TW201838243A - Arbitrary output power ratio branch-line coupler having fixed transmission line characteristic impedance value applicable to microwave systems of different center frequencies through changing the electrical length and capacitance of the grounding capacitor - Google Patents

Abstract

The present invention is an arbitrary output power ratio branch-line coupler having a fixed transmission line characteristic impedance value, which comprises a transmission line group overlaid on a substrate, the transmission line group includes a first transmission line, a second transmission line, a third transmission line and a fourth transmission line. The two ends of the first transmission line have a first extension portion and a second extension portion. The third transmission line has a third extension portion and a fourth extension portion. Each of the four inner corners of the transmission line group having a rectangular connection with each other is respectively provided with a ground block, and each of the ground blocks is electrically connected to a capacitor; wherein, a trapezoidal fifth extension portion is formed from the first transmission line to extend upward to the upper edge of the first extension portion. A trapezoidal sixth extension portion is formed from the first transmission line to extend upward to the upper edge of the second extension portion. A trapezoidal seventh extension portion is formed from the third transmission line to extend downward to the lower edge of the third extension portion. A trapezoidal eighth extension portion is formed from the third transmission line to extend downward to the lower edge of the fourth extension portion, so that the output power of the branch-line coupler reaches an arbitrary ratio of output power, and is applicable to microwave systems of different center frequencies.

Description

   Fixed output line characteristic impedance value arbitrary output ratio branch coupler   

The invention relates to a branch coupler with fixed output line characteristic impedance value and arbitrary output ratio, especially a branch coupler which can make the output power of the branch coupler reach any ratio of output power and is applicable to microwave systems with different center frequencies. technology.

With the continuous evolution of technology, in recent years, digital communication systems have become an indispensable part of modern life. In order to meet the needs of consumers, today's communications are developing in the direction of high efficiency, thinness and shortness, easy production and low cost. Wireless communication has become a modern development trend. Whether it is a digital television system, a global satellite system, or a mobile phone communication system, people's lives are inseparable from the transmission of wireless information, and the branch coupler also plays a role in the above system. An important role, therefore, how to make a branch coupler with a new circuit architecture is indeed a key technical issue of concern to the industry, government, and academic circles.

Furthermore, branch couplers (such as reference [1-2]) are used in microwave and RF circuits for power distribution (such as reference [3-4]) or as part of an antenna array (such as reference [5]). In order to enable more flexible use in communication systems, the function of adjusting the output power ratio has become an important advantage for the development of radio frequency components. The traditional branch coupler is composed of four quarter-wavelength transmission lines. The output power ratio of the circuit output port | S21 | and the coupling port | S31 | is determined by the impedance of the transmission line. The two output signals are 90 degrees out of phase. Moreover, the two ports of | S11 | and | S41 | can reach below -15dB; however, designing the coupler in this way will cause the situation of too large size and the output power ratio cannot be converted. Use inductors or capacitors (such as reference [6]) It can reduce the size and achieve the conversion ratio. Therefore, how to develop a microwave system branch coupler technology that can make the output power of the branch coupler reach any ratio of output power has become an urgent need for related industries. Technical issues to be solved and challenged.

According to the current knowledge, no patent or paper has been proposed to enable the output power of the branch coupler to achieve an arbitrary ratio of output power. Based on the urgent needs of the electronics industry, the creators of the present invention have made continuous efforts to develop As a result, a set of technical concepts different from the above-mentioned documents has finally been developed.

The main purpose of the present invention is to provide a branch coupler with a fixed transmission line characteristic impedance value and an arbitrary output ratio. The four transmission lines of the circuit are all based on a given characteristic impedance value, and by changing the electrical length of the transmission line and the ground capacitance The capacitance value enables the output power of the branch coupler to reach any ratio. Therefore, the circuit structure is indeed applicable to microwave systems with different center frequencies. Therefore, the circuit is highly supportive, easy to manufacture, and can greatly reduce system construction and expenditure costs. Features. The technical means adopted to achieve the above purpose includes a transmission line group covering a substrate, and the transmission line group includes a first transmission line, a second transmission line, a third transmission line, and a fourth transmission line. The two ends of the first transmission line have a first extension section and a second extension section. The third transmission line has a third extension and a fourth extension. The four inner corners of the transmission line group connected in a rectangular shape are each provided with a ground block, and each ground block is electrically connected to a capacitor; wherein, the upper edge of the first transmission line to the first extension section extends upward with a trapezoidal section. Five extensions. A sixth extension section extending trapezoidally extends from the first transmission line to the upper edge of the second extension section. A seventh extension section extending trapezoidally extends from the lower edge of the third transmission line to the third extension section. An eighth extension having a trapezoidal shape extends downward from the lower edge of the third transmission line to the fourth extension.

