A terahertz direct amplitude modulator based on scattering path reconstruction

Abstract

The application discloses a terahertz direct amplitude modulator based on scattering path reconstruction and belongs to the technical field of terahertz high-speed communication radio frequency devices. The application solves the defects of the current terahertz amplitude modulation device, such as the lack of scattering path reconstruction design idea, the limited modulation amplitude swing, and the difficulty in balancing the performance of insertion loss and switch isolation degree. The application comprises a waveguide body and a modulation chip integrated on the waveguide body. The modulation chip comprises a substrate, and the substrate sequentially forms, along the signal transmission flow direction, a first feed filter circuit, a quasi-fish line electrically-controlled switch unit, a ring-shaped coupling scattering transmission structure and a second feed filter circuit through metal wiring. The quasi-fish line electrically-controlled switch unit is located inside the waveguide body, and the rest of the structures are located outside the waveguide body. The ring-shaped coupling scattering transmission structure comprises a metal coupling ring and two sections of first impedance matching microstrips connected with the metal coupling ring. The application can simultaneously realize low transmission loss and high off-signal suppression.

Description

Technical Field

[0001] This invention belongs to the field of terahertz high-speed communication radio frequency device technology, specifically relating to a terahertz direct amplitude modulator based on scattering path reconstruction. Background Technology

[0002] The 0.1~10THz terahertz spectrum possesses advantages such as ultra-large communication bandwidth and ultra-high carrier frequency, making it a core candidate spectrum for next-generation high-speed wireless transmission, inter-chip interconnection, and high-precision radar imaging systems. Schottky diode-type terahertz direct amplitude modulation devices, as the core signal loading unit in the terahertz transceiver front-end, achieve carrier ASK amplitude modulation by relying on impedance switching caused by diode conduction / turn-off.

[0003] Several studies on terahertz / Asia-Pacific hertz modulation and emission have been published in the existing technology:

[0004] Reference 1: T. Zhou, Y. Dong, S. Gong et al. published “A sub-terahertz high-speed traveling-wave switch modulator based on dynamically tunable double-resonant coupling units” in IEEE Transactions on Microwave Theory and Techniques, Volume 71, Issue 10, 2023, pp. 4346–4356, which discloses a scheme for a sub-terahertz high-speed traveling-wave switch modulator based on dynamically tunable double-resonant coupling units.

[0005] Reference 2: Zhang YX, Ding KS, Zeng HX et al. published "Ultrafast modulation of terahertz waves using on-chip dual-layer near-field coupling" in Volume 9, Issue 11 of Optica in 2022, pages 1268-1275, which proposed an ultrafast modulation technology for terahertz waves based on on-chip dual-layer near-field coupling.

[0006] Reference 3: "A 220-GHz energy-efficient high-data-rate wireless ASK transmitter array", published by B. Hadidian, F. Khoeini et al. in IEEE Journal of Solid-State Circuits, Volume 57, Issue 6, 2022, pp. 1623–1634, discloses an implementation scheme for a 220GHz energy-efficient high-data-rate wireless ASK transmitter array.

[0007] As can be seen from the above, the existing methods for improving the dynamic range of modulation amplitude in similar modulation devices are relatively limited. Most rely on methods such as superimposed resonance of multiple resonant units and near-field coupling of metasurfaces to optimize the modulation range. There is currently no design approach to improve modulation performance by reconstructing the electromagnetic wave scattering propagation path. At the same time, traditional modulation circuits have difficulty simultaneously achieving low RF insertion loss and high switching isolation suppression capability. The chip topology has poor compatibility with standardized terahertz waveguides, making it difficult to integrate with passive and active RF front-end devices. This makes it impossible to meet the requirements of ultra-high-speed, high-capacity terahertz transmission systems of 100Gbps and above. Summary of the Invention

[0008] To address the shortcomings of existing terahertz amplitude modulation devices, such as the lack of scattering path reconstruction design ideas, limited space for modulation amplitude swing improvement, difficulty in balancing insertion loss and switching isolation performance, and high difficulty in waveguide integration, this invention provides a terahertz direct amplitude modulator based on scattering path reconstruction. It uses a single-sided independent ring-coupled scattering transmission structure as the core to reshape the terahertz wave scattering path, significantly widening the dynamic range of modulation amplitude while keeping the insertion loss at a low level. The cavity structure directly matches the standardized terahertz waveguide, facilitating the integration and assembly of the RF front-end system.

