Terahertz amplitude modulator based on waveguide directional coupling hole

Abstract

The invention belongs to but is not limited to the technical field of electromagnetic functional devices, and particularly relates to a terahertz amplitude modulator based on waveguide directional coupling holes, which comprises an input rectangular waveguide, an output rectangular waveguide, a first waveguide directional coupling hole, a second waveguide directional coupling hole, a first reflection short-circuit surface, a second reflection short-circuit surface and an amplitude modulation circuit structure, wherein the input rectangular waveguide is directly connected with the first reflection short circuit surface; the output rectangular waveguide is directly connected with the second reflection short circuit surface; the input rectangular waveguide and the output rectangular waveguide are connected through a first waveguide directional coupling hole and a second waveguide directional coupling hole; one end of the amplitude modulation circuit structure is inserted into the second waveguide directional coupling hole, and the other end of the amplitude modulation circuit structure is provided with an external feed opening for external voltage regulation and control. The waveguide directional coupling hole and the amplitude modulation circuit structure are creatively combined, simple and convenient terahertz amplitude modulation is achieved, and a new terahertz regulation and control scheme is provided.

Description

Technical Field

[0001] The present invention belongs to but is not limited to the technical field of electromagnetic functional devices, and in particular relates to a terahertz amplitude modulator based on a waveguide directional coupling hole. Background Art

[0002] Terahertz technology has undergone a certain development and has shown broad application prospects in imaging, spectroscopy, biological detection and communication. In particular, terahertz communication technology is regarded as an important component of the next generation of mobile communications and has received extensive attention from researchers. However, how to efficiently realize the direct modulation of terahertz waves remains a major challenge.

[0003] At present, researchers mainly use terahertz metasurface quasi-optical amplitude modulators composed of artificial microstructure arrays and semiconductor materials. However, this type of amplitude modulator faces two major problems: First, due to the large number of periodic unit structures contained in the modulator, the additional parasitic effects are significant, and it is difficult to match the impedance with the control circuit, which makes it very difficult to control the electromagnetic properties of semiconductor materials, thereby limiting the increase in modulation rate; second, the quasi-optical modulator usually needs to be assembled on a complex optical platform, and its feeding system is complex in structure, which is not conducive to the miniaturization of the system. These problems greatly restrict the application potential of terahertz metasurface quasi-optical amplitude modulators.

[0004] In order to overcome these obstacles, an effective solution is to use transmission line structures such as microstrip lines, fin lines and coplanar waveguides to achieve terahertz amplitude modulation. In this way, the electromagnetic properties of high electron mobility transistors or diodes can be precisely controlled by voltage, and the resonant mode in the artificial electromagnetic resonance unit can be adjusted to modulate the amplitude of the terahertz wave. The specific process includes: first, the terahertz wave is input into the rectangular waveguide, and then coupled to the specific microstructure modulation unit of the integrated transistor through the transition structure. By applying voltage through an external circuit, the state of the modulation unit (on / off) can be flexibly switched, thereby changing the propagation characteristics of the terahertz wave and achieving fast and efficient amplitude modulation. Finally, the modulated terahertz wave is output through the corresponding transition structure.

[0005] The waveguide directional coupling structure has four ports. After the electromagnetic wave is input from the input port, it will be output from the straight-through port and the coupled port, and there will be no output from the isolated port. If the straight-through port and the coupled port are short-circuit reflection surfaces, the reflected wave will be output from the original isolated port. In the terahertz band, a waveguide directional coupling structure is usually used to achieve functions such as 3dB power division, orthogonal signal generation, and phase shifting. However, in the prior art, the realization of these functions is rarely related to the coupling hole of the waveguide directional coupling structure. The coupling hole of the waveguide directional coupling structure has a fixed function and only serves to couple the terahertz wave to the coupling port.

[0006] In view of the above analysis, the technical problems that need to be solved urgently in the prior art are:

[0007] 1. The design of on-chip circuits to achieve terahertz amplitude modulation is complex and requires high processing accuracy. In addition, there are many parasitic parameters introduced by transistors and artificial microstructures, making it difficult to meet the design requirements of high-speed modulation.

[0008] 2. The coupling hole of the waveguide directional coupling structure in the prior art solution has a fixed function and only plays the role of coupling the terahertz wave to the coupling port, and lacks functional development of the directional coupling hole.

