Waveguide coupling and power divider based on gap waveguide structure and design method

Abstract

The invention provides a waveguide coupling and power divider based on a gap waveguide structure and a design method, and can be applied to the technical field of terahertz. The waveguide coupling and power divider comprises a pin structure, a waveguide adapter and an adjustable structure, the pin structure comprises a plurality of pins, the plurality of pins are distributed on two sides of a transverse axis of the coupling and power divider and on the transverse axis, and the plurality of pins are asymmetrically arranged based on the transverse axis and a longitudinal axis, at least one pin in the plurality of pins is configured to be arranged on the cover plate of the gap waveguide structure; the waveguide adapter interface is configured to be arranged at a plurality of ports of the gap waveguide structure; and the adjustable structure is configured to be arranged at the cover plate of the gap waveguide structure, and the adjustable structure is used for controlling the cover plate to move so as to change the arrangement positions of the pins.

Description

Technical Field

[0001] The present disclosure relates to the field of terahertz technology, and more particularly to a waveguide coupling and power divider based on a gap waveguide structure and a design method thereof. Background Art

[0002] With the rapid development of wireless communication technology, traditional microwave and millimeter wave communication frequency bands are becoming increasingly crowded, and the demand for new spectrum resources is becoming more and more urgent. Since the terahertz band has a large amount of untapped spectrum resources and has the potential for ultra-high-speed wireless communications, the demand for modern communication systems is developing towards the terahertz band.

[0003] Couplers and power splitters are common, fundamental components in communication circuits, performing diverse functions such as power distribution and sampling detection. In their design, gap waveguide technology, due to its unique physical structure, is virtually unaffected by current manufacturing errors. Its advantages include ease of assembly and processing, ease of integration, low transmission loss, and high power capacity, making it suitable for terahertz research. However, traditional couplers and power splitters exhibit reciprocity and a fixed structure, making them inflexible in achieving bandgap conversion. Summary of the Invention

[0004] In view of this, the present disclosure provides a waveguide coupling and power divider based on a gap waveguide structure and a design method.

[0005] One aspect of the present disclosure provides a waveguide coupler and power divider based on a gap waveguide structure, including a pin structure, a waveguide adapter and an adjustable structure, wherein the pin structure includes a plurality of pins, and the plurality of pins are distributed on both sides of the transverse axis of the coupler and power divider and on the transverse axis, and the plurality of pins are asymmetrically arranged based on the transverse axis and the longitudinal axis, wherein at least one of the plurality of pins is configured to be arranged on the cover plate of the gap waveguide structure; the waveguide adapter is configured to be arranged at multiple ports of the gap waveguide structure; the adjustable structure is configured to be arranged at the cover plate of the gap waveguide structure, and the adjustable structure is used to control the movement of the cover plate to change the arrangement position of the plurality of pins.

[0006] According to an embodiment of the present disclosure, the above-mentioned pin structure includes a stepped pin structure, a single-sided protruding pin structure and a flat pin structure. The above-mentioned stepped pin structure is configured to be arranged on both sides of the transverse axis of the above-mentioned coupler and power divider. The multiple pins included in the above-mentioned stepped pin structure are arranged in a stepped shape in a direction away from the long side of the above-mentioned coupler and power divider, and the above-mentioned multiple pins are arranged asymmetrically based on the above-mentioned transverse axis; the above-mentioned single-sided protruding pin structure and the above-mentioned flat pin structure are configured to be arranged on both sides of the longitudinal axis of the above-mentioned coupler and power divider.

[0007] According to an embodiment of the present disclosure, the above-mentioned stepped pin structure includes a first singular pin substructure and a second singular pin substructure, and the above-mentioned first singular pin substructure and the second singular pin substructure are asymmetrically arranged based on the above-mentioned transverse axis and the above-mentioned longitudinal axis; wherein, the above-mentioned coupling and power divider includes an input port, a through port, an isolation port, and a coupling port, and the above-mentioned first singular pin substructure is used to guide the electromagnetic wave to radiate from the above-mentioned input port to the sub-waveguide, and the above-mentioned second singular pin substructure is used to guide the above-mentioned electromagnetic wave radiated to the above-mentioned sub-waveguide to propagate toward the above-mentioned coupling port.

[0008] According to an embodiment of the present disclosure, the above-mentioned first singular pin substructure includes an odd number of first singular pins, and the above-mentioned odd number of first singular pins are configured to be arranged on the above-mentioned cover plate of the above-mentioned gap waveguide structure; the above-mentioned second singular pin substructure includes an even number of second singular pins, and the above-mentioned even number of second singular pins are configured to be arranged on the bottom plate of the above-mentioned gap waveguide structure.

[0009] According to an embodiment of the present disclosure, the above-mentioned single-sided protruding pin structure is configured to be arranged on the above-mentioned cover plate of the above-mentioned gap waveguide structure, and the above-mentioned single-sided protruding pin structure is used to guide the above-mentioned electromagnetic wave to propagate from the above-mentioned input port to the above-mentioned coupling port, and prevent the reflected wave of the above-mentioned straight-through port from propagating to the above-mentioned coupling port.

[0010] According to an embodiment of the present disclosure, the flat pin structure includes at least two third singular pins, and the third singular pins are configured to be flat, so as to introduce resonance points and increase the bandwidth of the gap waveguide structure.

[0011] According to an embodiment of the present disclosure, the flat pin structure is configured to be disposed on a bottom plate of the gap waveguide structure.

[0012] According to an embodiment of the present disclosure, the above-mentioned waveguide-to-interface includes a first waveguide-to-interface, a second waveguide-to-interface, a third waveguide-to-interface, and a fourth waveguide-to-interface, wherein the above-mentioned first waveguide-to-interface is connected to the above-mentioned input port, the above-mentioned second waveguide-to-interface is connected to the above-mentioned straight-through port, the above-mentioned third waveguide-to-interface is connected to the isolation port, and the above-mentioned fourth waveguide-to-interface is connected to the above-mentioned coupling port.

[0013] According to an embodiment of the present disclosure, the adjustable structure includes an adjustable screw and a chamfer structure.

[0014] The adjustable screw is used to control the movement of the cover plate to change the arrangement position of the pin structure; the chamfered structure is used to reduce the movement friction of the cover plate.

[0015] Another aspect of the present disclosure provides a design method for a waveguide coupler and power divider based on a gap waveguide structure, wherein the waveguide coupler and power divider include a pin structure, a waveguide adapter, and an adjustable structure. The method includes: determining an arrangement of multiple pins in the pin structure based on characteristic parameters of the waveguide coupler and power divider, wherein the multiple pins are distributed on both sides of the transverse axis of the coupler and power divider and on the transverse axis, and the multiple pins are asymmetrically arranged based on the transverse axis and the longitudinal axis, and at least one of the multiple pins is configured to be arranged in the gap. The waveguide adapter is arranged on the cover plate of the gap waveguide structure; based on the arrangement of the multiple pins, the installation position of the waveguide adapter and the installation position of the adjustable structure are respectively determined, wherein the waveguide adapter is configured to be arranged at multiple ports of the gap waveguide structure, and the adjustable structure is configured to be arranged at the cover plate of the gap waveguide structure, and the adjustable structure is used to control the movement of the cover plate to change the arrangement position of the multiple pins; based on the arrangement of the multiple pins in the pin structure, the installation position of the waveguide adapter and the installation position of the adjustable structure, the waveguide coupling and power divider are obtained.

[0016] According to the embodiments of the present disclosure, a waveguide coupling and power divider based on a gap waveguide structure is proposed, which mainly includes an adjustable structure, a pin structure and a waveguide conversion interface. By designing the number and arrangement of pins in the pin structure, the pins are arranged asymmetrically to achieve high-bandwidth coupling function in the high frequency band while saving costs; in addition, the arrangement positions of multiple pins are changed through the adjustable structure to change the width of the branch line, thereby converting the electromagnetic wave from the bandgap effect to the passband effect, so that the waveguide coupling and power divider based on the gap waveguide structure can achieve flexible conversion between coupling function and power dividing function under different coupling degrees. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0018] Figure 1 Schematically shows a schematic diagram of a waveguide coupling and power splitter based on a gap waveguide structure according to an embodiment of the present disclosure;

[0019] Figure 2 Schematically shows a schematic diagram of the pin structure of a 20db coupling and power splitter according to an embodiment of the present disclosure;

[0020] Figure 3 Schematically shows a top view of the pin structure of a 20db coupling and power splitter according to an embodiment of the present disclosure;

[0021] Figure 4Schematically shows a top view of the pin arrangement of the cover plate of the 20dB coupler and power splitter according to an embodiment of the present disclosure;

[0022] Figure 5 Schematically shows a top view of the pin arrangement of the bottom plate of the 20dB coupling and power splitter according to an embodiment of the present disclosure;

[0023] Figure 6 Schematically shows a schematic diagram of an adjustable structure according to an embodiment of the present disclosure;

[0024] Figure 7 Schematically shows a schematic diagram of the adjustable structure of the waveguide coupling and power divider according to an embodiment of the present disclosure;

[0025] Figure 8 Schematically shows a side view of an adjustable structure of a waveguide coupling and power divider according to an embodiment of the present disclosure;

