A fin-line terahertz multi-phase shifter based on gallium arsenide diodes

Abstract

The present invention belongs to the field of electromagnetic functional devices, and specifically relates to a fin-line terahertz multi-phase shifter based on a gallium arsenide diode, comprising: a rectangular waveguide input port, a substrate, a rectangular waveguide-fin-line transition structure, a fin-line structure, a probe-type microstructure phase shifter unit, its feeding opening portion, a fin-line-rectangular waveguide transition structure, and a rectangular waveguide output port. The present invention addresses the problems of the existing terahertz wave phase modulator having few phase shifting technical solutions, large insertion loss during phase shifting, a small phase shift range, a large device size, and low integrability. By controlling the on-off of the diode on the probe-type microstructure phase shifter unit by voltage, the perturbation intensity of the probe on the fin line is changed, so that the equivalent dielectric constant of the fin line changes, thereby achieving the phase shift of the terahertz wave; then, by superimposing the phase shifters in a centrally symmetrical and parallel arrangement, a low-insertion-loss multi-bit terahertz wave phase shift is finally achieved, ensuring a good working state and promoting the development of terahertz phase control technology.

Description

Technical Field

[0001] The present invention belongs to the field of electromagnetic functional devices, and in particular relates to a fin-line terahertz multi-phase shifter based on a gallium arsenide diode. Background Art

[0002] Terahertz waves refer to electromagnetic waves with frequencies between 0.1 and 10 THz, lying between millimeter waves and infrared and visible light. Due to the specificity of this frequency band, established technologies for millimeter waves and infrared light cannot be directly applied to the terahertz band, leading to a need for the development of various types of terahertz modulation devices. Compared to millimeter waves, terahertz waves offer significant advantages in beam directivity, communication speed, response rate, and imaging resolution. Terahertz modulation devices have potential applications in communications, imaging, radar systems, bioimaging, and other fields, and represent a key technological advancement for future 6G technologies.

[0003] Multi-bit terahertz phase modulation involves dividing the phase shift into multiple steps, each with a fixed phase shift angle that can be superimposed. It is widely used in wireless communication systems and phased array radar systems. Wireless communication systems can utilize multi-bit coding to increase communication rates and enhance noise and interference immunity. Multi-bit phase shift keying (PSK) coding is a successful coding technique, requiring multi-bit, high-precision phase control technology. In radar systems, phased array radar technology has gradually replaced mechanical scanning radar technology, particularly terahertz phased array radar, which features small size, high speed, narrow beam, and high integration. These communication and radar system fields have a high demand for terahertz phase modulation technology, but high-precision dynamic phase modulation devices remain underdeveloped.

[0004] Dynamic phase modulation devices are typically developed based on materials with variable electromagnetic properties, and their dynamic changes require external stimulation such as heat, electric fields, and lasers. By controlling the variable electromagnetic material in a metal structure, its electromagnetic properties, such as conductivity, capacitance, resistance, and equivalent dielectric constant, can be altered, thereby achieving dynamic control of terahertz wave phase modulation. Gallium arsenide diodes are Schottky-type diodes made using gallium arsenide as a substrate. The diode can be turned on by applying a forward voltage and turned off by applying a reverse voltage, providing a foundation for dynamic control of terahertz phase modulation devices.

[0005] Fin wire is a common structure for transmitting electromagnetic waves and is widely used in various circuits. It can be well combined with rectangular waveguides and is suitable for the design of terahertz modulation devices.

[0006] Through the above analysis, the problems and defects of the existing technology are as follows:

[0007] (1) There are few feasible phase shifting technology solutions available, which cannot adapt to different working environments;

[0008] (2) The existing phase shifting technology structure has large insertion loss, small phase shift range and poor working condition during phase shifting;

[0009] (3) Existing phase-shifting technology has a complex structure, large size and low integration. Summary of the Invention

[0010] (1) Technical issues to be resolved

[0011] To solve the problems that there are few feasible phase shifting technology solutions available and they cannot adapt to different working environments; the existing phase shifting technology structure has large insertion loss, small phase shift range and poor working condition during phase shifting; the existing phase shifting technology structure is complex, large in size and has low integration, a fin-line terahertz multi-phase shifter based on gallium arsenide diode is provided.

