A millimeter-wave terahertz microstrip to waveguide feeding structure and debugging method thereof

Abstract

The present invention discloses a millimeter wave terahertz microstrip to waveguide feeding structure and a debugging method thereof. The feeding structure comprises: a PCB board, a plurality of metallized through holes are provided on the PCB board, and the plurality of metallized through holes are arranged in a rectangular array, and a microstrip line is provided on the top of the PCB board; a filling medium, the filling medium is filled in the metallized through holes, and the size of the filling medium is calculated according to the following formula: λ1=λ / (ε r ) 0.5 Where λ1 is the diameter of the filling medium, mm; λ is the transmission wavelength of the filling medium, mm; ε r is the relative dielectric constant of the filling medium; the transmission waveguide is arranged at the bottom of the PCB board, and the microstrip line is connected to the transmission waveguide. The feeding structure suppresses the excitation of high-order modes in the waveguide by accurately designing the size of the filling medium and the arrangement of the metallized through holes, reduces the transmission instability and energy loss caused by resonance, and effectively improves the stability and efficiency of signal transmission.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a millimeter wave terahertz microstrip to waveguide feeding structure and a debugging method thereof. Background Art

[0002] In recent years, high-frequency transmission technology in the millimeter wave and terahertz bands has become a research hotspot in the fields of wireless communications, radar detection, and imaging systems. The signal transmission in these frequency bands has extremely high rates and data capacity, providing technical support for the next generation of communications and high-precision detection. In this context, the transition structure from microstrip line to waveguide has become an important component of high-frequency RF systems due to its low loss and good transmission characteristics. However, with the increase in frequency, the transition structure faces greater challenges in design and application.

[0003] There is a key problem in the existing microstrip line to waveguide transition structure, that is, high-order mode resonance is prone to occur under high-frequency transmission conditions. The resonance phenomenon will cause a significant decrease in signal transmission efficiency and lead to unstable system performance. The main reason for this problem is that the dielectric-filled waveguide design in the transition structure fails to effectively suppress the excitation of high-order modes, thereby interfering with the normal transmission of the main mode. As the frequency increases further, the impact of high-order mode resonance becomes more significant, becoming the main bottleneck restricting the quality of high-frequency signal transmission.

[0004] Therefore, the microstrip line to waveguide transition structure in the prior art has a technical problem that the transmission efficiency is significantly reduced due to the resonance phenomenon. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a millimeter wave terahertz microstrip to waveguide feeding structure and a debugging method thereof.

[0006] The millimeter wave terahertz microstrip to waveguide feeding structure proposed in the present invention comprises: a PCB board, a plurality of metallized through holes are provided on the PCB board, and the plurality of metallized through holes are arranged in a rectangular array, and a microstrip line is provided on the top of the PCB board;

[0007] A filling medium is filled in the metallized through holes one by one, and the size of the filling medium is calculated according to the following formula:

[0008] λ1=λ / (ε r ) 0.5

[0009] Where λ1 is the diameter of the filling medium, mm; λ is the transmission wavelength of the filling medium, mm; ε r is the relative dielectric constant of the filling medium, unitless;

[0010] A transmission waveguide is arranged at the lower part of the PCB board, and the microstrip line is connected to the transmission waveguide.

[0011] In some examples of the present invention, the filling medium is made of Rogers RO3003 material, the PCB board includes a plurality of PCB boards, and the plurality of PCB boards are connected by pressing and bonding.

[0012] In some examples of the present invention, the PCB board includes:

[0013] A top layer plate, an inner layer plate and a lower layer plate, wherein the top layer plate, the inner layer plate and the lower layer plate are arranged in sequence from top to bottom;

[0014] Wherein, the microstrip line is arranged on the top layer board, and the transmission waveguide is arranged on the bottom layer board.

[0015] In some examples of the present invention, the top layer board, the inner layer board and the lower layer board are pressed and bonded using Rogers RO3003 special PP.

[0016] In some examples of the present invention, a radiation probe is provided at one end of the microstrip line, and the radiation probe is used to couple the electromagnetic wave radiation in the microstrip line into the filling medium.