[0026] Figure 9 Schematically shows a schematic diagram of the pin structure of a 3dB coupling and power splitter according to an embodiment of the present disclosure;

[0027] Figure 10 Schematically shows a top view of the pin structure of a 3dB coupling and power splitter according to an embodiment of the present disclosure;

[0028] Figure 11 Schematically shows a flow chart of a design method for a waveguide coupling and power splitter according to an embodiment of the present disclosure;

[0029] Figure 12 A typical structural diagram of a multi-branch directional coupler according to an embodiment of the present disclosure is schematically shown;

[0030] Figure 13 Schematically shows a schematic diagram of a corrugated groove structure according to an embodiment of the present disclosure;

[0031] Figure 14 Schematically shows a schematic diagram of the nail bed structure according to an embodiment of the present disclosure;

[0032] Figure 15 Schematically shows a schematic diagram of pin modeling according to an embodiment of the present disclosure;

[0033] Figure 16 Schematically shows a schematic diagram of a two-dimensional dispersion simulation result of a pin according to an embodiment of the present disclosure;

[0034] Figure 17 Schematically shows a schematic diagram of door structure modeling according to an embodiment of the present disclosure;

[0035] Figure 18 A schematic diagram schematically shows a one-dimensional dispersion simulation result of a gate structure according to an embodiment of the present disclosure;

[0036] Figure 19 A schematic diagram of a waveguide transfer interface structure according to an embodiment of the present disclosure is schematically shown;

[0037] Figure 20 Schematically shows a top view of a waveguide transfer interface structure according to an embodiment of the present disclosure;

[0038] Figure 21 Schematically shows a cross-sectional view of a waveguide transfer interface structure according to an embodiment of the present disclosure;

[0039] Figure 22 Schematically shows an S-parameter diagram of a waveguide-to-interface structure according to an embodiment of the present disclosure;

[0040] Figure 23 Schematically shows an S-parameter simulation diagram of a 20 dB coupling degree according to an embodiment of the present disclosure;

[0041] Figure 24 Schematically shows a phase diagram of an output port with a coupling degree of 20 dB according to an embodiment of the present disclosure;

[0042] Figure 25 Schematically shows a schematic diagram of S-parameter simulation of 3dB coupling degree according to an embodiment of the present disclosure;

[0043] Figure 26 Schematically shows a phase diagram of an output port with a 3dB coupling degree according to an embodiment of the present disclosure;

[0044] Figure 27 Schematically shows a schematic diagram of block splitting of a measured structure according to a specific embodiment of the present disclosure;

[0045] Figure 28 Schematically shows an S-parameter simulation diagram of a waveguide coupling and power splitter with a coupling degree of 20 dB according to a specific embodiment of the present disclosure;

[0046] Figure 29 Schematically shows an S-parameter simulation diagram of a waveguide coupling and a power splitter with a 3 dB coupling degree according to an embodiment of the present disclosure;

[0047] Figure 30 Schematically shows a schematic diagram of the output port phase of a waveguide coupling and a power divider with a coupling degree of 20 dB according to an embodiment of the present disclosure;

[0048] Figure 31 The figure schematically shows the phase diagram of the output port of the waveguide coupling and the power divider with a coupling degree of 3 dB according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0049] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0050] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise," "include," etc. used herein indicate the presence of the features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0051] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0052] When expressions such as "at least one of A, B and C, etc." are used, they should generally be interpreted in accordance with the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0053] With the rapid development of wireless communication technology, traditional microwave and millimeter wave communication frequency bands are becoming increasingly crowded, and the demand for new spectrum resources is becoming more and more urgent. Since the terahertz band has a large amount of untapped spectrum resources and has the potential for ultra-high-speed wireless communications, the demand for modern communication systems is developing towards the terahertz band.

[0054] Terahertz waves generally refer to electromagnetic waves with frequencies between 0.1THz and 10THz (wavelengths between 3mm-30μm). Since the frequency band of terahertz waves is located between the microwave and infrared spectra, and in a special frequency band between millimeter waves and light waves, it has the advantages of strong penetration, high resolution, low photon energy and high security. Therefore, terahertz communication has become a key candidate technology for 6G communication and has important application prospects in the construction of integrated air-space-ground network.

[0055] Couplers and power dividers are common basic components in communication circuits. They have multiple functions such as power distribution and sampling detection. They are one of the basic but indispensable components in modern electronic systems. Improving their performance, miniaturizing their size, and reducing processing costs on the design side are one of the research focuses in all frequency bands.

[0056] Because conventional cavity waveguide technology has gradually reached its processing limits in the high-frequency band, its electromagnetic structure has a low tolerance for current processing errors. However, gap waveguide technology, due to its unique physical structure, is virtually unaffected by current processing errors. It offers advantages such as low processing and assembly difficulty, ease of integration, low transmission loss, and high power capacity, making it suitable for application in terahertz research. However, during the implementation of the inventive concept disclosed herein, it was discovered that conventional gap waveguide structures exhibit reciprocity and a fixed structure, making it inflexible in achieving bandgap conversion.

[0057] In view of this, the embodiments of the present disclosure propose a waveguide coupling and power divider based on a gap waveguide structure, which mainly includes an adjustable structure, a pin structure and a waveguide conversion interface. By designing the number and arrangement of pins in the pin structure, the pins are arranged asymmetrically to achieve high-bandwidth coupling function in the high frequency band while saving costs; in addition, the arrangement positions of multiple pins are changed through the adjustable structure to change the width of the branch line, thereby converting the electromagnetic wave from the bandgap effect to the passband effect, so that the waveguide coupling and power divider based on the gap waveguide structure can achieve flexible function conversion under different coupling degrees.

[0058] Specifically, an embodiment of the present disclosure provides a waveguide coupler and power divider based on a gap waveguide structure, including a pin structure, a waveguide adapter and an adjustable structure. The pin structure includes multiple pins, and the multiple pins are distributed on both sides of the transverse axis and on the transverse axis of the coupler and power divider, and the multiple pins are arranged asymmetrically based on the transverse axis and the longitudinal axis, wherein at least one of the multiple pins is configured to be arranged on the cover plate of the gap waveguide structure; the waveguide adapter is configured to be arranged at multiple ports of the gap waveguide structure; the adjustable structure is configured to be arranged at the cover plate of the gap waveguide structure, and the adjustable structure is used to control the movement of the cover plate to change the arrangement position of the multiple pins.

[0059] According to an embodiment of the present disclosure, a coupler and a power splitter are microwave devices widely used in microwave systems. Both the coupler and the power splitter can be used to distribute the power of a microwave signal in a certain ratio.

[0060] According to the embodiments of the present disclosure, a gap waveguide is a structure for transmitting electromagnetic waves. Gap waveguide technology is a new type of low-loss transmission line based on parallel plate waveguides. One side is an ideal electrical conductor, and the other side is designed as a periodic surface. This periodic surface is an electromagnetic bandgap structure, which can be regarded as an ideal magnetic conductor. Among them, commonly used electromagnetic bandgap structures include at least periodic metal pin structures and mushroom-shaped structures. When the distance between two metal plates is less than or equal to 1 / 4 of the operating wavelength, this gap becomes a high-resistance region that can prevent the transmission of electromagnetic waves in any direction within a certain frequency range, forming an electromagnetic bandgap.

[0061] Figure 1 The figure schematically shows a waveguide coupling and power divider based on a gap waveguide structure according to an embodiment of the present disclosure.

[0062] like Figure 1 As shown, the waveguide coupling and power divider based on the gap waveguide structure includes a pin structure 1, an adjustable structure 2, a waveguide transfer interface 3, a cover plate 4, and a base plate 5.

[0063] According to an embodiment of the present disclosure, the pin structure 1 includes a plurality of pins, and one or more pins may be provided on the cover plate and the base plate, respectively. Specifically, at least one of the plurality of pins may be provided on the cover plate 4 of the gap waveguide structure, and the remaining pins may be provided on the base plate 5 of the gap waveguide structure.

[0064] According to an embodiment of the present disclosure, the multiple pins of the pin structure 1 are distributed on both sides of the transverse axis of the coupler and power divider and on the transverse axis, and the multiple pins are asymmetrically arranged based on the transverse axis and the longitudinal axis.

[0065] According to an embodiment of the present disclosure, the adjustable structure 2 can be set on the base plate 5 of the gap waveguide structure. The adjustable structure 2 is used to control the movement of the cover plate 4 to change the relative position of the cover plate 4 and the base plate 5, thereby changing the arrangement position of multiple pins to change the width of the branch line, so that the branch line converts the electromagnetic wave from the bandgap effect to the passband effect, thereby realizing the conversion of the coupling degree.

[0066] According to the embodiment of the present disclosure, since the coupling degree is changed by moving the cover plate 4, movable space needs to be reserved in the moving direction, so the input and output ports cannot derive electromagnetic wave signals in the original gap waveguide structure.

[0067] According to embodiments of the present disclosure, waveguide adapters 3 can be provided at multiple input and output ports of the gap waveguide structure. The waveguide adapters 3 redirect electromagnetic waves originally propagating horizontally in the gap waveguide to propagate vertically at a 90-degree angle and then pass into the cavity waveguide. The cavity waveguide then extracts electromagnetic wave signals from four sides.