[0012] (2) Technical solution

[0013] To address the problems and shortcomings of existing technologies, the present invention provides a fin-line terahertz multi-phase shifter based on a gallium arsenide diode. This invention can provide multi-bit terahertz phase control, with low insertion loss and simple and convenient control.

[0014] The present invention is achieved through the following technical solutions:

[0015] A fin-line terahertz multi-phase shifter structure based on gallium arsenide diodes includes:

[0016] Rectangular waveguide input port, which realizes the input of terahertz waves and can be connected with other terahertz devices;

[0017] The substrate is located on the center line of the long side of the rectangular waveguide, and metal structures can be made on the front and back sides of the substrate;

[0018] The rectangular waveguide-to-fin transition structure is located on the back of the substrate and realizes the terahertz wave transmission transition from the rectangular waveguide to the fin, which can reduce the size of the device and ensure good working condition.

[0019] The fin line structure is located on the back of the substrate and is connected to the rectangular waveguide-fin line transition structure. It can confine the terahertz wave in the middle of the structure to achieve low insertion loss propagation of the terahertz wave.

[0020] The probe-type microstructure phase shifter is located on the front of the substrate. The GaAs diode on the voltage control unit can achieve the phase shift of the terahertz wave. The superposition of the centrally symmetric phase shifters increases the terahertz wave phase control range, ultimately achieving multi-bit terahertz phase shifting.

[0021] The feeding opening is located on the long side of the rectangular waveguide, which can control the probe-type microstructure phase shift unit while reducing the impact on the propagation of terahertz waves;

[0022] The fin-line-rectangular waveguide transition structure is located on the back of the substrate and is connected to the fin-line structure to achieve the terahertz wave transmission transition from the fin-line to the rectangular waveguide and output the phase-shifted terahertz wave;

[0023] Rectangular waveguide output port realizes the output of terahertz waves.

[0024] Furthermore, the rectangular waveguide input port and the rectangular waveguide output port are both international standard waveguides.

[0025] Furthermore, the rectangular waveguide-fin line transition structure and the fin line-rectangular waveguide transition structure are a segmented function gradient fin line structure, whose function is an exponential, parabola, sine square, cosine square function, etc., which can achieve low insertion loss terahertz wave propagation transition.

[0026] Furthermore, the fin line structure is located on the back side of the substrate and is connected to the rectangular waveguide-fin line transition structure and the fin line-rectangular waveguide transition structure, thereby confining the terahertz wave to the middle opening of the fin line.

[0027] Furthermore, the probe-type microstructure phase-shifting unit is located on the front side of the substrate, and includes a probe structure, a grounding structure, a gallium arsenide diode, a matching phase-shifting structure, and a feeding structure, wherein one end of the probe structure is located on the middle opening of the fin line, and the other end is connected to the negative electrode of the gallium arsenide diode. The grounding structure connects the probe structure and the rectangular waveguide wall. The positive electrode of the gallium arsenide diode is connected to one end of the matching phase-shifting structure, and the other end of the matching phase-shifting structure is connected to the feeding structure. A control voltage is fed into the feeding structure to control the on-off state of the gallium arsenide diode, thereby changing the influence of the probe-type microstructure phase-shifting unit on the electromagnetic field of the middle opening of the fin line, thereby affecting the relative dielectric constant and phase velocity of the fin line structure, thereby obtaining a terahertz wave phase shift.

[0028] Furthermore, the shapes and sizes of the probe structure and the matching phase shift structure are adjustable, thereby achieving phase shifts of different degrees with low insertion loss.

[0029] Furthermore, the metal materials used in the fin line, rectangular waveguide-fin line transition structure, fin line-rectangular waveguide transition structure, and probe type microstructure phase shift unit are Au, Ag, Cu, or Al.