10‧‧‧ substrate

20‧‧‧ Transmission line group

21‧‧‧The first transmission line

210‧‧‧first extension

211‧‧‧second extension

212‧‧‧Fifth extension

212a‧‧‧First beveled edge

213‧‧‧Sixth Extension

213a‧‧‧Second beveled edge

22‧‧‧Second transmission line

23‧‧‧Third transmission line

230‧‧‧ Third Extension

231‧‧‧Fourth Extension

232‧‧‧Seventh extension

232a‧‧‧ Third beveled edge

233‧‧‧eighth extension

233a‧‧‧Fourth beveled edge

234‧‧‧9th extension

234a‧‧‧Fifth beveled edge

235‧‧‧tenth extension

235a‧‧‧Sixth beveled edge

24‧‧‧ Fourth Transmission Line

25‧‧‧Inner corner

30‧‧‧ Ground Block

40‧‧‧input port

41‧‧‧Output port

42‧‧‧Coupling Port

43‧‧‧ isolated port

C‧‧‧Capacitor

FIG. 1 is a schematic structural diagram of a coupler circuit of the present invention.

FIG. 2 is a schematic diagram of the symmetrical structure of the coupler of the present invention.

FIG. 3 is a schematic diagram of equivalent circuits of four different symmetry plane conditions of the present invention.

FIG. 4 is a schematic diagram of the output power ratio (f = 2.45GHz, Z ₁ = 75Ω, Z ₂ = 50Ω) curve corresponding to the electrical length ( θ ₁ , θ ₂ ) and the capacitance value of the transmission line of the present invention.

FIG. 5 is a schematic diagram of a forming circuit of 1: 2 power Z ₁ = 75Ω and Z ₂ = 50Ω according to the present invention.

FIG. 6 is a schematic diagram of a physical circuit of 1: 2 power Z ₁ = 75Ω and Z ₂ = 50Ω according to the present invention.

FIG. 7 is a schematic diagram of simulation and measurement data of the first embodiment of the present invention.

FIG. 8 is a schematic diagram of a forming circuit of 1: 5 power Z ₁ = 75Ω and Z ₂ = 50Ω according to the present invention.

FIG. 9 is a schematic diagram of a physical circuit of 1: 5 power (Z ₁ = 75Ω, Z ₂ = 50Ω) of the present invention.

FIG. 10 is a schematic diagram of simulation and measurement data of the second specific embodiment of the present invention.

In order to allow your reviewers to further understand the overall technical features of the present invention and the technical means for achieving the purpose of the present invention, detailed descriptions are given in specific embodiments in conjunction with the drawings: In short, the present invention is a fixed transmission line with an arbitrary impedance characteristic The design of the branch coupler for output power is mainly based on the structure of the four transmission lines of the circuit with a given characteristic impedance value. By changing the electrical length of the transmission line and the capacitance of the ground capacitor, the output power of the branch coupler is reached. Any scale. The circuit is realized with an engraving machine, using a FR-4 substrate, with a thickness of 1.6mm and a relative dielectric coefficient of 4.3. The circuit of the present invention has been verified by electromagnetic simulation software. At the operating frequency, its output power ratio can be applied to any proportion of output power. The actual circuit is measured by a vector network analyzer, and the simulation data in the operating frequency band is in good agreement with the implementation. It can be seen that the circuit structure design of the present invention can indeed be applied to microwave systems with different center frequencies. Therefore, the circuit of the present invention is indeed highly supportive, easy to manufacture, and greatly reduces the cost of system construction.

