Terahertz modulator with embedded diode in cavity-loaded resonant unit

Abstract

The present invention provides a terahertz modulator with a cavity-loaded resonant unit and a nested diode, comprising a rectangular waveguide and a modulation chip, wherein the modulation chip is disposed on the cavity wall of the rectangular waveguide; the rectangular waveguide is provided with an input waveguide port and an output waveguide port; the modulation chip comprises a semiconductor substrate and an artificial microstructure disposed on the semiconductor substrate; one side of the semiconductor substrate contacts the cavity wall of the rectangular waveguide, and the artificial microstructure does not contact the cavity wall of the rectangular waveguide; the upper and lower longitudinal walls of the rectangular waveguide contact the modulation chip, and air windows are respectively provided on the upper and lower longitudinal walls of the rectangular waveguide, the air windows being used to electrically connect an external control circuit to electrodes on the chip. The artificial microstructure on the modulation chip of the present invention uses very few modulation units. Compared with traditional large array designs, parasitic modes existing in large array structures are effectively suppressed, which is conducive to the high-frequency characteristics of the diodes in the chip, thereby improving the modulation rate of the device.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic functional devices, and in particular to a terahertz modulator with a cavity-loaded resonant unit and a nested diode. Background Art

[0002] Due to the frequency band and inherent properties of terahertz waves, terahertz research holds significant application value in fields such as medicine, testing, imaging, and wireless communications. Wireless communications are a key development area in the electronic information sector. Terahertz communication combines the advantages of microwave and optical communications, making it key to achieving wireless communications approaching wired data rates. Compared to millimeter-wave frequencies, terahertz communication offers greater bandwidth and enhanced security. Compared to optical frequencies, terahertz communication is easier to track and align beams and adapts to challenging climatic conditions. It has the potential for point-to-point wireless communications, with a total capacity of up to terabits per second within a kilometer. Furthermore, the relatively short terahertz wavelength allows for smaller antennas, making terahertz communication systems relatively simple and compact. These significant advantages have led to extensive research in terahertz communications worldwide. IEEE 802.15 established a terahertz interest group as early as 2008 and released the first wireless communication standard in the 300 GHz band in 2017. In 2019, the 6G Technology R&D Group and Expert Group were established, marking the beginning of 6G research in China. In addition, the World Radiocommunication Conference (WRC-19) allowed the identification of frequency bands in the 275-475 GHz frequency range for land mobile and fixed communication services.

[0003] Terahertz modulators are core components in terahertz wireless communication systems. They can dynamically control physical parameters such as the amplitude, phase, and frequency of transmitted terahertz waves through external excitation signals. However, single metals lack this capability, so the introduction of semiconductor materials offers broad application prospects for dynamic terahertz carrier modulation. Currently, most widely used modulators utilize quasi-optical methods, combining metamaterials with semiconductors. These typically employ optical, electrical, and thermal methods to combine metamaterials with variable materials such as doped silicon, doped heterojunctions, phase-change materials, graphene, and liquid crystals to alter the metamaterial's reflectivity or transmittance. However, these modulators often operate in open space and employ large arrays of artificial microstructures containing hundreds or even thousands of modulation elements. This excessive number of elements not only introduces significant parasitic capacitance and inductance into the device but also induces parasitic modes between elements. This also complicates circuit matching within the modulation array, hindering the efficient delivery of the modulation signal and hindering the ability to increase the modulation rate. Furthermore, the modulation method of the external space corresponding to the large-area array of artificial microstructures makes terahertz waves extremely susceptible to interference from external factors during the modulation process. To achieve effective ultra-high-speed terahertz communication, terahertz modulators must reduce parasitic parameters and circuit matching difficulties in the artificial microstructures and possess high performance such as low insertion loss, wide operating bandwidth, and high modulation depth. Therefore, the continuous optimization and improvement of terahertz modulators are of great significance to terahertz communication systems based on direct modulation.

[0004] Patent publication number CN109298547A discloses a terahertz modulator and modulation method, comprising a waveguide silicon layer, a graphene layer, electrodes, and an insulating layer. The insulating layer is placed between two graphene layers, a waveguide silicon layer is placed outside each graphene layer, and electrodes are placed on each graphene layer. Because graphene has the highest electron mobility currently discovered, using graphene as a modulation medium can effectively increase the modulation speed of the terahertz modulator. However, this patent still suffers from the drawback of being difficult to increase the modulation rate. Summary of the Invention

[0005] In view of the defects in the prior art, the object of the present invention is to provide a terahertz modulator with a cavity-loaded resonant unit and a nested diode.

