WO2024055600A1

WO2024055600A1 - Terahertz radar system, front end, and waveguide structure

Info

Publication number: WO2024055600A1
Application number: PCT/CN2023/092067
Authority: WO
Inventors: 张波; 牛中乾; 孟祥翱; 于馨菲; 袁军; 马飞; 周闻达
Original assignee: 四川太赫兹通信有限公司
Priority date: 2022-09-15
Filing date: 2023-05-04
Publication date: 2024-03-21
Also published as: CN115207587B; CN115207587A

Abstract

The present invention relates to the technical field of terahertz radars, and in particular to a terahertz radar system, a front end, and a waveguide structure. The waveguide structure comprises an upper waveguide cavity, a middle waveguide cavity, and a lower waveguide cavity; a transmitting antenna cavity and a first radio frequency channel are arranged between the upper waveguide cavity and the middle waveguide cavity; and a receiving antenna cavity and a second radio frequency channel are arranged between the middle waveguide cavity and the lower waveguide cavity. According to the present invention, the upper waveguide cavity, the middle waveguide cavity, and the lower waveguide cavity are combined together to form a waveguide structure, and a signal transmitting terahertz radio frequency circuit and a signal receiving terahertz radio frequency circuit of the terahertz radar system are respectively mounted by using the first radio frequency channel and the second radio frequency channel, thereby ensuring the channel consistency between the first radio frequency channel and the second radio frequency channel, effectively reducing the volume of the front end of the terahertz radar system, and achieving the miniaturized integrated arrangement of the terahertz radar system.

Description

A terahertz radar system, front end and waveguide structure

Technical field

The invention relates to the technical field of terahertz radar, and in particular to a terahertz radar system, front end and waveguide structure.

Background technique

At present, preliminary research on terahertz solid-state radar systems has been conducted internationally, but the imaging resolution and frame rate cannot meet application requirements at the same time, and in complex environments, new complex targets such as drone groups and micro-gestures are still unable to be clearly detected. Fast imaging or identification is mainly due to the fact that terahertz solid-state radar systems still mainly use single transmitter and single receiver or non-integrated multiple transmitters and multiple receivers. A single transmitter and a single receiver will result in an insufficient number of RF channels, making it impossible to effectively collect micro-Doppler information. Non-integrated multiple transmitters and multiple receivers will cause connection loss, and the consistency between channels is difficult to control, resulting in difficulties in identifying small targets. Inaccurate.

In addition, when combining the front end of the terahertz radar system with the rectangular waveguide structure, due to the small size of the terahertz circuit and the need for micromachining of the rectangular waveguide structure on pure metal, the processing flexibility is poor. Therefore, based on processing efficiency and processing Due to cost considerations, the existing technology generally uses a waveguide structure to match and install some circuit units in the front-end of the terahertz radar system, and then combines multiple waveguide structures to form a complete terahertz radar system front-end circuit. However, this method has many defects. The waveguide structure is large and cannot meet the miniaturization requirements of the front end of the terahertz radar system.

Contents of the invention

The purpose of this application is to provide a terahertz radar system, front end and waveguide structure to solve the above technical problems existing in the existing technology, mainly including the following three aspects:

The first aspect of this application provides a front-end waveguide structure of a terahertz radar system, including an upper waveguide cavity, a middle waveguide cavity and a lower waveguide cavity. At least one transmitting antenna is disposed between the upper waveguide cavity and the middle waveguide cavity. cavity, and a first radio frequency channel provided corresponding to the transmitting antenna cavity, the first radio frequency The channel is used to install the terahertz radio frequency circuit of the transmitting front end of the terahertz radar system. The first radio frequency channel is connected with the transmitting antenna cavity. At least one receiving antenna cavity is provided between the middle waveguide cavity and the lower waveguide cavity, and with the receiving antenna cavity. The antenna cavity corresponds to a second radio frequency channel, which is connected to the receiving antenna cavity. The second radio frequency channel is used to install the terahertz radio frequency circuit of the receiving front end of the terahertz radar system.