[0009] 3. Terahertz amplitude modulation focuses on insertion loss. The existing technology uses a transition structure to increase insertion loss and reduce modulation performance. Summary of the invention

[0010] In view of the problems existing in the prior art, the present invention provides a terahertz amplitude modulator based on a waveguide directional coupling hole.

[0011] The present invention is implemented as follows: a terahertz amplitude modulator based on a waveguide directional coupling hole comprises an input rectangular waveguide, an output rectangular waveguide, a first waveguide directional coupling hole, a second waveguide directional coupling hole, a first reflection short-circuit surface, a second reflection short-circuit surface, and an amplitude modulation circuit structure. The input rectangular waveguide is directly connected to the first reflection short-circuit surface; the output rectangular waveguide is directly connected to the second reflection short-circuit surface; the input rectangular waveguide and the output rectangular waveguide are connected through the first waveguide directional coupling hole and the second waveguide directional coupling hole; one end of the amplitude modulation circuit structure is inserted into the second waveguide directional coupling hole, and the other end has an external feeding opening for external voltage regulation.

[0012] The first waveguide directional coupling hole and the second waveguide directional coupling hole simultaneously connect the input rectangular waveguide and the output rectangular waveguide, and the connection length is lengthened to meet the insertion of the modulation circuit structure; the first waveguide directional coupling hole and the second waveguide directional coupling hole have the same size; there is a certain distance between the first waveguide directional coupling hole and the second waveguide directional coupling hole to achieve a double-hole coupling effect.

[0013] The amplitude modulation circuit structure includes a substrate, a probe structure, a grounding structure, a first matching metal strip, a diode, a second matching metal strip, a feeding structure, and a feeding opening. The substrate is used to carry all metal structures and diodes. The probe structure is inserted into the second waveguide directional coupling hole from half of the connection length of the second waveguide directional coupling hole; the probe structure is directly connected to one end of the first matching metal strip, and the other end of the first matching metal strip is connected to the cathode of the diode; one end of the thin metal wire of the grounding structure is connected to the side of the first matching metal strip, and the other end of the thin metal wire is connected to a small metal block, and the small metal contacts the metal cavity wall to provide a grounding zero potential; the anode of the diode is connected to one end of the second matching metal strip, and the other end of the second matching metal strip is connected to the thin feeding wire of the feeding structure; the thin feeding wire in the feeding structure is first connected to the fan-shaped filtering metal block, and then continues to extend and connect to the feeding metal block; the feeding metal block is close to the feeding opening to realize the connection with the gold wire jumper of the external feeding circuit, so as to achieve the function of feeding the modulation signal; after the modulation signal is fed in, the on-off state of the diode can be controlled, thereby changing the impedance of the amplitude modulation circuit structure, and realizing the control of the terahertz coupling function of the second waveguide directional coupling hole.

[0014] Furthermore, the specific working principle of the terahertz amplitude modulator based on the waveguide directional coupling hole is:

[0015] After the terahertz wave is input through the input rectangular waveguide, when the dual coupling holes work together, half of its power reaches the first reflection short-circuit surface, and the other half reaches the second reflection short-circuit surface; the distance between the two reflection short-circuit surfaces and the dual coupling holes is designed according to the wavelength of the terahertz wave, and the reflected terahertz wave will all reach the output rectangular waveguide, and will not return to the input rectangular waveguide. Since the amplitude modulation circuit structure is inserted into the second waveguide directional coupling hole, when the modulation signal controls the diode to switch on and off, the coupling function of the second waveguide directional coupling hole can be destroyed, so that the dual coupling holes work together and become the first coupling hole work independently, causing the terahertz wave to return to the input rectangular waveguide after reflection, and will not reach the output rectangular waveguide, thereby realizing the amplitude regulation of the output terahertz wave.

[0016] Furthermore, the first reflective short-circuit surface and the second reflective short-circuit surface have the same size and are mirror-symmetrical.

[0017] Furthermore, the distances between the first waveguide directional coupling hole, the second waveguide directional coupling hole and the first reflection short-circuit surface, the second reflection short-circuit surface are adjustable, and the sizes and connection lengths of the first waveguide directional coupling hole and the second waveguide directional coupling hole are adjustable to adjust the operating frequency and the operating bandwidth.