[0006] According to the present invention, a terahertz modulator with a cavity-loaded resonant unit and a nested diode includes a rectangular waveguide and a modulation chip, wherein the modulation chip is arranged on the cavity wall of the rectangular waveguide;

[0007] An input waveguide port and an output waveguide port are provided on the rectangular waveguide, and the plane where the modulation chip is located is perpendicular to the input waveguide port surface and the output waveguide port surface;

[0008] The modulation chip includes a semiconductor substrate and an artificial microstructure disposed on the semiconductor substrate; one side of the semiconductor substrate contacts the cavity wall of the rectangular waveguide, and the artificial microstructure does not contact the cavity wall of the rectangular waveguide;

[0009] The upper and lower longitudinal walls of the rectangular waveguide are in contact with the modulation chip. Air windows are respectively provided on the upper and lower longitudinal walls of the rectangular waveguide. The air windows are used to electrically connect the external control circuit with the electrodes on the chip.

[0010] Preferably, the artificial microstructure includes a modulation array and a socket circuit, and the modulation array is connected to the socket circuit.

[0011] Preferably, the modulation array is a 1*N array composed of modulation units, 1 represents the number of rows of the modulation array, and N represents the number of modulation units in each row, wherein N≥1.

[0012] Preferably, there are two modulation units in the modulation array, and the modulation units are connected in parallel in sequence according to the terahertz wave transmission direction in the rectangular waveguide, and are connected to the external feeding area through the common branches of each modulation unit.

[0013] Preferably, the modulation unit includes a diode, an anode resonator and a cathode resonator;

[0014] The anode resonator and the cathode resonator are rectangular structures of the same size, and are symmetrically arranged on both sides of the diode. The anode resonator and the cathode resonator are mirror images of each other with respect to the diode;

[0015] Adjacent anode resonators are connected to each other through transverse branches, and adjacent cathode resonators are connected to each other through transverse branches;

[0016] The diode is placed above the gap between the cathode resonator and the anode resonator, and the positive and negative poles of the diode are connected to the cathode resonator and the anode resonator respectively;

[0017] The sleeve circuit is connected to the anode resonator and the cathode resonator.

[0018] Preferably, the sleeve circuit includes a grounding structure and a filtering and feeding structure, and both the grounding structure and the filtering and feeding structure are compact microstrip resonators;

[0019] The transverse branch on the grounding structure is connected to one end of the cathode resonator, and the transverse branch on the filter feeding structure is connected to one end of the anode resonator.

[0020] Preferably, the diode is connected to the cathode resonator and the anode resonator respectively through conductive glue.

[0021] Preferably, the diode is narrower than the cathode resonator and the anode resonator.

[0022] Preferably, the diode is a planar Schottky barrier diode, and the material of the planar Schottky barrier diode is GaN, InP or GaAs.

[0023] Preferably, the cavity wall of the rectangular waveguide is made of metal material, and the metal material is oxygen-free copper, brass or aluminum.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The artificial microstructure on the modulation chip of the present invention uses very few modulation units. Compared with traditional large array designs, the parasitic modes existing in large array structures are effectively suppressed, which is conducive to the high-frequency characteristics of the diodes in the chip, thereby improving the modulation rate of the device;

[0026] 2. The modulation units in the modulation chip of the present invention are connected in parallel, and the grounding structure and the filter feed structure both use compact microstrip resonators. These designs simplify the circuit of the modulation chip, suppress the leakage of terahertz waves in the rectangular waveguide, and reduce the difficulty of circuit impedance matching, which is conducive to the efficient feeding of the modulation signal and improves the modulation depth and modulation rate of the device.

[0027] 3. The present invention adopts a waveguide-loaded form, and the modulation chip is embedded in the rectangular waveguide, thereby being effectively protected from interference from external factors such as smoke and dust. The present invention can operate under normal temperature, normal pressure, and non-vacuum conditions and has good operating stability. In addition, the waveguide-loaded modulator is more convenient to integrate with other solid-state devices in the terahertz communication system, reducing the complexity of the system.