[0009] The technical solution adopted in this invention is as follows:

[0010] A terahertz direct amplitude modulator based on scattering path reconstruction includes a waveguide body and a modulation chip integrated on the waveguide body.

[0011] The modulation chip includes a substrate on which, along the signal transmission direction, the following are sequentially formed by metal wiring: a first feed filter circuit, a quasi-fin line electronically controlled switch unit, a ring-shaped coupled scattering transmission structure, and a second feed filter circuit; the quasi-fin line electronically controlled switch unit is located inside the waveguide body, and the remaining structures are located outside the waveguide body;

[0012] The ring-shaped coupled scattering transmission structure consists of a metal coupling ring and two first impedance matching microstrips connected to the metal coupling ring.

[0013] The core innovation of this invention, achieved by employing this technical solution, lies in the reshaping of the terahertz wave scattering propagation path using a single-sided independently configured metal ring-shaped coupled scattering transmission structure. When a 0V zero bias is applied to the Schottky diode array, the entire device is turned on, and the terahertz carrier is efficiently transmitted along the quasi-fin line channel within the waveguide. Upon incident on the metal coupling ring outside the waveguide, coupled scattering occurs, forming a high-energy output path. When a 1V reverse bias is applied, the diode array is turned off, resulting in impedance mismatch in the quasi-fin line transmission channel within the waveguide. The metal coupling ring outside the waveguide then alters the electromagnetic wave scattering and reflection path, suppressing the majority of the carrier signal through reflection. Compared to a reference circuit without a metal ring-shaped coupled scattering transmission structure, this invention actively reshapes the electromagnetic wave scattering propagation path through the metal coupling ring outside the waveguide, amplifying the output amplitude difference between the diode's on and off states. Without significantly deteriorating the RF insertion loss, it can significantly broaden the dynamic range of the modulation amplitude and achieve superior switching signal suppression capabilities.

[0014] Preferably, the metal coupling ring is a circular ring or a square ring, and the two first impedance matching microstrips are both fan-shaped or rectangular.

[0015] With this technical solution, the present invention only sets up a single independent structure between the quasi-fin wire electronically controlled switch unit and the second feed filter circuit. This structure consists of two first impedance matching microstrip sections and a single-piece metal coupling ring. The metal coupling ring is either circular or square and is the core functional structure for reshaping the electromagnetic wave scattering path. The terahertz carrier wave, after impedance modulation by a Schottky diode, is incident on the metal coupling ring outside the waveguide body. The metal coupling ring reconstructs the electromagnetic wave scattering propagation path, reshaping the transmission spatial field distribution, thereby increasing the amplitude difference between the output signal in the on and off operating states.

[0016] Preferably, the metal coupling ring is a circular ring with an inner diameter of 60 μm, an outer diameter of 80 μm, and a thickness of 1 μm. The two first impedance matching microstrips are both rectangular with a length of 220 μm, a width of 20 μm, and a thickness of 1 μm.

[0017] After adopting this technical solution, the width is the minimum processing width based on minimum loss, and the length is determined based on the distance between the ring coupling structure and the core modulation structure during design optimization. If it is too long, energy will be lost in the path; if it is too short, the ring will be too close to the adjustment structure and the coupling will be too strong, which may significantly affect the modulation area and change the overall working state. Therefore, the final length was chosen as 220μm. At this length, the ring can just make appropriate adjustments to the amplitude of the core modulation.

[0018] Preferably, the modulation chip includes a substrate with dimensions of 2521.5μm*750μm*50μm.