Please refer to FIG. 5, FIG. 6, FIG. 8, and FIG. 9. The embodiment for achieving the main purpose of the present invention includes technical features such as a substrate 10 and a transmission line group 20 disposed on the substrate 10. The transmission line group 20 includes four segments of a first transmission line 21, a second transmission line 22, a third transmission line 23, and a fourth transmission line 24 which are vertically connected in a rectangular connection in sequence and can generate characteristic impedances, respectively. One end of the first transmission line 21 has a first extension section 210 extending in one direction, and the other end thereof has a second extension section 211 extending in the opposite direction. One end of the third transmission line 23 extends a third extension section 230 in this direction, and the other end thereof extends a fourth extension section 231 in the opposite direction. Each of the four inner corners 25 of the transmission line group 20 that are vertically connected in a rectangular connection is provided with a ground block 30 disposed at an oblique interval. The four ground blocks 30 are electrically connected to one end of four capacitors C, and four The other end of the capacitor C is electrically connected to the inner corner 25 corresponding to the transmission line group 20, wherein a fifth extension 212 in a trapezoidal shape extends from one end of the first transmission line 21 to the upper edge of the first extension 210, and the first transmission line A sixth extension section 213 having a trapezoidal shape extends upward from the other end to the upper edge of the second extension section 211. The fifth extension section 212 and the sixth extension section 213 each have a first beveled edge 212a and a left-right symmetry. Second chamfered edge 213a. A seventh extension section 232 extending trapezoidally extends from one end of the third transmission line 23 to the lower edge of the third extension section 230, and a trapezoidal extension extending downward from the other end of the third transmission line 23 to the lower edge of the fourth extension section 231. Each of the eight extension sections 233, the seventh extension section 232, and the eighth extension section 233 has a third chamfered edge 232a and a fourth chamfered edge 233a which are symmetrical to the left and right.

Specifically, in the embodiment shown in FIGS. 5 and 8, the bottom angle formed by the bottom edge of the fifth extension section 212 and the first chamfered edge 212 a is close to or aligned with the first transmission line 21 and the fourth transmission line 24.的 内角 角 25。 The formed inner corner 25. In addition, the bottom corner formed by the bottom edge below the sixth extension section 213 and the second chamfered edge 213a is close to or aligned with the inner corner angle 25 formed by the third transmission line 23 and the fourth transmission line 24; The bottom corner formed by the lower bottom edge and the third chamfered edge 232 a is close to or aligned with the inner edge corner 25 formed by the third transmission line 23 and the fourth transmission line 24. The bottom corner formed by the bottom edge of the eighth extension section 233 and the fourth chamfered edge 233 a is close to or aligned with the inner corner angle 25 formed by the second transmission line 22 and the third transmission line 23.

Specifically, as shown in FIG. 5, the first chamfered edge 212 a of the fifth extension section 212 is gradually inclined downward toward the second extension section 211; the second chamfered edge 213 a of the sixth extension section 213 is directed toward the first extension section 213. The direction of an extension 210 is gradually inclined downward. The third chamfered edge 232a of the seventh extension 232 gradually slopes upward in the direction of the fourth extension 231; the fourth chamfered edge 233a of the eighth extension 233 gradually slopes upward in the direction of the third extension 230. The bottom angles of the fifth extension section 212, the sixth extension section 213, the seventh extension section 232, and the eighth extension section 233 are all between 30 to 45 degrees. The fifth extension section 212, the sixth extension section 213, the The apex angles of each of the seventh extension section 232 and the eighth extension section 233 are between 140-160 degrees.

Please refer to FIGS. 5 and 6 for the first embodiment of the present invention. The capacitance values of the four capacitors C are between 2.5 and 4 pF, and the preferred capacitance value is C = 3.37 pF. The impedances of the first transmission line 21 and the third transmission line 23 are Z ₁ = 75Ω; the impedances of the second transmission line 22 and the fourth transmission line 24 are Z ₂ = 50Ω; the electrical length θ _{1 of the} first transmission line 21 and the third transmission line 23 = 22.6 °, the electrical length θ _{2 of the} second transmission line 22 and the fourth transmission line 24 = 45 ° ; the output port ratio is P2: P3 = 1: 2. The lengths of the upper and lower sides of the fifth extension 212, the sixth extension 213, the seventh extension 232, and the eighth extension 233 are all L1 = L2 = L3 = L4 = 12.2mm; the first extension 210 plus Width of fifth extension 212, width of second extension 211 plus sixth extension 213, width of third extension 230 plus seventh extension 232, and fourth extension 231 plus eighth extension 233 The width is W1 = W2 = W3 = W4 = 3.1mm; the length of the upper and lower inner edges of the transmission line group 20 connected in a rectangle is L5 = L6 = 6.7mm; the length of the first transmission line 21 is L5 + L7 + L8 = 12.9mm, the width is W5 = 1.4mm; the length of the second transmission line 21 and the fourth transmission line 24 is W7 = W8 = 11.5mm, and the width is L7 = L8 = 3.1m; the length of the third transmission line 23 is L6 + L7 + L8 = 12.9mm, width is W6 = 1.4mm.