[0028] 4. The present invention uses a Schottky diode that has a fast response to terahertz waves as a switching device, which can improve the modulation rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0030] Figure 1 A structural diagram of a terahertz modulator with a cavity-loaded resonant unit and nested diodes according to the present invention;

[0031] Figure 2A schematic structural diagram of a modulation chip of a terahertz modulator with a cavity-loaded resonant unit and embedded diodes according to the present invention;

[0032] Figure 3 The electric field distribution diagram of the terahertz modulator with a cavity-loaded resonant unit and a nested diode in the present invention when the diode is disconnected;

[0033] Figure 4 The electric field distribution diagram of the terahertz modulator with the cavity loaded with the resonant unit and the embedded diode in the diode connected state of the present invention;

[0034] Figure 5 Transmission characteristic curves of the terahertz modulator with a cavity-loaded resonant unit and nested diodes under different states of the present invention.

[0035] The figure shows:

[0036] Rectangular waveguide 1 diode 7

[0037] Modulation chip 2 cathode resonator 8

[0038] Semiconductor substrate 3 anode resonator 9

[0039] Modulation array 4 input waveguide port 10

[0040] Ground structure 5 output waveguide port 11

[0041] Filter feed structure 6 DETAILED DESCRIPTION

[0042] The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0043] Example 1:

[0044] like Figure 1 and Figure 2As shown, this embodiment provides a terahertz modulator with a cavity-loaded resonant unit and an embedded diode. The modulator includes a rectangular waveguide 1 and a modulation chip 2, which is disposed on the cavity wall of the rectangular waveguide 1. The rectangular waveguide 1 is provided with an input waveguide port 10 and an output waveguide port 11. The modulation chip 2 is located in a plane perpendicular to the input waveguide port 10 and the output waveguide port 11. The modulation chip 2 includes a semiconductor substrate 3 and an artificial microstructure disposed on the semiconductor substrate 3. One side of the semiconductor substrate 3 contacts the cavity wall of the rectangular waveguide 1, while the artificial microstructure does not contact the cavity wall of the rectangular waveguide 1. The upper and lower longitudinal walls of the rectangular waveguide 1 contact the modulation chip 2. Air windows are provided on each of the upper and lower longitudinal walls of the rectangular waveguide 1. The air windows are used to electrically connect the external control circuit to the electrodes on the chip. The cavity wall of the rectangular waveguide 1 is made of metal, such as oxygen-free copper, brass, or aluminum. The artificial microstructure includes a modulation array 4 and a socket circuit, with the modulation array 4 connected to the socket circuit.

[0045] The modulation array 4 is a 1*N array composed of modulation units, where 1 represents the number of rows in the modulation array 4 and N represents the number of modulation units in each row, where N ≥ 1. There are two modulation units in the modulation array 4. The modulation units are connected in parallel in the order of the terahertz wave transmission direction in the rectangular waveguide 1 and are connected to the external feeding area through the common branches of each modulation unit. The modulation unit includes a diode 7, an anode resonator 9, and a cathode resonator 8. The anode resonator 9 and the cathode resonator 8 are rectangular structures of the same size and are symmetrically arranged on both sides of the diode 7. The anode resonator 9 and the cathode resonator 8 are mirror images of each other with respect to the diode 7. Adjacent anode resonators 9 are connected to each other through lateral branches, and adjacent cathode resonators 8 are connected to each other through lateral branches. The diode 7 is placed above the gap between the cathode resonator 8 and the anode resonator 9. The cathode and cathode electrodes of the diode 7 are connected to the cathode resonator 8 and the anode resonator 9, respectively. The sleeve circuit is connected to the anode resonator 9 and the cathode resonator 8. The diode 7 is connected to the cathode resonator 8 and the anode resonator 9 respectively through conductive glue. The diode 7 is narrower than the cathode resonator 8 and the anode resonator 9. The diode 7 is a planar Schottky barrier diode 7, and the material of the planar Schottky barrier diode 7 is GaN, InP or GaAs.

[0046] The sleeve circuit includes a grounding structure 5 and a filter feed structure 6. Both the grounding structure 5 and the filter feed structure 6 are compact microstrip resonators. The lateral branch on the grounding structure 5 is connected to one end of the cathode resonator 8, and the lateral branch on the filter feed structure 6 is connected to one end of the anode resonator 9.

[0047] Example 2:

[0048] Those skilled in the art may understand this embodiment as a more specific description of Embodiment 1.

[0049] like Figure 1 and Figure 2 As shown, this embodiment provides a terahertz modulator with a cavity-loaded resonant unit and a nested diode, including a rectangular waveguide 1 and a modulation chip 2.