[0019] Preferably, the two first impedance matching microstrips are respectively connected to the quasi-fin wire electronically controlled switching unit and the second power supply filter circuit.

[0020] Preferably, the waveguide body is a WR-4.3 standardized waveguide.

[0021] Preferably, the metal coupling ring is made of gold, and the first impedance matching microstrip is also made of gold.

[0022] As a preferred option, the operating frequency band is 207 GHz to 217 GHz.

[0023] As a preferred option, the operating frequency band is 213 GHz.

[0024] Preferably, the quasi-fin wire electronic control switch unit includes a quasi-fin wire body, on which a composite fold is provided. The composite fold includes a transverse fold segment and a longitudinal fold segment. The transverse fold segment extends along the width direction of the waveguide body, and the longitudinal fold segment extends along the length direction of the waveguide body. A Schottky diode array is arranged in parallel across the longitudinal fold segment on the quasi-fin wire body.

[0025] After adopting this technical solution, terahertz Schottky diodes are arranged in parallel in the folded area. All devices are placed on both sides of the fold with common anode and common cathode respectively. The overall equivalent impedance of the diode array is changed by externally applied control voltage to complete the switching between the two working modes of transmission channel conduction and cutoff.

[0026] Preferably, a through slot is provided on the waveguide body along the width direction, and the modulation chip penetrates the waveguide body vertically through the through slot. The connection position between the modulation chip and the waveguide body is such that the first feed filter circuit and the second feed filter circuit are asymmetrically arranged on both sides of the waveguide body. The circuit plane of the modulation chip is orthogonal to the port end face of the waveguide body.

[0027] After adopting this technical solution, the first and second power supply filter circuits are distributed at both ends of the chip in an asymmetrical layout; one side of the path introduces the high-speed low-frequency modulation control signal, and the other side is connected to the standard impedance matching load to block the terahertz radio frequency signal from leaking to the modulation port and the matching load, allowing only the low-frequency control signal to pass normally.

[0028] As a preferred option, the waveguide body adopts the WR-4.3 standardized millimeter-wave / terahertz waveguide, and the substrate is selected as a high-frequency low-loss dielectric substrate, which can be selected from high-frequency adaptable materials such as gallium arsenide, silicon carbide, silicon substrate, quartz, and sapphire; the metal wiring on the chip surface is prepared by low-loss high-conductivity metal films such as copper and gold.

[0029] As a preferred option, by changing the geometric dimensions of the metal sheet of the quasi-fin wire electronically controlled switch unit, adjusting the spacing and position of the Schottky diode array, and optimizing the size of the annular coupling scattering transmission structure, the device's center operating frequency can be adjusted, insertion loss and modulation depth can be optimized, and it can be adapted to different terahertz frequency bands above 200 GHz.

[0030] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0031] 1. This invention constructs a waveguide outer ring coupled scattering transmission structure, and significantly improves the dynamic range of modulation amplitude through a scattering path reconstruction and control mechanism: the terahertz wave scattering propagation path is reconstructed with a single-sided single-metal ring microstrip structure as the core, and the amplitude transmission swing is improved by about 62.1% compared with the reference topology without a ring; the optimal operating frequency of the device is 213GHz, at which the RF insertion loss is only 1.8dB and the switching isolation can reach 34.1dB, which can simultaneously achieve low transmission loss and high turn-off signal suppression, and construct a feasible scheme for improving the amplitude swing of a novel modulation device.

[0032] 2. This invention has strong portability and can be matched with multiple terahertz bands: by optimizing the metal size of the quasi-fin line electronically controlled switch unit, adjusting the number of Schottky diodes and the array spacing, and adjusting the size of the circular ring coupled scattering transmission structure, the device center operating frequency can be flexibly configured through multiple means to achieve different insertion loss and modulation depth effects, and is suitable for various high-speed terahertz wireless communication and imaging equipment application scenarios above 200GHz.

