CN115265770A - Terahertz-based detectors and equipment - Google Patents

Abstract

The present application relates to a terahertz-based detector and equipment. The terahertz-based detector includes a waveform generator, a transmitting antenna, a receiving antenna, at least two-stage filter circuits and a signal processing module, and the waveform generator is used to generate a terahertz triangular wave, The transmitting antenna is used to transmit the corresponding signal of the terahertz triangular wave, the receiving antenna is used to receive the corresponding signal of the terahertz triangular wave, and the at least two-stage filter circuit is used to filter the corresponding signal of the terahertz triangular wave at least twice, and the signal processing module is used to After filtering, the terahertz triangular wave corresponds to the signal output detection result. In the present application, at least two-stage filter circuits are used to filter the corresponding signal of the terahertz triangular wave at least twice, which can filter out the interference signal and make the detection result more accurate.

Description

Terahertz-based detectors and devices

technical field

The application belongs to the technical field of detectors, and in particular relates to a terahertz-based detector and equipment.

Background technique

Terahertz (THz) wave/radiation is a general term for a specific electromagnetic radiation. The frequency of terahertz wave is between 0.1THz and 10THz, and the wavelength is between 0.03mm and 3mm between microwave and infrared. In the field of electronics, Known as millimeter waves and submillimeter waves, in the field of spectroscopy, they are also known as far-infrared rays. Because terahertz radiation has so many advantages, researchers from all over the world have devoted a lot of energy to research on terahertz radiation. After rapid development in recent years, important progress has been made in the fields of terahertz spectroscopy, terahertz communication, terahertz radar and terahertz imaging. In particular, terahertz imaging has been initially applied in the fields of non-destructive testing and security inspection. However, since the modulation based on terahertz detection is susceptible to interference from signals in other frequency bands, the detection results are inaccurate, which affects the use of users.

Contents of the invention

In order to overcome at least to a certain extent the problem that traditional terahertz-based detectors are easily interfered by signals in other frequency bands during modulation, resulting in inaccurate detection results and affecting users' use, the present application provides a terahertz-based detector and equipment.

In a first aspect, the present application provides a terahertz-based detector, including:

A waveform generator, a transmitting antenna, a receiving antenna, at least two stages of filtering circuits and a signal processing module;

The waveform generator is used to generate a terahertz triangle wave;

The transmitting antenna is used to transmit a signal corresponding to the terahertz triangle wave outward;

The receiving antenna is used to receive the signal corresponding to the terahertz triangle wave;

The at least two-stage filter circuit is used to perform at least two filter processes on the signal corresponding to the terahertz triangle wave;

The signal processing module is used to output detection results according to the signal corresponding to the filtered terahertz triangle wave.

Further, it also includes:

A voltage-controlled oscillator, the voltage-controlled oscillator is used to generate a triangular wave sweep signal according to the terahertz triangular wave.

Further, it also includes:

Power splitters and amplifiers;

The power splitter is used to distribute power to the triangular wave sweep signal to generate two or more triangular wave sweep signals;

The amplifier is used to perform signal amplification processing on the two or more triangular wave sweep signals;

The transmitting antenna is also used to transmit the two or more channels of triangular wave sweeping signals after the signal amplification and processing to the outside.

Further, it also includes:

A low-noise amplifier, the low-noise amplifier is used to receive the two-way or multi-way triangular wave sweep signals to generate receiving signals;

A mixer, the mixer is used to output a difference frequency signal according to the local signal and the received signal.

Further, the at least two-stage filter circuit includes:

A first-stage filter circuit and a second-stage filter circuit, the difference frequency signal enters the second-stage filter circuit after being filtered by the first-stage filter circuit, and the second-stage filter circuit outputs an intermediate frequency amplified differential signal after filtering.

Further, the first stage filter circuit includes:

a first amplifier, a first low-pass filter circuit and a first high-pass filter circuit;

The first low-pass filter circuit is used to filter out modulated interference signals in the difference frequency signal;

The first high-pass filter circuit is used to filter out high-frequency interference signals in the difference frequency signal;

The first amplifier includes a first input terminal and a second input terminal, and the first low-pass filter circuit includes a first resistor and a first capacitor connected in series, and a second resistor and a second capacitor connected in series, the first The input terminal is connected in series with the first resistor and the first capacitor, and the second input terminal is connected in series with the second resistor and the second capacitor;

The first amplifier also includes a first output terminal and a second output terminal, the first high-pass filter circuit includes a third resistor, a third capacitor connected in parallel, and a fourth resistor and a fourth capacitor connected in parallel, the The third resistor and the third capacitor are connected in parallel between the first input terminal and the first output terminal; the fourth resistor and the fourth capacitor are connected in parallel between the second input terminal and the second output terminal.