Further, the first radio frequency channel and the second radio frequency channel are respectively rectangular waveguide structures, and/or the transmitting antenna cavity and receiving antenna cavity are respectively standard waveguide horn antennas.

Further, the ratio of the length of the mouth surface of the transmitting antenna cavity, the width of the mouth surface of the transmitting antenna cavity, the length of the wide side of the first radio frequency channel and the length of the narrow side of the first radio frequency channel is 10:10:1.092:0.546, and the ratio of the length of the mouth surface of the transmitting antenna cavity is 10:10:1.092:0.546. The ratio of the length of the mouth surface, the width of the mouth surface of the receiving antenna cavity, the length of the wide side of the second radio frequency channel and the length of the narrow side of the second radio frequency channel is 10:10:1.092:0.546.

Further, the ratio of the depth of the transmitting antenna cavity to the depth of the first radio frequency channel, and the ratio of the depth of the receiving antenna cavity to the depth of the second radio frequency channel are both 25:20.

Further, the transmitting antenna cavity is at least partially disposed on the upper waveguide cavity, and the receiving antenna cavity is at least partially disposed on the lower waveguide cavity.

Further, when multiple first radio frequency channels are provided, the first radio frequency channels are arranged in parallel with each other, and/or, when multiple second radio frequency channels are provided, the second radio frequency channels are arranged in parallel with each other.

Further, the distance between the mouth surfaces of adjacent transmitting antenna cavities is 0.2 mm, and/or the distance between the mouth surfaces of adjacent receiving antenna cavities is 0.2 mm.

Further, when at least two intermediate waveguide cavities are provided between the upper waveguide cavity and the lower waveguide cavity, the intermediate waveguide cavities are arranged sequentially along the longitudinal direction;

At least one transmitting antenna cavity and a first radio frequency channel corresponding to the transmitting antenna cavity are provided between two adjacent intermediate waveguide cavities,

And/or, at least one receiving antenna cavity and a second radio frequency channel corresponding to the receiving antenna cavity are provided between two adjacent intermediate waveguide cavities.

The second aspect of this application provides a terahertz radar system front-end, including a local oscillator drive signal, a frequency multiplier amplifier, a multi-channel power divider, at least one signal transmitting terahertz radio frequency circuit, and at least one signal interface. The terahertz radio frequency receiving circuit and the above-mentioned front-end waveguide structure of the terahertz radar system, the local oscillator driving signal, the frequency multiplier amplifier, and the multi-channel power splitter are connected in sequence along the signal transmission direction. The signal input end of the signal transmitting terahertz radio frequency circuit and the signal The signal input terminals of the terahertz radio frequency receiving circuit are respectively connected to the signal output terminals of the multiplexer. The signal transmitting terahertz radio frequency circuit is arranged in the first radio frequency channel, and the signal receiving terahertz radio frequency circuit is arranged in the second radio frequency channel.

The third aspect of this application provides a terahertz radar system, which is characterized by including the above-mentioned terahertz radar system front-end waveguide structure, or the above-mentioned terahertz radar system front-end.

Compared with the prior art, the present invention at least has the following technical effects:

The present invention uses an upper waveguide cavity, a middle waveguide cavity and a lower waveguide cavity to form a waveguide structure, and uses the first radio frequency channel and the second radio frequency channel to respectively transmit the terahertz radio frequency circuit and signal to the signal of the terahertz radar system. The installation of the receiving terahertz radio frequency circuit not only integrates the transmitting front end and receiving front end of the terahertz radar system into a waveguide structure, but also ensures the channel consistency between the first radio frequency channel and the second radio frequency channel, and the radio frequency The high isolation between channels effectively reduces the front-end volume of the terahertz radar system, enabling the miniaturization and integration of the terahertz radar system, which is conducive to wider and more flexible applications of the terahertz communication system.