[0068] The embodiments of the present disclosure propose a waveguide coupling and power divider based on a gap waveguide structure, which mainly includes an adjustable structure, a pin structure and a waveguide conversion interface. By designing the number and arrangement of pins in the pin structure, the pins are arranged asymmetrically to achieve high-bandwidth coupling function in the high frequency band while saving costs; in addition, the arrangement positions of multiple pins are changed through the adjustable structure to change the width of the branch line, thereby converting the electromagnetic wave from the bandgap effect to the passband effect, so that the waveguide coupling and power divider based on the gap waveguide structure can achieve flexible conversion between coupling function and power dividing function under different coupling degrees.

[0069] According to an embodiment of the present disclosure, the pin structure includes a stepped pin structure, a single-sided protruding pin structure and a flat pin structure. The stepped pin structure is configured to be arranged on both sides of the transverse axis of the coupler and power divider. The stepped pin structure includes multiple pins arranged in a stepped shape in a direction away from the long side of the coupler and power divider, and the multiple pins are arranged asymmetrically based on the transverse axis; the single-sided protruding pin structure and the flat pin structure are configured to be arranged on both sides of the longitudinal axis of the coupler and power divider.

[0070] According to an embodiment of the present disclosure, the stepped pin structure includes a first singular pin substructure and a second singular pin substructure, and the first singular pin substructure and the second singular pin substructure are asymmetrically arranged based on the transverse axis; wherein, the gap waveguide structure includes an input port, a through port, an isolation port, and a coupling port, and the first singular pin substructure is used to guide electromagnetic waves to radiate from the input port to the sub-waveguide, and the second singular pin substructure is used to guide the electromagnetic waves radiated to the sub-waveguide to propagate toward the coupling port.

[0071] According to an embodiment of the present disclosure, the first singular pin substructure includes an odd number of first singular pins, which are configured to be arranged on the cover plate of the gap waveguide structure; the second singular pin substructure includes an even number of second singular pins, which are configured to be arranged on the bottom plate of the gap waveguide structure.

[0072] Reference below Figures 2 to 5 , the pin structure is further explained in conjunction with specific embodiments.

[0073] Figure 2 The figure schematically shows a pin structure diagram of a 20db coupling and power splitter according to an embodiment of the present disclosure.

[0074] Figure 3 A schematic top view of the pin structure of a 20 dB coupling and power divider according to an embodiment of the present disclosure is shown.

[0075] like Figure 2 and Figure 3As shown, a plurality of pins are distributed on both sides of the transverse axis of the coupling and power divider and on the transverse axis, and the plurality of pins are asymmetrically arranged based on the transverse axis and the longitudinal axis.

[0076] Specifically, if Figure 3 As shown, the pin structure 1 includes a stepped pin structure 11, a single-side protruding pin structure 12, and a flat pin structure 13. The stepped pin structure 11 is disposed on both sides of the transverse axis of the coupler and power splitter. The multiple pins included in the stepped pin structure 11 are arranged in a stepped shape away from the long side of the coupler and power splitter, and are asymmetrically arranged about the transverse axis.

[0077] According to an embodiment of the present disclosure, the coupling and power splitter further includes a plurality of input and output ports, wherein the input and output ports of the coupling and power splitter may include an input port, a through port, an isolation port, and a coupling port.

[0078] like Figure 3 As shown, the multiple input and output ports include a first port 31, a second port 32, a third port 33, and a fourth port 34. When the coupling degree is set to 20 dB, the first port 31 can serve as an input port, the second port 32 can serve as a pass-through port, the third port 33 can serve as an isolation port, and the fourth port 34 can serve as a coupling port. The stepped pin structure 11 includes a first singular pin substructure 111 and a second singular pin substructure 112. The first singular pin substructure includes an odd number of first singular pins, and the second singular pin substructure includes an even number of second singular pins. The first singular pin substructure 111 and the second singular pin substructure 112 are arranged asymmetrically about both the transverse and longitudinal axes. In this case, the branch line width of the waveguide coupling and power divider is W0.

[0079] For example, Figure 3 As shown, the first singular pin substructure 111 includes at least two levels of pins: a first level with 11 pins and a second level with three first singular pins. The three first singular pins in the second level may include one middle pin and two smaller edge pins. The second singular pin substructure 112 includes at least two levels of pins: a first level with 13 pins and a second level with six second singular pins. The six second singular pins in the second level include one middle pin and five smaller edge pins.

[0080] According to an embodiment of the present disclosure, the first singular pin substructure 111 is used to guide electromagnetic waves entering from the first port 31, serving as the input port, to radiate toward the auxiliary waveguide. Specifically, when the electromagnetic wave enters the first port 31, serving as the input port, and then travels toward the second port 32, serving as the through port, the first singular pin substructure 111, with its stepped structure gradually decreasing downward, guides a portion of the electromagnetic wave to radiate downward, thereby coupling to the auxiliary waveguide.

[0081] According to an embodiment of the present disclosure, the second singular pin substructure 112 is used to guide the electromagnetic wave radiated into the auxiliary waveguide to propagate toward the fourth port 34, which serves as the coupling port. Specifically, when the electromagnetic wave is coupled to the auxiliary waveguide, the second singular pin substructure 112 is used to guide the electromagnetic wave radiated into the auxiliary waveguide to be more transmitted toward the fourth port 34, which serves as the coupling port, rather than toward the third port 33, which serves as the isolation port, thereby enhancing the directionality of the electromagnetic wave transmission.

[0082] According to an embodiment of the present disclosure, the single-sided protruding pin structure is configured to be set on the cover plate of the gap waveguide structure, and the single-sided protruding pin structure is used to guide electromagnetic waves to propagate from the input port to the coupling port, and prevent the reflected waves of the through port from propagating to the coupling port.

[0083] According to the embodiments of the present disclosure, in order to achieve the directionality requirement, it is required that the coupled waves radiated to the sub-waveguide are directed to the fourth port serving as the coupling port as much as possible rather than to the third port serving as the isolation port. At the same time, the reflected waves of the second port serving as the through port are also required to be reduced as much as possible in their transmission to the fourth port serving as the coupling port. Therefore, it is necessary to design a single-sided protruding pin structure with unidirectional guidance.

[0084] like Figure 3 As shown, the pin structure 1 also includes a single-sided protruding pin structure 12, which is arranged on one side of the longitudinal axis of the gap waveguide, and is used to guide the electromagnetic wave to propagate from the first port to the fourth port, and prevent the reflected wave from the second port from propagating to the fourth port, so that the electromagnetic environment of the branch line faced by the electromagnetic wave transmitted from the first port and the reflected wave reflected from the second port is different, thereby achieving the purpose of unidirectional guidance.

[0085] According to an embodiment of the present disclosure, the flat pin structure includes at least two third singular pins, and the third singular pins are configured to be flat and used to introduce resonance points to increase the bandwidth of the gap waveguide structure.

[0086] According to an embodiment of the present disclosure, the flat pin structure is configured to be disposed on a bottom plate of the gap waveguide structure.

[0087] like Figure 3As shown, the pin structure 1 includes a flat pin structure 13, which includes at least two third singular pins in a flat shape. The flat pin structure 13 is arranged near the passband boundary on the other side of the longitudinal axis of the gap waveguide to introduce a new resonance point. The parameters of the flat pin structure 13 can be selected so that the resonance frequency is around 200 GHz, thereby increasing the bandwidth to meet the target requirements.

[0088] Figure 4 A top view schematically shows the pin arrangement of the cover plate of the 20 dB coupler and power divider according to an embodiment of the present disclosure.

[0089] According to an embodiment of the present disclosure, the plurality of pins included in the pin structure 1 may be respectively disposed on the cover plate 4 and the bottom plate 5 .

[0090] Specifically, if Figure 4 As shown, the multiple pins arranged on the cover plate 4 may include an odd number of first singular pins in a first singular pin substructure 111, an even number of second singular pins in a second singular pin substructure 112, a single-sided protruding pin structure 12, and a plurality of pins included in the passband on one side of the single-sided protruding pin structure 12.

[0091] Figure 5 The figure schematically shows a top view of the pin arrangement of the bottom plate of the 20db coupling and power splitter according to an embodiment of the present disclosure.

[0092] like Figure 5 As shown, the multiple pins arranged on the base plate 5 may include the first-order pins in the first singular pin substructure 111, the first-order pins in the second singular pin substructure 112, the third singular pin in the flat pin structure 13, and the multiple pins included in the passband on one side of the flat pin structure 13.

