transmit it to the vector network analyzer 1;

[0044] Terahertz S-parameter detection module 4 12 is used to downconvert the received terahertz band 2 signal to the microwave band and transmit it to the vector network analyzer 1;

[0045] The vector network analyzer 1 is used to transmit and receive signals, as well as to analyze the properties of the substance to be tested.

[0046] Specifically, such as Figure 2 As shown, the trace substance detection chip 3 includes a receiving antenna, a power divider I, a phase shifter group, a near-field sensing unit group, a power divider II, and a transmitting antenna arranged sequentially in the signal transmission direction. The phase shifter group includes phase shifter I and phase shifter II connected in parallel. The near-field sensing unit group includes near-field sensing unit I and near-field sensing unit II connected in parallel. The detection sample and the reference sample are respectively placed on near-field sensing unit I and near-field sensing unit II.

[0047] Specifically, the transmitting or receiving ends of the terahertz S-parameter detection module 1 (4), terahertz S-parameter detection module 2 (6), terahertz S-parameter detection module 3 (10), and terahertz S-parameter detection module 4 (12) are all equipped with horn antennas for transmitting or receiving signals.

[0048] A broadband non-contact terahertz near-field trace substance detection method includes the following steps:

[0049] The signal emitted by the vector network analyzer 1 is frequency-multiplied by the terahertz S-parameter detection module to the terahertz detection band 1, transmitted by the horn antenna, collimated by the lens 5, and irradiated onto the frequency-selective surface 8 and transmitted through it. After the optical path is deflected by the reflector 9, it irradiates the extended hemispherical lens 2. The extended hemispherical lens 2 focuses the collimated terahertz signal onto the trace substance detection chip 3. The receiving antenna of the trace substance detection chip 3 receives the terahertz signal, which is divided into two signals of equal amplitude and phase by a power divider. The two signals pass through a phase shifter and a phase shifter, respectively. After phase shifting, the two signals are transmitted through a near-field sensing unit and a near-field sensing unit, respectively. A detection sample and a reference sample are placed on the near-field sensing unit and the near-field sensing unit, respectively. After interacting with the detection sample and the reference sample, the two terahertz signals carrying sample information are combined into one terahertz signal after passing through the power divider. This signal is transmitted by the transmitting antenna to the extended hemispherical lens 2. After being reflected by the second reflector 15, it is transmitted to the frequency selective surface 14 and finally reaches the terahertz S-parameter detection module 10 through the lens 11. The terahertz S-parameter detection module 10 downconverts the detection signal to the microwave frequency band, and then the vector network analyzer 1 analyzes the characteristics of the detection sample.

[0050] The signal emitted by the vector network analyzer 1 is frequency-multiplied by the terahertz S-parameter detection module 2 to the terahertz detection band 2. After transmission, it is collimated by the lens 2 7 and reflected onto the frequency selection surface 1 8, then reflected by the mirror 1 9. After the optical path is deflected by the mirror 1 9, it is reflected onto the extended hemispherical lens 2. The extended hemispherical lens 2 focuses the collimated terahertz signal onto the trace substance detection chip 3. The receiving antenna of the trace substance detection chip 3 receives the terahertz signal, which is then divided into two signals of equal amplitude and phase by a power divider. The two signals pass through a phase shifter and a phase shifter, respectively, and are transmitted through a near-field sensing unit and a near-field sensing unit. A detection sample and a reference sample are placed on the near-field sensing unit and the near-field sensing unit, respectively. After interacting with the detection sample and the reference sample, the two terahertz signals carrying sample information are combined into one interference terahertz signal after passing through a power divider. This signal is transmitted by the transmitting antenna to the extended hemispherical lens 2; then reflected by a mirror 15, and after reflection by a frequency selective surface 14, it finally reaches the terahertz S-parameter detection module 12 through a lens 13. The terahertz S-parameter detection module 12 downconverts the detection signal to the microwave frequency band, and then the vector network analyzer 1 analyzes the characteristics of the detection sample.

[0051] In this embodiment, the first terahertz detection band is 110-170 GHz, and the second terahertz detection band is 170-220 GHz. The detection of the two bands is performed separately.

[0052] Because the detection device uses band splicing technology, when detecting the frequency characteristics of different bands, there is no need to replace the terahertz S-parameter detection module and readjust the optical path. Only the trace substance detection chip 3 at different detection frequencies needs to be replaced, which can greatly improve the detection speed.