Please refer to FIG. 8 and FIG. 9 for a second specific embodiment of the present invention. A ninth extension 234 having a trapezoidal shape extending longitudinally extends at the end of the seventh extension 232. The ninth extension 234 has a fifth oblique The cut edge 234a, the upper half of the bottom edge below the ninth extension 234 is connected to the ends of the third extension 230 and the seventh extension 232. The end of the eighth extension section 233 extends downwardly with a tenth extension section 235 in the shape of a trapezoid in a longitudinal distribution. The tenth extension section 235 has a sixth beveled edge 235a; the upper half of the bottom edge below the tenth extension section 235 is connected to the first section. The four extensions 231 and the eighth extension 233 are at the ends. The ninth extension 234 is different from one of the fifth beveled edges 234a. The length of the waist is L4 = 3.1mm, and the length of the upper bottom edge is W4 = 3.1mm. The tenth extension 235 is different from the sixth beveled edges 235a. The length of one waist is L3 = 3.1mm, and the length of the upper bottom is W3 = 3.1mm.

In the second specific embodiment, the capacitance values of the four capacitors C are between 5 and 6 pF, and the preferred capacitance value is C = 5.66F. The impedances of the first transmission line 21 and the third transmission line 23 are Z ₁ = 75Ω; the impedances of the second transmission line 22 and the fourth transmission line 24 are Z ₂ = 50Ω; the electrical length θ _{1 of the} first transmission line 21 and the third transmission line 23 = 15.79 °, the electrical length θ _{2 of the} second transmission line 22 and the fourth transmission line 24 = 26.5 ° ; the output port ratio is P2: P3 = 1: 5.

The lengths of the upper and lower sides of the fifth extension section 212, the sixth extension section 213, the seventh extension section 232, and the eighth extension section 233 are all L1 = L2 = L3 = L4 = 9.2mm. First extension 210 plus fifth extension 212, second extension 211 plus sixth extension 213, third extension 230 plus seventh extension 232, and fourth extension 231 In addition, the width of the eighth extension section 233 is W1 = W2 = W3 = W4 = 3.1mm; the length of the upper and lower inner sides of the transmission line group 20 connected in a rectangle is L5 = L6 = 5.8mm; the first transmission line 21 The length is L5 + L7 + L8 = 12mm and the width is W5 = 1.6mm; the length of the second transmission line 22 and the fourth transmission line 24 is W7 = W8 = 11.5mm, and the width is L7 = L8 = 3.1m; the third transmission line 23 The length is L6 + L7 + L8 = 12mm, and the width is W6 = 1.6mm.

The invention is mainly a circuit in which the impedance values of the four transmission lines are fixed as a framework. By changing the electrical length of the transmission line and the capacitance value of the ground at both ends, the circuit power ratio can reach an arbitrary ratio of output power (such as reference [7- 9]), and maintain good characteristics. Through the calculation of the formula, the advantages of couplers with different output ratios (such as references [10-11]) can be realized, which is very convenient for system construction. The circuit only needs to be designed in this way to apply a variety of different center frequencies. Microwave systems and circuits not only have a high degree of system support, but also reduce the cost of the entire system.