[0093] According to an embodiment of the present disclosure, when the coupling degree is set to 20db, when the electromagnetic wave enters from the first port 31 serving as the input port and then is transmitted to the second port 32 serving as the through port, the first singular pin substructure 111 is used to form a stepped structure that decreases step by step downward to guide part of the electromagnetic wave to radiate downward, so that it can be coupled to the sub-waveguide. When the electromagnetic wave is coupled to the sub-waveguide, the second singular pin substructure 112 is used to guide the electromagnetic wave radiated to the sub-waveguide to be transmitted more toward the fourth port 34 serving as the coupling port. However, when the coupling degree is set to 20db, only a very small amount of energy is sampled to the fourth port 34 serving as the coupling port, and the second port 32 serves as a through port, and most of the energy will be transmitted to the second port 32. However, the second port 32 serving as a through port cannot be completely matched with the downstream device, that is, among the most of the energy transmitted from the first port 31 serving as the input port to the second port 32 serving as the through port, a small part of the energy will be reflected back. Therefore, the single-sided protruding pin structure 12 can guide the electromagnetic wave to propagate from the first port 31 serving as the input port to the fourth port 34 serving as the coupling port, and prevent the reflected wave of the second port 32 serving as the through port from propagating to the fourth port 34 serving as the coupling port.

[0094] According to an embodiment of the present disclosure, the waveguide-to-interface includes a first waveguide-to-interface, a second waveguide-to-interface, a third waveguide-to-interface, and a fourth waveguide-to-interface, wherein the first waveguide-to-interface is connected to the input port, the second waveguide-to-interface is connected to the through port, the third waveguide-to-interface is connected to the isolation port, and the fourth waveguide-to-interface is connected to the coupling port.

[0095] like Figure 3 As shown, the waveguide-to-interface 3 includes a first waveguide-to-interface 35, a second waveguide-to-interface 36, a third waveguide-to-interface 37, and a fourth waveguide-to-interface 38. When the coupling degree is 20db, the first waveguide-to-interface 35 is connected to the input port, the second waveguide-to-interface 36 is connected to the through port, the third waveguide-to-interface 37 is connected to the isolation port, and the fourth waveguide-to-interface 38 is connected to the coupling port.

[0096] According to an embodiment of the present disclosure, the adjustable structure includes an adjustable screw and a chamfer structure. The adjustable screw is used to control the movement of the cover plate to change the arrangement position of the pin structure; the chamfer structure is used to reduce the movement friction of the cover plate.

[0097] According to the embodiments of the present disclosure, since there is no direct physical contact between the cover and base of the gap waveguide, the multiple pins included in the gap waveguide, whether on the cover or base, have almost no impact on its performance. The structural design of the cover and base interlacing can even relax the restrictions on the tool during processing. The coupling degree is directly related to the width of the branch line. Whether the electromagnetic wave can pass through the branch line has certain requirements on the width of the branch line. Therefore, an adjustable structure can be provided to change the relative position of the cover and base. By moving the cover, the relative arrangement of the pins is changed, so that the width of the branch line converts the electromagnetic wave from the bandgap effect to the passband effect, thereby realizing the transition between different coupling degrees of the coupling and power divider.

[0098] Reference below Figures 6 to 8 , the adjustable structure is further explained in conjunction with specific embodiments.

[0099] Figure 6 The figure schematically shows an adjustable structure diagram according to an embodiment of the present disclosure.

[0100] Figure 7 The figure schematically shows an adjustable structure diagram of a waveguide coupling and a power divider according to an embodiment of the present disclosure.

[0101] Figure 8 A side view schematically shows an adjustable structure of a waveguide coupling and power divider according to an embodiment of the present disclosure.

[0102] like Figures 6 to 8 As shown, the embodiment of the present disclosure realizes the movable function of the cover plate by arranging an adjustable screw 21 outside the cover plate, and reduces the friction force when the cover plate 4 moves by providing a chamfer structure 22.

[0103] Specifically, if Figure 6 As shown, considering that the pitch of the screw is 0.25 mm during actual processing, the moving distance Δd when switching between the two coupling degrees of 20 dB and 3 dB can be set to 1.125 mm.

[0104] like Figure 7 As shown, for the support and fixation of the cover plate 4, the cover plate 4 can be lifted up by the protruding structures 7 designed on the four sides inside, and fixed with four screws 6 so that the cover plate 4 fits tightly with the protruding structures 7. A gap of 1 mm is set on the left and right of the four screws 6. These gaps are used to leave enough space for the cover plate 4 to move.

[0105] In addition, if Figure 7 As shown, four cavity waveguide outlets 31 can also be introduced into the waveguide coupling and power divider, and their function is to lead the input and output ports 3 from the bottom plate 5 to the four surfaces for convenient addition of flanges.

[0106] According to a specific embodiment of the present disclosure, by moving and adjusting the adjustable structure, the relative arrangement positions of multiple pins are changed, so that the waveguide coupling and power divider can be transformed from a waveguide sampling coupler based on a gap waveguide structure with a coupling degree of 20dB to a waveguide power dividing coupler based on a gap waveguide structure with a coupling degree of 3dB.

[0107] Reference below Figures 9 and 10 , the 3dB coupling and power divider are further explained in conjunction with specific embodiments.

[0108] Figure 9 The figure schematically shows a pin structure diagram of a 3dB coupling and power splitter according to an embodiment of the present disclosure.

[0109] Figure 10 A top view of the pin structure of a 3dB coupling and power divider according to an embodiment of the present disclosure is schematically shown.

[0110] like Figure 9 and Figure 10 As shown, by moving and adjusting the cover plate through the adjustable structure, multiple pins set on the cover plate move with the cover plate, so that the branch line width of the waveguide coupling and power divider changes from W0 to W1, thereby realizing the transformation of the waveguide coupling and power divider from a waveguide coupler based on a gap waveguide structure with a coupling degree of 20 dB to a waveguide power divider based on a gap waveguide structure with a coupling degree of 3 dB.

[0111] Specifically, if Figure 10 As shown, if the cover is moved horizontally to the right through the adjustable structure, the odd number of first singular pins in the first singular pin substructure 111, the even number of second singular pins in the second singular pin substructure 112, the single-sided protruding pin structure 12 and the multiple pins included in the passband on one side of the single-sided protruding pin structure 12 are moved horizontally to the right with the cover. At this time, the branch line width of the waveguide coupling and the power divider changes from W0 to W1, so that the branch line width increases from the forbidden band to the passband, thereby realizing the power distribution effect.

[0112] like Figure 10 As shown in the figure, when the coupling degree is 3dB, the first port 31 can be used as an input port, and the second port 32 can be used as a through port. Due to the change of the branch line width of the waveguide coupling and the power divider from W0 to W1, the energy of the third port 33 is much greater than that of the fourth port 34. At this time, the fourth port 34 cannot be used for output sampling. Therefore, when the coupling degree is 3dB, the third port 33 can be used as a coupled port, and the fourth port 34 can be used as an isolated port.

[0113] According to an embodiment of the present disclosure, with a coupling degree of 3 dB, when an electromagnetic wave enters the first port 31 (input port) and then propagates toward the second port 32 (through port), the first singular pin substructure 111, with its stepped structure gradually decreasing downward, guides a portion of the electromagnetic wave to radiate downward, thereby coupling to the auxiliary waveguide. When the electromagnetic wave is coupled to the auxiliary waveguide, the second singular pin substructure 112 guides more of the electromagnetic wave radiated into the auxiliary waveguide toward the third port 33 (coupling port). Because a small portion of the energy transmitted from the first port 31 (input port) to the second port 32 (through port) is reflected back, the single-side protruding pin structure 12 can guide the electromagnetic wave from the first port 31 (input port) to the third port 33 (coupling port), while preventing the reflected wave from the second port 32 (through port) from propagating toward the third port 33 (coupling port).

[0114] The embodiments of the present disclosure change the relative positions of the cover plate and the base plate by setting an adjustable structure, and change the relative arrangement of the pins by moving the cover plate, so that the width of the branch line changes, thereby converting the electromagnetic wave from the bandgap effect to the passband effect, thereby realizing the transition between different coupling degrees of the coupling and power divider.

[0115] Figure 11 The flowchart of the design method of the waveguide coupling and power divider according to the embodiment of the present disclosure is schematically shown.

[0116] like Figure 11 As shown, the design method of the waveguide coupling and power divider based on the gap waveguide structure includes S1110 to S1130.

[0117] In operation S1110 , an arrangement of a plurality of pins in a pin structure is determined based on characteristic parameters of the waveguide coupling and the power divider.

[0118] In operation S1120, based on the arrangement of the plurality of pins, an installation position of the waveguide transfer interface and an installation position of the adjustable structure are determined respectively.

[0119] In operation S1130, a waveguide coupling and power divider is obtained based on the arrangement of the plurality of pins in the pin structure, the installation position of the waveguide interface, and the installation position of the adjustable structure.

[0120] According to an embodiment of the present disclosure, before operation S1110 , the method further includes determining characteristic parameters of the waveguide coupling and the power splitter based on the design principles of the waveguide coupling and the power splitter.

[0121] Specifically, based on the design principles of waveguide coupling and power dividers, the structure and characteristic parameters of waveguide coupling and power dividers can be determined by the branch line coupling method or the small hole coupling method. The embodiments of the present disclosure are not limited to the determination using the branch line coupling method.

[0122] Figure 12 A typical structural diagram of a multi-branch line directional coupler according to an embodiment of the present disclosure is schematically shown.