Further, the second stage filter circuit includes:

a second amplifier, a second low-pass filter circuit and a second high-pass filter circuit;

The second low-pass filter circuit is used to filter out the modulated interference signal in the output signal of the first-stage filter circuit;

The second high-pass filter circuit is used to filter out high-frequency interference signals in the output signal of the first-stage filter circuit;

The second amplifier includes a third input terminal and a fourth input terminal, and the second low-pass filter circuit includes a fifth resistor and a fifth capacitor connected in series, and a sixth resistor and a sixth capacitor connected in series, the second The three input terminals are connected in series with the fifth resistor and the fifth capacitor, and the fourth input terminal is connected in series with the sixth resistor and the sixth capacitor;

The second amplifier also includes a third output terminal and a fourth output terminal, the second high-pass filter circuit includes a seventh resistor and a seventh capacitor connected in parallel, and an eighth resistor and an eighth capacitor connected in parallel, the The seventh resistor and the seventh capacitor are connected in parallel between the third input terminal and the third output terminal; the eighth resistor and the eighth capacitor are connected in parallel between the fourth input terminal and the fourth output terminal.

Further, the signal processing module includes:

An analog-to-digital conversion module, which is used to perform analog-to-digital conversion on the intermediate frequency amplified differential signal to generate a difference frequency signal frequency;

The digital processing module is used to calculate the distance from the frequency of the difference frequency signal to calculate the distance R to the detection target:

其中，c为光速，T为扫频时宽，Δf为差频信号频率，B为扫频带宽。

Among them, c is the speed of light, T is the sweep time width, Δf is the difference frequency signal frequency, and B is the sweep bandwidth.

In a second aspect, the present application provides a device, including:

A terahertz-based detector as described in the first aspect.

The technical solutions provided by the embodiments of the present application may include the following beneficial effects:

The terahertz-based detector and equipment provided by the embodiments of the present invention, the terahertz-based detector includes a waveform generator, a transmitting antenna, a receiving antenna, at least two stages of filtering circuits and a signal processing module, and the waveform generator is used to generate a terahertz triangular wave , the transmitting antenna is used to transmit the signal corresponding to the terahertz triangular wave, the receiving antenna is used to receive the signal corresponding to the terahertz triangular wave, at least two stages of filtering circuits are used to filter the signal corresponding to the terahertz triangular wave at least twice, and the signal processing module is used for According to the output detection result of the signal corresponding to the terahertz triangular wave after the filter processing, at least two stages of filter circuits are used to filter the signal corresponding to the terahertz triangular wave at least twice, so that the interference signal can be filtered out to make the detection result more accurate.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description serve to explain the principles of the application.

FIG. 1 is a functional structural diagram of a terahertz-based detector provided by an embodiment of the present application.

FIG. 2 is a functional structural diagram of another terahertz-based detector provided by an embodiment of the present application.

FIG. 3 is a circuit diagram of a two-stage filter circuit provided by an embodiment of the present application.

Detailed ways

In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be described in detail below. Apparently, the described embodiments are only some of the embodiments of this application, not all of them. Based on the embodiments in the present application, all other implementation manners obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present application.

Fig. 1 is a functional diagram of a terahertz-based detector provided by an embodiment of the present application. As shown in Fig. 1, the terahertz-based detector includes:

A waveform generator 101, a transmitting antenna 102, a receiving antenna 103, at least two stages of filtering circuits 104 and a signal processing module 105;

The waveform generator 101 is used to generate a terahertz triangle wave;

The transmitting antenna 102 is used to transmit the signal corresponding to the terahertz triangle wave to the outside;

The receiving antenna 103 is used to receive the signal corresponding to the terahertz triangle wave;

The at least two-stage filter circuit 104 is used to perform at least two filter processes on the signal corresponding to the terahertz triangle wave;

The signal processing module 105 is configured to output detection results according to the signal corresponding to the filtered terahertz triangle wave.

The traditional terahertz-based detection modulation is susceptible to interference from signals in other frequency bands, resulting in inaccurate detection results and affecting user use.