[0018] Furthermore, the base material of the amplitude modulation circuit structure may be silicon, high-resistance silicon, quartz, gallium arsenide, silicon carbide, aluminum nitride, or diamond.

[0019] Furthermore, the metal material used in the amplitude modulation circuit structure may be aluminum, copper, silver, gold, platinum, or nickel alloy.

[0020] Furthermore, the length, width and position of the probe structure, the first matching metal strip and the second matching metal strip in the amplitude modulation circuit structure are adjustable to obtain different amplitude modulation frequencies and depths.

[0021] Furthermore, the diode may be a high electron mobility planar diode, a Schottky diode, or a terahertz PIN diode, and its shape and size may vary with the size and position of the first matching metal strip and the second matching metal strip to achieve the best tuning effect.

[0022] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0023] First, the beneficial effects of the present invention include:

[0024] 1. The present invention creatively combines the waveguide directional coupling hole with the amplitude modulation circuit structure to achieve simple and convenient terahertz amplitude modulation and provide a new terahertz control solution.

[0025] 2. The amplitude modulation circuit structure used for regulating the waveguide directional coupling hole only requires a single diode, reducing the circuit complexity.

[0026] 3. The present invention does not require a transition structure from waveguide to chip, which effectively reduces transmission loss and is easy to integrate with other terahertz functional modules.

[0027] 4. The rectangular waveguide, directional coupling hole and amplitude modulation circuit structure involved in the present invention have mature processing technology, controllable cost and potential for large-scale application.

[0028] Second, the expected benefits and commercial value of the technical solution of the present invention after transformation are as follows: the present invention is the core component of the terahertz amplitude modulation communication system. By combining it with a 340GHz terahertz source, a photoelectric conversion structure, a waveguide antenna and a terahertz detector, it can achieve lossless conversion of optical fiber-wireless communication. At the same time, it can constitute a convenient and mobile high-speed terahertz digital modulation communication platform, which is suitable for wireless emergency communication.

[0029] The technical solution of the present invention fills the technical gap in the industry at home and abroad: the present invention innovatively combines the waveguide directional coupling hole with the amplitude modulation circuit structure to achieve convenient terahertz amplitude modulation and provide a new terahertz control solution.

[0030] Third, the technical solution of the present invention mainly solves many technical problems of existing terahertz amplitude modulators in terms of accuracy, response speed, stability and cost. In industrial applications, the present invention demonstrates significant technological progress, which is specifically reflected in the following aspects:

[0031] 1. Improve the modulation accuracy and sensitivity of terahertz waves: This invention significantly improves the modulation accuracy of terahertz waves through the structural design based on the waveguide directional coupling hole and the precise modulation circuit coupling. The directional coupling hole and the microstructure combined with the diode control can achieve subtle signal amplitude control, meet the industry's demand for high-precision, low-error terahertz signal modulation, and cover application scenarios from precision medical imaging to high-resolution communications.

[0032] 2. Fast response and dynamic regulation capability: Compared with traditional modulators, the present invention significantly improves the modulation response speed by utilizing the diode Schottky characteristics. This fast response characteristic is particularly suitable for dynamic data transmission environments, such as high-speed wireless communication and real-time monitoring. At the same time, the dynamic real-time regulation of the terahertz wave amplitude is achieved through the regulation of the feed circuit, meeting the real-time control needs of industrial equipment.

[0033] 3. Enhanced signal transmission stability: The microstructure and matching design used in the present invention effectively reduce the reflection loss and noise interference in signal transmission, and maintain stable signal transmission. This feature is particularly important in the fields of precision industrial detection, non-contact detection, and communication in complex environments, providing stable and reliable data transmission for key equipment.

[0034] 4. Save industry costs and improve device integration: Through innovative structural design, the present invention realizes efficient integration of terahertz wave modulators based on standard waveguides. Thanks to the reasonable diode microstructure layout and efficient signal control circuit, the device cost is significantly reduced, and it is compatible with existing equipment standards, greatly reducing the cost of industrial promotion and application.

[0035] 5. Expand the application scope of terahertz technology: Based on the innovative technology of this invention, the application of terahertz amplitude modulator has expanded from traditional scientific research fields to a wide range of industrial scenarios, such as high-precision medical imaging, security scanning, and intelligent perception of automated factories. Its good signal control and modulation characteristics have laid the foundation for the widespread promotion of terahertz technology in emerging application scenarios.