[0033] 3. The waveguide-chip integrated embedded structure of this invention is suitable for commercial RF front-end cascading: It adopts the WR-4.3 standardized waveguide embedded assembly scheme, with spatial partitioning and isolation of the first feed filter circuit, quasi-fin wire electronic control switch unit, ring coupling scattering transmission structure and second feed filter circuit. The overall structure is compact and small, and can be directly cascaded with existing commercial terahertz waveguide RF front-ends; the device can work stably under normal temperature and pressure environment, without the need for vacuum packaging, the assembly process is simple, and it has strong practicality for engineering implementation.

[0034] 4. The chip topology is simple and the chip fabrication process has a low threshold: It is equipped with only a single ring-shaped coupled scattering transmission structure, combined with a parallel Schottky diode array and a quasi-fin transition structure. All functional circuits are integrated on a single chip with only one layer of metal and one layer of dielectric, a two-layer structure. There is no need for a multi-layer composite dielectric stacking structure. It can be mass-produced by relying on existing mature processes. Attached Figure Description

[0035] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0036] Figure 2 This is a front plan view of the present invention.

[0037] Figure 3 This is a schematic diagram of the modulation chip in this invention.

[0038] Figure 4 This is a dimension diagram of the quasi-fin wire electronically controlled switch unit in this invention.

[0039] Figure 5 This is a schematic diagram of the metal coupling ring in this invention;

[0040] Figure 6 This is a dimension diagram of the first power supply filter circuit in this invention;

[0041] Figure 7 This is a schematic diagram showing the positional relationship between the waveguide body and the modulation chip in this invention;

[0042] Figure 8 This is a simulation curve of the transmission coefficient S21 under both on and off operating conditions of the present invention.

[0043] Figure 9 This is a comparison curve of the transmission amplitude |S21| in the control voltage range of 0V~1V of the present invention.

[0044] Figure 10 The figures show the simulation curves of the influence of key dimensional parameters on the modulation amplitude swing of the present invention. Figure a shows the simulation curve of the influence of the ring width (metal coupling ring) on ​​the modulation amplitude swing when the ring width (metal coupling ring) changes, and figure b shows the simulation curve of the influence of the ring inner diameter (metal coupling ring) on ​​the modulation amplitude swing when the ring inner diameter (metal coupling ring) changes.

[0045] Figure 11 This is a diagram showing the insertion loss and modulation depth results when the length of the metal sheet changes according to the present invention.

[0046] Figure Labels

[0047] 1-Input standard waveguide, 2-Output standard waveguide, 3-Modulation chip, 31-First feed filter circuit, 32-Quasi-fin wire electronically controlled switch unit, 33-Schottky diode array, 34-Ring-shaped coupled scattering transmission structure, 341-Metal coupling ring, 342-First impedance matching microstrip, 35-Second feed filter circuit. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0049] In the description of the embodiments of this application, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0050] A terahertz direct amplitude modulator based on scattering path reconstruction operates in the 213 GHz frequency band, such as... Figure 1 and Figure 2 The diagram shows a waveguide body, which includes an input standard waveguide 1 and an output standard waveguide 2. In this embodiment, a WR-4.3 standardized waveguide is used. The input standard waveguide 1 is responsible for introducing the original terahertz carrier, and the output standard waveguide 2 outputs the RF envelope signal after amplitude-keying modulation. A through-slot is provided on the waveguide body along its width direction. The modulation chip 3 passes through the center of the waveguide body vertically through the through-slot. The connection position of the modulation chip 3 and the waveguide body allows the first feed filter circuit 31 and the second feed filter circuit 35 to be asymmetrically arranged on both sides of the waveguide body. The circuit plane of the modulation chip 3 is orthogonal to the port end face of the waveguide body. The modulation chip 3 is directly suspended in the through-slot of the waveguide body, exposing the core modulation structure in the waveguide body. This allows the modulation signal to be modulated by the carrier in the waveguide body when it is loaded in the modulation region. The through-slot size leaves a 20μm gap between the waveguide body and the size of the modulation chip 3 to accommodate the modulation chip 3 (e.g., ...). Figure 7 ).