Description of drawings

In order to explain the technical solutions of the embodiments of the present invention more clearly, the drawings needed to be used in describing the embodiments of the present invention or the prior art will be briefly introduced below. Obviously, the drawings described below are only illustrative of the present invention. For some embodiments, for those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic structural diagram of the front-end waveguide structure of the terahertz radar system in Embodiment 1;

Figure 2 is a schematic exploded structural diagram of the front-end waveguide structure of the terahertz radar system in Embodiment 1;

Figure 3 is a schematic structural diagram of the upper waveguide cavity in Figure 1;

Figure 4 is a schematic structural diagram of the intermediate waveguide cavity in Figure 1;

Figure 5 is a schematic structural diagram of the lower waveguide cavity in Figure 1;

Figure 6 is another structural schematic diagram of the front-end waveguide structure of the terahertz radar system;

Figure 7 is a schematic diagram of the circuit connection of the front end of the terahertz radar system in Embodiment 2;

In the picture,
10. Upper waveguide cavity; 110. First radio frequency channel; 120. Transmitting antenna cavity; 20. Middle waveguide cavity; 30. Lower waveguide cavity; 310. Second radio frequency channel; 320. Receiving antenna cavity; 410. This Oscillation drive signal; 420, frequency multiplier amplifier; 430, multi-channel power divider; 440, first local oscillator drive frequency multiplier; 450, 340GHz frequency multiplier; 460, second local oscillator drive frequency multiplier; 470, 340GHz Subharmonic mixer.

Detailed ways

The following description provides many different embodiments, or examples, for implementing various features of the invention. The components and arrangements described in the following specific examples are only used to concisely express the present invention. They are only used as examples and are not intended to limit the present invention.

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention. Accordingly, the following detailed description of embodiments of the invention provided in the appended drawings is not intended to limit the scope of the claimed invention, but rather to represent selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

In the present invention, unless otherwise clearly stated and limited, the terms "installation", "connection", "connection", "fixing" and other terms should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. , or integrated; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements or an interaction between two elements. For those of ordinary skill in the art, it can be understood that the above terms are used in specific meaning in the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish descriptions and shall not be understood as indicating or implying relative importance.

In the present invention, unless otherwise clearly stated and limited, the first feature being above or below the second feature may include the first and second features being in direct contact, or the first and second features not being in direct contact. is through additional characteristic contact between them. Furthermore, the first feature on, above and above the second feature includes the first feature directly above and diagonally above the second feature, or simply means that the first feature is higher level than the second feature. The first feature below, below and below the second feature includes the first feature directly below and diagonally below the second feature, or simply means that the first feature has a smaller horizontal height than the second feature.

Example 1:

The embodiment of the present application provides a front-end waveguide structure of a terahertz radar system, as shown in Figures 1 and 2, including an upper waveguide cavity 10, a middle waveguide cavity 20 and a lower waveguide cavity 30. The upper waveguide cavity 10 and At least one transmitting antenna cavity 120 is disposed between the intermediate waveguide cavities 20, and a first radio frequency channel 110 is provided corresponding to the transmitting antenna cavity 120. The first radio frequency channel 110 is used to install the terahertz radar system transmitting front end. In the radio frequency circuit, the first radio frequency channel 110 is connected to the transmitting antenna cavity 120. There is at least one receiving antenna cavity 320 between the middle waveguide cavity 20 and the lower waveguide cavity 30, and a second receiving antenna cavity 320 corresponding to the receiving antenna cavity 320. The radio frequency channel 310 and the second radio frequency channel 310 are connected with the receiving antenna cavity 320. The second radio frequency channel 310 is used to install the terahertz radio frequency circuit of the receiving front end of the terahertz radar system.