[0036] 6. Reliability in adapting to different industrial environments: By adopting stable materials and structures, the modulator of the present invention still maintains high performance stability in complex environments such as temperature changes and mechanical vibrations, and is suitable for industrial-scale production. This shows significant technological progress in terms of increasing the service life of industrial equipment and reducing maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a three-dimensional schematic diagram of a terahertz amplitude modulator based on a waveguide directional coupling hole provided in an embodiment of the present invention;

[0038] Figure 2 This is a front view of a terahertz amplitude modulator based on a waveguide directional coupling hole provided by an embodiment of the present invention;

[0039] Figure 3 It is a schematic diagram of the amplitude modulation circuit structure of a terahertz amplitude modulator based on a waveguide directional coupling hole provided in an embodiment of the present invention;

[0040] Figure 4 is a parameter curve diagram of S21 of a terahertz amplitude modulator based on a waveguide directional coupling hole provided in an embodiment of the present invention;

[0041] In the figure: A, input rectangular waveguide; B, output rectangular waveguide; C, first waveguide directional coupling hole; D, second waveguide directional coupling hole; E, first reflection short-circuit surface; F, second reflection short-circuit surface; G, amplitude modulation circuit structure; G1, substrate; G2, probe structure; G3, grounding structure; G4, first matching metal strip; G5, diode; G6, second matching metal strip; G7, feeding structure; G8, feeding opening. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0043] like Figure 1 , Figure 2 As shown, the present invention is a terahertz amplitude modulator based on a waveguide directional coupling hole, wherein the input rectangular waveguide A is directly connected to the first reflection short-circuit surface E, the input rectangular waveguide A is connected to the output rectangular waveguide B through the first waveguide directional coupling hole C and the second waveguide directional coupling hole D, and the output rectangular waveguide B is directly connected to the second reflection short-circuit surface F. The input rectangular waveguide and the output waveguide adopt the WR2.8 international standard waveguide size. The length of the first waveguide directional coupling hole C and the second waveguide directional coupling hole D is 711 μm, the width is 180 μm, the connection length is 260 μm, and the distance between the two coupling holes is 120 μm. The distance between the second waveguide directional coupling hole D and the first reflection short-circuit surface E is 510 μm. The first reflection short-circuit surface E and the second reflection short-circuit surface F have the same size, with a long side of 711 μm and a wide side of 356 μm, which are symmetrical.

[0044] One end of the amplitude modulation circuit structure G is inserted from a position half the connection length of the second waveguide directional coupling hole, and the other end of the amplitude modulation circuit structure G is a feeding opening G8.

[0045] like Figure 3 As shown, in the amplitude modulation circuit structure G, the substrate G1 is made of quartz material, the metal structure it carries is made of gold, and the diode connected in the metal structure is a terahertz Schottky diode. The probe structure G2 has a size of 160μm×60μm, which is inserted into the second waveguide directional coupling hole. One end of it is at a certain distance from the coupling hole wall, and the other end is connected to the first matching metal strip G4. The first matching metal strip G4 has a size of 67μm×40μm, and its side is connected to the grounding structure G3, and it is also connected to the anode of the diode G5. In the grounding structure G3, a thin metal wire with a size of 30μm×5μm is connected to a small metal block of 30μm×25μm, and provides a grounding zero potential by contacting the metal cavity wall. The size of the diode G5 is 180μm×50μm, and its anode is connected to the second matching metal strip G6. The size of the second matching metal strip G6 is 107μm×40μm, and its other end is connected to the feeding structure G7. The thin feed line in the feed structure G7 is first connected to the fan-shaped filter metal block, and then is further extended to connect to the feed metal block. The feed metal block is close to the feed opening G8 to facilitate the external circuit to feed the modulated signal.

[0046] The terahertz amplitude modulator based on the waveguide directional coupling hole of the present invention realizes accurate amplitude modulation of terahertz waves through the coupling structure of the input and output rectangular waveguides and the design of the modulation circuit. The working principle is as follows:

[0047] 1. Waveguide coupling and reflection control: The input rectangular waveguide A is directly connected to the first reflection short-circuit E, allowing the terahertz wave to enter at the input end and pass through the first and second waveguide directional coupling holes (C and D) to the output rectangular waveguide B. The size and distance of the coupling holes between the waveguides are strictly controlled to optimize signal coupling and transmission. The symmetrical design of the first reflection short-circuit E and the second reflection short-circuit F causes the reflected waves to interfere, which can effectively control and limit the phase of the transmitted signal, optimize the coupling effect of the input signal and reduce noise interference.

