A Design Method of Broadband Power Divider Based on Air Suspended Stripline

Abstract

The present invention discloses a design method for a broadband power divider based on an air-suspended strip line. The method is as follows: Step 1: Determine the cross-sectional width and thickness dimensions of the air-suspended strip line according to the requirements of the system structure size; Step 2: Select the strip line width K and the strip line width K1 so that the port impedance is 50 ohms or the required impedance value; Step 3: Connect the strip line port P1 to the port P2 through a PCB copper-clad wire with a strip line width of K1, and the line width of the metal copper-clad wire is the strip line width K1; Step 4: The copper-clad wire of the strip line port P3 is etched on the other side of the PCB, and the non-overlapping part has a line width of the strip line width K1. The beneficial effects of the present invention are: Based on the suspended strip line structure, a broadband high-power-division ratio power divider is realized through short stub coupling; the optimized design is obtained by optimizing parameters with the help of electromagnetic simulation software; the use of electromagnetic simulation software can greatly shorten the R & D cycle, save costs, and has good practical value.

Description

Technical Field

[0001] The present invention belongs to the technical field of broadband power dividers, and particularly relates to a design method of a broadband power divider based on air-suspended stripline. Background Art

[0002] A power divider, abbreviated as a power splitter, is an important microwave passive device; power dividers are widely used in the field of wireless communication, mainly including aspects such as microwave power amplification and linearization circuits; a power splitter can divide an input signal into two or more output signals with equal or unequal amounts, or conversely, combine multiple signals into one output.

[0003] In the mid-1950s to the 1960s, the world's first power splitter, called the Wilkinson power splitter, was proposed, which uses the impedance transformation characteristics of a quarter-wavelength transmission line to achieve; with the rapid development of communication technology and the intensification of competition in the communication industry, new requirements have been put forward for the performance of the Wilkinson power splitter; the traditional Wilkinson power splitter can only work at a single frequency band and its odd harmonics, and can no longer meet the requirements of dual-band, multi-band, and broadband in modern wireless communication; the development trend of power dividers is small size, high power handling capacity, wide frequency band, small distribution loss, small insertion loss, good voltage standing wave ratio, and isolation; however, in some special occasions, the requirements for power dividers are also getting higher and higher.

[0004] With the rapid development of modern electronic technology, in an electronic system, whether it is a receiving or transmitting system, broadband devices are needed to meet the requirements of signal bandwidth; a broadband power divider is an important passive device in a microwave radio frequency circuit, especially meeting the requirements of the development of high-efficiency high-power amplifiers, and has significance in civil and military applications.

[0005] The suspended stripline structure not only has the characteristics of small transmission loss, weak dispersion characteristics, wide frequency band, and loose manufacturing tolerance requirements, but can also be used to design broadband inverters, meeting the design requirements of wide frequency band and high isolation for power dividers in practical applications.

[0006] Currently, using a suspended stripline network as the feeding network of an antenna array has the characteristics of small loss and compact structure; however, conventional broadband high-power-division-ratio power dividers usually use multiple impedance transformation sections to achieve, and often have a relatively large size. Summary of the Invention

[0007] The purpose of the present invention is to provide a design method of a broadband power divider based on air-suspended stripline, and to achieve a broadband high-power-division-ratio power divider through short stub coupling.

[0008] To achieve the above object, the present invention provides the following technical solution: A design method of a broadband power divider based on air-suspended stripline, the method is as follows:

[0009] Step 1: Determine the cross-sectional width and thickness dimensions of the air suspension strip line according to the system structure size requirements;

[0010] Step 2: Select the strip line width K and strip line width K1 so that the port impedance is 50 ohms or the required impedance value;

[0011] Step 3: Connect the strip line port P1 to the port P2 through a PCB copper clad wire with a strip line width of K1, and the width of the metal copper clad wire is the strip line width K1;

[0012] Step 4: Etch the copper clad wire of the strip line port P3 on the other side of the PCB, and the non-overlapping part has a line width of the strip line width K1;

[0013] Step 5: The overlapping part of the strip line port P3 and the strip line ports P1 and P2 has a line width of the strip line width K2, a line length of L2, and is offset from the center by Dx and Dy;

[0014] Step 6: Calculate the operating wavelength of the operating frequency in the suspension strip line as λ, and the value of L2 is taken as λ / 4;

[0015] Step 7: The strip line width K2 and the eccentricity distance Dx of the strip line port P3 determine the amount of energy transmitted from the strip line port P1 to the strip line port P3; by optimizing the design, appropriate strip line width K2 and eccentricity distance Dx are obtained, so that the energy of the corresponding port of the strip line 1 can be reasonably distributed to the corresponding ports of the strip line 2 and the strip line 3;

[0016] Step 8: Cut the right angle at the connection of the strip line 1 and the strip line 2 to adjust the impedance matching characteristics of the corresponding port of the strip line 1.