The present invention proposes an arbitrary ratio output power branch coupler design for a given transmission line impedance. The circuit structure is shown in FIG. 1, Port 1 is an input port 40, Port 2 is an output port 41, and Port 3 is a coupling port 42. Port 4 is isolated port 43, Z ₁ and Z ₂ are the transmission line characteristic impedance, C is the parallel ground capacitor, and θ ₁ and θ ₂ are electrical lengths, where θ ₁ <90 ° and θ ₂ <90 °. The double symmetry of the structure is used for analysis. The structure is shown in Figure 2. The proper excitation is selected to make the plane of symmetry AA 'make the corresponding electric field wall (short circuit) or magnetic field wall (open circuit), and the plane of symmetry BB' also corresponds. Make an electric field wall (short circuit) or magnetic field wall (open circuit). When the BB 'plane corresponds to the electric field wall, the propagation mode of the coupling line has the characteristics of the odd function impedance admittance Y _o and the propagation constant β _o ; when the BB' plane corresponds to the magnetic field wall, the propagation mode of the coupling line has the characteristic of the even function. admittance Y _e impedance and propagation constant β _e, d is the length of the transmission line, wherein β. d = θ is the electrical length of the transmission line, c is the capacitance value, and Y _o , Y ₁ , Y ₂ are the admittance values of the transmission line. The corresponding formulas are as formulas (1) to (4), and (1) is the symmetry plane AA 'and The plane of symmetry BB 'is a magnetic field wall, (2) is the plane of symmetry AA' is an electric field wall, the plane of symmetry BB 'is a field wall, (3) is the plane of symmetry AA' is a field wall, and the plane of symmetry BB 'is an electric field wall, ( 4) The symmetry plane AA ′ and the symmetry plane BB ′ are both electric field walls. In the case of symmetry, the equivalent circuit diagrams are shown in Figures 3 (a)-(d). From Figure 3 (a) (b) (c) (d) four different symmetry plane conditions (Figure 3 (a) is the symmetry plane AA 'and BB' are magnetic field walls, and Figure 3 (b) is the symmetry plane AA ' Is the electric field wall, the plane of symmetry BB is the magnetic field wall, Fig. 3 (c) is the plane of symmetry AA 'is the field wall, the plane of symmetry BB' is the electric field wall, Fig. 3 (d) is the plane of symmetry AA ', and the plane of symmetry BB' are Electric field wall.). According to the definition of the scattering coefficients ( S ₁₁ , S ₁₂ , S ₁₃ , S ₁₄ ) and the reflection coefficients (Γ _a , Γ _b , Γ _c , Γ _d ) under the four conditions, the formula requirements for designing the branch coupler are: S ₁₁ = 0, S ₁₄ = 0, where the relationship of | S ₁₁ | is formula (5), the relationship of | S ₂₁ | is formula (6), and the relationship of | S ₃₁ | is formula (7), The relation of | S ₄₁ | is formula (8), where , Ω = 2 πf , f is the operating frequency.

V ₁ ⁺ = V ₂ ⁺ = V ₃ ⁺ = V ₄ ⁺ = V ⁺ AA ': magnetic field wall BB': magnetic field wall (1)

V ₁ ⁺ = V ₄ ⁺ = V ⁺ , V ₂ ⁺ = V ₃ ⁺ = -V ⁺ AA ': electric field wall BB': magnetic field wall (2)

V ₁ ⁺ = -V ₄ ⁺ = V ⁺ , V ₂ ⁺ = -V ₃ ⁺ = V ⁺ AA ': magnetic field wall BB': electric field wall (3)

V ₁ ⁺ = -V ₄ ⁺ = V ⁺ , V ₂ ⁺ = -V ₃ ⁺ = -V ⁺ AA ': electric field wall BB': electric field wall (4)

(7)

At a given characteristic impedance Zc = 50Ω, center frequency f = 2.45GHz, transmission line impedance value is set to Z ₁ = 75Ω, Z ₂ = 50Ω frequency is 2.45GHz and the scattering parameter | S ₂₁ | is the power ratio value you want to design, that is Corresponding electrical lengths θ ₁ , θ ₂ and capacitance C can be obtained as shown in FIG. 4. In Figure 4, the horizontal axis X axis is the value of the electrical length θ ₁ in units of angle, and the left axis of the vertical axis is the value of the electrical length θ ₂ in units of angle, and the right axis of the vertical axis is the value of the capacitor C in pF. In the figure, the square curve is the ratio curve of P2: P3 power ratio, and the triangle curve is the ratio curve of capacitor C. From the case where the center frequency f = 2.45GHz, Zc = 50Ω, and the transmission line impedance values are Z ₁ = 75Ω and Z ₂ = 50Ω in Figure 4, two groups of cases are identified as P2: P3 = 1: 2 ratio (Z ₁ = 75Ω, Z ₂ = 50Ω), P2: P3 = 1: 5 ratio (Z ₁ = 75Ω, Z ₂ = 50Ω) for simulation and implementation.