[0017] In some examples of the present invention, it also includes:

[0018] A matching cavity is provided on the upper part of the PCB board, the matching cavity is a metal-enclosed cavity, and the matching cavity is used to reduce the overall impedance of the microstrip to waveguide feeding structure.

[0019] In some examples of the present invention, the transmission waveguide comprises:

[0020] a first waveguide connected to the lower plate;

[0021] A second waveguide is vertically connected to the first waveguide and is parallel to the lower plate.

[0022] In some examples of the present invention, both the first waveguide and the second waveguide are BJ1200 waveguides, and an internal step structure is formed at the intersection of the first waveguide and the second waveguide.

[0023] The debugging method of the millimeter-wave terahertz microstrip to waveguide feeding structure proposed in the present invention comprises:

[0024] Determine the dimensions of the transmission waveguide;

[0025] A simulation model of the debugging method of the microstrip to waveguide feeding structure is established according to the size of the transmission waveguide;

[0026] Set the solution parameters according to the use frequency of the feeding structure, set the distribution spacing of the filling medium and set the size of the matching cavity;

[0027] According to the distribution spacing of the filling medium set in the set simulation model and the size of the matching cavity set, the standing wave value S and the loss value P are determined;

[0028] If the standing wave value S ≥ -10dB or the loss value P ≤ -0.15dB, reset the spacing of the filling medium and the size of the matching cavity, and return to the previous step to redetermine the standing wave value S and the loss value P;

[0029] If the standing wave value S is less than -10dB and the loss value P is greater than -0.15dB, the debugging is completed and the set value in step 3 is taken as the actual value.

[0030] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be understood through practice of the present invention to have the following beneficial effects:

[0031] Efficient transmission: By precisely designing the size of the filling medium and the arrangement of the metallized through-holes, the excitation of the higher-order modes in the waveguide is successfully suppressed, significantly reducing the transmission instability and energy loss caused by resonance. This optimized design ensures that the electromagnetic wave is transmitted in the waveguide in the main mode (such as the TE10 mode), effectively improving the stability and efficiency of signal transmission;

[0032] Impedance matching optimization: The size of the filling medium is based on the formula: λ1=λ / (ε r ) 0.5 Accurate calculation, combined with the structural parameters of the microstrip line and waveguide, achieves precise impedance matching, reduces the generation of reflected waves, and improves the stability of signal transmission;

[0033] Miniaturized design: The effective wavelength of the waveguide is reduced by using the dielectric filling characteristics, which significantly reduces the size of the waveguide, meeting the requirements for compact structure in the millimeter wave and terahertz bands, and is particularly suitable for portable or high-density integrated circuit applications;

[0034] Enhanced electromagnetic shielding: The rectangular array structure of metallized through holes not only forms a waveguide cavity, but also effectively isolates external electromagnetic interference, improving the anti-interference ability and signal integrity of the transmission channel;

[0035] Broadband performance: The optimized filling medium design and rectangular array structure improve the bandwidth performance of the transmission waveguide, making it adaptable to the needs of multi-band signal transmission and meeting the application scenarios of high-frequency communication systems;

[0036] Manufacturing process feasibility: The design is based on common PCB manufacturing processes and utilizes a combination of metallized through holes and filling media, making it easy to achieve mass production and reducing manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0038] Figure 1 A schematic structural diagram of a millimeter-wave terahertz microstrip to waveguide feeding structure provided by the present invention;

[0039] Figure 2 An exploded diagram of a millimeter-wave terahertz microstrip to waveguide feeding structure provided by the present invention;

[0040] Figure 3 A flow chart of a debugging method for a millimeter-wave terahertz microstrip to waveguide feeding structure.

[0041] Description of reference numerals:

[0042] 100-PCB board; 110-top board; 120-inner board; 130-lower board;

[0043] 200-filling medium;

[0044] 300-metalized through hole;

[0045] 400-microstrip line;

[0046] 500 - Radiation probe;

[0047] 600-matching cavity;

[0048] 700 - transmission waveguide; 710 - first waveguide; 720 - second waveguide. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0051] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0053] Figure 1 for Figure 1 A schematic structural diagram of a millimeter-wave terahertz microstrip to waveguide feeding structure provided by the present invention; Figure 2 An exploded diagram of a millimeter-wave terahertz microstrip to waveguide feeding structure provided by the present invention; Figure 3 A flow chart of a debugging method for a millimeter-wave terahertz microstrip to waveguide feeding structure.

