A high-frequency signal feeding structure design method and system based on microwave multilayer board

Abstract

The present invention provides a method and system for designing a high-frequency signal feed structure based on a microwave multilayer board. The method calculates the width of a microstrip transmission line based on a multilayer dielectric board with a preset thickness and dielectric constant. Based on the width of the microstrip transmission line, the dimensions of the slot above the metal stratum of the microstrip transmission line's reference stratum are determined according to matching criteria, thereby determining the dimensional parameters of the feed structure. Based on the dimensional parameters of the feed structure, the high-frequency signal feed structure is simulated and designed in electromagnetic field simulation software and optimized according to preset criteria. This invention solves the prior art problem that, when operating at frequencies above the X-band or with a wide operating bandwidth, the standing wave of the feed structure deteriorates, thereby affecting the performance of the entire functional circuit.

Description

Technical Field

[0001] The present invention relates to the field of microwave circuit design, and in particular to a method and system for designing a high-frequency signal feeding structure based on a microwave multilayer board. Background Art

[0002] With the trend toward miniaturization and integrated design of RF systems, multilayer dielectric board technology has been widely used in microwave circuit design. Microwave circuit design using multilayer dielectric boards enables the integrated design of analog and digital microwave circuits, as well as the embedded design of numerous microwave passive components such as power dividers, filters, and resistors. This significantly improves the integration level of RF systems and reduces their size and weight. Microwave circuit modules on multilayer dielectric boards are mostly interconnected with the outside world via RF connectors. The microwave signal transmission characteristics between the RF connectors and the multilayer dielectric board affect the standing wave level of the entire functional circuit, thereby affecting system performance indicators such as noise figure and passband flatness.

[0003] Traditional microwave circuit design typically employs a method where the signal is directly fed into a 50-ohm microstrip line with edge or bottom grounding. At low frequencies and narrow operating bandwidths, this feed structure's port standing wave (SWR) levels meet the microwave circuit's SWR requirements. However, when operating above the X-band or with a wide bandwidth, the SWR deteriorates, impacting the overall circuit performance. Therefore, a design method for high-frequency signal feed structures based on microwave multilayer boards is needed. Summary of the Invention

[0004] In view of this, an embodiment of the present invention provides a method for designing a high-frequency signal feed structure based on a microwave multilayer board to address the technical problem in the prior art that, when the operating frequency is above the X-band or the operating bandwidth is wide, the standing wave of the feed structure deteriorates, thereby affecting the performance of the entire functional circuit. The method includes:

[0005] Calculate the width of a microstrip transmission line based on a multilayer dielectric plate with a preset thickness and a preset dielectric constant;

[0006] According to the width of the microstrip transmission line, the size of the slot on the metal layer of the reference layer of the microstrip transmission line is determined according to the matching standard, thereby determining the size parameters of the feeding structure;

[0007] According to the dimensional parameters of the feeding structure, a simulation design of the high-frequency signal feeding structure is performed in electromagnetic field simulation software and optimized according to preset standards.

[0008] Furthermore, the matching criteria include: the width of the reference stratum groove is 4 times the width of the microstrip line, and the length is 1 / 4 wavelength.

[0009] Furthermore, the feeding structure includes:

[0010] a metal microstrip layer, the metal microstrip layer being located on top of the feed structure, the metal microstrip layer comprising a microstrip transmission line, a signal reference ground, and metallized through-holes, wherein two signal reference grounds are located on either side of the microstrip transmission line, respectively, and the metallized through-holes penetrate the feed structure by connecting the metal microstrip layer to the metal layer;

[0011] a dielectric layer, the dielectric layer being located below the metal microstrip layer;

[0012] The metal layer is a reference layer for the microstrip transmission line and is located below the dielectric layer. The metal layer includes slots and metalized through holes.

[0013] an adhesive layer, the adhesive layer being located at the lower end of the metal stratum and including metallized through holes;

[0014] The first metal layer, the second metal layer, the third metal layer, and the fourth metal layer are located at the lower end of the bonding layer, and all include metallized through holes and metallized vias. The metallized vias are blind holes that penetrate from the first metal layer to the fourth metal layer. A first dielectric layer is sandwiched between the first metal layer and the second metal layer, a second dielectric layer is sandwiched between the second metal layer and the third metal layer, and a third dielectric layer 10 is sandwiched between the third metal layer and the fourth metal layer.