An example of the experiment performed by the present invention with respect to the first specific embodiment is as follows: The output ratio of this experimental example is the ratio of P2: P3 = 1: 2, given Z ₁ = 75Ω, Z ₂ = 50Ω, and the frequency is 2.45GHz, Z _o = 50Ω. The circuit structure is shown in Figure (1). The circuit design is based on the data in Figure 4, because the given output port ratio is P2: P3 = 1: 2, the A point of the square point curve in Figure 4 is compared with the X axis of the horizontal axis and On the left side of the Y-axis of the vertical axis, the electrical length θ ₁ = 22.6 ° and the electrical length θ ₂ = 45 ° are obtained, and the capacitance value C = 3.37pF is obtained by comparing the A 'point of the triangular point curve with the right Y-axis. , The selected plate is FR4 (1.6mm), and the relative permittivity is 4.3. The structure is optimized and adjusted as shown in Figure 5. Circuit size: L1 = 12.2mm, W1 = 3.1mm, L2 = 12.2mm, W2 = 3.1mm, L3 = 12.2mm, W3 = 3.1mm, L4 = 12.2mm, W4 = 3.1mm, L5 = 6.7mm, W5 = 1.4mm, L6 = 6.7mm, W6 = 1.4mm, L7 = 3.1mm, 7 = 11.5mm, L8 = 3.1mm, W8 = 11.5mm, and fine-tune the capacitance value to make the circuit The output power ratio reaches the expected ratio. The circuit is processed by the engraving machine as shown in Figure 6, measured by an Anritsu-MS2034A network analyzer, and compared with the simulation results. The simulation results and the physical circuit frequency response are shown in Figure 7. The measured frequencies are all from 0 to 4 GHz. 0 to -50dB, in the working frequency band (fo = 2.45GHz), the reflection coefficient | S ₁₁ | and isolation | S ₄₁ | are both below -15dB, and the output power ratios at both ends | S ₂₁ | ² and | S ₃₁ | ² is 1: 2 power. The above simulation and measurement results are quite close to expectations.

An example of the experiment performed by the present invention with respect to the second specific embodiment is as follows: The output ratio of this experimental example is the ratio of P2: P3 = 1: 5, given Z ₁ = 75Ω, Z ₂ = 50Ω, the frequency is 2.45GHz, Z _o = 50Ω. The circuit structure is shown in Figure (1). The circuit design is based on the data in Figure 4. Because the given output port ratio is P2: P3 = 1: 5, the B point of the square point curve in Figure 4 is compared with the X axis of the horizontal axis and The electrical length θ ₁ = 15.79 ° and electrical length θ ₂ = 26.5 ° are obtained on the left side of the vertical axis Y axis, and the capacitance value C = 5.66F is obtained by comparing the triangle point B 'point with the right Y axis. The selected plate is FR4 (1.6mm), and the relative permittivity is 4.3. The structure is optimized and adjusted as shown in Figure 8. Circuit size: L1 = 9.2mm, W1 = 3.1mm, L2 = 9.2mm, W2 = 3.1mm, L3 = 3.1mm, W3 = 3.1mm, L4 = 3.1mm, W4 = 3.1mm, L5 = 5.8mm, W5 = 1.6mm, L6 = 5.8mm, W6 = 1.6mm, L7 = 3.1mm, W7 = 7.1, mm, L8 = 3.1mm, W8 = 7.1mm, and fine-tune the capacitance to make the circuit The output power ratio reaches the expected ratio. The circuit is processed by the engraving machine as shown in Figure 9. It is measured by an Anritsu-MS2034A network analyzer and compared with the simulation results. The simulation results and the physical circuit frequency response are shown in Figure 10. The measured frequencies are all from 0 to 4 GHz. 0 to -40dB, in the operating frequency band (fo = 2.45GHz), | S ₁₁ | and | S ₄₁ | also have good values below -15dB. The output power ratio f at both ends is 1: 5 power. The measurement results are quite close to expectations.

According to the specific embodiments described above, a fixed coupler design of a fixed transmission line characteristic impedance value with an arbitrary output ratio is proposed. The circuit uses the fixed transmission line impedance value as a framework and uses double symmetry to derive the structure's scattering parameters. The formula, by changing the electrical length of the transmission line and the capacitors grounded at both ends, the power output by the coupler can be made to any ratio. In this article, two different electrical lengths and two different ratios are given as conditions: P2 with impedance values Z ₁ = 75Ω, Z ₂ = 50Ω: P3 = 1: 2 ratio (Z ₁ = 75Ω, Z ₂ = 50Ω, C = 3.37pF) and P2: P3 = 1: 5 ratio (Z ₁ = 75Ω, Z ₂ = 50Ω, C = 5.66pF), conduct circuit simulation and actual production, verify by electromagnetic simulation software, and implement the circuit with an engraving machine. Finally, the results are measured by a network analyzer. The conditional circuit design with two different electrical lengths and two different output power ratios shows that the value is close to the analog frequency response. From this result, the circuit is feasible and applicable. This design method is a system in different frequency bands.

