A fan-shaped microstrip line array structure, circuit and design method

Abstract

The present invention discloses a fan-shaped microstrip line array structure, circuit, and design method, wherein the fan-shaped microstrip line array structure includes: a main fan-shaped microstrip line for providing two first resonance points; two groups of auxiliary fan-shaped microstrip lines, the two groups of auxiliary fan-shaped microstrip lines have the same structure and are symmetrically arranged on both sides of the main fan-shaped microstrip line, and the auxiliary fan-shaped microstrip lines are used to provide multiple second resonance points; the arcs of the main fan-shaped microstrip line and the auxiliary fan-shaped microstrip line are both designed in a shape similar to a sine function; the frequencies of the two first resonance points and the frequencies of the multiple second resonance points are respectively distributed on both sides of a preset center frequency; the sum of the angular radians of the main fan-shaped microstrip line and the angular radians of the two groups of auxiliary fan-shaped microstrip lines is less than 180°. The present invention controls the resonance frequency of the fan-shaped microstrip line structure, and then constructs a fan-shaped microstrip line array unit to form a broadband circuit structure with multiple resonance frequency points to meet the design requirements of a broadband RF bias circuit. The present invention can be widely used in RF front-end systems.

Description

Technical Field

[0001] The present invention relates to a radio frequency front-end system, and in particular to a fan-shaped microstrip line array structure, circuit and design method. Background Art

[0002] With the rapid development of modern communication technology, the scale of the communication industry continues to expand, and high-performance wireless communication systems require faster speeds and wider bandwidths. As a key component of the RF front-end wireless communication system, the power amplifier is used to amplify low-power signals to obtain sufficiently large RF output power. Its performance is directly related to the overall system. The fan-shaped microstrip structure is often used in the bias circuit. By setting the DC operating point of the amplifier transistor, the system is in a stable and efficient working state. A typical RF bias circuit consists of a quarter-wavelength line and a fan-shaped microstrip line structure. Its advantage is that it avoids the welding of capacitors, and the fan-shaped microstrip line is suitable for circuit integration. The input port is very small and easy to form a contact point. In addition, compared with the equivalent square capacitor block, the fan-shaped microstrip input impedance usually changes more slowly with frequency, which is more conducive to circuit matching design.

[0003] However, the disadvantage of the existing fan-shaped microstrip structure is that the operating bandwidth is narrow, which is not conducive to its application in future broadband communication systems. Summary of the Invention

[0004] In order to solve at least one of the technical problems existing in the prior art to a certain extent, the present invention aims to provide a fan-shaped microstrip line array structure, circuit and design method.

[0005] The technical solution adopted in the present invention is:

[0006] A fan-shaped microstrip line array structure, comprising:

[0007] A main fan-shaped microstrip line, used for providing two first resonance points;

[0008] Two groups of auxiliary fan-shaped microstrip lines, the two groups of auxiliary fan-shaped microstrip lines have the same structure and are symmetrically arranged on both sides of the main fan-shaped microstrip line, the auxiliary fan-shaped microstrip lines are used to provide multiple second resonance points;

[0009] The arcs of the main fan-shaped microstrip line and the auxiliary fan-shaped microstrip line are both designed in a shape similar to a sine function;

[0010] The frequencies of the two first resonance points and the frequencies of the plurality of second resonance points are respectively distributed on both sides of a preset center frequency;

[0011] The sum of the angular radians of the main sector-shaped microstrip line and the angular radians of the two groups of auxiliary sector-shaped microstrip lines is less than 180°.

[0012] Furthermore, the arc of the main fan-shaped microstrip line includes two crests and one trough;

[0013] Among them, the frequency of a first resonance point is:

[0014]

[0015] The frequency of the other first resonance point is:

[0016]

[0017] Wherein, L11 is the first equivalent inductance of the main fan-shaped microstrip line, L12 is the second equivalent inductance of the main fan-shaped microstrip line, C11 is the first equivalent capacitance of the main fan-shaped microstrip line, and C12 is the second equivalent capacitance of the main fan-shaped microstrip line; the frequencies of the two first resonance points are both less than the center frequency;

[0018] The equivalent inductance is related to the outer diameter, inner radius and angular radian of the main fan-shaped microstrip line, and the equivalent capacitance is related to the inner diameter, outer diameter and angular radian of the main fan-shaped microstrip line. Among them, in the fan-shaped microstrip line, the distance from the crest to the center of the circle is called the outer diameter, the distance from the trough to the center of the circle is called the inner diameter, and the distance from the center of the circle to the connection point between the fan-shaped microstrip line and the external microstrip is called the inner radius.

[0019] Furthermore, the trough is located at the midpoint of the arc of the main sector-shaped microstrip line, and the two crests are symmetrically arranged on both sides of the trough; the three line segments connecting the trough, the two crests and the center of the circle respectively divide the angular arc of the main sector-shaped microstrip line into four equal parts;

[0020] The line segment between the trough and the crest is a curve or a straight line.