[0030] Furthermore, the probe-type microstructure phase shift unit includes M phase shift units, M≥2, which are superimposed in a centrally symmetrical and parallel arrangement, thereby reducing the chip size and increasing the phase shift range.

[0031] Furthermore, the feed opening portion is located at the long side of the rectangular waveguide and is aligned with the large metal plate portion of the feed structure, which can simply and conveniently implement voltage control of the phase shift unit by an external circuit.

[0032] Furthermore, the substrate material is quartz, silicon carbide, high-resistance silicon, sapphire or gallium arsenide.

[0033] (3) Beneficial effects

[0034] The beneficial effects of the present invention are:

[0035] (1) In view of the problems that there are few phase shifting technology solutions for existing terahertz wave phase modulators, large insertion loss during phase shifting, small phase shift range, large device size and low integrability, the present invention proposes a fin-line terahertz multi-phase shifter based on gallium arsenide diodes, which combines the fin-line's binding function for terahertz waves with a probe-type microstructure phase shifter. By controlling the on and off of the diode on the probe-type microstructure phase shifter by voltage, the probe's perturbation intensity on the fin line is changed, causing the equivalent dielectric constant of the fin line to change, thereby achieving the phase shift of the terahertz wave; and then superimposing the phase shifters in a centrally symmetrical and parallel arrangement, finally achieving multi-bit terahertz wave phase shift with low insertion loss, ensuring a good working state, and promoting the development of terahertz phase control technology.

[0036] (2) The present invention proposes a fin-line terahertz multi-phase shifter based on a gallium arsenide diode, which uses an international standard waveguide as an input and output port, and utilizes a rectangular waveguide-fin-line transition in a functional form and a centrally symmetrical, parallel-arranged unit superposition method to reduce the insertion loss of the device, streamline the structure and reduce the size, which is beneficial to the heat dissipation of the device during operation and is easy to work with other terahertz devices to achieve good working effects;

[0037] (3) The present invention uses voltage to control the on / off of the diode on the probe-type microstructure phase shift unit, changing the intensity of the probe's perturbation on the fin line, causing the equivalent dielectric constant of the fin line to change and ultimately achieving phase shift. Since the perturbation does not directly cut off the propagation of the terahertz wave, it has a lower insertion loss;

[0038] (4) The present invention utilizes the feed opening to individually control the probe-type microstructure phase shift unit, ultimately achieving multi-bit terahertz phase modulation with low insertion loss and high linearity;

[0039] (5) The cutoff frequency of the gallium arsenide diode used in the present invention can reach the THz level, and high-speed control of phase shift can be achieved through voltage, thereby improving the operating speed of the system;

[0040] (6) The shape and size of the probe structure and the matching phase-shifting structure of the present invention are adjustable, and the number of the probe-type microstructure phase-shifting units is adjustable, which can change the phase-shifting accuracy and range. The present invention has an insertion loss of less than 3 dB in the 216 GHz-224 GHz frequency band, achieves a 176° phase shift at 220 GHz, and can achieve multi-position phase shifts with a step of 22.5° in the 216 GHz-224 GHz frequency band.

[0041] (7) The present invention can be manufactured and realized by means of vapor deposition, laser etching, micro-machining and the like, and the method of use is simple and convenient, with good application potential and prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 This is a schematic diagram of the three-dimensional structure of a fin-line terahertz multi-phase shifter based on a gallium arsenide diode according to the present invention.

[0044] Figure 2 for Figure 1 A partial enlarged top view of the .

[0045] Figure 3 This is the S21 curve diagram of Example 1.

[0046] Figure 4 This is the phase curve diagram of Example 1.