[0050] The rectangular waveguide 1 has two waveguide ports: input waveguide port 10 and output waveguide port 11. Its cavity walls are made of metal, such as oxygen-free copper, brass, or aluminum. The modulator chip plane is perpendicular to the rectangular waveguide port plane. The modulator chip includes a semiconductor substrate 3 and an artificial microstructure placed on the semiconductor substrate. One side of the semiconductor substrate of the modulator chip contacts the rectangular waveguide cavity wall, while the surface of the artificial microstructure does not directly contact the rectangular waveguide cavity wall, with a distance of 180 μm between the two. An air window is provided at the junction of the upper and lower longitudinal walls of the rectangular waveguide with the modulator chip, allowing electrical connection between the external control circuit and the electrodes on the chip. The semiconductor substrate is made of quartz.

[0051] The artificial microstructure includes a modulation array 4 and a socket circuit. The artificial microstructure is made of Al, Ag or Au.

[0052] The modulation array is a 1xN array of modulation units, where 1 represents the number of rows in the modulation array and N represents the number of modulation units in each row, with N ≥ 1. There are two modulation units in the modulation array, connected in parallel along the terahertz wave transmission direction in the rectangular waveguide. Each modulation unit is connected to an external feed region via shared branches between the modulation units. Each modulation unit comprises a diode 7, an anode resonator 8, and a cathode resonator 9. The anode and cathode resonators are rectangular structures of equal size, symmetrically arranged on either side of the diode and mirror-imaged. Connected anode resonators are connected to each other via lateral branches, and adjacent cathode resonators are connected to each other via lateral branches. The diode is placed above the gap between the cathode and anode resonators, with the cathode and anode electrodes of the diode connected to the cathode and anode resonators, respectively. The diode is connected to the cathode and anode resonators, respectively, via conductive adhesive. The diode is narrower than the cathode and anode resonators. The diode is a planar Schottky barrier diode made of GaN, InP, or GaAs.

[0053] The sleeve circuit includes a grounding structure 5 and a filter feed structure 6, wherein the grounding structure and the filter feed structure are both compact microstrip resonators (Compact Microstrip Resonanting Cell, CMRC). The lateral branch on the grounding structure is connected to one end of the cathode resonator, and the lateral branch on the filter feed structure is connected to one end of the anode resonator.

[0054] This embodiment provides a terahertz modulator with a cavity-loaded resonant unit and a nested diode. The modulator switches the diode switching state through an external bias voltage, thereby changing the resonant characteristics of the unit structure and ultimately regulating the terahertz wave transmitted in the waveguide. The modulator can effectively control the transmission of terahertz waves in the waveguide within the operating frequency band and has high modulation efficiency. The waveguide loading method is more conducive to the miniaturization and integration of the modulator, reducing the complexity of the communication system. It also has high stability and is not easily affected by interference from the external environment.

[0055] Example 3:

[0056] Those skilled in the art may understand this embodiment as a more specific description of Embodiment 1.

[0057] like Figures 1 to 4 As shown, this embodiment provides a terahertz modulator with a cavity-loaded resonant unit and nested diodes, including a rectangular waveguide 1 and a modulation chip 2. The modulation chip 2 includes a semiconductor substrate 3, a modulation array 4, a ground structure 5, and a filter feed structure 6. The modulation array 4, the ground structure 5, and the filter feed structure 6 constitute a metal layer structure, which is grown above the semiconductor substrate 3.

[0058] The modulation array consists of two modulation units in a single row. The modulation units are connected in parallel, and the cathode resonators of the two modulation units are connected to the same grounding structure. The anode resonators of the two modulation units are connected to the same filtering structure for feeding external voltage signals. This design simplifies the circuit structure of the modulation chip, reduces the difficulty of circuit matching, and reduces the parasitic parameters in the array, which is conducive to the effective feeding of the modulation signal, thereby improving the modulation efficiency.

[0059] The modulation unit is composed of a metal resonant structure in which a diode is nested. Each modulation unit contains a diode 7, which is a planar Schottky barrier diode. The resonant structure in the modulation unit is composed of a cathode resonator 8 and an anode resonator 9. The cathode and anode resonators have the same structure and are both rectangular structures. The lower rectangular structure is the cathode resonator, and the upper rectangular structure is the anode resonator. The upper and lower rectangular structures are symmetrical about the diode in the middle. The diode 7 is located above the gap between the upper and lower rectangular structures. The cathode end of the diode is connected to the cathode resonator by applying conductive glue, and the anode end of the diode is connected to the anode resonator by applying conductive glue.