[0053] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A broadband non-contact terahertz near-field trace substance detection device, characterized in that, The system includes a vector network analyzer, a terahertz signal transmitter, an extended hemispherical lens, a trace substance detection chip, and a terahertz signal receiver. The terahertz signal transmitter includes a terahertz S-parameter detection module one, a lens one, a terahertz S-parameter detection module two, a lens two, a frequency selective surface one, and a reflector one. The terahertz signal receiver includes a terahertz S-parameter detection module three, a lens three, a terahertz S-parameter detection module four, a lens four, a frequency selective surface two, and a reflector two. The terahertz S-parameter detection module is used to multiply the signal emitted by the vector network analyzer to the terahertz band. The second terahertz S-parameter detection module is used to multiply the signal emitted by the vector network analyzer to the second terahertz band. Lens 1, Lens 2, Lens 3 and Lens 4 are used to collimate terahertz signals; The frequency selective surface one and frequency selective surface two are used to achieve full transmission of signals in terahertz band one and total reflection of signals in terahertz band two. The first reflector is used to reflect the signal passing through the first frequency-selective surface to the extended hemispherical lens; The second reflector is used to reflect the signal that has passed through the extended hemispherical lens to the second frequency selective surface; The extended hemispherical lens is used to transmit the signal reflected by the first reflector to the trace substance detection chip, and to transmit the signal passed through the trace substance detection chip to the second reflector. The trace substance detection chip is based on the principle of interference. It is used to transmit the received terahertz signal in two paths to the detection sample and the reference sample, and to combine the detection signals carrying sample information to form an interferometric terahertz signal, which is then transmitted to the extended hemispherical lens. The third terahertz S-parameter detection module is used to downconvert the received signal from the first terahertz band to the microwave band and transmit it to the vector network analyzer. The fourth terahertz S-parameter detection module is used to downconvert the received terahertz band II signal to the microwave band and transmit it to the vector network analyzer. The vector network analyzer is used to transmit signals, receive signals, and analyze the properties of the substance to be tested. The trace substance detection chip includes a receiving antenna, a power divider I, a phase shifter group, a near-field sensing unit group, a power divider II, and a transmitting antenna arranged sequentially in the signal transmission direction. The phase shifter group includes a phase shifter I and a phase shifter II connected in parallel. The near-field sensing unit group includes a near-field sensing unit I and a near-field sensing unit II connected in parallel. The detection sample and the reference sample are respectively placed on the near-field sensing unit I and the near-field sensing unit II. Terahertz detection band 1 is 110-170 GHz, and terahertz detection band 2 is 170-220 GHz.

2. The broadband non-contact terahertz near-field trace substance detection device according to claim 1, characterized in that, The transmitting or receiving ends of the terahertz S-parameter detection modules 1, 2, 3, and 4 are all equipped with horn antennas.

3. A broadband non-contact terahertz near-field trace substance detection method, employing the broadband non-contact terahertz near-field trace substance detection device as described in claim 1, characterized in that, The process includes the following: The signal emitted by the vector network analyzer is frequency-doubled to the first terahertz detection band by the first terahertz S-parameter detection module. After transmission, it is collimated by the first lens, illuminates the first frequency-selective surface, and passes through. After the optical path is deflected by the first reflector, it illuminates the extended hemispherical lens. The extended hemispherical lens focuses the collimated terahertz signal onto the trace substance detection chip. The terahertz signal carrying the sample information is then transmitted through the extended hemispherical lens and the second reflector to the second frequency-selective surface, and finally reaches the third terahertz S-parameter detection module by the third lens. The third terahertz S-parameter detection module downconverts the detection signal to the microwave band, and then the vector network analyzer analyzes the characteristics of the detected sample. The signal emitted by the vector network analyzer is frequency-doubled to terahertz detection band two by the terahertz S-parameter detection module. After transmission, it is collimated by lens two, illuminates frequency selective surface one, and reflected to mirror one. After optical path deflection by mirror one, it illuminates the extended hemispherical lens. The extended hemispherical lens focuses the collimated terahertz signal onto the trace substance detection chip. The terahertz signal carrying sample information is then transmitted through the extended hemispherical lens and mirror two, reflected by frequency selective surface two, and finally reaches terahertz S-parameter detection module four through lens four. Terahertz S-parameter detection module four downconverts the detection signal to the microwave band, and then the vector network analyzer analyzes the characteristics of the detected sample.

4. The broadband non-contact terahertz near-field trace substance detection method according to claim 3, characterized in that, The receiving antenna of the trace substance detection chip receives terahertz signals, which are then divided into two signals of equal amplitude and phase by a power divider. The two signals pass through a phase shifter and a phase shifter, respectively. After phase shifting, the two signals are transmitted through a near-field sensing unit and a near-field sensing unit, respectively. A detection sample and a reference sample are placed on the near-field sensing unit and the near-field sensing unit, respectively. After interacting with the detection sample and the reference sample, the two terahertz signals carrying sample information are combined into one terahertz signal after passing through a power divider, forming an interference terahertz signal. This signal is 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, characterized in that, The detection in terahertz detection band 1 and terahertz detection band 2 are performed separately.

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