[0054] Reference below Figure 1-Figure 2 A millimeter wave terahertz microstrip to waveguide feeding structure provided according to an embodiment of the present invention is described, comprising: a PCB board 100, a plurality of metallized through holes 300 are opened on the PCB board 100, and the plurality of metallized through holes 300 are arranged in a rectangular array, and a microstrip line 400 is arranged on the top of the PCB board 100;

[0055] The filling medium 200 is filled in the metallized through holes 300 one by one, and the size of the filling medium 200 is calculated according to the following formula:

[0056] λ1=λ / (ε r ) 0.5

[0057] Where, λ1 is the diameter of the filling medium, mm;

[0058] λ is the transmission wavelength of the filling medium, mm;

[0059] ε r is the relative dielectric constant of the filling medium, unitless;

[0060] The transmission waveguide 700 is disposed at the lower portion of the PCB board 100 , and the microstrip line 400 is connected to the transmission waveguide 700 .

[0061] Specifically, a waveguide cavity is formed by the rectangular array of metallized through holes 300 of the PCB board 100 and the filling medium 200 to suppress the excitation of the higher-order modes of the electromagnetic wave and maintain the standard transmission mode (such as the TE10 mode). The connection between the microstrip line 400 at the top and the filling waveguide is ensured by adjusting the size and designing the probe structure to ensure impedance matching while reducing reflection losses. This structure uses the characteristics of dielectric filling to shorten the wavelength of the electromagnetic wave in the waveguide, thereby reducing the overall size of the waveguide. Compared with traditional metal waveguides, this structure achieves a significant improvement in signal transmission efficiency by optimizing the size of the filling medium 200 and the arrangement of the metallized through holes 300. Its design solves the problems of narrow frequency band and significant resonance effect in the prior art, effectively reduces system losses, and improves transmission stability.

[0062] Please continue to participate Figure 1-Figure 2 As shown, the filling medium 200 is made of Rogers RO3003 material, the PCB board 100 includes a plurality of PCB boards 100, and the plurality of PCB boards 100 are connected by pressing and bonding.

[0063] Specifically, Rogers RO3003 is a low-loss, stable high-frequency dielectric material with a dielectric constant of εr≈3 and a low loss tangent value (usually less than 0.001), which is very suitable for efficient transmission applications in the millimeter wave and terahertz bands. The multi-layer PCB board 100 connected by press bonding can reduce the attenuation of signals between layers and improve the mechanical strength and thermal stability of the overall structure.

[0064] It should be noted that by selecting Rogers RO3003 as the filling medium 200 material, the structure of the present invention has extremely low loss characteristics in the high frequency band, and the lamination process reduces the impact of interlayer errors on signal integrity, thereby improving the consistency and efficiency of production. In addition, the design is relatively low-cost in large-scale production and is suitable for commercial millimeter wave and terahertz communication systems.

[0065] The filling medium 200 may be made of other materials with excellent high-frequency performance, such as a ceramic-filled PTFE substrate, to further reduce losses; the pressing method may be changed to directly use a high-strength adhesive to simplify the process.

[0066] Please continue to see Figure 1-2 As shown, according to one embodiment of the present invention, the PCB board 100 includes:

[0067] A top plate 110, an inner plate 120 and a lower plate 130, wherein the top plate 110, the inner plate 120 and the lower plate 130 are arranged in sequence from top to bottom;

[0068] The microstrip line 400 is disposed on the top layer board 110 , and the transmission waveguide 700 is disposed on the bottom layer board 130 .

[0069] Specifically, the design of the multi-layer PCB board 100 separates the functional modules of the microstrip line 400 and the waveguide, thereby optimizing the performance of each part. The microstrip line 400 couples the electromagnetic wave signal to the waveguide cavity of the lower board 130 through the radiation probe 500 on the top, and the shielding design of the inner board 120 reduces the crosstalk between adjacent signals and improves the overall stability of the signal. The layered structure not only improves the transmission efficiency of the signal, but also provides a high degree of integration, so that the entire feeding structure can realize complex electromagnetic signal processing functions in a small size.