[0060] The plane of the modulator chip 2 is perpendicular to the rectangular waveguide's opening. One side of the modulator chip's semiconductor substrate is bonded to the rectangular waveguide cavity wall via a conductive adhesive. The surface of the modulator chip's artificial microstructures is not in direct contact with the rectangular waveguide cavity wall, with a distance of 180 μm between them. An air window is provided at each of the upper and lower longitudinal walls of the rectangular waveguide where it meets the modulator chip, allowing electrical connection between the external control circuitry and the on-chip electrodes.

[0061] The rectangular waveguide of this embodiment is WR2.8 with a size of 0.356mm*0.711mm. The material of the waveguide cavity wall is oxygen-free copper, the modulation chip is a composite metal-semiconductor junction, the semiconductor substrate 3 is 50um quartz, the diode 7 is GaAs, and the cathode resonator 8, anode resonator 9, grounding structure 5 and filter feeding structure 6 are all made of Al.

[0062] The modulation mechanism of the terahertz modulator with a cavity-loaded resonant unit and a nested diode is to change the state of the diode by applying an external voltage, control the resonant mode in the artificial microstructure, and modulate the amplitude of the terahertz wave in the waveguide.

[0063] The specific modulation process is as follows: the grounding structure in the modulator is located at the opening of the waveguide side wall and is connected to the waveguide wall through conductive glue to achieve grounding; the feeding filter structure located at the opening of the other waveguide side wall is loaded with an external voltage signal. When the external voltage signal is 0, the diode is in the off state. At this time, the cathode resonator and the anode resonator are independent of each other due to the disconnection of the diode, and no obvious resonance is generated within the test frequency band. Therefore, the terahertz wave transmitted in the rectangular waveguide can be smoothly transmitted from the input waveguide port to the output port, such as Figure 3 shown.

[0064] When the external voltage increases and exceeds the diode's turn-on voltage, the diode is in the on state. At this time, the upper and lower mirror-symmetrical cathode and anode resonators form a whole under the connection of the diode. Under the excitation of the terahertz wave, the resonant unit resonates. When the terahertz wave in the rectangular waveguide is transmitted to the modulation chip, a large amount of reflection is generated. At this time, the terahertz wave is cut off and cannot be transmitted to the output port. Figure 4 shown.

[0065] Therefore, by applying an external voltage to control the state of the diode, the resonant mode of the resonant unit can be switched to achieve the purpose of regulating the transmission of terahertz waves in the rectangular waveguide. The transmission coefficient of the modulator in different states is as follows: Figure 5As shown, at the 340 GHz operating frequency, when the modulator is disconnected, the transmission coefficient is -5 dB, and when the modulator is connected, the transmission coefficient is -30 dB, with a modulation depth greater than 25 dB. Furthermore, the modulation depth in the 320 GHz to 360 GHz range is greater than 7 dB, demonstrating a wide modulation bandwidth. This result demonstrates that the terahertz modulator provided by the present invention can achieve amplitude control of terahertz waves, and its simple structure facilitates fabrication, making it a highly practical, efficient, and high-speed terahertz modulation device.

[0066] This example fabricates a modulation chip by embedding a diode within an artificial microstructure. This modulation chip is then loaded into a waveguide cavity. An external voltage signal is used to change the diode's on / off state, thereby controlling the switching of electromagnetic resonant modes within the artificial microstructure and achieving amplitude modulation of terahertz waves within the rectangular waveguide. Simulations demonstrate that this cavity-loaded resonant unit with a diode embedded within it exhibits excellent performance, including high modulation depth and wide modulation bandwidth.

[0067] The present invention uses microfabrication techniques to nest diodes within an artificial microstructure containing a minimal number of modulation units, creating a terahertz modulation chip. The unidirectional conductivity of the diodes is exploited to control the on / off switching of the diodes via an applied voltage signal, thereby achieving conversion of electromagnetic resonance modes within the artificial microstructure. By reducing the number of modulation units on the modulation chip, the present invention can reduce the chip's parasitic parameters, suppress parasitic modes, and simplify the matching circuit, significantly improving the modulation efficiency of the modulator. Furthermore, by using a compact microstrip resonator as a socket circuit connected to the modulation unit, the present invention suppresses terahertz waves from leaking through the air window within the rectangular waveguide and reduces the impedance mismatch introduced when the applied voltage signal is connected to the modulation unit, thereby resolving the problem of large external voltage reflections during high-frequency signal input.