[0017] As a preferred technical solution of the present invention, in the step 6, the dielectric constant of the dielectric plate is , the operating frequency is f, and the wavelength corresponding to the operating frequency of the suspension strip line is λ.

[0018] As a preferred technical solution of the present invention, in the step 7, when the strip line width K2 is increased, the frequency bandwidth can be increased and the power division ratio can be reduced; when Dx increases, the power distribution ratio of the strip line 2 and the strip line 3 can be increased.

[0019] As a preferred technical solution of the present invention, in the step 7, the optimization design is obtained by optimizing the parameters with the help of electromagnetic simulation software; using electromagnetic simulation software can greatly shorten the R & D cycle, save costs, and has good practical value.

[0020] As a preferred technical solution of the present invention, the optimization design is as follows: construct a model using electromagnetic simulation software to achieve the analysis of the "field"; design a matching circuit using circuit simulation software to achieve the calculation of the "circuit"; then use the optimization algorithm program in the numerical calculation software to call the electromagnetic simulation software and the circuit simulation software respectively to iteratively calculate the optimal values.

[0021] As a preferred technical solution of the present invention, in step eight, when the strip line 1 and the strip line 2 are interconnected at a right angle and it is necessary to match the total port standing wave, the right angle at the connection of the strip line 1 and the strip line 2 can be chamfered. The chamfer is a right triangle, and the two right sides of the right triangle respectively correspond to the strip line 1 and the strip line 2.

[0022] As a preferred technical solution of the present invention, the length of the right side corresponding to the strip line 1 is half of the width of the strip line 1, and the length of the right side corresponding to the strip line 2 is half of the width of the strip line 2.

[0023] As a preferred technical solution of the present invention, it also includes testing the operating frequency band, insertion loss, return loss, and isolation of the power divider. The instrument used for testing is a vector network analyzer.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. Based on the suspended strip line structure, a broadband high-power-division-ratio power divider is realized through short stub coupling;

[0026] 2. The optimization design is obtained by optimizing parameters with the help of electromagnetic simulation software; using electromagnetic simulation software can greatly shorten the R & D cycle, save costs, and has good practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of a T-shaped power divider based on an air-suspended strip line of the present invention;

[0028] Figure 2 It is an internal circuit diagram of a T-shaped power divider based on an air-suspended strip line of the present invention;

[0029] Figure 3 It is a schematic size diagram of a T-shaped power divider based on an air-suspended strip line of the present invention;

[0030] Figure 4 It is a schematic diagram of chamfer matching of a T-shaped power divider based on an air-suspended strip line of the present invention;

[0031] Figure 5 It is a schematic diagram of the power division ratio of the power division port of the present invention;

[0032] Figure 6 It is a schematic diagram of the total port voltage standing wave ratio of the present invention;

[0033] Figure 7 Schematic diagram of multi - level dimensions of the T - type power divider based on air - suspended stripline of the present invention;

[0034] Figure 8 Flow chart of the design method of the present invention. Specific embodiments

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0036] Embodiment 1

[0037] Please refer to Figures 1 - 8 , which is the first embodiment of the present invention. This embodiment provides a design method for a broadband power divider based on air - suspended stripline, and the method is as follows:

[0038] Step 1: Determine the cross - sectional width and thickness dimensions of the air - suspended stripline according to the system structure size requirements;

[0039] Step 2: Select the stripline width K and stripline width K1 so that the port impedance is 50 ohms or the required impedance value;

[0040] Step 3: Connect the stripline port P1 to the port P2 through a PCB copper - clad wire with a width of K1, and the width of the metal copper - clad wire is the stripline width K1;

[0041] Step 4: Etch the copper - clad wire of the stripline port P3 on the other side of the PCB, and the width of the non - overlapping part is the stripline width K1;

[0042] Step 5: The width of the overlapping part between the stripline port P3 and the stripline ports P1 and P2 is the stripline width K2, the line length is L2, and it deviates from the center by Dx and Dy;

[0043] Step 6: Calculate that the operating wavelength in the suspended stripline at the operating frequency is λ, and the value of L2 is taken as λ / 4; the relative permittivity of the dielectric substrate is , then the equivalent relative permittivity of the suspended stripline is , , the operating frequency is f, and the speed of light is , then the wavelength corresponding to the operating frequency of the suspended stripline ;

[0044] Step 7: The strip width K2 and the eccentricity distance Dx of the strip port P3 determine the amount of energy transmitted from the strip port P1 to the strip port P3. By optimizing the design, appropriate strip width K2 and eccentricity distance Dx are obtained, so that the energy of the corresponding port of strip 1 can be reasonably distributed to the corresponding ports of strip 2 and strip 3. When the strip width K2 is increased, the frequency bandwidth can be increased and the power division ratio can be reduced. When Dx increases, the power distribution ratio of strip 2 and strip 3 can be increased. The optimization design is obtained by optimizing parameters with electromagnetic simulation software. Using electromagnetic simulation software can greatly shorten the R & D cycle, save costs, and has good practical value.