[0123] like Figure 12 As shown in the figure, the multi-branch line coupler includes an input port p1, a through port p2, a coupled port p3, and an isolated port p4. The structure has N branch lines, and usually each branch line has the same size, which is w g *l g , the interval between branch lines t g The outputs of the through port p2 and the coupled port p3 have a 90° phase difference. When a signal is fed into the input port p1, P1, P2, P3, and P4 can represent the power at the four ports, respectively. The important characteristic parameters of the coupler include at least coupling, insertion loss, isolation, and directivity.

[0124] According to an embodiment of the present disclosure, the coupling degree can be used to characterize the logarithmic ratio of the total power P1 of the input port p1 to the output power P3 of the coupled port p3 when the device is well matched. The coupling degree is calculated as follows:

[0125]

[0126] Where C represents the coupling degree in dB, S 31 It is expressed as the S parameter from the input port p1 to the coupled port p3, P1 is the total power of the input port p1, and P3 is the output power of the coupled port p3.

[0127] According to the embodiments of the present disclosure, coupling degree is an important indicator of the coupler design target. The specific size of the coupling degree is determined by the design target of the coupler. The key to determining the quality of the coupler's coupling degree lies on the one hand in whether the obtained coupler can achieve the target coupling degree, and on the other hand in whether the obtained coupler can achieve the unevenness after the target coupling degree, that is, the floating range of the curve. If the floating range of the curve is smaller, the performance of the coupler is better.

[0128] According to the embodiments of the present disclosure, insertion loss can be used to represent the loss caused by the absorption or reflection of electromagnetic waves by the material's inherent properties when a signal is transmitted in a medium or conductor. Alternatively, if the gain of some designs is less than 1, the target gain less than 1 in the design is usually included in the insertion loss. Insertion loss is calculated as follows:

[0129]

[0130] Where, T represents the insertion loss in dB, S 21It is expressed as the S parameter from the input port p1 to the through port p2, and P2 is expressed as the output power of the through port p2.

[0131] According to the embodiments of the present disclosure, under normal circumstances, the absolute value of the insertion loss is as small as possible, because the absolute value of the insertion loss represents the energy loss from the input port to the output port. However, depending on the specific design goals, there will be different requirements for the insertion loss. For example, the target insertion loss in the power divider is 3dB.

[0132] According to an embodiment of the present disclosure, isolation can be used to characterize the logarithmic ratio of the total power P1 of the input port p1 to the output power P4 of the isolated port p4 in actual situations. The isolation is calculated as follows:

[0133]

[0134] Where, I represents isolation in dB, S 41 It is expressed as the S parameter from the input port p1 to the isolated port p4, and P4 is expressed as the output power of the isolated port p4.

[0135] According to the embodiments of the present disclosure, ideally, the signals coupled to the secondary waveguide cancel each other out at the isolated port p4, and theoretically, the output power of the isolated port p4 should be 0. However, in actual transmission, the situation is not entirely ideal, and some signals may be transmitted to the isolated port p4.

[0136] According to an embodiment of the present disclosure, directivity can be used to characterize the logarithmic ratio between the output power of the target port (generally the coupled port) and the output power of the interference port (generally the isolated port). The directivity is calculated as follows:

[0137]

[0138] Where D represents directivity in dB.

[0139] According to an embodiment of the present disclosure, the difference between the isolation degree of the isolation port p4 and the coupling degree of the coupling port p3 can be used as a directivity index of the coupler. The directivity index is an important indicator for evaluating the performance of the coupler. Under normal circumstances, the greater the directivity, the better the coupler performance.

[0140] According to the embodiment of the present disclosure, the working principle of the branch line coupler is as follows: Assume that an electromagnetic wave with an amplitude of A1 is input from the input port p1 and transmitted to the through port p2. When passing through the coupling branch, the electromagnetic wave will be coupled to the sub-waveguide. These N coupling branches will all excite two types of electromagnetic waves, forward coupling waves and backward coupling waves. All forward electromagnetic waves are superimposed to form a coupled signal, which is output from the coupling port p3 with an amplitude of A3. The backward electromagnetic waves are superimposed to form an isolated signal, which is output from the isolation port p4 with an amplitude of A4. Assume that the coupling coefficient of the coupling branch to the forward electromagnetic wave is f3, the coupling coefficient to the backward electromagnetic wave is f4, and the transmission coefficient is f2. Then, the amplitude of the forward electromagnetic wave of each coupling branch is f3A1f2 i-1 (i=1~N), the transmission distance to the coupling port p3 is (Ni)*tg, then the forward electromagnetic wave signal amplitude obtained at the coupling port p3 is calculated as follows:

[0141]

[0142] Where A3 represents the amplitude of the electromagnetic wave output from the coupling port p3, β represents the phase constant of the waveguide transmission line, N represents the number of branches of the coupling branch, f3 represents the coupling coefficient of the coupling branch to the forward electromagnetic wave, A1 represents the amplitude of the electromagnetic wave input from the input port p1, f2 represents the transmission coefficient of the coupling branch to the backward electromagnetic wave, i represents the i-th branch, t g Expressed as the intervals between branch lines.

[0143] According to an embodiment of the present disclosure, on the other hand, the amplitude of the backward electromagnetic wave of each coupling branch is f4A1f2 i-1 (i=1~N), the transmission distance from the input port p1 to the isolated port p4 is 2(i-1)*t g , then the amplitude of the backward electromagnetic wave signal obtained at the isolated port p4 is calculated as follows:

[0144]

[0145] Where A4 represents the amplitude of the electromagnetic wave output from the isolation port p4, and f2 represents the coupling coefficient of the coupling branch to the backward electromagnetic wave.

[0146] t g =λ / 4, i.e. βt g =π / 2 and put it into equations (5) and (6), then the coupling and isolation can be expressed as:

[0147]

[0148]

[0149] According to the embodiment of the present disclosure, since the branch line coupler has a vertically symmetrical structure, an odd-even mode analysis method can be used for design.

[0150] According to an embodiment of the present disclosure, for an N-branch line coupler, the spacing between the two coupling branches is set to a quarter of the waveguide wavelength λ g / 4, the width of the two outermost coupling branches and the inner (N-2) coupling branches are the same, and the normalized characteristic impedances are represented by a and b, respectively. Because the branch line is connected in series with the main and auxiliary waveguides, the two branch lines can be regarded as a cascade connection. Combining the transmission line equivalent circuit and the odd-even mode analysis method, the even-mode transmission matrix can be obtained as follows:

[0151]

[0152]

[0153] Where, [M] e It is represented as an even-mode transmission matrix, and A, B, and C are respectively represented as the values ​​of the result matrix, and the specific value of the result is related to the number of branch lines N.

[0154] According to an embodiment of the present disclosure, the odd-mode transmission matrix is ​​expressed as follows:

[0155]

[0156] Where, [M] o is represented as an odd-mode transmission matrix.

[0157] According to the embodiments of the present disclosure, from equations (9) and (10), the transmission coefficient and reflection coefficient of the odd and even modes are calculated as follows:

[0158]

[0159] Where T e , Γ e 、T o , Γ o They are respectively expressed as the transmission coefficient and reflection coefficient of even mode transmission and odd mode transmission.

[0160] According to an embodiment of the present disclosure, based on formula (11), the calculation method of the S parameters of each port can be obtained as follows:

[0161]

[0162] According to the embodiments of the present disclosure, since N is a known term in the actual design, the relationship between a, b and A, B, C, and D can be obtained according to formula (10). Since the reflection of the input port p1 and the isolated port p4 is zero, B=C can be obtained. Therefore, a relationship between a and b can be obtained. Then, combined with the amplitude relationship between the through port p2 and the coupled port p3 (determined by the target coupling degree), the specific theoretical values ​​of the normalized characteristic impedances a and b of the two outermost coupled branches and the inner (N-2) coupled branches can be determined.

[0163] According to the embodiments of the present disclosure, after determining the characteristic parameters of the waveguide coupling and the power divider, based on the structural principle of the electromagnetic bandgap unit, the pin structure parameters that can achieve the bandgap effect in the terahertz frequency band and the gate structure parameters that guide the propagation of electromagnetic waves are determined.

[0164] According to the embodiments of the present disclosure, currently commonly used electromagnetic bandgap units for gap waveguides include pin-type electromagnetic bandgap units and mushroom-type electromagnetic bandgap units. The bandgap principle of the pin-type electromagnetic bandgap unit can be explained by a corrugated groove structure.

[0165] Reference below Figures 13 and 14 , the corrugated groove structure of the pin-type electromagnetic band gap unit is further explained.

[0166] Figure 13 A schematic diagram of a corrugated groove structure according to an embodiment of the present disclosure is shown schematically.

[0167] First consider the one-dimensional corrugated groove structure. Figure 13 The figure shows an all-metal corrugated groove structure with a groove depth of h = λ / 4. The corrugation's tangential direction is the x-direction, the normal direction is the z-direction, and the Poynting vector direction is the y-direction. When the incident electromagnetic wave propagates in the y-direction and the electric field direction is the z-direction, each groove structure is equivalent to a transmission line with a short-circuited terminal and a branch distance of one-quarter wavelength. According to the impedance transformation formula, the groove structure is equivalent to an open circuit, that is, the longitudinal wave impedance is infinite. When the incident electromagnetic wave propagates in the y-direction and the electric field direction is the x-direction, the surface of the corrugated groove structure can be equivalent to the surface of an ideal conductor, that is, the transverse wave impedance is zero. Therefore, for electromagnetic waves with an incident direction in the y-direction, the surface of the corrugated groove structure is a soft surface, and the electromagnetic wave cannot propagate. For electromagnetic waves with an incident direction in the x-direction, the surface of the corrugated groove structure is a hard surface, and the electromagnetic wave can propagate.