[0068] The present invention loads a modulation chip into a rectangular waveguide and uses the conversion of resonant modes in an artificial microstructure to control the transmission of terahertz waves in the rectangular waveguide. Since Schottky diodes have a rapid response capability to terahertz waves, the modulator can achieve an extremely high modulation rate. The waveguide-loaded device form enables the modulation chip to be effectively protected by the metal waveguide, effectively resisting interference from external factors and greatly enhancing the stability of the device operation.

[0069] In the description of this application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and 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, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0070] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A terahertz modulator with a cavity-loaded resonant unit and a nested diode, characterized in that: It comprises a rectangular waveguide (1) and a modulation chip (2), wherein the modulation chip (2) is arranged on a cavity wall of the rectangular waveguide (1); The rectangular waveguide (1) is provided with an input waveguide port (10) and an output waveguide port (11), and the plane where the modulation chip (2) is located is perpendicular to the plane of the input waveguide port (10) and the plane of the output waveguide port (11); The modulation chip (2) comprises a semiconductor substrate (3) and an artificial microstructure disposed on the semiconductor substrate (3); one side of the semiconductor substrate (3) contacts the cavity wall of the rectangular waveguide (1), and the artificial microstructure does not contact the cavity wall of the rectangular waveguide (1); The upper and lower longitudinal walls of the rectangular waveguide (1) are in contact with the modulation chip (2), and air windows are respectively provided on the upper and lower longitudinal walls of the rectangular waveguide (1), and the air windows are used to electrically connect an external control circuit with electrodes on the chip; The artificial microstructure comprises a modulation array (4) and a socket circuit, wherein the modulation array (4) is connected to the socket circuit; The modulation array (4) is a 1*N type array composed of modulation units, 1 represents the number of rows of the modulation array (4), and N represents the number of modulation units in each row, wherein N≥1; There are two modulation units in the modulation array (4), and the modulation units are connected in parallel in sequence according to the terahertz wave transmission direction in the rectangular waveguide (1), and are connected to the external feeding area through the common branches of each modulation unit; The modulation unit includes a diode (7), an anode resonator (9) and a cathode resonator (8); The anode resonator (9) and the cathode resonator (8) are rectangular structures of the same size, the anode resonator (9) and the cathode resonator (8) are symmetrically arranged on both sides of the diode (7), and the anode resonator (9) and the cathode resonator (8) are mirror images of each other with respect to the diode (7); Adjacent anode resonators (9) are connected to each other via transverse branches, and adjacent cathode resonators (8) are connected to each other via transverse branches; The diode (7) is placed above the gap between the cathode resonator (8) and the anode resonator (9), and the positive and negative poles of the diode (7) are connected to the cathode resonator (8) and the anode resonator (9) respectively; The sleeve circuit is connected to the anode resonator (9) and the cathode resonator (8); The sleeve circuit includes a grounding structure (5) and a filtering and feeding structure (6), wherein the grounding structure (5) and the filtering and feeding structure (6) are both compact microstrip resonators; The transverse branch on the grounding structure (5) is connected to one end of the cathode resonator (8), and the transverse branch on the filter feeding structure (6) is connected to one end of the anode resonator (9).

2. The terahertz modulator with a cavity-loaded resonant unit and a nested diode (7) according to claim 1 is characterized in that: The diode (7) is connected to the cathode resonator (8) and the anode resonator (9) respectively through conductive glue.

3. The terahertz modulator with a cavity-loaded resonant unit and a nested diode (7) according to claim 1 is characterized in that: The diode (7) is narrower than the cathode resonator (8) and the anode resonator (9).

4. The terahertz modulator with a cavity-loaded resonant unit and a nested diode (7) according to claim 1, characterized in that: The diode (7) is a planar Schottky barrier diode (7), and the material of the planar Schottky barrier diode (7) is GaN, InP or GaAs.

5. The terahertz modulator with a cavity-loaded resonant unit and a nested diode (7) according to claim 1, characterized in that: The cavity wall of the rectangular waveguide (1) is made of metal material, and the metal material is oxygen-free copper, brass or aluminum.

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