The waveguide flange is of international standard size. The size of a single waveguide flange is about 2 cm. The volume of the terahertz circuit is in the micron level. However, in the existing terahertz communication system, only one terahertz circuit is installed in a waveguide cavity. When a terahertz circuit is integrated into a terahertz radar system, multiple waveguide structures are actually integrated, resulting in low internal space utilization of a single waveguide structure. The front-end of the integrated terahertz radar system is large, and when the waveguide structures are connected, there is still a problem. It will cause connection loss, and the consistency between channels is also difficult to control; in this embodiment, the upper waveguide cavity 10, the middle waveguide cavity 20 and the lower waveguide cavity 30 are combined to form a waveguide structure, and the upper waveguide cavity is The transmitting antenna cavity 120 and the first radio frequency channel 110 are arranged between 10 and the middle waveguide cavity 20, and between the middle waveguide cavity 20 and the lower waveguide cavity 30 The receiving antenna cavity 320 and the second radio frequency channel 310 are arranged between them. The first radio frequency channel 110 and the second radio frequency channel 310 are used to install the signal transmitting terahertz radio frequency circuit and the signal receiving terahertz radio frequency circuit of the terahertz radar system respectively. Not only The transmitting front-end and receiving front-end of the terahertz radar system are integrated into a waveguide structure, and the channel consistency between the first radio frequency channel 110 and the second radio frequency channel 310 is ensured, as well as the high degree of isolation between radio frequency channels; In addition, because only one waveguide structure is used, the transmitting front-end and receiving front-end of the terahertz radar system can be integrated, effectively avoiding the connection loss when multiple waveguide structures are connected, reducing the front-end volume of the terahertz radar system, and realizing the terahertz radar The system's miniaturized integrated setup is conducive to wider and more flexible applications of terahertz communication systems.

Specifically, the first radio frequency channel 110 and the second radio frequency channel 310 are respectively rectangular waveguide structures.

Specifically, the transmitting antenna cavity 120 and the receiving antenna cavity 320 are standard waveguide horn antennas respectively.

Specifically, the ratio of the length of the mouth of the transmitting antenna cavity 120, the width of the mouth of the transmitting antenna cavity 120, the length of the wide side of the first radio frequency channel 110 and the length of the narrow side of the first radio frequency channel 110 is 10:10:1.092:0.546 , the ratio of the length of the mouth of the receiving antenna cavity 320, the width of the mouth of the receiving antenna cavity 320, the length of the wide side of the second radio frequency channel 310 and the length of the narrow side of the second radio frequency channel 310 is 10:10:1.092:0.546. By reasonably setting the structural size of the antenna, the front end of the terahertz radar system can achieve good scanning angle performance.

Specifically, the ratio of the depth of the transmitting antenna cavity 120 to the depth of the first radio frequency channel 110 and the depth ratio of the receiving antenna cavity 320 to the second radio frequency channel 310 are both 25:20.

Specifically, as shown in FIGS. 2 to 5 , the transmitting antenna cavity 120 is at least partially disposed on the upper waveguide cavity 10 , and the receiving antenna cavity 320 is at least partially disposed on the lower waveguide cavity 30 . Preferably, half of the transmitting antenna cavity 120 is disposed on the upper waveguide cavity 10 , and the other half of the transmitting antenna cavity 120 is disposed on the middle waveguide cavity 20 ; half of the receiving antenna cavity 320 is disposed on the lower waveguide cavity 30 On the other hand, the other half of the receiving antenna cavity 320 is disposed on the middle waveguide cavity 20 .

In some embodiments, for the transmitting antenna cavity 120 , it is possible to choose to provide a smaller portion of the transmitting antenna cavity 120 on one of the lower surface of the upper waveguide cavity 10 and the upper surface of the intermediate waveguide cavity 20 . A plurality of transmitting antenna cavities 120 are provided on the other one of the lower surface and the upper surface of the middle waveguide cavity 20; for the receiving antenna cavity 320, the upper surface of the lower waveguide cavity 30 and the middle waveguide cavity can be selected. A smaller portion of the receiving antenna cavity 320 is disposed on one of the lower surfaces of the lower waveguide cavity 30 and a larger portion of the receiving antenna cavity 320 is disposed on the other of the upper surface of the lower waveguide cavity 30 and the lower surface of the middle waveguide cavity 20 .

Specifically, when multiple first radio frequency channels 110 are provided, the first radio frequency channels 110 are arranged in parallel with each other.

Specifically, when multiple second radio frequency channels 310 are provided, the second radio frequency channels 310 are arranged in parallel with each other.

Specifically, the plurality of first radio frequency channels 110 and the plurality of second radio frequency channels 310 are respectively arranged in an array.