The above description is only a feasible embodiment of the present invention, and is not intended to limit the patent scope of the present invention. Any equivalent implementation of other changes based on the content, characteristics and spirit of the following claims should be It is included in the patent scope of the present invention. The structural features specifically defined in the present invention are not found in similar items, and are practical and progressive. They have met the requirements for invention patents. They have filed applications in accordance with the law. I would like to request the Bureau to verify the patents in accordance with the law in order to maintain this document. Applicants' legitimate rights and interests.

references

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[3] Chun-Han Yu, Yi-Hsin Pang, “ Dual-Band Unequal - Power Quadrature Branch - Line Coupler With Coupled Lines ,” IEEE Microwave and Wireless Components Letters , Volume: 23, Issue: 1, pp.10-12 , 2013.

[4] Everett D. Lin, Yi-Hsin Pang, Hsiang-Cheh Huang, “ Ring-resonator branch - line coupler with unequalpower division ,” 2014 Asia-Pacific Microwave Conference , pp.699-701, 2014.

[5] S. Cheng, E. Ojefors, P. Hallbjomer, and A. Rydberg, “Compact reflective microstrip phase shifter for traveling wave antenna applications,” IEEE Microw. Wireless Compon. Lett. , Vol. 16, no. 7, pp. 431-433, Jul. 2006.

[6] Sung-Chan Jung; Renato Negra; Fadhel M. Ghannouchi, "A Miniaturized Double-Stage 3dB Broadband Branch-Line Hybrid Coupler Using Distributed Capacitors," IEEE Transactions on Microwave Theory and Techniques , Volume: 56, Issue: 12, pp. 2950-2953, 2008.

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Claims (10)