[0015] Furthermore, the metal microstrip layer, the metal ground layer, the first metal layer, the second metal layer, the third metal layer, and the fourth metal layer are all copper-clad metal layers.

[0016] Furthermore, the dielectric layer is a Rogers 4350 dielectric board, and the first dielectric layer and the second dielectric layer are Rogers 6002 dielectric boards.

[0017] Furthermore, the adhesive layer and the second dielectric layer are both adhesive dielectric layers of the microwave multilayer dielectric plate.

[0018] Furthermore, a high-frequency signal feeding structure is simulated and designed in electromagnetic field simulation software based on the obtained dimensional parameters of the feeding structure, and the feeding structure is optimized to achieve a return loss within the operating frequency band of less than -20 dB (decibel).

[0019] The present invention also provides a high-frequency signal feed structure design system based on a microwave multilayer board to address the technical problem in the prior art that when the operating frequency is above the X-band or the operating bandwidth is wide, the standing wave of the feed structure will deteriorate, thereby affecting the performance of the entire functional circuit. The system includes:

[0020] A width acquisition module, the width acquisition module being used to calculate the width of the microstrip transmission line based on a multilayer dielectric plate of a preset thickness and a preset dielectric constant;

[0021] a parameter determination module, the parameter determination module being used to determine the size of a slot on a metal stratum of a reference stratum of the microstrip transmission line according to a matching standard based on the width of the microstrip transmission line, thereby determining the size parameters of the feeding structure;

[0022] A simulation design module is used to perform simulation design of a high-frequency signal feeding structure in electromagnetic field simulation software according to the dimensional parameters of the feeding structure and optimize it according to preset standards.

[0023] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above-mentioned technical solutions adopted in the embodiments of this specification include at least the following: By proposing a method for designing a high-frequency signal feeding structure based on a microwave multilayer board, the width of the microstrip transmission line is calculated according to a multilayer dielectric board with a preset thickness and a preset dielectric constant; according to the width of the microstrip transmission line, the size of the slot above the metal stratum of the reference stratum of the microstrip transmission line is determined according to the matching standard, thereby determining the size parameters of the feeding structure; according to the size parameters of the feeding structure, a simulation design of the high-frequency signal feeding structure is performed in the electromagnetic field simulation software and optimized according to the preset standards. The present invention achieves good standing wave performance of the high-frequency signal fed into the microwave multilayer board through the matching design of the reference stratum for signal transmission at the port of the microwave multilayer board, thereby reducing the technical effect of the influence of the port standing wave level on the function of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0025] Figure 1 This is a schematic diagram of the side structure of a microwave multilayer board provided by an embodiment of the present invention;

[0026] Figure 2 is a three-dimensional schematic diagram of a feeding structure provided by an embodiment of the present invention;

[0027] Figure 3 1 is a schematic structural diagram of a metal microstrip line layer provided in an embodiment of the present invention;

[0028] Figure 4 A schematic diagram of the structure of the feed structure matching the metal stratum provided in an embodiment of the present invention;

[0029] Figure 5 A schematic structural diagram of other metal layers provided in an embodiment of the present invention;

[0030] Figure 6 A test return loss curve diagram provided by an embodiment of the present invention;

[0031] Figure 7 A schematic structural diagram of a high-frequency signal feeding structure design system based on a microwave multilayer board provided in an embodiment of the present invention.

[0032] The reference numerals in the figure are: 1. metal microstrip layer; 2. dielectric layer; 3. metal ground layer; 4. bonding layer; 5. first metal layer; 6. first dielectric layer; 7. second metal layer; 8. second dielectric layer; 9. third metal layer; 10. third dielectric layer; 11. fourth metal layer; 12. metallized through hole; 13. metallized via; 14. microstrip transmission line; 16. signal reference ground; 17. slot; 700. system; 701. width acquisition module; 702. parameter determination module; 703. simulation design module. DETAILED DESCRIPTION

[0033] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0034] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the features in the following embodiments and embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of this application.