In some embodiments, the plurality of first radio frequency channels 110 can be arranged in a one-dimensional array, that is, arranged in a column or a row. The plurality of first radio frequency channels 110 can also be arranged in a two-dimensional array. In the example, there are 6 in a row. The first radio frequency channel 110 is divided into 3 rows, each row has 2 first radio frequency channels 110, or 9 first radio frequency channels 110 are divided into 3 rows, the first row has 1 first RF channel 110, and the second row has 3 There are one first radio frequency channel 110 and a third row of five first radio frequency channels 110; similarly, the plurality of second radio frequency channels 310 can also be arranged in a one-dimensional or two-dimensional array.

Specifically, when at least two intermediate waveguide cavities 20 are provided between the upper waveguide cavity 10 and the lower waveguide cavity 30 , the intermediate waveguide cavities 20 are arranged in sequence along the longitudinal direction; between two adjacent intermediate waveguide cavities 20 At least one transmitting antenna cavity 120 and a first radio frequency channel 110 corresponding to the transmitting antenna cavity 120 are provided to adapt to a plurality of first radio frequency channels 110 arranged in a two-dimensional array.

In some embodiments, at least one receiving antenna cavity 320 and a second radio frequency channel 310 corresponding to the receiving antenna cavity 320 are provided between two adjacent intermediate waveguide cavities 20 to adapt to multiple two-dimensional layouts. The second radio frequency channel 310 of the array; for example, as shown in Figure 6, four transmitting antenna cavities 120 are provided in the upper waveguide cavity 10 and the middle waveguide cavity 20, and a first radio frequency channel corresponding to the transmitting antenna cavity 120 is provided. Channel 110, four receiving antenna cavities 320 are provided between the two middle waveguide cavities 20, and a second radio frequency channel 310 is provided corresponding to the receiving antenna cavities 320, between the middle waveguide cavity 20 and the lower waveguide cavity 30 Four receiving antenna cavities 320 and a second radio frequency channel 310 corresponding to the receiving antenna cavities 320 are provided to form a front-end integrated structure of a 4-transmitter and 8-receive terahertz radar system.

In some embodiments, at least one transmitting antenna cavity 120 and the first radio frequency channel 110 corresponding to the transmitting antenna cavity 120 are provided between two adjacent intermediate waveguide cavities 20 , and at least one receiving antenna cavity 320 is also provided. , and a second radio frequency channel 310 provided corresponding to the receiving antenna cavity 320 to adapt to a plurality of first radio frequency channels 110 in a two-dimensional array and a plurality of second radio frequency channels 310 in a two-dimensional array.

Specifically, the distance between the mouth surfaces of adjacent transmitting antenna cavities 120 is 0.2 mm.

Specifically, the distance between the opening surfaces of adjacent receiving antenna cavities 320 is 0.2 mm.

Specifically, the distance between the mouth surface of the transmitting antenna cavity 120 and the mouth surface of the adjacent receiving antenna cavity 320 is 0.2 mm.

Example 2

The embodiment of the present application provides a terahertz radar system front end, as shown in Figure 7, including a local oscillator drive signal 410, a frequency multiplier amplifier 420, a multi-channel power divider 430, at least one signal transmitting terahertz radio frequency circuit, at least one The signal receiving terahertz radio frequency circuit, and the front-end waveguide structure of the terahertz radar system in Embodiment 1, the local oscillator driving signal 410, the frequency multiplier amplifier 420, and the multi-channel power divider 430 are connected in sequence along the signal transmission direction, and the signal transmits the terahertz radio frequency The signal input end of the circuit and the signal input end of the signal receiving terahertz radio frequency circuit are respectively connected to the signal output end of the multi-channel power splitter 430. The signal transmitting terahertz radio frequency circuit is arranged in the first radio frequency channel 110, and the signal receiving terahertz radio frequency circuit The circuit is provided in the second radio frequency channel 310.