[0051] The modulation chip 3 includes a substrate. In this embodiment, the substrate is a quartz high-frequency dielectric with a dielectric constant of 3.78 and dimensions of 2521.5μm*750μm*50μm. In another embodiment, the substrate can be replaced with any one of gallium arsenide, silicon carbide, or silicon substrate. In this embodiment, all metal wiring on the modulation chip 3 is made of a highly conductive metal thin film such as gold. Along the signal transmission direction, the following are sequentially formed on the substrate via metal wiring: a first feed filter circuit 31, a quasi-fin line electrically controlled switch unit 32, a ring-shaped coupled scattering transmission structure 34, and a second feed filter circuit 35. The various circuit structures on the substrate are connected sequentially, and the quasi-fin line electrically controlled switch unit 32 is completely located within the through-slot, while the remaining structures are located outside the waveguide body. The filter adopts an asymmetrical layout distributed on both sides of the waveguide axis. The external modulation control signal is introduced by the filter circuit on one side, and the filter circuit on the other side is connected to a standard impedance-matched load. The quasi-fin line electrically controlled switch unit 32 is embedded in the waveguide cavity to achieve field coupling, and all feed filter circuits are arranged on the outside of the waveguide.

[0052] The annular coupled scattering transmission structure 34 comprises a metal coupling ring 341 and two first impedance matching microstrips 342 connected to the metal coupling ring 341. In this embodiment, the metal coupling ring 341 is a circular ring, and the annular coupled scattering transmission structure 34 is arranged in a single set to meet the high-frequency terahertz modulation requirements above 200 GHz. In this embodiment, the metal coupling ring 341 is a circular ring with an inner diameter of 60 μm, an outer diameter of 80 μm, a ring width of 20 μm, and a thickness of 1 μm. The two first impedance matching microstrips 342 are symmetrically arranged on both sides of the metal coupling ring 341. Both first impedance matching microstrips 342 are rectangular, with a width of 20 μm, a length of 220 μm, and a thickness of 1 μm. The two first impedance matching microstrips 342 are respectively connected to the quasi-fin wire electronically controlled switch unit 32 and the second feed filter circuit 35. The metal coupling ring 341 is made of gold, and the first impedance matching microstrips 342 are made of gold. It should be noted that, as shown in the figure, the length of the first impedance matching microstrip 342 connected to the quasi-fin wire electronic control switch unit 32 is greater than that of the first impedance matching microstrip 342 connected to the second power supply filter circuit 35. This is because the two ends of the quasi-fin wire electronic control switch unit 32 originally have two built-in second impedance matching microstrips, which have the same width and thickness and appear to be a single unit after connection.

[0053] like Figure 3 and Figure 4As shown, the quasi-fin wire electronically controlled switch unit 32 is composed of symmetrical metal transmission lines (0.32mm*0.67mm). The gaps between the transmission lines form transverse slits, and alignment notches are opened on opposite sides of the transmission lines. Two sets of notches are spliced ​​together to form a longitudinal slit, which extends parallel to the width of the waveguide. A Schottky diode array 33 is arranged in parallel across the longitudinal slit on the quasi-fin wire body. The anode and cathode of the devices are respectively arranged on the metal transmission lines on both sides of the transverse slit, and all devices are arranged in parallel with a common anode and a common cathode. By adjusting the number of diodes assembled and the spacing between the device arrays, the modulation amplitude and center frequency of the devices can be flexibly adjusted to meet different system design specifications. In this embodiment, the Schottky diode array 33 contains two Schottky diodes, placed in parallel, with a spacing of 110um between the two Schottky diodes. In other embodiments, in addition to Schottky diodes, the switching element can also be replaced with controllable semiconductor devices such as PIN diodes and high-frequency field-effect transistors.