    A branch coupler with a fixed transmission line characteristic impedance value and an arbitrary output ratio includes a substrate and a transmission line group disposed on the substrate. The transmission line group includes four segments that are vertically surrounded in a rectangular connection in order to generate characteristic impedances. A first transmission line, a second transmission line, a third transmission line, and a fourth transmission line; one end of the first transmission line extends in one direction with a first extension section, and the other end extends with a second extension section in the opposite direction; One end of the third transmission line extends with a third extension in the direction, and the other end extends with a fourth extension in the reverse direction. The four inner corners of the transmission line group which are vertically surrounded by a rectangle are each provided with an oblique direction. The four ground blocks are electrically connected to one end of four capacitors, and the other ends of the four capacitors are electrically connected to the inner corners corresponding to the transmission line group. The first transmission line A trapezoidal fifth extension extends upward from the first half to the upper edge of the first extension; the first transmission line extends from the second half to the upper edge of the second extension A trapezoidal sixth extension section has a first beveled edge and a second beveled edge that are bilaterally symmetrical, and the third transmission line is near the first half to the first beveled edge. The lower edge of the three extensions extends downwardly with a trapezoidal seventh extension; the third transmission line near the last half of the third extension line extends downwardly with a trapezoidal eighth extension, the seventh extension The segment and the eighth extension segment each have a third chamfered edge and a fourth chamfered edge that are bilaterally symmetrical.         The fixed transmission line characteristic impedance value arbitrary output ratio branch coupler according to claim 1, wherein a bottom angle formed by a bottom edge below the fifth extension and the first chamfered edge is close to or aligned with the first transmission line And the inner corner formed by the fourth transmission line; the bottom corner formed by the bottom edge below the sixth extension and the second chamfered edge is close to or aligned with the corner formed by the third transmission line and the fourth transmission line Inner corner; the bottom corner formed by the bottom edge below the seventh extension and the third chamfered edge is close to or aligned with the inner corner formed by the third transmission line and the fourth transmission line; the eighth extension The bottom corner formed by the lower bottom edge and the fourth beveled edge is close to or aligned with the inner corner formed by the second transmission line and the third transmission line.         The fixed transmission line characteristic impedance value arbitrary output ratio branch coupler according to claim 1, wherein the first beveled edge of the fifth extension section gradually slopes downward toward the second extension section; the first The second beveled edge of the six extensions gradually slopes downward toward the first extension; the third beveled edge of the seventh extension is gradually inclined upwards toward the fourth extension; the The fourth chamfered edge of the eighth extension section gradually slopes upward in the direction of the third extension section.         The arbitrary output ratio branch coupler of the fixed transmission line characteristic impedance value according to claim 1 or 2, wherein each of the fifth extension section, the sixth extension section, the seventh extension section, and the eighth extension section has a bottom. The angles are all between 30-45 degrees, and the vertex angles of the fifth extension, the sixth extension, the seventh extension and the eighth extension are between 140-160 degrees.         The fixed transmission line characteristic impedance value arbitrary output ratio branch coupler as described in claim 1, wherein the end of the seventh extension is extended with a ninth extension having a trapezoidal shape distributed longitudinally, and the ninth extension has a fifth Beveled edges, the upper half of the bottom edge below the ninth extension is connected to the third extension and the end of the seventh extension; the end of the eighth extension is extended downward with a tenth trapezoid in a longitudinal distribution. The extension, the tenth extension has a sixth chamfered edge, and the upper half of the bottom edge below the tenth extension is connected to the ends of the fourth extension and the eighth extension.         The fixed transmission line characteristic impedance value arbitrary output ratio branch coupler as described in claim 5, wherein the length of the ninth extension section which is different from one of the fifth chamfered edges is L4 = 3.1mm, and the upper end is The length of the side is W4 = 3.1mm; the length of the waist side of the tenth extension different from that of the sixth beveled side is L3 = 3.1mm, and the length of the upper bottom side is W3 = 3.1mm.     The fixed transmission line characteristic impedance value as described in claim 1 is an arbitrary output ratio branch coupler, wherein the capacitance values of the four capacitors are between 2.5 and 4 pF; the impedances of the first transmission line and the third transmission line are Z ₁ = 75Ω; the impedance of the second transmission line and the fourth transmission line is Z ₂ = 50Ω; the electrical length of the first transmission line and the third transmission line θ ₁ = 22.6 °, the second transmission line and the fourth transmission line The electrical length θ ₂ = 45 ° ; the output port ratio is P2: P3 = 1: 2.     The arbitrary output ratio branch coupler of the fixed transmission line characteristic impedance value according to claim 1, wherein the fifth extension, the sixth extension, the seventh extension, and the eighth extension are respectively above and below the bottom edge. The length is L1 = L2 = L3 = L4 = 12.2mm; the first extension plus the width of the fifth extension, the second extension plus the width of the sixth extension, and the third extension Adding the width of the seventh extension and the width of the fourth extension and the eighth extension are W1 = W2 = W3 = W4 = 3.1mm; the transmission line group is connected by the upper and lower sides of the rectangle. The length of the side is L5 = L6 = 6.7mm; the length of the first transmission line is L5 + L7 + L8 = 12.9mm and the width is W5 = 1.4mm; the length of the second transmission line and the fourth transmission line W7 = W8 = 11.5 mm, the width is L7 = L8 = 3.1m; the length of the third transmission line is L6 + L7 + L8 = 12.9mm, and the width is W6 = 1.4mm.     The fixed transmission line characteristic impedance value described in claim 1 is an arbitrary output ratio branch coupler, wherein the capacitance values of the four capacitors are between 5 and 6 pF; the impedances of the first transmission line and the third transmission line are all Z ₁ = 75Ω; the impedances of the second transmission line and the fourth transmission line are Z ₂ = 50Ω; the electrical length of the first transmission line and the third transmission line θ ₁ = 15.79 °, the second transmission line and the fourth transmission line The electrical length of the transmission line θ ₂ = 26.5 °; the output port ratio is P2: P3 = 1: 5.     The arbitrary output ratio branch coupler of the fixed transmission line characteristic impedance value according to claim 1, wherein the fifth extension, the sixth extension, the seventh extension, and the eighth extension are respectively above and below the bottom edge. The length is L1 = L2 = L3 = L4 = 9.2mm; the first extension plus the width of the fifth extension, the second extension plus the width of the sixth extension, and the third extension Adding the width of the seventh extension and the width of the fourth extension and the eighth extension are W1 = W2 = W3 = W4 = 3.1mm; the transmission line group is connected by the upper and lower sides of the rectangle. The length of the side is L5 = L6 = 5.8mm; the length of the first transmission line is L5 + L7 + L8 = 12mm and the width is W5 = 1.6mm; the length of the second transmission line and the fourth transmission line W7 = W8 = 11.5mm , The width is L7 = L8 = 3.1m; the length of the third transmission line is L6 + L7 + L8 = 12mm, and the width is W6 = 1.6mm.