In this embodiment, the terahertz-based detector includes a waveform generator, a transmitting antenna, a receiving antenna, at least two stages of filter circuits and a signal processing module, the waveform generator is used to generate a terahertz triangle wave, and the transmitting antenna is used to emit The signal corresponding to the triangular wave, the receiving antenna is used to receive the signal corresponding to the terahertz triangular wave, the at least two-stage filter circuit is used to filter the signal corresponding to the terahertz triangular wave at least twice, and the signal processing module is used to output the signal corresponding to the terahertz triangular wave according to the filter processing As for the detection result, the at least two-stage filter circuit is used to filter the signal corresponding to the terahertz triangular wave at least twice, so that the interference signal can be filtered out, so that the detection result is more accurate.

The embodiment of the present invention provides another terahertz-based detector, as shown in the functional structure diagram in FIG. 2 . On the basis of the previous embodiment, the terahertz-based detector further includes:

A voltage-controlled oscillator 106, the voltage-controlled oscillator 106 is used to generate a triangular wave sweep signal according to the terahertz triangular wave.

Power divider 107, power divider 107 is used to carry out power distribution to triangular wave sweep signal and generate two-way or multi-way triangular wave sweep signal;

Amplifier 108, the amplifier 108 is used to perform signal amplification processing on two-way or multi-way triangular wave sweep signals;

The transmitting antenna 102 is also used to transmit the amplified and processed two-way or multi-way triangular wave frequency sweep signals to the outside.

Low noise amplifier 109, the low noise amplifier 109 is used to receive two or more triangular wave sweep signals to generate receiving signals;

Low-noise amplifier (LNA) is a special type of electronic amplifier, which is mainly used in the communication system to amplify the signal received from the antenna, so as to facilitate the processing of the subsequent electronic equipment. Since the signal from the antenna is generally very weak, the low noise amplifier is generally located very close to the antenna to reduce the loss of the signal passing through the transmission line.

A mixer 110, the mixer 110 is configured to output a difference frequency signal according to the local signal and the received signal.

In this embodiment, the detector is a short-distance detector with an application range of 2m-30m. The continuous wave frequency modulation system is adopted. There will be interference of the modulation frequency in the design circuit. The influence of the modulation frequency and the high sub-frequency interference.

In some embodiments, the at least two-stage filtering circuit 104 includes:

The first-stage filter circuit and the second-stage filter circuit, the difference frequency signal enters the second-stage filter circuit after being filtered by the first-stage filter circuit, and the second-stage filter circuit outputs an intermediate frequency amplified differential signal after filtering.

As shown in Figure 3, the first-stage filter circuit includes:

a first amplifier, a first low-pass filter circuit and a first high-pass filter circuit;

The first low-pass filter circuit is used to filter out the modulated interference signal in the difference frequency signal;

The first high-pass filter circuit is used to filter out high-frequency interference signals in the difference frequency signal;

The first amplifier includes a first input terminal and a second input terminal, the first low-pass filter circuit includes a first resistor R1, a first capacitor C1 connected in series, and a second resistor R3 and a second capacitor C3 connected in series, the first The input terminal is connected in series with the first resistor R1 and the first capacitor C1, and the second input terminal is connected in series with the second resistor R3 and the second capacitor C3;

The first amplifier also includes a first output terminal and a second output terminal, the first high-pass filter circuit includes a third resistor R2, a third capacitor C2 connected in parallel, and a fourth resistor R4 and a fourth capacitor C4 connected in parallel, the third The resistor R2 and the third capacitor C2 are connected in parallel between the first input terminal and the first output terminal; the fourth resistor R4 and the fourth capacitor C4 are connected in parallel between the second input terminal and the second output terminal.

The second stage filter circuit includes:

a second amplifier, a second low-pass filter circuit and a second high-pass filter circuit;

The second low-pass filter circuit is used to filter out the modulated interference signal in the output signal of the first-stage filter circuit;

The second high-pass filter circuit is used to filter out the high-frequency interference signal in the output signal of the first-stage filter circuit;

The second amplifier includes a third input terminal and a fourth input terminal, and the second low-pass filter circuit includes a fifth resistor R5, a fifth capacitor C5 connected in series, and a sixth resistor R7 and a sixth capacitor C7 connected in series , the third input terminal is connected in series with the fifth resistor R5 and the fifth capacitor C5, and the fourth input terminal is connected in series with the sixth resistor R7 and the sixth capacitor C7;

The second amplifier also includes a third output terminal and a fourth output terminal, and the second high-pass filter circuit includes a seventh resistor R6, a seventh capacitor C6 connected in parallel, and an eighth resistor R8 and an eighth capacitor C8 connected in parallel, the The seventh resistor R6 and the seventh capacitor C6 are connected in parallel between the third input terminal and the third output terminal; the eighth resistor R8 and the eighth capacitor C8 are connected in parallel between the fourth input terminal and the fourth output terminal.