[0021] Furthermore, the angular arc of the main sector-shaped microstrip line is calculated by the following method:

[0022]

[0023]

[0024] Among them, ro1 is the outer diameter of the main sector-shaped microstrip line, rin1 is the inner radius of the main sector-shaped microstrip line, c is the speed of light, and h is the thickness of the dielectric substrate.

[0025] Furthermore, each group of auxiliary fan-shaped microstrip lines includes one auxiliary fan-shaped microstrip line, and the arc of the auxiliary fan-shaped microstrip line includes two peaks and one trough; the two groups of auxiliary fan-shaped microstrip lines provide two second resonance points, and the frequencies of the two second resonance points are greater than the center frequency.

[0026] Furthermore, each group of the main fan-shaped microstrip lines includes two or more auxiliary fan-shaped microstrip lines, and one auxiliary fan-shaped microstrip line provides two resonance points.

[0027] Another technical solution adopted in the present invention is:

[0028] A radio frequency bias circuit is provided on a dielectric substrate and comprises:

[0029] RF signal transmission microstrip line, used for inputting and outputting RF signals;

[0030] a bias branch microstrip line, one end of which is vertically connected to the RF signal transmission microstrip line, and the other end of which is used to input a DC bias signal;

[0031] The fan-shaped microstrip line array structure as described above is vertically connected to the middle of the bias branch microstrip line.

[0032] Furthermore, the length L2 between the fan-shaped microstrip line array structures is designed to be a quarter wavelength of the center frequency;

[0033] The specifications of the dielectric substrate are selected according to the operating frequency band.

[0034] Another technical solution adopted in the present invention is:

[0035] A method for designing a fan-shaped microstrip line array structure as described above comprises the following steps:

[0036] Get the center frequency f0;

[0037] Designing first characteristic parameters of the main sector-shaped microstrip line according to the center frequency f0 so that the frequency of the first resonance point generated by the main sector-shaped microstrip line is lower than the center frequency f0; wherein the first characteristic parameters include the angular radian, outer diameter, inner diameter and inner radius of the main sector-shaped microstrip line;

[0038] The second characteristic parameters of the auxiliary fan-shaped microstrip line are designed according to the center frequency f0 so that the frequency of the second resonance point generated by the main fan-shaped microstrip line is higher than the center frequency f0; wherein the second characteristic parameters include the angular radian, outer diameter and inner diameter of the auxiliary fan-shaped microstrip line.

[0039] Furthermore, the first characteristic parameter is designed in the following manner:

[0040] Based on the calculation formula of the angular radian of the main sector microstrip line, the value of the outer diameter ro1 and the inner diameter ri1 are adjusted to control the size of the equivalent capacitance, thereby determining the frequency distribution of the resonance points f1 and f2 and the value range of the angular radian;

[0041] Optimizing the first characteristic parameter to obtain a final first characteristic parameter;

[0042] The calculation formula for the angle in radians is:

[0043]

[0044]

[0045] Where ro1 is the outer diameter of the main sector-shaped microstrip line, rin1 is the inner radius of the main sector-shaped microstrip line, c is the speed of light, and h is the thickness of the dielectric substrate.

[0046] The beneficial effects of the present invention are as follows: the present invention provides a first resonance point through a main fan-shaped microstrip line and a second resonance point through an auxiliary fan-shaped microstrip line, and the first resonance point and the second resonance point are respectively distributed on both sides of a preset center frequency, thereby effectively widening the operating frequency band and achieving a good biasing effect; effectively isolating the main RF signal from the branch DC signal, and can be widely applied to modern RF front-end systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following introduction is made to the drawings of the embodiments of the present invention or the related technical solutions in the prior art. It should be understood that the drawings introduced below are only for the convenience of clearly describing some embodiments of the technical solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative work.

[0048] Figure 1 1 is an overall structural diagram of a fan-shaped microstrip line array structure according to an embodiment of the present invention;

[0049] Figure 2 2 is a schematic diagram of an equivalent circuit of a lumped element of a fan-shaped microstrip line array structure according to an embodiment of the present invention;

[0050] Figure 3 is a schematic diagram of different fan-shaped microstrip line structures;

[0051] Figure 4 This is the S31 parameter Smith impedance diagram simulation result of the traditional fan-shaped microstrip structure bias circuit;

[0052] Figure 5 This is the Smith impedance chart simulation result of the bias circuit S31 parameter of the smooth curved edge fan-shaped microstrip line array structure of the second embodiment of the present invention;

[0053] Figure 6 This is the Smith impedance circle simulation result of the bias circuit S31 parameter of the fan-shaped microstrip line array structure with straight edges in Example 3 of the present invention;

[0054] Figure 7 1. This is a comparison chart of S21 parameter simulation results of the bias circuit of the fan-shaped microstrip line array structure of the second embodiment of the present invention and the traditional fan-shaped structure;