[0048] 2. Coupling effect of modulation circuit: The probe structure G2 of the amplitude modulation circuit structure G is inserted from the second waveguide directional coupling hole D. The size and insertion position of the probe structure are precisely controlled so that it can effectively couple part of the transmission signal. The probe structure G2 is connected to the first matching metal strip G4, and the signal amplitude is modulated through the directional diode Schottky diode G5. The nonlinear characteristics of the diode are used to control the terahertz signal, realizing the amplitude modulation function of the terahertz wave. The anode and cathode of the diode are connected to the matching metal strip and the grounding structure respectively to ensure the stability of signal transmission.

[0049] 3. Signal matching and feedback mechanism: In the amplitude modulation circuit, the signal is well matched with the waveguide system through the first and second matching metal strips (G4 and G6), ensuring that the reflection loss is reduced when the signal is transmitted from the waveguide to the modulation circuit. After the diode is regulated, the modulated signal is fed back to the system through the feeding structure G7, and the adjusted signal can propagate in the direction of the output rectangular waveguide B. At the same time, the use of quartz material and matching metal in the base structure avoids unnecessary energy dissipation, allowing the modulator to maintain a stable signal output within a wider frequency band.

[0050] 4. Feed control of modulation signal: The feeding structure G7 is designed to include a thin feed line, a fan-shaped filter metal block and a feeding metal block. These structures are gradually connected to the external circuit to provide precise electrical signal regulation for the modulation circuit. The external modulation signal is connected through the feeding opening G8 to control the working state of the amplitude modulation circuit and achieve real-time adjustment of the amplitude modulation effect of the terahertz wave. By controlling the amplitude and frequency of the feeding signal, the intensity of the output terahertz wave can be dynamically adjusted, so that the system has good signal control performance and modulation accuracy.

[0051] In this embodiment: after the terahertz wave is input through the input rectangular waveguide, we control the on-off state of the diode through a voltage signal. When the diode is connected, the coupling function of the second waveguide directional coupling hole is guaranteed. When the diode is disconnected, the coupling function of the second waveguide directional coupling hole is destroyed, so that the dual coupling hole working state and the single coupling hole working state are switched, and finally the terahertz wave amplitude control is realized. Figure 4 As shown, in the frequency range of 315 GHz to 357 GHz, when the Schottky diode is connected, S21>-1.26 dB, and when the Schottky diode is disconnected, S21 decreases, the modulation depth is greater than 10 dB, and broadband amplitude modulation with a bandwidth of more than 40 GHz is achieved.

[0052] This embodiment realizes broadband terahertz amplitude modulation with low insertion loss. The cutoff frequency of the Schottky gallium arsenide diode used can exceed 600 GHz, and it has high-speed modulation capability at higher frequencies.

[0053] The present invention is a terahertz amplitude modulation device based on a waveguide directional coupling hole, which is a key component of a terahertz amplitude modulation communication system. The present invention can be combined with a 340GHz terahertz source, and then a high-speed digital voltage signal is directly input into the feeding structure to output a terahertz high-speed direct amplitude modulation signal. In an optical-wireless interconnection system, a high-speed digital voltage signal can be provided by a photodiode. After that, the waveguide antenna is used to transmit and receive, and a terahertz detector is used to demodulate the received signal, so that a convenient and mobile high-speed terahertz digital modulation communication system can be realized, which has great potential in wireless emergency communications and optical fiber-wireless switching.

[0054] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention 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 operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0055] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A terahertz amplitude modulator based on a waveguide directional coupling hole, characterized in that: include: An input rectangular waveguide, an output rectangular waveguide, a first waveguide directional coupling hole, a second waveguide directional coupling hole, a first reflection short-circuit surface, a second reflection short-circuit surface and an amplitude modulation circuit structure; The input rectangular waveguide is directly connected to the first reflection short-circuit surface, the output rectangular waveguide is directly connected to the second reflection short-circuit surface, and the input rectangular waveguide and the output rectangular waveguide are connected via the first waveguide directional coupling hole and the second waveguide directional coupling hole; One end of the amplitude modulation circuit structure is inserted into the second waveguide directional coupling hole, and the other end is provided with an external feeding opening for external voltage regulation; The first waveguide directional coupling hole and the second waveguide directional coupling hole simultaneously connect the input rectangular waveguide and the output rectangular waveguide, and the connection length of the two coupling holes is lengthened to facilitate the insertion of the modulation circuit structure; The two coupling holes have the same size and there is a preset distance between them, thus achieving a double-hole coupling effect.