[0168] Figure 14 The figure schematically shows a structural diagram of a bed of nails according to an embodiment of the present disclosure.

[0169] like Figure 14As shown, consider a two-dimensional corrugated groove structure. This structure then becomes a bed of nails. Similar to the corrugated groove structure, however, electromagnetic waves cannot propagate in either the x or y directions, effectively acting as an artificial magnetic conductor on a high-impedance surface. The bed of nails structure is then combined with an upper PEC metal plate to form an electromagnetic bandgap (EBG). Because the spacing between the upper parallel plate and the bed of nails is designed to be less than λ / 4, parallel plate waveguide field theory indicates that electromagnetic waves cannot propagate in the gap. Finally, this structure is divided into several periodic unit structures, resulting in an EBG unit structure that achieves a bandgap effect for the target frequency band.

[0170] According to the embodiments of the present disclosure, the design of a gap waveguide begins with designing pins that achieve a bandgap effect in the desired frequency band. The design process can include selecting the key parameters of the pins, performing a two-dimensional dispersion simulation in a three-dimensional electromagnetic field simulation tool such as CST, periodically laying out the pin unit structure in the X and Y directions, and then testing the propagation of electromagnetic waves in different modes.

[0171] Reference below Figures 15 and 16 , further explanation is given on the pins that can achieve the bandgap effect in the required frequency band.

[0172] Figure 15 The figure schematically shows a pin modeling diagram according to an embodiment of the present disclosure.

[0173] like Figure 15 As shown, the main parameters of the pin may include a height parameter h of the pin, a bottom side length parameter a of the pin, a unit period p of the electromagnetic band gap structure, and a height g of the air gap.

[0174] According to an embodiment of the present disclosure, the height parameter h of the pin determines the upper and lower frequency limits of the stopband, so h must meet the conditions of being greater than λ / 4=0.375 mm and less than λ / 2=0.75 mm.

[0175] According to an embodiment of the present disclosure, for the bottom side length parameter a of the pin, as a increases, the starting frequency of the stopband first increases and then decreases, and the ending frequency first decreases and then increases, that is, the bandwidth of the stopband first decreases and then increases as a increases, so the value of a is generally less than 0.3λ=0.45mm.

[0176] According to the embodiments of the present disclosure, for the unit period p of the electromagnetic bandgap structure, as the unit period p increases, the starting frequency of the stopband decreases due to the increase in the effective electrical length of the pins. However, the stopband's ending frequency is almost unaffected when the unit period p is relatively small (p < 0.1λ = 0.15mm), but drops sharply as the unit period p continues to increase due to the presence of new modes. Therefore, the stopband bandwidth tends to first increase and then decrease as the unit period p increases, and the value of p is generally less than 0.5λ = 0.75mm.

[0177] According to the embodiments of the present disclosure, for the height g of the air gap, as the air gap increases, the starting frequency of the stopband will increase slightly, but the ending frequency of the stopband will show different changing trends according to different size intervals of the unit period. When the unit period p is small (less than 0.25λ), the ending frequency decreases rapidly with the increase of g, and when the unit period p is large (greater than 0.25λ), it remains almost unchanged, and the value of g is generally selected to be less than 0.2λ=0.3mm.

[0178] According to an embodiment of the present disclosure, the model parameter configuration of the pin unit is shown in Table 1, wherein the pin height h = 0.44 mm, the pin bottom side length a = 0.125 mm, the unit period of the electromagnetic band gap structure p = 0.25 mm, the height of the air gap g = 0.05 mm, and the thickness of the pin cover plate and the base plate d = 0.2 mm, wherein the value of d has no effect on the performance.

[0179] Table 1 Model parameters of pin element

[0180] a p g h d 0.125mm 0.25mm 0.05mm 0.44mm 0.2mm

[0181] Figure 16 A schematic diagram of the two-dimensional dispersion simulation results of a pin according to an embodiment of the present disclosure is shown schematically.

[0182] like Figure 16 As shown in FIG, after configuring the model parameters of the pin unit, the band gap of the pin is now 135 GHz-280 GHz, so the design meets the requirements.

[0183] According to an embodiment of the present disclosure, after the model parameters of the pin unit are determined, a door structure capable of guiding electromagnetic wave propagation is designed based on the model parameters of the pin unit, and the door structure parameters guiding electromagnetic wave propagation are determined.

[0184] According to the embodiments of the present disclosure, the designed pins can be used on both sides of the door to achieve the bandgap effect, so that electromagnetic waves can only propagate inside the door and will not radiate outside the door. The designed groove structure or ridge structure can be used inside the door to guide the electromagnetic waves to propagate along the designed route, ultimately realizing the function of the waveguide.

[0185] Reference below Figures 17 and 18 , further explaining the gate structure that can guide the propagation of electromagnetic waves.

[0186] Figure 17 The figure schematically shows a door structure modeling diagram according to an embodiment of the present disclosure.

[0187] like Figure 17As shown, in the embodiment of the present disclosure, the slot gap can be selected to design the gate structure, and the main parameters of the one-dimensional dispersion include the slot width W. A conduction path with a width equal to the slot width can be left between the two rows of pins, and then a one-dimensional dispersion simulation can be performed using a three-dimensional electromagnetic field simulation tool such as CST, so that the gate structure composed of the pins and the slot gap is laid periodically in the X direction, and then the propagation of electromagnetic waves of different modes is tested. At this time, the conduction slot in the middle of the gate structure is equivalent to a rectangular waveguide, the difference being that its boundary conditions are different from those of the rectangular waveguide. In order to achieve single-mode transmission, it is required that W satisfies λ / 2<W<W at this time, and as W changes, the frequency band of the single-mode passband will also change. For example, referring to the standard a=1.295±0.025mm of the WR5 rectangular waveguide and the influence range of the pin unit structure, it can be finally determined that the parameter of W is 1.380mm.

[0188] Figure 18 The figure schematically shows the one-dimensional dispersion simulation result of the gate structure according to the embodiment of the present disclosure.

[0189] like Figure 18 As shown, in the frequency band of 145-220 GHz, electromagnetic waves meet single-mode transmission on the designed gate structure.

[0190] According to the embodiments of the present disclosure, when waveguide coupling and power splitter are manufactured based on the above-mentioned waveguide transmission theory and characteristic parameters of the coupler, the new performance indicators at this time must first be analyzed based on the special non-reciprocity of the design.

[0191] Specifically, since the influence of the gap waveguide bandgap effect at the physical level is difficult to calculate and it is impossible to accurately locate the distance between the branch lines to maintain λ / 4, the E-plane single branch line bridge principle can be adopted, that is, only one branch line can be configured in the gap waveguide.

[0192] According to the embodiments of the present disclosure, the coupling and power splitter is usually a four-port device and should have the characteristics of reciprocity. Figure 3 As shown in the figure, the pin arrangement at this time has no symmetry in both the longitudinal and transverse directions, that is, the coupling and power divider have no reciprocity. Therefore, for the four ports of the waveguide coupler and power divider, a total of 16 S parameters are required, and different indicators should be designed according to different usage scenarios.

[0193] According to the embodiments of the present disclosure, since only one branch line is configured in the gap waveguide of the waveguide coupling and power divider, when the electromagnetic wave is coupled from the branch line to the sub-waveguide, the situation in which the electromagnetic waves are constructive in phase at the coupling port and destructive in phase at the isolation port as occurs in a multi-branch line design will not occur. Therefore, there are no coupling ports and isolation ports in a strict theoretical sense at this time, so the two ports are referred to as the third port and the fourth port hereinafter.

[0194] For example, when the target coupling degree is 20dB, only a very small amount of energy is sampled to the fourth port, and the second port is a pass-through port, so most of the energy will be transmitted to the second port. However, it is impossible for the second port and the downstream device to be completely matched. Therefore, a small part of the most energy transmitted to the second port here will be reflected back. Although the reflected energy is only a small part of the energy transmitted to the second port, it is still a non-negligible impact compared to the 1% sampling of the fourth port.

[0195] Similarly, when an electromagnetic wave is input from the first port, a portion of the energy will be conducted to the third port. Compared with the propagation of energy from the third port to the fourth port, that is, the parameter S(4,3), it also belongs to the direct-through situation to a certain extent. Then, when the third port and the connected downstream load cannot be completely matched, energy will be reflected back from the third port and then pass directly to the fourth port through the secondary waveguide. If the energy of the third port cannot be much less than that of the fourth port when the coupling degree is 20db, or if the energy of the third port is greater than that of the fourth port when the coupling degree is 3dB, then the impact of this energy on the output of the fourth port will depend entirely on the external condition of the matching degree between the third port and the downstream load, which is an undesirable design.