[0047] 1. Rectangular waveguide input port; 2. Rectangular waveguide output port; 3. Substrate; 4. Rectangular waveguide-fin line transition structure; 5. Fin line-rectangular waveguide transition structure; 6. Fin line structure; 7. Probe-type microstructure phase shifter; 8. Feed opening; 9. Probe structure; 10. Grounding structure; 11. Gallium arsenide diode; 12. Matching phase shifter structure; 13. Feed structure. DETAILED DESCRIPTION

[0048] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] As shown in the accompanying drawings, the purpose of the present invention is achieved through the following technical solution: a fin-line terahertz multi-phase shifter based on gallium arsenide diodes.

[0050] 1. Explanation of the embodiment.

[0051] like Figure 1 、 Figure 2 As shown, an embodiment of the present invention proposes a fin-line terahertz multi-phase shifter based on a gallium arsenide diode, which includes:

[0052] Rectangular waveguide input port 1, which realizes the input of terahertz waves and can be connected with other terahertz devices;

[0053] Rectangular waveguide output port 2, realizing the output of terahertz waves;

[0054] The substrate 3 is located on the midline of the long side of the rectangular waveguide. The rectangular waveguide-fin line transition structure 4 is located on the back side of the substrate 3 and is connected to the fin line structure 6. This realizes the terahertz wave transmission transition from the rectangular waveguide to the fin line, which can reduce the size of the device and ensure good working condition.

[0055] The fin-to-rectangular waveguide transition structure 5 is located on the back of the substrate 3 and is connected to the rectangular waveguide output port 2 to achieve the terahertz wave transmission transition from the fin to the rectangular waveguide and output;

[0056] The fin structure 6 is located on the back side of the substrate 3, which confines the terahertz wave in the middle of the structure to achieve low insertion loss propagation of the terahertz wave. The probe-type microstructure phase shifter 7 is located on the front side of the substrate, which includes a probe structure 9, a grounding structure 10, a gallium arsenide diode 11, a matching phase shifter structure 12, and a feeding structure 13. One end of the probe structure 9 is located in the middle opening of the fin structure 6, and the other end is connected to the cathode of the gallium arsenide diode 11. The grounding structure 10 connects the probe structure to the rectangular waveguide wall. The anode of the gallium arsenide diode 11 is connected to one end of the matching phase shifter structure 12, and the other end of the matching phase shifter structure 12 is connected to the feeding structure 13.

[0057] The feeding opening portion 8 is located on the long side of the rectangular waveguide and is aligned with the large metal plate portion of the feeding structure 13 , which can control the probe-type microstructure phase shift unit while reducing the impact on terahertz wave propagation.

[0058] The rectangular waveguide input port and rectangular waveguide output port used in the embodiment are international standard WR4 waveguides.

[0059] The rectangular waveguide-fin line transition structure and the fin line-rectangular waveguide transition structure used in the embodiment are a cosine square function gradient fin line structure.

[0060] The metal material used in the fin line structure, the rectangular waveguide-fin line transition structure, the fin line-rectangular waveguide transition structure, and the probe-type microstructure phase shift unit of the embodiment is Au.

[0061] The embodiment adopts 8 probe-type microstructure phase shifting units, which are superimposed in a centrally symmetrical and parallel arrangement.

[0062] The substrate material used in the embodiment is quartz.

[0063] In the embodiment of the present invention, a terahertz wave is input through a rectangular waveguide input port, and reaches the fin line through a rectangular waveguide-fin line transition structure; a feeding opening is used to connect the feeding structure and an external circuit, and the on-off state of the gallium arsenide diode on the probe-type microstructure phase shifter unit is controlled. The probe generates a perturbation effect to change the equivalent dielectric constant of the fin line, thereby changing the terahertz wave transmission phase velocity on the middle opening of the fin line, and thus obtaining a phase shift with low insertion loss; eight probe-type microstructure phase shifters are superimposed in a centrally symmetrical and parallel arrangement, which increases the phase shift range while reducing the chip area, and realizes multi-phase shift of the terahertz wave with low insertion loss; the phase-shifted terahertz wave reaches the rectangular waveguide output port through the fin line-rectangular waveguide transition structure for output.