In some embodiments, the signal processing module 105 includes:

An analog-to-digital conversion module, which is used to perform analog-to-digital conversion on the intermediate frequency amplified differential signal to generate a difference frequency signal frequency;

The digital processing module is used to calculate the distance from the frequency of the difference frequency signal to calculate the distance R to the detection target:

其中，c为光速，T为扫频时宽，Δf为差频信号频率，B为扫频带宽。

Among them, c is the speed of light, T is the sweep time width, Δf is the difference frequency signal frequency, and B is the sweep bandwidth.

The speed of light is a definite value, and the sweep time width and sweep bandwidth are determined by hardware and software design, so the distance value to the object under test can be obtained by difference frequency signal frequency.

Terahertz has good penetrability to many dielectric materials and non-polar substances, and can perform perspective imaging on opaque objects. It is an effective complement to X-ray imaging and ultrasonic imaging technologies. In addition, the transmission loss of terahertz is very small in the environment of dense smoke and dust.

The energy of terahertz radiation is only on the order of millielectron volts, and its energy is lower than the bond energy of various chemical bonds, so it will not cause harmful ionization reactions. In addition, because water has a very strong absorption of terahertz waves, too Hertzian waves cannot penetrate human skin.

Safety design, terahertz is also a frequency band that is not commonly used in the field of detectors at present, so it has the advantages of not being interfered by signals of other frequency bands and not detected by receivers of other frequency bands in complex environments. This feature is very practical for drones.

In some embodiments, the terahertz-based detector adopts a miniaturized design, the size of which is the size of a dollar coin, and can be applied to various application scenarios, and is easy to install and use.

The terahertz-based detector provided in this embodiment adopts a combination of two-stage amplification and filtering circuits, and will not be interfered by signals in other frequency bands. The radio frequency band is terahertz, and the signal will not be detected by receivers in other frequency bands, thereby improving detection accuracy.

An embodiment of the present invention provides a device, including: the terahertz-based detector as described in the above embodiments.

In some embodiments, the device is a drone, and the terahertz-based detector is arranged on the drone.

It can be understood that, the same or similar parts in the above embodiments can be referred to each other, and the content that is not described in detail in some embodiments can be referred to the same or similar content in other embodiments.

It should be noted that in the description of the present application, terms such as "first" and "second" are used for description purposes only, and should not be understood as indicating or implying relative importance. In addition, in the description of the present application, unless otherwise specified, the meaning of "plurality" means at least two.

Any process or method descriptions in flowcharts or otherwise described herein may be understood to represent modules, segments or portions of code comprising one or more executable instructions for implementing specific logical functions or steps of the process , and the scope of preferred embodiments of the present application includes additional implementations in which functions may be performed out of the order shown or discussed, including in substantially simultaneous fashion or in reverse order depending on the functions involved, which shall It should be understood by those skilled in the art to which the embodiments of the present application belong.

It should be understood that each part of the present application may be realized by hardware, software, firmware or a combination thereof. In the embodiments described above, various steps or methods may be implemented by software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one or combination of the following techniques known in the art: Discrete logic circuits, ASICs with suitable combinational logic gates, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

Those of ordinary skill in the art can understand that all or part of the steps carried by the methods of the above embodiments can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. During execution, one or a combination of the steps of the method embodiments is included.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing module, each unit may exist separately physically, or two or more units may be integrated into one module. The above-mentioned integrated modules can be implemented in the form of hardware or in the form of software function modules. If the integrated modules are realized in the form of software function modules and sold or used as independent products, they can also be stored in a computer-readable storage medium.

The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, and the like.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations on the present application, and those skilled in the art can make the above-mentioned The embodiments are subject to changes, modifications, substitutions and variations.

It should be noted that the present invention is not limited to the above-mentioned preferred embodiment, and those skilled in the art can draw other various forms of products under the enlightenment of the present invention, but no matter make any changes in its shape or structure, any Technical solutions that are identical or similar to those of the present application all fall within the protection scope of the present invention.