[0196] According to the embodiments of the present disclosure, the symbol S′(n,n) can be defined to represent the return loss of the nth port reflected back into the device due to the failure to fully match the next stage. The calculation formula for the directivity is as follows:

[0197] D1= |S(2,1)+S′(2,2)+S(4,2)-S(4,1)| (13)

[0198] D2= |S(3,1)+S′(3,3)+S(4,3)-S(4,1)| (14)

[0199] According to the embodiments of the present disclosure, the fundamental reason for the change in the calculation formula of directivity includes the lack of reciprocity in the structure. Because S(2,1) is an important indicator of the insertion loss of the straight-through port, the simulation results are basically stable at -0.7dB (composed of the 0.1dB insertion loss of the coupling and power divider itself, the 0.3dB insertion loss of the gap-cavity 90° transition interface, and the 0.3dB insertion loss of the curved waveguide introduced by the measured topology structure). S(4,3) is a parameter with a similar position to the insertion loss of the straight-through port, and the simulation results are basically less than -1.8dB. Both take the worst performance case and substitute it into formula (13) and formula (14), and we can get:

[0200] D1= |[-0.7dB + S′(2,2)]+[S(4,2)-S(4,1)]| (15)

[0201] D2= |[-1.8dB + S′(3,3)]+[S(3,1)-S(4,1)]| (16)

[0202] The values ​​of S'(2,2) and S'(3,3) are determined by the matching with the downstream circuit and are exogenous givens. Here, a value of -10dB is used for poor matching. Therefore, to ensure a directivity of 20dB, the values ​​[S(4,2)-S(4,1)] and [S(3,1)-S(4,1)] must provide directivities of 9.3dB and 8.2dB, respectively.

[0203] According to the embodiments of the present disclosure, as described above, the coupling degree can be changed by moving the cover plate. However, since the movement of the cover plate only changes the relative position of the pin arrangement, the design principle for the 3dB coupling degree is the same as the design principle for the 20dB coupling degree, both of which are based on the E-plane single-branch bridge principle. In this case, when an electromagnetic wave is input from the first port, a portion of the energy is directly transmitted to the through-port, i.e., the second port, while another portion of the energy is coupled to the secondary waveguide when passing through the branch line. Guided by the stepped shape of the first and second singular pin substructures, the majority of the energy is transmitted to the third port.

[0204] According to the embodiment of the present disclosure, in the energy distribution inside the coupling and power splitter at this time, only the second port and the third port, that is, the two output ports, are on the same order of magnitude, so the directivity calculation formula at this time is as follows:

[0205] D1=|S(2,1)+S′(2,2)+S(3,2)-S(3,1)| (17)

[0206] D2=|S(3,1)+S′(3,3)+S(2,3)-S(2,1)| (18)

[0207] According to the embodiment of the present disclosure, as a coupling and power divider with a power distribution function, S(2,1) and S(3,1) are almost equal in numerical value. In order to ensure a directivity of 20dB, it is required that S(3,2) and S(2,3) can both provide a directivity of 10dB.

[0208] According to an embodiment of the present disclosure, based on the different index requirements corresponding to the above-mentioned different usage scenarios, the arrangement of multiple pins in the pin structure and the pin parameters of the multiple pins are determined.

[0209] Specifically, if Figure 4The pin arrangement of the cover plate of the 20dB coupling and power splitter is shown, where l0 and l1 can be used to represent some of the first singular pin parameters included in the first singular pin substructure 111, l2, l3, and l4 can be used to represent some of the second singular pin parameters included in the second singular pin substructure 112, and S0 can be used to represent the parameters of the single-side protruding pin structure 12. Figure 5 The pin arrangement of the bottom plate of the 20dB coupling and power splitter is shown, where S1 can be used to represent the parameters of the flat pin structure 13. Based on the different performance requirements corresponding to the above different usage scenarios, the pin parameters of the above pins in the pin structure are determined, and the specific parameters are shown in Table 2.

[0210] Table 2 Parameters of some singular pins

[0211] <![CDATA[S0]]> <![CDATA[S1]]> <![CDATA[l0]]> <![CDATA[l1]]> <![CDATA[l2]]> <![CDATA[l3]]> <![CDATA[l4]]> 0.132mm 0.09mm 0.12mm 0.06mm 0.12mm 0.07mm 0.06mm

[0212] According to an embodiment of the present disclosure, based on pin parameters of multiple pins, it can be determined that when the coupling degree is 20dB, the width W0 of the branch line can be set to 0.58mm, and when the coupling degree is 3dB, the width W1 of the branch line can be set to 1.075mm.

[0213] According to the embodiments of the present disclosure, since the performance requirements for 3dB coupling degree and 20dB coupling degree are different, the proportion of the single-sided protruding pin structure relative to the branch line is larger at the 20dB branch line scale, and smaller at the 3dB branch line scale. Therefore, the single-sided protruding pin structure has less impact in the 3dB design.

[0214] According to the embodiments of the present disclosure, when designing the waveguide adapter, since the waveguide coupling and power splitter proposed in the present disclosure can change the coupling degree by moving the cover plate, it is necessary to leave space in the horizontal direction for the cover plate to move, so the input and output ports cannot be set on the cover plate. In addition, because the flange diameter of the WR5 standard waveguide port reaches 19.05mm, and the horizontal cross-section of the waveguide coupling and power splitter disclosed in the present disclosure is only 7.625mm*3.885mm, and the distance between the center lines of the upper and lower ports is only 1.755mm, only the upper and lower surfaces cannot meet the requirements of four ports. Therefore, a gap-cavity waveguide adapter can be set at the four input and output ports of the gap waveguide respectively, and the waveguide outlets set on the four front, back, left and right surfaces of the cavity will turn the electromagnetic waves originally propagating horizontally in the gap waveguide to 90° vertical propagation and pass into the cavity waveguide, and then the signal is led out from the four surfaces of the cavity waveguide, and the cavity waveguide used at this time can be a WR5 standard waveguide.

[0215] Reference below Figures 19 to 22 , further explain the waveguide interface structure.

[0216] Figure 19 A schematic diagram of a waveguide-to-interface structure according to an embodiment of the present disclosure is shown schematically.

[0217] Figure 20 A top view of a waveguide-to-interface structure according to an embodiment of the present disclosure is schematically shown.

[0218] Figure 21 A cross-sectional view of a waveguide-to-interface structure according to an embodiment of the present disclosure is schematically shown.

[0219] like Figure 19 、 Figure 20 、 Figure 21 As shown, the structural parameters W0, h0, h1, h2, h3, d0, d1, d2, and d3 of the waveguide interface can be selected. The specific structural parameters are shown in Table 3:

[0220] Table 3 Structural parameters of waveguide-to-interface

[0221] <![CDATA[W0]]> <![CDATA[h0]]> <![CDATA[h1]]> <![CDATA[h2]]> <![CDATA[h3]]> 0.58mm 0.11mm 0.2mm 0.08mm 0.19mm <![CDATA[d0]]> <![CDATA[d1]]> <![CDATA[d2]]> <![CDATA[d3]]> 0.28mm 0.14mm 0.055mm 0.08mm

[0222] Figure 22 The S-parameter diagram of the waveguide-to-interface structure according to an embodiment of the present disclosure is schematically shown.

[0223] like Figure 22 As shown in the figure, in the 172GHz-202GHz frequency band, the waveguide-to-interface has excellent performance with an insertion loss of less than 0.1dB and a return loss of less than 20dB. Therefore, as far as the waveguide coupling and power splitter are concerned, the introduction of the waveguide-to-interface will not affect the performance of the waveguide coupling and power splitter. However, since the introduction of the waveguide-to-interface adds a load to the input and output ports, it still has a certain impact on the final value of the parameter design.

[0224] According to the embodiments of the present disclosure, based on the above-mentioned design of the waveguide interface structure and the pin structure and the determined structural parameters, the gap waveguide with a coupling degree of 20dB and the gap waveguide with a coupling degree of 3dB are modeled and simulated respectively to verify whether the above-mentioned structures meet the directivity indicators.

[0225] Reference below Figures 23 to 26 , further explanation is given on the gap waveguide with a coupling degree of 20 dB and the gap waveguide with a coupling degree of 3 dB.

[0226] Figure 23 The figure schematically shows an S-parameter simulation diagram of a 20 dB coupling degree according to an embodiment of the present disclosure.

[0227] like Figure 23As shown in the figure, at 180GHz-200GHz, the above design satisfies the requirements of insertion loss better than 0.35dB, return loss less than 15dB, the output electromagnetic wave of the fourth port (the coupling port in this design) is -20dB, the unevenness is less than 1dB, and S(3,1) and S(4,2) are both less than -30dB, that is, both can provide directivity better than 10dB.

[0228] Figure 24 The diagram schematically shows the phase diagram of the output port with a coupling degree of 20 dB according to an embodiment of the present disclosure.

[0229] like Figure 24 As shown in FIG, within the operating frequency band, the phase difference between the two output ports is not completely stable. As the frequency increases, the phase difference decreases from 160° to 130°.

[0230] Figure 25 The figure schematically shows an S-parameter simulation diagram of a 3dB coupling degree according to an embodiment of the present disclosure.