[0035] In the embodiment of the present invention, Figure 1 As shown, a method for designing a high-frequency signal feeding structure based on a microwave multilayer board is provided, characterized in that the method includes: step S100: calculating the width of a microstrip transmission line 14 based on a multilayer dielectric board with a preset thickness and a preset dielectric constant; step S200: determining the size of a slot 17 on a reference stratum metal layer 3 of the microstrip transmission line 14 according to a matching standard based on the width of the microstrip transmission line 14, thereby determining the size parameters of the feeding structure; step S300: performing a simulation design of the high-frequency signal feeding structure in an electromagnetic field simulation software based on the size parameters of the feeding structure and optimizing it according to preset standards.

[0036] The present invention proposes a method for designing a high-frequency signal feed structure based on a microwave multilayer board. The method calculates the width of a microstrip transmission line based on a multilayer dielectric board with a preset thickness and a preset dielectric constant. Based on the width of the microstrip transmission line, the dimensions of a slot above a metal stratum of the microstrip transmission line's reference stratum are determined according to matching criteria, thereby determining the dimensional parameters of the feed structure. Based on the dimensional parameters of the feed structure, a simulation design of the high-frequency signal feed structure is performed in electromagnetic field simulation software and optimized according to preset criteria. By matching the reference stratum for signal transmission at the ports of the microwave multilayer board, the present invention achieves excellent standing wave performance for high-frequency signals fed into the microwave multilayer board, thereby reducing the impact of the port standing wave level on the overall system function.

[0037] like Figure 1 and Figure 2 As shown, the first embodiment of the present invention specifically includes the following steps:

[0038] Step S100: Calculating the width of the microstrip transmission line 14 based on a multilayer dielectric plate with a preset thickness and a preset dielectric constant;

[0039] Step S200: determining the size of the slot 17 on the reference metal layer 3 of the microstrip transmission line 14 according to the width of the microstrip transmission line 14 and the matching standard, thereby determining the size parameters of the feeding structure;

[0040] Step S300: performing simulation design of a high-frequency signal feeding structure in electromagnetic field simulation software according to the size parameters of the feeding structure and optimizing the structure according to preset standards.

[0041] Furthermore, the matching criteria include: the width of the reference stratum groove is 4 times the width of the microstrip line, and the length is 1 / 4 wavelength.

[0042] Furthermore, a high-frequency signal feeding structure is simulated and designed in electromagnetic field simulation software based on the obtained dimensional parameters of the feeding structure, and the feeding structure is optimized to achieve a return loss of less than -20 dB within the frequency band used.

[0043] Specifically, based on the selected multilayer dielectric board with a specific thickness and dielectric constant, the width of the 50-ohm microstrip line and the size of the signal transmission reference layer matching structure are calculated. The specific method is to open a slot 17 on the metal layer 3, which is a specific reference layer of the microstrip line. The width of the slot is about 4 times the width of the microstrip line and the length is about 1 / 4 wavelength. The characteristic impedance Z0 of the microstrip transmission line is calculated as shown in the following formula (1). The effective dielectric constant Ɛ of the microstrip transmission line is eff The calculation method is shown in the following formula (2):

[0044] (1)

[0045] (2)

[0046] In formula (1) and formula (2), Ɛr is the dielectric constant of the microstrip dielectric plate, h is the thickness of the microstrip dielectric plate, and Z f is the wave impedance constant, and w is the microstrip line width.

[0047] After calculating the specific dimensions of the feed structure using the above formula, a high-frequency signal feed structure is simulated and designed using electromagnetic field simulation software based on the obtained feed structure dimensional parameters. The feed structure is optimized to achieve a return loss of less than -20dB (decibels) within the operating frequency band. The resulting feed structure is then imported into a drafting design, and the fabrication, welding, and testing steps are completed to complete the design. This invention achieves good standing wave performance for high-frequency signal feeding into a microwave multilayer board, thereby reducing the impact of the port standing wave level on the overall system function.