The local oscillator drive signal 410 is used to generate a drive signal, the signal is amplified to the local oscillator drive frequency through the frequency multiplier amplifier 420, and then divided into multiple channels that match the number of terahertz radio frequency circuits through the multi-channel power divider 430, which are respectively used for signal transmission. The terahertz radio frequency circuit and the signal receiving terahertz radio frequency circuit provide driving signals. For the signal transmitting terahertz radio frequency circuit, the signal is frequency multiplied and power synthesized in the signal transmitting terahertz radio frequency circuit, and then transmitted to the transmitting antenna (the transmitting antenna cavity 120 serves as Transmitting antenna) performs signal transmission to generate a transmitting signal; for the signal receiving terahertz radio frequency circuit, the signal undergoes frequency doubling and mixing in the signal receiving terahertz radio frequency circuit. At the same time, the transmitting signal is transmitted back after encountering the target to be measured, and is transmitted by four The receiving antenna (the receiving antenna cavity 320 serves as the receiving antenna) receives and performs down-conversion in the signal receiving terahertz radio frequency circuit to achieve coherence and increase the parameter resolution capability and parameter estimation accuracy of the system; In addition, by integrating the signal transmitting terahertz radio frequency circuit, the signal receiving terahertz radio frequency circuit, the transmitting antenna, and the receiving antenna into a waveguide structure, the channel consistency between the first radio frequency channel 110 and the second radio frequency channel 310 is ensured , as well as a high degree of isolation between the signal transmitting terahertz radio frequency circuit and the signal receiving terahertz radio frequency circuit, and effectively reducing the front-end volume of the terahertz radar system, realizing the miniaturization and integration of the terahertz radar system, which is conducive to the development of the terahertz communication system Wider and more flexible applications; at the same time, the multi-shot and multi-shot type system has a higher degree of spatial spectrum freedom, and can use space-time adaptation and other technologies to improve resolution.

Specifically, the signal transmitting terahertz radio frequency circuit includes a first local oscillator driving frequency multiplier 440 and a 340GHz frequency multiplier 450. The first local oscillator drive frequency multiplier 440 is a 170GHz local oscillator drive frequency multiplier.

Specifically, the signal receiving terahertz radio frequency circuit includes a second local oscillator drive frequency multiplier 460 and a 340GHz sub-harmonic mixer 470. The second local oscillator driving frequency multiplier 460 is a 170GHz local oscillator driving frequency multiplier.

Specifically, the front end of the terahertz radar system also includes an intermediate frequency signal, and the intermediate frequency signals are respectively connected to the 340GHz sub-harmonic mixer 470. Preferably, the intermediate frequency signal is an intermediate frequency signal with adjustable frequency.

Specifically, the front end of the terahertz radar system includes two signal transmitting terahertz radio frequency circuits and four signal receiving terahertz radio frequency circuits, and the multi-channel power divider 430 is a six-way power divider. In the two-transmit and four-receive terahertz radar system, the transmitting antenna and the receiving antenna are arranged in a compact space, and the echo signals are coherent with respect to the transmitting and receiving antennas. Compared with traditional radar, the virtual aperture due to waveform diversity is , which is equivalent to expanding the radar antenna space, so it can improve the parameter resolution capability and parameter estimation accuracy of the target; in addition, since four receiving antennas are used to detect the target, the scattering cross-sectional area of the target is different for each antenna. , so it can optimally suppress the target signal flicker and improve detection capabilities; at the same time, the waveforms emitted by the two-transmitter and four-receiver radar in different directions are orthogonal to each other, so it is relatively difficult for the target object to track, locate and counter-interference it, so anti-interference More capable, with low interception capability.

Specifically, the local oscillator driving signal 410 is a frequency modulated continuous wave source.