[0064] like Figure 3 、 Figure 4 As shown, this embodiment uses digital coding to represent the on and off states of each gallium arsenide diode 11. The number "1" represents on and the number "0" represents off. Through simulation superposition, we can obtain a total of 9 states from "00000000", "10000000" to "11111111", which respectively represent the states of all being off, the first one being on and the others being off, and all being on. Figure 3 This is the S21 curve of this embodiment, that is, the insertion loss. In the 216 GHz-224 GHz frequency band, the insertion loss of the nine states of the present invention is less than 3 dB. Figure 4 This is the phase curve of this embodiment. In 9 states, it can achieve a wide range of phase shift of 176° at 220 GHz, and a multi-position phase shift with a step of 22.5° in the 216 GHz-224 GHz frequency band.

[0065] The results show that the fin-line terahertz multi-phase shifter based on gallium arsenide diodes of the present invention can achieve low-insertion-loss multi-bit phase modulation of terahertz waves in the 216GHz-224GHz frequency band, which provides a strong foundation for terahertz phase modulation application systems.

[0066] 2. Application Examples

[0067] In order to prove the creativity and technical value of the technical solution of the present invention, this section provides application examples of the claimed technical solution on specific products or related technologies.

[0068] The present invention proposes a fin-line terahertz multi-phase shifter based on gallium arsenide diodes, which combines the fin-line's terahertz wave binding function with a probe-type microstructure phase shifter. By controlling the on and off of the diode on the probe-type microstructure phase shifter through voltage, the probe's perturbation intensity on the fin line is changed, causing the equivalent dielectric constant of the fin line to change, thereby achieving a phase shift of the terahertz wave. The phase shifters are then superimposed in a centrally symmetrical and parallel arrangement, ultimately achieving multi-bit terahertz wave phase shifting with low insertion loss.

[0069] The present invention provides a feed opening, allowing connection to a probe-type microstructured phase-shifting unit via a Rogers plate circuit or PCB circuit. The diodes on the phase-shifting unit are controlled by controlling the input voltage via a digital circuit substrate. Therefore, this device can be used in conjunction with a terahertz signal source and a high-frequency baseband signal board module to form a phase-shift keying terahertz communication system, achieving high-speed phase control and ultimately realizing high-speed terahertz phase-shift keying communication.

[0070] Working principle: The terahertz wave is input through the rectangular waveguide input port and reaches the fin line through the rectangular waveguide-fin line transition structure; the feeding opening is used to connect the feeding structure and the external circuit to control the on-off state of the gallium arsenide diode on the probe-type microstructure phase shifter unit, and the probe generates a microperturbation that affects the terahertz wave transmission phase velocity on the middle opening of the fin line, thereby obtaining a phase shift with low insertion loss; multiple probe-type microstructure phase shifters are superimposed in a centrally symmetrical and parallel arrangement, which increases the phase shift range while reducing the chip area, realizing multi-phase shift of the terahertz wave; the phase-shifted terahertz wave reaches the rectangular waveguide output port through the fin line-rectangular waveguide transition structure.

[0071] The above embodiments are merely descriptions of preferred implementations of the present invention and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary persons in the art should fall within the scope of protection of the present invention. The technical contents for which protection is sought in the present invention are all recorded in the claims.

Claims

1. A fin-line terahertz multi-phase shifter structure based on gallium arsenide diodes, characterized in that: include: Rectangular waveguide input port, which realizes the input of terahertz waves and can be connected with other terahertz devices; A substrate, which is located on the center line of the long side of the rectangular waveguide and can be made into metal structures on the front and back sides; The rectangular waveguide-to-fin transition structure is located on the back of the substrate and realizes the terahertz wave transmission transition from the rectangular waveguide to the fin, which can reduce the size of the device and ensure good working condition. The fin structure is located on the back of the substrate and is connected to the rectangular waveguide-fin transition structure. It can confine the terahertz wave in the middle of the structure to achieve low insertion loss propagation of the terahertz wave. The probe-type microstructure phase shifter is located on the front of the substrate. The GaAs diode on the voltage control unit can achieve the phase shift of the terahertz wave. The superposition of the centrally symmetric phase shifters increases the terahertz wave phase control range, ultimately achieving multi-bit terahertz phase shifting. The feeding opening is located on the long side of the rectangular waveguide, which can control the probe-type microstructure phase shift unit while reducing the impact on the propagation of terahertz waves; The fin-line-rectangular waveguide transition structure is located on the back of the substrate and is connected to the fin-line structure to achieve the terahertz wave transmission transition from the fin-line to the rectangular waveguide and output the phase-shifted terahertz wave; Rectangular waveguide output port realizes the output of terahertz waves.