2. The terahertz amplitude modulator according to claim 1, characterized in that: The amplitude modulation circuit structure comprises: a substrate, a probe structure, a ground structure, a first matching metal strip, a diode, a second matching metal strip, a feed structure, and a feed opening; The probe structure is inserted from the midpoint of the connection length of the second waveguide directional coupling hole, one end of the probe structure is connected to the first matching metal strip, and the other end of the first matching metal strip is connected to the cathode of the diode; The grounding structure includes a thin metal wire, one end of which is connected to the side of the first matching metal strip, and the other end of which is connected to a small metal block to provide a grounding zero potential; The anode of the diode is connected to one end of the second matching metal strip, and the other end of the second matching metal strip is connected to the thin feeding wire of the feeding structure; The thin feed line in the feeding structure is connected to the fan-shaped filter metal block and extends to the feeding metal block. The feeding metal block is located near the feeding opening to achieve connection with the external feeding circuit, so as to control the on-off state of the diode by feeding in a modulation signal, and adjust the impedance of the amplitude modulation circuit structure to control the coupling effect of the terahertz wave.

3. The terahertz amplitude modulator based on waveguide directional coupling hole according to claim 1, characterized in that: The specific working principle of the terahertz amplitude modulator based on waveguide directional coupling hole is: After the terahertz wave is input through the input rectangular waveguide, when the double coupling holes work together, half of its power reaches the first reflection short-circuit surface, and the other half of its power reaches the second reflection short-circuit surface; the distances between the two reflection short-circuit surfaces and the double coupling holes are designed according to the wavelength of the terahertz wave, and the reflected terahertz wave will all reach the output rectangular waveguide without returning to the input rectangular waveguide; because the amplitude modulation circuit structure is inserted into the second waveguide directional coupling hole, when the modulation signal controls the on-off switching of the diode, the coupling function of the second waveguide directional coupling hole can be destroyed, so that the double coupling holes work together and become the first coupling hole work independently, resulting in the terahertz wave returning to the input rectangular waveguide after reflection, and not reaching the output rectangular waveguide, thereby realizing the amplitude regulation of the output terahertz wave.

4. The terahertz amplitude modulator based on waveguide directional coupling hole according to claim 1, characterized in that: The first reflection short-circuit surface and the second reflection short-circuit surface have the same size and are mirror-symmetrical.

5. The terahertz amplitude modulator based on waveguide directional coupling hole according to claim 1, characterized in that: The distances between the first waveguide directional coupling hole, the second waveguide directional coupling hole and the first reflection short-circuit surface, the second reflection short-circuit surface are adjustable, and the sizes and connection lengths of the first waveguide directional coupling hole and the second waveguide directional coupling hole are adjustable to adjust the working frequency and working bandwidth.

6. The terahertz amplitude modulator based on waveguide directional coupling hole according to claim 1, characterized in that: The base material of the amplitude modulation circuit structure can be silicon, high-resistance silicon, quartz, gallium arsenide, silicon carbide, aluminum nitride, or diamond.

7. The terahertz amplitude modulator based on waveguide directional coupling hole according to claim 1, characterized in that: The metal material used in the amplitude modulation circuit structure can be aluminum, copper, silver, gold, platinum, or nickel alloy.

8. The terahertz amplitude modulator based on waveguide directional coupling hole according to claim 1, characterized in that: The length, width and position of the probe structure, the first matching metal strip and the second matching metal strip in the amplitude modulation circuit structure are adjustable to obtain different amplitude modulation frequencies and depths.

9. The terahertz amplitude modulator based on waveguide directional coupling hole according to claim 1, characterized in that: The diode may be a high electron mobility planar diode, a Schottky diode, or a terahertz PIN diode, and its shape and size may vary with the size and position of the first matching metal strip and the second matching metal strip to achieve the best tuning effect.

Images