[0070] According to another embodiment of the present invention, the top layer board 110, the inner layer board 120 and the lower layer board 130 are pressed and bonded by Rogers RO3003 special PP.

[0071] Specifically, a special PP bonding material is used to bond the multi-layer PCB board 100 together through heating and high pressure processes. The low dielectric constant and low loss characteristics of the Rogers RO3003 PP layer further optimize the electrical performance of the overall structure, while the lamination process ensures the mechanical reliability between the board layers.

[0072] The professional bonding process achieves a low-loss, high-stability multi-layer structure, ensuring the consistency and reliability of millimeter-wave and terahertz signals during transmission. In addition, the PP lamination process greatly improves production efficiency and is suitable for large-scale production.

[0073] It is worth noting that the temperature and pressure parameters of the lamination process can be adjusted according to actual needs; the PP bonding material can be replaced by other materials with similar dielectric properties, such as polyimide film.

[0074] Please continue to see Figure 1 and Figure 2 As shown, according to another embodiment of the present invention, a radiation probe 500 is provided at one end of the microstrip line 400, and the radiation probe 500 is used to radiate and couple the electromagnetic waves in the microstrip line 400 into the filling medium 200 to achieve transitional transmission of signals.

[0075] Specifically, the design of the radiation probe 500 precisely adjusts its size and shape to enable it to play the role of energy conversion between the microstrip line 400 and the dielectric-filled waveguide. The probe converts the electromagnetic wave signal in the microstrip line 400 into the TE10 mode suitable for the waveguide, thereby achieving efficient coupling. The length, width and geometric shape of the probe tip need to be optimized through simulation to ensure that the radiation waveform matches the waveguide mode and reduce reflection loss.

[0076] It should be noted that the design of the radiation probe 500 significantly improves the signal conversion efficiency from the microstrip line 400 to the waveguide, while reducing the signal loss caused by electromagnetic wave reflection. The design is compact and suitable for high-frequency application scenarios in the millimeter wave and terahertz bands. The geometric shape of the radiation probe 500 can be changed to other forms, such as arc or pointed cone, to meet the optimization requirements of different frequency bands; the material of the probe can be selected from highly conductive materials, such as silver plating or aluminum, to further reduce conductive losses.

[0077] Please continue to see Figure 1-2 As shown, according to an optional embodiment of the present invention, it also includes:

[0078] The matching cavity 600 is disposed on the upper portion of the PCB board 100 . The matching cavity 600 is a metal-enclosed cavity. The matching cavity 600 is used to reduce the overall impedance of the microstrip-to-waveguide feeding structure.

[0079] Specifically, the matching cavity 600 adjusts the impedance matching by reflecting electromagnetic waves and interfering with the transmission waveform. The dimensions of the cavity (including length, width and height) directly affect the phase and amplitude of the reflected wave. By optimizing the cavity parameters, the standing wave phenomenon in the signal transition area is reduced, the reflection loss is further reduced, and the overall transmission efficiency is improved. The introduction of the matching cavity 600 effectively solves the impedance mismatch problem in the transition process from the microstrip line 400 to the waveguide, and significantly improves the efficiency and bandwidth performance of the feeding structure. At the same time, the metal closed cavity design provides additional electromagnetic shielding effect to prevent external interference signals.

[0080] Please continue to see Figure 1-2As shown, according to a further embodiment of the present invention, the transmission waveguide 700 includes:

[0081] A first waveguide 710, wherein the first waveguide 710 is connected to the lower plate 130;

[0082] The second waveguide 720 is vertically connected to the first waveguide 710 , and the second waveguide 720 is parallel to the lower plate 130 .

[0083] Specifically, the first waveguide 710 transmits the signal from the microstrip line 400 to the vertical direction, and the second waveguide 720 converts the vertically transmitted signal into horizontal transmission again, realizing a 90° turn in the signal direction. The seamless connection and size optimization of the two waveguides ensure the efficiency and integrity of signal energy transmission. At the same time, an internal step structure is set at the intersection of the two waveguides to suppress high-order mode excitation and reflected wave interference, further improving signal transmission performance.