[0054] The first feed filter circuit 31 and the second feed filter circuit 35 have the same structure as the dual I-shaped low-pass filter, and their structural dimensions are as follows: Figure 6 As shown (unit: μm).

[0055] The overall operation of this invention relies on the scattering path reconstruction mechanism of the ring-coupled scattering transmission structure 34, combined with a Schottky diode array 33, a quasi-fin wire electrically controlled switch unit 32, and a dual-path feeding filter circuit to form a complete modulation chip 3, achieving terahertz carrier amplitude modulation. A WR-4.3 standard waveguide feeds in the terahertz carrier, and the modulation chip 3 performs carrier modulation: when the diodes are zero-biased and conducting, the transmission channel is open, and the terahertz carrier is output normally; when the Schottky diode array 33 is reverse-biased and turned off, the transmission channel impedance mismatch occurs, and the carrier output is significantly suppressed. The core advantage lies in the fact that after the carrier passes through the quasi-fin wire fold and the Schottky array, it is incident on the metal coupling ring 341 and scatters, actively reconstructing the electromagnetic wave propagation path and significantly widening the on / off amplitude difference.

[0056] The invention was simulated using HFSS electromagnetic simulation software. Simulation conditions were set as follows: after model creation, corresponding plate parameters were set, a waveguide and an air box were constructed, and the excitation condition at the waveguide's input and output ports was set to wave port excitation. The simulation frequency band was set to 200-230 GHz. Lumped boundary conditions were set at the diode's die. The conduction and cutoff states of the diode were simulated using parameters such as rj, rs, and cj, with a step size of 0.01 GHz. The S-parameter curves were observed. The simulation test results are as follows: Figure 8 , Figure 9 , Figure 10 , Figure 11 As shown, the specific explanation is as follows:

[0057] Figure 8The red curve represents the simulated insertion loss curve of the modulation chip 3 in the on state, and the blue curve represents the simulated isolation curve in the off state. The optimal operating frequency of this embodiment is around 213 GHz, with a minimum insertion loss of 1.8 dB and a switching isolation of 34.1 dB. It achieves excellent modulation performance in the frequency band above 200 GHz. Through the scattering parameters formed by the single-sided ring-coupled scattering transmission structure 34, the electromagnetic wave propagation path is actively reconstructed, significantly increasing the on-off amplitude difference. Combined with the impedance switching of the Schottky diode, efficient control is achieved.

[0058] Figure 9 The colored curve represents the transmission amplitude curve of this invention in the 0V~1V control voltage range, while the blue curve represents the amplitude curve corresponding to the non-circular reference topology. Within the 0V to 1V voltage switching range, this scheme increases the transmission amplitude swing from 0.48478 in the non-circular reference topology to 0.78599, improving the dynamic range by approximately 62.1%, fully verifying the effect of the single-sided circular ring scattering reconstruction structure on improving modulation performance.

[0059] Through such Figure 5 and Figure 10 As can be seen, by changing the ring parameters (a single variable, with other parameters remaining constant; when the ring width Wt is changed, the inner diameter r of the ring is 60 μm; when the inner diameter r is changed, the ring width Wt is 20 μm), the output transmission amplitude under diode switching states changes significantly. For example, in the low-voltage region, by adjusting the output amplitude through the ring parameters, the output amplitude in the low-voltage region changes from approximately 0.5 to 0.05. Compared to the traditional method of changing the resonant metal structure of the core modulation region within the waveguide, this further verifies the feasibility of the waveguide outer ring scattering reconstruction structure in significantly increasing the switching amplitude difference by actively reconstructing the electromagnetic wave propagation path.

[0060] In another embodiment, by changing the geometry of the metal sheet in the quasi-finline electronically controlled switching unit, and adjusting the spacing and position of the Schottky diode array, the dimensions of the annular coupled scattering transmission structure can be optimized. This can achieve the effect of adjusting the device's center operating frequency, optimizing insertion loss and modulation depth, and adapting to different terahertz frequency bands above 200 GHz. For example, changing the length of the modulation metal sheet from 670 μm to other dimensions can adjust its operating frequency, insertion loss, and modulation depth, etc. Specific results are as follows... Figure 11 As shown, simulations of other lengths of the metal sheet, from the original 670μm, reveal changes in insertion loss and modulation depth.