[0045] Step 8: Cut the right angle at the connection of strip 1 and strip 2 to adjust the impedance matching characteristics of the corresponding port of strip 1. When strip 1 and strip 2 are interconnected at a right angle and the standing wave of the total port needs to be matched, the right angle at the connection of strip 1 and strip 2 can be chamfered. The chamfer is a right triangle, and the two right sides of the right triangle correspond to strip 1 and strip 2 respectively. The length of the right side corresponding to strip 1 is half of the width of strip 1, and the length of the right side corresponding to strip 2 is half of the width of strip 2.

[0046] Embodiment 2

[0047] Please refer to Figures 1 - 8 , which is the second embodiment of the present invention. This embodiment is based on the previous embodiment. The difference is:

[0048] The optimization design is as follows: Use electromagnetic simulation software to build a model to realize the analysis of "field". Use circuit simulation software to design a matching circuit to realize the calculation of "circuit". Then use the optimization algorithm program in the numerical calculation software to call the electromagnetic simulation software and the circuit simulation software respectively to iteratively calculate the optimal values.

[0049] It also includes the tests on the working frequency band, insertion loss, return loss, and isolation of the power divider. The instrument used for the test is a vector network analyzer.

[0050] Although the embodiments of the present invention have been shown and described, as detailed in the above description, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A design method for a broadband power divider based on an air suspension strip line, characterized in that: The method is as follows: Step 1: Determine the cross-sectional width and thickness dimensions of the air suspension strip line according to the system structure size requirements; Step 2: Select the strip line width K and strip line width K1 so that the port impedance is 50 ohms or the required impedance value; Step 3: Connect the strip line port P1 to the port P2 through the PCB copper-clad wire with the strip line width K1, and the width of the metal copper-clad wire is the strip line width K1; Step 4: The copper-clad wire of the strip line port P3 is etched on the other side of the PCB, and the non-overlapping part has a line width of the strip line width K1; Step 5: The overlapping part of the strip line port P3 and the strip line ports P1 and P2 has a line width of the strip line width K2 and a line length of L2, and is offset from the center by Dx and Dy; Step 6: Calculate the operating wavelength of the operating frequency in the suspension strip line as λ, and the value of L2 is taken as λ / 4; Step 7: The strip line width K2 and the eccentricity distance Dx of the strip line port P3 determine the magnitude of the energy transmitted from the strip line port P1 to the strip line port P3; By optimizing the design, the appropriate strip line width K2 and eccentricity distance Dx are obtained, so that the energy of the corresponding port of the strip line 1 can be reasonably distributed to the corresponding ports of the strip line 2 and the strip line 3; Step 8: Cut the right angle at the connection of the strip line 1 and the strip line 2 to adjust the impedance matching characteristics of the corresponding port of the strip line 1.

2. The design method of a broadband power divider based on an air suspension strip line according to claim 1, characterized in that: In the sixth step, the dielectric constant of the dielectric substrate is , the operating frequency is f, and the wavelength corresponding to the operating frequency of the suspended stripline is λ.

3. A design method for a broadband power divider based on an air suspension strip line according to claim 1, characterized in that: In the above Step 7, when the strip line width K2 is increased, the frequency bandwidth can be increased and the power division ratio can be reduced; when Dx increases, the power distribution ratio of the strip line 2 and the strip line 3 can be increased.

4. A design method for a broadband power divider based on an air suspension strip line according to claim 1, characterized in that: In the above Step 7, the optimized design is obtained by optimizing the parameters with the electromagnetic simulation software.

5. A design method for a broadband power divider based on an air suspension strip line according to claim 4, characterized in that: The above optimized design is as follows: Use the electromagnetic simulation software to build a model to realize the analysis of the "field"; Use the circuit simulation software to design the matching circuit to realize the calculation of the "circuit"; Then use the optimization algorithm program in the numerical calculation software to call the electromagnetic simulation software and the circuit simulation software respectively to iteratively calculate the optimal values.

6. A design method of a broadband power divider based on an air suspension strip line according to claim 1, characterized in that: In the above Step 8, when the strip line 1 and the strip line 2 are interconnected at a right angle and the standing wave of the total port needs to be matched, the right angle at the connection of the strip line 1 and the strip line 2 can be chamfered. The chamfer is a right triangle, and the two right sides of the right triangle correspond to the strip line 1 and the strip line 2 respectively.

7. A design method of a broadband power divider based on an air suspension strip line according to claim 6, characterized in that: The length of the right side corresponding to the strip line 1 is half of the width of the strip line 1, and the length of the right side corresponding to the strip line 2 is half of the width of the strip line 2.

8. A design method of a broadband power divider based on an air suspension strip line according to claim 1, characterized in that: It also includes the tests on the operating frequency band, insertion loss, return loss, and isolation of the power divider. The instrument used for the test is a vector network analyzer.

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