Example 3

The embodiment of the present application provides a terahertz radar system, including the terahertz radar system front-end waveguide structure in Embodiment 2, or the terahertz radar system front-end in Embodiment 3.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims

A front-end waveguide structure of a terahertz radar system, which is characterized in that it includes an upper waveguide cavity, a middle waveguide cavity and a lower waveguide cavity, and at least one transmitting antenna cavity is provided between the upper waveguide cavity and the middle waveguide cavity, and A first radio frequency channel is provided corresponding to the transmitting antenna cavity. The first radio frequency channel is used to install the terahertz radio frequency circuit of the transmitting front end of the terahertz radar system. The first radio frequency channel is connected to the transmitting antenna cavity. The intermediate waveguide cavity and At least one receiving antenna cavity and a second radio frequency channel corresponding to the receiving antenna cavity are provided between the lower waveguide cavities. The second radio frequency channel is connected to the receiving antenna cavity. The second radio frequency channel is used to install the receiving front end of the terahertz radar system. of terahertz radio frequency circuits.
The front-end waveguide structure of the terahertz radar system according to claim 1, wherein the first radio frequency channel and the second radio frequency channel are respectively rectangular waveguide structures, and/or the transmitting antenna cavity and the receiving antenna cavity are respectively It is a standard waveguide horn antenna.
The front-end waveguide structure of the terahertz radar system according to claim 2, characterized in that the length of the mouth of the transmitting antenna cavity, the width of the mouth of the transmitting antenna cavity, the width of the first radio frequency channel and the narrowness of the first radio frequency channel. The ratio of the side lengths is 10:10:1.092:0.546. The ratio of the length of the receiving antenna cavity, the width of the receiving antenna cavity, the wide side length of the second radio frequency channel and the narrow side length of the second radio frequency channel is 10:10. :1.092:0.546.
The front-end waveguide structure of the terahertz radar system according to claim 2, characterized in that the ratio of the depth of the transmitting antenna cavity to the depth of the first radio frequency channel, and the depth ratio of the depth of the receiving antenna cavity to the second radio frequency channel are both 25 :20.
The front-end waveguide structure of a terahertz radar system according to any one of claims 1 to 4, characterized in that the transmitting antenna cavity is at least partially disposed on the upper waveguide cavity, and the receiving antenna cavity is at least partially disposed on the lower waveguide cavity. physically.
The front-end waveguide structure of a terahertz radar system according to claim 5, wherein when multiple first radio frequency channels are provided, the first radio frequency channels are arranged parallel to each other, and/or when multiple first radio frequency channels are provided. When using two radio frequency channels, the second radio frequency channels are arranged parallel to each other.
The front-end waveguide structure of a terahertz radar system according to claim 6, wherein the distance between the mouth surfaces of adjacent transmitting antenna cavities is 0.2 mm, and/or the distance between the mouth surfaces of adjacent receiving antenna cavities is 0.2 mm. 0.2mm.
The front-end waveguide structure of the terahertz radar system according to claim 5, characterized in that when at least two intermediate waveguide cavities are provided between the upper waveguide cavity and the lower waveguide cavity, the intermediate waveguide cavities are arranged in sequence along the longitudinal direction. ;

At least one transmitting antenna cavity and a first radio frequency channel corresponding to the transmitting antenna cavity are provided between two adjacent intermediate waveguide cavities,

And/or, at least one receiving antenna cavity and a second radio frequency channel corresponding to the receiving antenna cavity are provided between two adjacent intermediate waveguide cavities.
A front-end of a terahertz radar system, characterized by including a local oscillator drive signal, a frequency multiplier amplifier, a multi-channel power divider, at least one signal transmitting terahertz radio frequency circuit, at least one signal receiving terahertz radio frequency circuit, and claim 1 The front-end waveguide structure of the terahertz radar system described in any one of ~8, the local oscillator driving signal, frequency multiplication amplifier, and multi-channel power splitter are connected in sequence along the signal transmission direction, and the signal input end and signal receiving end of the signal transmitting terahertz radio frequency circuit The signal input terminals of the terahertz radio frequency circuit are respectively connected to the signal output terminals of the multi-channel power divider. The signal transmitting terahertz radio frequency circuit is arranged in the first radio frequency channel, and the signal receiving terahertz radio frequency circuit is arranged in the second radio frequency channel.
A terahertz radar system, characterized by comprising the terahertz radar system front-end waveguide structure according to any one of claims 1 to 8, or the terahertz radar system front-end according to claim 9.