[0061] The embodiments described above merely illustrate specific implementation methods of this application, and while the descriptions are detailed and specific, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the technical solution of this application, and these modifications and improvements all fall within the scope of protection of this application.

Claims

1. A terahertz direct amplitude modulator based on scattering path reconstruction, characterized in that: Includes the waveguide body and the modulation chip integrated on the waveguide body (3). The modulation chip (3) includes a substrate on which the following components are sequentially formed along the signal transmission direction by metal wiring: a first feed filter circuit (31), a quasi-fin line electronically controlled switch unit (32), a ring-shaped coupled scattering transmission structure (34), and a second feed filter circuit (35); the quasi-fin line electronically controlled switch unit (32) is located inside the waveguide body, and the other structures are located outside the waveguide body; The ring-shaped coupled scattering transmission structure (34) consists of a metal coupling ring (341) and two first impedance matching microstrips (342) connected to the metal coupling ring (341).

2. The terahertz direct amplitude modulator based on scattering path reconstruction according to claim 1, characterized in that: The metal coupling ring (341) is a circular ring or a square ring, and the two first impedance matching microstrips (342) are both fan-shaped or rectangular.

3. A terahertz direct amplitude modulator based on scattering path reconstruction according to claim 1, characterized in that: The metal coupling ring (341) is a circular ring with an inner diameter of 60 μm, an outer diameter of 80 μm, and a thickness of 1 μm. The two first impedance matching microstrips (342) are rectangular with a length of 220 μm, a width of 20 μm, and a thickness of 1 μm.

4. A terahertz direct amplitude modulator based on scattering path reconstruction according to claim 3, characterized in that: The fin wire electronic control switch unit (32) has a second impedance matching microstrip at each end. The second impedance matching microstrip is rectangular in shape, with a width of 20μm and a thickness of 1μm. One of the first impedance matching microstrips (342) is connected to its adjacent second impedance matching microstrip.

5. A terahertz direct amplitude modulator based on scattering path reconstruction according to claim 1, characterized in that: The operating frequency band is 207 GHz - 217 GHz.

6. A terahertz direct amplitude modulator based on scattering path reconstruction according to any one of claims 1-5, characterized in that: The modulation chip (3) includes a substrate with dimensions of 2521.5μm*750μm*50μm.

7. A terahertz direct amplitude modulator based on scattering path reconstruction according to any one of claims 1-5, characterized in that: The waveguide body is a WR-4.3 standardized waveguide.

8. A terahertz direct amplitude modulator based on scattering path reconstruction according to any one of claims 1-5, characterized in that: The metal coupling ring (341) is made of gold, and the first impedance matching microstrip (342) is made of gold.

9. A terahertz direct amplitude modulator based on scattering path reconstruction according to any one of claims 1-5, characterized in that: The quasi-fin wire electronic control switch unit (32) includes a quasi-fin wire body, on which a composite fold is provided. The composite fold includes a transverse fold and a longitudinal fold. The transverse fold extends along the width direction of the waveguide body, and the longitudinal fold extends along the length direction of the waveguide body. A Schottky diode array (33) is arranged in parallel across the longitudinal fold on the quasi-fin wire body.

10. A terahertz direct amplitude modulator based on scattering path reconstruction according to any one of claims 1-5, characterized in that: A through slot is provided on the waveguide body along the width direction. The modulation chip (3) passes through the waveguide body vertically through the through slot. The connection position between the modulation chip (3) and the waveguide body makes the first feed filter circuit (31) and the second feed filter circuit (35) asymmetrically arranged on both sides of the waveguide body. The circuit plane of the modulation chip (3) is orthogonal to the port end face of the waveguide body.

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