[0084] This waveguide design effectively solves the problems of high loss and difficult direction change in traditional waveguide connections, with a short transmission path and high efficiency. The step structure at the intersection further reduces loss and inter-mode coupling, improving the reliability of the transmission system.

[0085] Please continue to see Figure 1 and Figure 2 As shown, in an optional manner of the present invention, both the first waveguide 710 and the second waveguide 720 are BJ1200 waveguides, and an internal step structure is formed at the intersection of the first waveguide 710 and the second waveguide 720 .

[0086] Specifically, the BJ1200 waveguide is a standardized design suitable for signal transmission in the terahertz band. The step structure at the intersection ensures efficient transmission of signals in the TE10 mode by suppressing unnecessary high-order mode fluctuations and electromagnetic wave leakage. The height and width of the step are determined by simulation calculation to achieve the best match and the lowest loss.

[0087] The BJ1200 waveguide standard design is adopted, which is easy to process and assemble and suitable for industrial production. The intersection step design further reduces signal reflection and inter-mode interference, and improves signal integrity and transmission efficiency.

[0088] See also Figure 3 The present invention also provides a debugging method for a microstrip to waveguide feeding structure, comprising:

[0089] Determining the dimensions of the transmission waveguide 700;

[0090] A simulation model of a debugging method of a microstrip to waveguide feeding structure is established according to the size of the transmission waveguide 700;

[0091] The solution parameters are set according to the use frequency of the feeding structure, and the distribution spacing of the filling medium 200 and the size of the matching cavity 600 are set;

[0092] According to the distribution spacing of the filling medium 200 and the size of the matching cavity 600 set in the set simulation model, the standing wave value S and the loss value P are determined;

[0093] If the standing wave value S ≥ -10dB or the loss value P ≤ -0.15dB, reset the spacing of the filling medium 200 and the size of the matching cavity 600, and return to the previous step to redetermine the standing wave value S and the loss value P;

[0094] If the standing wave value S is less than -10dB and the loss value P is greater than -0.15dB, the debugging is completed and the set value in step 3 is taken as the actual value.

[0095] Specifically, determine the size of the transmission waveguide 700. According to the target operating frequency band and design requirements, refer to the size specifications of standard waveguides (such as BJ1200 waveguides), and use formulas to calculate key size parameters such as the length and width of the waveguide to ensure that the waveguide can support the transmission of the main mode (such as TE10 mode) at the target frequency.

[0096] Use simulation software (such as HFSS, CST, etc.) to establish a complete microstrip to waveguide feeding structure simulation model based on the determined waveguide dimensions. The simulation model should include microstrip line 400, filling medium 200, metallized through hole 300, waveguide structure and matching cavity 600, and define material properties, boundary conditions and excitation methods.

[0097] Among them, the key parameters are set according to the target performance requirements to set the simulation parameters: the spacing of the filling medium 200: the arrangement density and aperture size of the metallized through-holes 300 should be optimized according to the electromagnetic shielding performance and impedance matching requirements of the waveguide. The size of the matching cavity 600: including the length, width and height of the cavity, is used to adjust the phase and amplitude of the reflected wave.

[0098] Probe structural parameters: length and shape of the microstrip probe to achieve optimal energy coupling.

[0099] By adjusting the spacing and aperture size of the filling medium 200 and the size of the matching cavity 600 through simulation, the changes in the standing wave ratio (S11) and the transmission loss (S21) are monitored in real time to ensure that: the standing wave ratio is less than -10 dB, indicating good impedance matching; the transmission loss is less than 0.15 dB, ensuring efficient signal transmission.

[0100] Parameter optimization and performance evaluation are performed through simulation software, and electromagnetic field simulation technology is used to accurately model and analyze the role and performance of each structure in the transition process from microstrip line 400 to waveguide. By adjusting the spacing of the filling medium 200 and the size of the matching cavity 600, the impedance matching is optimized, the reflection loss and the standing wave ratio are reduced, and the feeding structure is ensured to maintain efficient signal transmission performance in a wide frequency band. At the same time, multiple iterative simulations are used to further refine the design to achieve performance limit optimization.