[0231] like Figure 25 As shown, at 195 GHz to 200 GHz, the through-port output S(2,1) and the coupled-port output S(3,1) intersect at a point. However, due to the insertion loss introduced by the 90° waveguide transition from the gap to the cavity, even when the outputs of the two output ports are equal, the insertion loss reaches 3.4 dB, 0.4 dB below the theoretical target, and there is a 0.5 dB non-flatness within the passband. Port 4's isolation remains better than 10 dB throughout the passband. Because the curves for S(2,3) and S(3,2) overlap, the directivity parameters S(2,3) and S(3,2) are both below -15 dB, and the return loss remains below 18 dB.

[0232] Figure 26 The figure schematically shows the output port phase diagram of 3dB coupling degree according to an embodiment of the present disclosure.

[0233] like Figure 26 As shown, within the operating frequency band, the phase difference between the two output ports remains unchanged at 90°, that is, the two output ports maintain equally divided orthogonal outputs.

[0234] According to the embodiments of the present disclosure, based on the arrangement of the pin structures, structural parameters, waveguide adapter structural parameters and the design of the adjustable structure, a waveguide coupler and power divider based on a gap waveguide structure can be obtained.

[0235] Reference below Figures 27 to 31 , further explains the waveguide coupling and power divider based on the gap waveguide structure.

[0236] Figure 27The schematic diagram of the block splitting of the measured structure according to the specific embodiment of the present disclosure is schematically shown.

[0237] like Figure 27 As shown, during the actual processing of the waveguide coupling and power divider, since the processing of the cavity waveguide is achieved by digging grooves on the metal surface and then merging it with another piece of metal, the overall design can be split into several pieces, and the cavity waveguide for lead-out is dug out in the module where it is convenient to dig grooves, and then they are pieced together.

[0238] Figure 28 The figure schematically shows an S-parameter simulation diagram of a waveguide coupling and a power divider with a coupling degree of 20 dB according to a specific embodiment of the present disclosure.

[0239] Figure 29 The figure schematically shows an S-parameter simulation diagram of a waveguide coupling and a power divider with a coupling degree of 3 dB according to an embodiment of the present disclosure.

[0240] like Figure 28 、 Figure 29 As shown, the main difference in performance at this time compared to the internal structure is that the output insertion loss increases by 0.3dB. The main reason for the increase in insertion loss is the curved waveguide structure in the cavity waveguide lead-out structure.

[0241] Figure 30 The figure schematically shows the phase diagram of the output port of the waveguide coupling and the power divider with a coupling degree of 20 dB according to an embodiment of the present disclosure.

[0242] Figure 31 The figure schematically shows the phase diagram of the output port of the waveguide coupling and the power divider with a coupling degree of 3 dB according to an embodiment of the present disclosure.

[0243] like Figure 30 、 Figure 31 As shown in the figure, the phase difference of 20dB coupling is stable at 130°, and the phase difference of 3dB coupling is stable at 180°. The stability of the former is enhanced, and the reason for the change of the phase difference of the latter is that the curved waveguide in the lead-out structure of the first port and the third port itself has a 90° phase offset, so the phase difference changes from 90° to 180°.

[0244] It should be noted that, unless it is explicitly stated that there is a sequence of execution between different operations shown in the flowchart in the embodiments of the present disclosure, or there is a sequence of execution between different operations in technical implementation, otherwise, the execution order between multiple operations may not be prioritized, and multiple operations may also be executed simultaneously.

[0245] The embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. It should be noted that any implementations not depicted or described in the drawings or the main text of the specification are known to those skilled in the art and are not described in detail. Furthermore, the above definitions of the various elements and methods are not limited to the various specific structures, shapes, or methods described in the embodiments, and can be easily modified or replaced by those skilled in the art.

[0246] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of the systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram may represent a module, program segment, or portion of code, which contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the boxes may occur in an order different from that marked in the accompanying drawings. For example, two boxes shown in succession may actually be executed substantially in parallel, or they may sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, as well as the combination of boxes in the block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or may be implemented using a combination of dedicated hardware and computer instructions. It will be understood by those skilled in the art that the features described in the various embodiments and / or claims of the present disclosure may be combined and / or coupled in various ways, even if such combinations or couplings are not explicitly described in the present disclosure. In particular, without departing from the spirit and teachings of the present disclosure, the features described in the various embodiments and / or claims of the present disclosure may be combined and / or coupled in various ways, and all such combinations and / or couplings fall within the scope of the present disclosure.

[0247] The embodiments of the present disclosure are described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although each embodiment has been described separately above, this does not mean that the measures in each embodiment cannot be used in combination to advantage. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A waveguide coupling and power divider based on a gap waveguide structure, comprising a pin structure, a waveguide adapter and an adjustable structure. The pin structure includes a plurality of pins, the plurality of pins are distributed on both sides of the transverse axis of the coupling and power divider and on the transverse axis, and the plurality of pins are asymmetrically arranged based on the transverse axis and the longitudinal axis, wherein: At least one pin of the plurality of pins is configured to be disposed on a cover plate of the gap waveguide structure; The waveguide transfer interface is configured to be arranged at a plurality of ports of the gap waveguide structure; The adjustable structure is configured to be disposed on a cover plate of the gap waveguide structure, and the adjustable structure is used to control the movement of the cover plate to change the arrangement positions of the plurality of pins.

2. The method according to claim 1, wherein The pin structure includes a stepped pin structure, a single-side protruding pin structure and a flat pin structure. The stepped pin structure is configured to be disposed on both sides of a transverse axis of the coupling and power divider, wherein the stepped pin structure comprises a plurality of pins arranged in a stepped shape in a direction away from a long side of the coupling and power divider, and the plurality of pins are arranged asymmetrically with respect to the transverse axis; The single-side protruding pin structure and the flat pin structure are configured to be disposed on both sides of a longitudinal axis of the coupling and power divider.

3. The method according to claim 2, wherein: The stepped pin structure includes a first singular pin substructure and a second singular pin structure, wherein the first singular pin structure and the second singular pin structure are asymmetrically arranged based on the transverse axis and the longitudinal axis; The gap waveguide structure includes an input port, a through port, an isolation port, and a coupling port. The first singular pin substructure is used to guide electromagnetic waves to radiate from the input port to the auxiliary waveguide, and the second singular pin substructure is used to guide the electromagnetic waves radiated to the auxiliary waveguide to propagate toward the coupling port.

4. The method according to claim 3, wherein: The first singular pin substructure includes an odd number of first singular pins, and the odd number of first singular pins are configured to be disposed on the cover plate of the gap waveguide structure; The second singular pin substructure includes an even number of second singular pins, and the even number of second singular pins are configured to be disposed on a bottom plate of the gap waveguide structure.

5. The method according to claim 2, wherein: The single-sided protruding pin structure is configured to be set on the cover plate of the gap waveguide structure, and the single-sided protruding pin structure is used to guide the electromagnetic wave to propagate from the input port to the coupling port and prevent the reflected wave of the through port from propagating to the coupling port.

6. The method according to claim 2, wherein: The flat pin structure includes at least two third singular pins, and the third singular pins are configured to be flat and used to introduce resonance points to increase the bandwidth of the gap waveguide structure.

7. The method according to claim 6, wherein: The flat pin structure is configured to be disposed on a bottom plate of the gap waveguide structure.

8. The method according to claim 1, wherein The waveguide-to-interface includes a first waveguide-to-interface, a second waveguide-to-interface, a third waveguide-to-interface, and a fourth waveguide-to-interface, wherein the first waveguide-to-interface is connected to the input port, the second waveguide-to-interface is connected to the through port, the third waveguide-to-interface is connected to the isolation port, and the fourth waveguide-to-interface is connected to the coupling port.

9. The method according to claim 1, wherein The adjustable structure includes an adjustable screw and a chamfer structure, The adjustable screw is used to control the movement of the cover plate to change the arrangement position of the pin structure; The chamfered structure is used to reduce the movement friction of the cover plate.

10. A design method for waveguide coupling and power divider based on a gap waveguide structure, wherein: The waveguide coupling and power divider includes a pin structure, a waveguide adapter and an adjustable structure, and the method includes: determining, based on characteristic parameters of the waveguide coupler and power divider, an arrangement of a plurality of pins in the pin structure, wherein the plurality of pins are distributed on both sides of a transverse axis of the coupler and power divider and on the transverse axis, and the plurality of pins are asymmetrically arranged about the transverse axis and the longitudinal axis, and at least one of the plurality of pins is configured to be disposed on a cover plate of the gap waveguide structure; Based on the arrangement of the plurality of pins, the installation positions of the waveguide adapter and the installation position of the adjustable structure are respectively determined, wherein the waveguide adapter is configured to be disposed at a plurality of ports of the gap waveguide structure, and the adjustable structure is configured to be disposed at a cover plate of the gap waveguide structure, and the adjustable structure is used to control the movement of the cover plate to change the arrangement positions of the plurality of pins; The waveguide coupling and power divider is obtained based on the arrangement of multiple pins in the pin structure, the installation position of the waveguide adapter and the installation position of the adjustable structure.

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