2. The fin-line terahertz multi-phase shifter structure based on a gallium arsenide diode according to claim 1, characterized in that: The rectangular waveguide input port and the rectangular waveguide output port are both international standard waveguides.

3. The fin-line terahertz multi-phase shifter structure based on a gallium arsenide diode according to claim 1, characterized in that: The rectangular waveguide-fin line transition structure and the fin line-rectangular waveguide transition structure are a segmented function gradient fin line structure, whose functions are exponential, parabola, sine square, and cosine square functions, and can realize terahertz wave propagation transition with low insertion loss.

4. The fin-line terahertz multi-phase shifter structure based on a gallium arsenide diode according to claim 1, characterized in that: The fin line structure is located on the back of the substrate and is connected to the rectangular waveguide-fin line transition structure and the fin line-rectangular waveguide transition structure, thereby confining the terahertz wave to the middle opening of the fin line.

5. The fin-line terahertz multi-phase shifter structure based on gallium arsenide diode according to claim 1, characterized in that: The probe-type microstructure phase-shifting unit is located on the front side of the substrate and includes a probe structure, a grounding structure, a gallium arsenide diode, a matching phase-shifting structure, and a feeding structure. One end of the probe structure is located on the middle opening of the fin line, and the other end is connected to the negative electrode of the gallium arsenide diode. The grounding structure connects the probe structure and the rectangular waveguide wall. The positive electrode of the gallium arsenide diode is connected to one end of the matching phase-shifting structure, and the other end of the matching phase-shifting structure is connected to the feeding structure. A control voltage is fed into the feeding structure to control the on and off of the gallium arsenide diode, thereby changing the influence of the probe-type microstructure phase-shifting unit on the electromagnetic field of the middle opening of the fin line, thereby affecting the relative dielectric constant and phase velocity of the fin line structure, thereby obtaining a terahertz wave phase shift.

6. The fin-line terahertz multi-phase shifter structure based on gallium arsenide diode according to claim 5, characterized in that: The shapes and sizes of the probe structure and the matching phase shift structure are adjustable, thereby achieving phase shifts of different degrees under low input loss conditions.

7. The fin-line terahertz multi-phase shifter structure based on a gallium arsenide diode according to claim 1, characterized in that: The metal materials used for the fin line, the rectangular waveguide-fin line transition structure, the fin line-rectangular waveguide transition structure, and the probe-type microstructure phase shift unit are Au, Ag, Cu, or Al.

8. The fin-line terahertz multi-phase shifter structure based on a gallium arsenide diode according to claim 1, characterized in that: The probe-type microstructure phase shift unit includes M phase shift units, M≥2, which are superimposed in a centrally symmetrical and parallel arrangement, thereby reducing the chip size and increasing the phase shift range.

9. The fin-line terahertz multi-phase shifter structure based on a gallium arsenide diode according to claim 1, characterized in that: The feeding opening portion is located at the long side of the rectangular waveguide and is aligned with the large metal plate portion of the feeding structure, which can simply and conveniently implement voltage control of the phase shift unit by an external circuit.

10. The fin-line terahertz multi-phase shifter structure based on gallium arsenide diode according to claim 1, characterized in that: The substrate material is quartz, silicon carbide, high-resistance silicon, sapphire or gallium arsenide.

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