[0048] Further, such as Figure 1 and Figure 2 As shown, the feeding structure includes: a metal microstrip layer 1, the metal microstrip layer 1 is located on the top of the feeding structure, and the metal microstrip layer 1 includes a microstrip transmission line 14, a signal reference ground 16 and a metallized through hole 12, as shown in FIG. Figure 3 As shown, two signal reference grounds 16 are located on both sides of the microstrip transmission line 14, and the metallized through-hole 12 penetrates the feeding structure by connecting the metal microstrip layer 1 to the metal layer 11; the dielectric layer 2 is located below the metal microstrip layer 1; the metal ground layer 3 is the reference ground layer of the microstrip transmission line 14, located below the dielectric layer 2, and the metal ground layer includes a slot 17 and a metallized through-hole 12, as shown in FIG. Figure 4 As shown; bonding layer 4, bonding layer 4 is located at the lower end of the metal layer 3, including metallized through-holes 12; the first metal layer 5, the second metal layer 7, the third metal layer 9, and the fourth metal layer 11 are located at the lower end of the bonding layer 4, each including metallized through-holes 12 and metallized vias 13, as shown Figure 5 As shown, the metallized via 13 is a blind hole that passes through the first metal layer 5 to the fourth metal layer 11, wherein a first dielectric layer 6 is sandwiched between the first metal layer 5 and the second metal layer 7, a second dielectric layer 8 is sandwiched between the second metal layer 7 and the third metal layer 9, and a third dielectric layer 10 is sandwiched between the third metal layer 9 and the fourth metal layer 11.

[0049] Furthermore, the metal microstrip layer 1 , the metal ground layer 3 , the first metal layer 5 , the second metal layer 7 , the third metal layer 9 , and the fourth metal layer 11 are all copper-clad metal layers.

[0050] Preferably, the dielectric layer 2 is a Rogers 4350 dielectric plate with a thickness of 0.168 mm; the first dielectric layer 6 and the second dielectric layer 8 are Rogers 6002 dielectric plates with a thickness of 0.254 mm.

[0051] Preferably, the adhesive layer 4 and the second dielectric layer 8 are both adhesive dielectric layers of a microwave multilayer dielectric plate, and have a thickness of 0.1 mm.

[0052] Furthermore, if Figure 6 As shown, Figure 6 This paper describes a test return loss curve for an embodiment of the design method for a high-frequency signal feed structure based on a microwave multilayer board, demonstrating the structure's standing wave (SW) level. The horizontal axis (freq, GHz) represents the frequency range, while the vertical axis shows the return loss amplitude (dB(S1.1)). The figure shows that the feed structure employing the design method maintains a return loss below -15dB for most frequencies below the Ku-band, achieving excellent SW matching.

[0053] Based on the same inventive concept, an embodiment of the present invention also provides a high-frequency signal feeding structure design system based on a microwave multilayer board, as described in the following embodiments. Since the principle of solving the problem by a high-frequency signal feeding structure design system based on a microwave multilayer board is similar to that of a high-frequency signal feeding structure design method based on a microwave multilayer board, the implementation of a high-frequency signal feeding structure design system based on a microwave multilayer board can refer to the implementation of a high-frequency signal feeding structure design method based on a microwave multilayer board, and the repeated parts will not be repeated. As used below, the term "unit" or "module" can be a combination of software and / or hardware that implements a predetermined function. Although the system described in the following embodiments is preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and conceivable.

[0054] like Figure 7 As shown, it is a structural block diagram of a high-frequency signal feeding structure design system 700 based on a microwave multilayer board according to an embodiment of the present invention, including: a width acquisition module 701, the width acquisition module 701 is used to calculate the width of the microstrip transmission line 14 according to a multilayer dielectric board with a preset thickness and a preset dielectric constant; a parameter determination module 702, the parameter determination module 702 is used to determine the size of the slot 17 on the reference stratum metal layer 3 of the microstrip transmission line 14 according to the matching standard based on the width of the microstrip transmission line 14, thereby determining the size parameters of the feeding structure; a simulation design module 703, the simulation design module 703 is used to perform simulation design of the high-frequency signal feeding structure in electromagnetic field simulation software according to the size parameters of the feeding structure and optimize it according to preset standards.