Claims (9)

1. A detector based on terahertz, comprising: A waveform generator, a transmitting antenna, a receiving antenna, at least two stages of filtering circuits and a signal processing module; The waveform generator is used to generate a terahertz triangle wave; The transmitting antenna is used to transmit a signal corresponding to the terahertz triangle wave outward; The receiving antenna is used to receive the signal corresponding to the terahertz triangle wave; The at least two-stage filter circuit is used to perform at least two filter processes on the signal corresponding to the terahertz triangle wave; The signal processing module is used to output detection results according to the signal corresponding to the filtered terahertz triangle wave. 2. The terahertz-based detector according to claim 1, further comprising: A voltage-controlled oscillator, the voltage-controlled oscillator is used to generate a triangular wave sweep signal according to the terahertz triangular wave. 3. The terahertz-based detector according to claim 2, further comprising: Power splitters and amplifiers; The power splitter is used to distribute power to the triangular wave sweep signal to generate two or more triangular wave sweep signals; The amplifier is used to perform signal amplification processing on the two or more triangular wave sweep signals; The transmitting antenna is also used to transmit the two or more channels of triangular wave sweeping signals after the signal amplification and processing to the outside. 4. The terahertz-based detector according to claim 3, further comprising: A low-noise amplifier, the low-noise amplifier is used to receive the two-way or multi-way triangular wave sweep signals to generate receiving signals; A mixer, the mixer is used to output a difference frequency signal according to the local signal and the received signal. 5. The terahertz-based detector according to claim 4, wherein the at least two-stage filtering circuit comprises: A first-stage filter circuit and a second-stage filter circuit, the difference frequency signal enters the second-stage filter circuit after being filtered by the first-stage filter circuit, and the second-stage filter circuit outputs an intermediate frequency amplified differential signal after filtering. 6. The terahertz-based detector according to claim 5, wherein the first stage filter circuit comprises: a first amplifier, a first low-pass filter circuit and a first high-pass filter circuit; The first low-pass filter circuit is used to filter out modulated interference signals in the difference frequency signal; The first high-pass filter circuit is used to filter out high-frequency interference signals in the difference frequency signal; The first amplifier includes a first input terminal and a second input terminal, and the first low-pass filter circuit includes a first resistor and a first capacitor connected in series, and a second resistor and a second capacitor connected in series, the first The input terminal is connected in series with the first resistor and the first capacitor, and the second input terminal is connected in series with the second resistor and the second capacitor; The first amplifier also includes a first output terminal and a second output terminal, the first high-pass filter circuit includes a third resistor, a third capacitor connected in parallel, and a fourth resistor and a fourth capacitor connected in parallel, the The third resistor and the third capacitor are connected in parallel between the first input terminal and the first output terminal; the fourth resistor and the fourth capacitor are connected in parallel between the second input terminal and the second output terminal. 7. The terahertz-based detector according to claim 5, wherein the second stage filter circuit comprises: a second amplifier, a second low-pass filter circuit and a second high-pass filter circuit; The second low-pass filter circuit is used to filter out the modulated interference signal in the output signal of the first-stage filter circuit; The second high-pass filter circuit is used to filter out high-frequency interference signals in the output signal of the first-stage filter circuit; The second amplifier includes a third input terminal and a fourth input terminal, and the second low-pass filter circuit includes a fifth resistor and a fifth capacitor connected in series, and a sixth resistor and a sixth capacitor connected in series, the first The three input terminals are connected in series with the fifth resistor and the fifth capacitor, and the fourth input terminal is connected in series with the sixth resistor and the sixth capacitor; The second amplifier also includes a third output terminal and a fourth output terminal, the second high-pass filter circuit includes a seventh resistor and a seventh capacitor connected in parallel, and an eighth resistor and an eighth capacitor connected in parallel, the The seventh resistor and the seventh capacitor are connected in parallel between the third input terminal and the third output terminal; the eighth resistor and the eighth capacitor are connected in parallel between the fourth input terminal and the fourth output terminal. 8. The terahertz-based detector according to claim 5, wherein the signal processing module comprises: An analog-to-digital conversion module, which is used to perform analog-to-digital conversion on the intermediate frequency amplified differential signal to generate a difference frequency signal frequency; The digital processing module is used to calculate the distance from the frequency of the difference frequency signal to calculate the distance R to the detection target:

Among them, c is the speed of light, T is the sweep time width, Δf is the difference frequency signal frequency, and B is the sweep bandwidth. 9. A device, characterized by comprising: the terahertz-based detector according to any one of claims 1-8.

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