[0101] This debugging method has the following beneficial effects:

[0102] 1. High efficiency and high precision: The systematic parameter debugging method significantly reduces the number of experiments, optimizes the design process, and ensures that the final design has excellent performance.

[0103] 2. Cost and time saving: Simulation debugging reduces material waste and time consumption in traditional physical experiments, greatly reducing R&D costs.

[0104] 3. Strong adaptability: The debugging method is applicable to a variety of working frequency bands and different waveguide structures. By adjusting the simulation model parameters, it can meet various application requirements in the millimeter wave and terahertz bands.

[0105] 4. Performance optimization: Through the dual optimization of standing wave ratio and transmission loss, ensure that the feeding structure maintains low-loss and high-efficiency signal transmission characteristics within the target frequency band.

[0106] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0107] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A millimeter wave terahertz microstrip to waveguide feeding structure, characterized in that: include: A PCB board, wherein the PCB board comprises a top board, an inner board and a lower board, wherein the top board, the inner board and the lower board are arranged in sequence from top to bottom, wherein a plurality of metallized through holes are provided on the PCB board, and the plurality of metallized through holes are arranged in a rectangular array, wherein a microstrip line is provided on the top board, and a transmission waveguide is provided on the lower board; A filling medium is filled in the metallized through holes one by one, and the size of the filling medium is calculated according to the following formula: λ1=λ / (ε r ) 0.5 Where λ1 is the diameter of the filling medium, mm; λ is the transmission wavelength of the filling medium, mm; ε r is the relative dielectric constant of the filling medium, unitless; Wherein, a radiation probe is provided at one end of the microstrip line, and the radiation probe is used to couple the electromagnetic wave radiation in the microstrip line into the filling medium; A transmission waveguide is arranged at the lower part of the PCB board, and the microstrip line is connected to the transmission waveguide.

2. The millimeter wave terahertz microstrip to waveguide feeding structure according to claim 1, characterized in that: The filling medium is made of Rogers RO3003 material, the PCB board includes multiple PCB boards, and the multiple PCB boards are connected by pressing and bonding.

3. The millimeter wave terahertz microstrip to waveguide feeding structure according to claim 1 or 2, characterized in that: The top layer board, the inner layer board and the lower layer board are pressed and bonded by Rogers RO3003 special PP.

4. The millimeter wave terahertz microstrip to waveguide feeding structure according to claim 1 or 2, characterized in that: Also includes: A matching cavity is provided on the upper part of the PCB board, the matching cavity is a metal-enclosed cavity, and the matching cavity is used to reduce the overall impedance of the microstrip to waveguide feeding structure.

5. The millimeter wave terahertz microstrip to waveguide feeding structure according to claim 4, characterized in that: The transmission waveguide comprises: a first waveguide connected to the lower plate; A second waveguide is vertically connected to the first waveguide and is parallel to the lower plate.

6. The millimeter wave terahertz microstrip to waveguide feeding structure according to claim 5, characterized in that: The first waveguide and the second waveguide are both BJ1200 waveguides, and an internal step structure is formed at the intersection of the first waveguide and the second waveguide.

7. A debugging method for a millimeter-wave terahertz microstrip to waveguide feeding structure as claimed in claim 1, characterized in that: include: Determine the dimensions of the transmission waveguide; A simulation model of the debugging method of the microstrip to waveguide feeding structure is established according to the size of the transmission waveguide; Set the solution parameters according to the use frequency of the feeding structure, set the distribution spacing of the filling medium and set the size of the matching cavity; According to the distribution spacing of the filling medium set in the set simulation model and the size of the matching cavity set, the standing wave value S and the loss value P are determined; If the standing wave value S ≥ -10dB or the loss value P ≤ -0.15dB, reset the spacing of the filling medium and the size of the matching cavity, and return to the previous step to redetermine the standing wave value S and the loss value P; If the standing wave value S is less than -10dB and the loss value P is greater than -0.15dB, the debugging is completed and the set value in step 3 is taken as the actual value.

Images