[0055] The embodiments of the present invention achieve the following technical effects:

[0056] The present invention proposes a design method for a high-frequency signal feeding structure based on a microwave multilayer dielectric plate, which matches the reference stratum for high-frequency signal transmission. It has a simple structure and does not increase the size of the circuit layout. It achieves good matching of the port standing wave of the microwave signal in the frequency range of DC-18GHz, and is particularly suitable for the development of radio frequency modules with large bandwidth and high operating frequency. The design method has good versatility and is applicable to the design of high-frequency signal feeding structures for multilayer dielectric plates with different dielectric constants and thicknesses. The invention can be widely used in microwave circuit design, including communication systems, radar systems, electronic warfare systems, etc., and is easy to mass-produce. The above is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the embodiments of the present invention may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for designing a high-frequency signal feeding structure based on a microwave multilayer board, characterized in that: The method comprises: Calculating the width of a microstrip transmission line (14) based on a multilayer dielectric plate with a preset thickness and a preset dielectric constant; According to the width of the microstrip transmission line (14), the size of the slot (17) on the metal layer (3) of the microstrip transmission line (14) is determined according to a matching standard, thereby determining the size parameters of the feeding structure; Perform simulation design of the high-frequency signal feeding structure in electromagnetic field simulation software according to the dimensional parameters of the feeding structure and optimize it according to preset standards; Wherein, the feeding structure includes: A metal microstrip layer (1), the metal microstrip layer (1) is located on the top of the feed structure, the metal microstrip layer (1) includes a microstrip transmission line (14), a signal reference ground (16), and a metallized through hole (12), the two signal reference grounds (16) are respectively located on both sides of the microstrip transmission line (14), and the metallized through hole (12) passes through the feed structure by connecting the metal microstrip layer (1) to the metal layer (11); a dielectric layer (2), the dielectric layer (2) being located below the metal microstrip layer (1); A metal layer (3), which is a reference layer of the microstrip transmission line (14) and is located below the dielectric layer (2), and includes a slot (17) and a metalized through hole (12); An adhesive layer (4), the adhesive layer (4) is located at the lower end of the metal layer (3) and includes a metallized through hole (12); The first metal layer (5), the second metal layer (7), the third metal layer (9), and the fourth metal layer (11) are located at the lower end of the bonding layer (4), and each includes a metallized through hole (12) and a metallized via hole (13). The metallized via hole (13) is a blind hole that passes through the first metal layer (5) to the fourth metal layer (11). A first dielectric layer (6) is sandwiched between the first metal layer (5) and the second metal layer (7), a second dielectric layer (8) is sandwiched between the second metal layer (7) and the third metal layer (9), and a third dielectric layer (10) is sandwiched between the third metal layer (9) and the fourth metal layer (11).

2. The method for designing a high-frequency signal feeding structure based on a microwave multilayer board according to claim 1, characterized in that: The matching standard includes: the width of the slot of the metal layer (3) is 4 times the width of the microstrip transmission line, and the length is 1 / 4 wavelength.

3. The method for designing a high-frequency signal feeding structure based on a microwave multilayer board according to claim 1, characterized in that: The metal microstrip layer (1), the metal ground layer (3), the first metal layer (5), the second metal layer (7), the third metal layer (9), and the fourth metal layer (11) are all copper-clad metal layers.

4. The method for designing a high-frequency signal feeding structure based on a microwave multilayer board according to claim 1, characterized in that: The dielectric layer (2) is a Rogers 4350 dielectric plate, and the first dielectric layer (6) and the second dielectric layer (8) are Rogers 6002 dielectric plates.

5. The method for designing a high-frequency signal feeding structure based on a microwave multilayer board according to claim 1, characterized in that: The adhesive layer (4) and the second dielectric layer (8) are both adhesive dielectric layers of a microwave multilayer dielectric plate.

6. The method for designing a high-frequency signal feeding structure based on a microwave multilayer board according to claim 1, characterized in that: According to the obtained dimensional parameters of the feeding structure, a simulation design of the high-frequency signal feeding structure is performed in electromagnetic field simulation software, and the feeding structure is optimized to achieve a return loss within the operating frequency band lower than -20 dB.

7. A high-frequency signal feeding structure design system based on microwave multilayer board, characterized in that: Based on the high-frequency signal feeding structure design method according to any one of claims 1 to 6, the system includes: A width acquisition module, the width acquisition module being used to calculate the width of a microstrip transmission line (14) based on a multilayer dielectric plate of a preset thickness and a preset dielectric constant; A parameter determination module, the parameter determination module is used to determine the size of the slot (17) on the metal layer (3) of the microstrip transmission line (14) according to the width of the microstrip transmission line (14) and the matching standard, thereby determining the size parameters of the feed structure; A simulation design module is used to perform simulation design of a high-frequency signal feeding structure in electromagnetic field simulation software according to the dimensional parameters of the feeding structure and optimize it according to preset standards.

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