[0055] Figure 8 3. This is a comparison chart of S33 parameter simulation results of the bias circuit of the fan-shaped microstrip line array structure of the second embodiment of the present invention and the traditional fan-shaped structure;

[0056] Figure 9 3. This is a comparison chart of S31 parameter simulation results of the bias circuit of the fan-shaped microstrip line array structure of the second embodiment of the present invention and the traditional fan-shaped structure;

[0057] Figure 10 1. This is a comparison chart of S21 parameter simulation results of the bias circuit of the fan-shaped microstrip line array structure of the third embodiment of the present invention and the traditional fan-shaped structure;

[0058] Figure 11 3 is a comparison diagram of S33 parameter simulation results of the bias circuit of the fan-shaped microstrip line array structure of the third embodiment of the present invention and the traditional fan-shaped structure;

[0059] Figure 12 3 is a comparison chart of S31 parameter simulation results of the bias circuit of the fan-shaped microstrip line array structure of the third embodiment of the present invention and the traditional fan-shaped structure. DETAILED DESCRIPTION

[0060] The 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 are not to be construed as limiting the present invention. The step numbers in the following embodiments are provided for ease of explanation only and do not limit the order of the steps. The order of execution of the steps in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0061] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0062] In the description of the present invention, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0063] Furthermore, in the description of this invention, unless otherwise specified, "plurality" refers to two or more. "And / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0064] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0065] Example 1

[0066] The existing traditional fixed radius fan-shaped microstrip line structure (such as Figure 3 (a)), this embodiment provides a fan-shaped microstrip line array structure for use in RF bias circuits to achieve an expansion of the operating bandwidth. Figure 1 The fan-shaped microstrip line array structure includes:

[0067] A main fan-shaped microstrip line, used for providing two first resonance points;

[0068] Two groups of auxiliary fan-shaped microstrip lines, the two groups of auxiliary fan-shaped microstrip lines have the same structure and are symmetrically arranged on both sides of the main fan-shaped microstrip line, the auxiliary fan-shaped microstrip lines are used to provide multiple second resonance points;

[0069] The arcs of the main fan-shaped microstrip line and the auxiliary fan-shaped microstrip line are both designed in a shape similar to a sine function;

[0070] The frequencies of the two first resonance points and the frequencies of the plurality of second resonance points are respectively distributed on both sides of a preset center frequency;

[0071] The sum of the angular radians of the main sector-shaped microstrip line and the angular radians of the two groups of auxiliary sector-shaped microstrip lines is less than 180°.

[0072] The working principle of the fan-shaped microstrip line array structure of this embodiment is: to control the resonant frequency of the fan-shaped microstrip line structure to achieve a dual-resonance mode structure, and then construct the fan-shaped microstrip line array unit to form a broadband circuit structure with multiple resonant frequency points to meet the design requirements of the broadband RF bias circuit. Specifically, with the center frequency f0 as a reference, the working bandwidth is expanded to both sides of the center frequency, one side is the resonant frequency of the main fan-shaped microstrip line structure, and the other side is the resonant frequency of the auxiliary fan-shaped microstrip line structure. The design of the fan-shaped structure is realized based on the distribution of the two resonant frequencies. It should be noted that the sine-like function described in this application is a broad definition, not a sinusoidal function. This type of sine function can provide periodic peaks and troughs.

[0073] Specifically, in the fan-shaped microstrip line structure, the equivalent inductance of the fan-shaped microstrip line is:

[0074]

[0075] The equivalent capacitance is:

[0076]

[0077] Where c is the speed of light, ε and h are the effective dielectric constant and thickness of the dielectric substrate, respectively, θ is the angular span angle of the fan-shaped arc (i.e., angular radians), rin is the inner radius of the connection point of the fan-shaped structure, and ro is the outer diameter of the fan-shaped structure. It should be noted that the above formula for equivalent capacitance is not an expression for the equivalent capacitance of the existing fan-shaped microstrip line structure, but is not an expression for the equivalent capacitance of the main fan-shaped microstrip line and the auxiliary fan-shaped microstrip line of this application. The influencing factors of the equivalent capacitance of this application also include the inner diameter ri1.

[0078] The following explanation is given by taking each group of auxiliary fan-shaped microstrip lines including one auxiliary fan-shaped microstrip line as a specific embodiment, that is, two groups of auxiliary fan-shaped microstrip lines provide two resonance points.

[0079] See also Figure 2 , Figure 2 for Figure 1 The lumped element equivalent circuit of the fan-shaped microstrip line structure is shown. Each fan-shaped microstrip line unit of the designed array structure has dual resonance points.

[0080] Taking the main fan-shaped microstrip line structure as an example, its resonant frequency is:

[0081]

[0082]

[0083] At the two resonant frequencies, the inductance of the fan-shaped microstrip line is equal. The relationship between the two equivalent capacitances determines the distribution of the dual resonant frequencies. The equivalent capacitance is affected by the fan-shaped inner radius ri1 and the outer radius ro1, respectively. The design relationship between the dual resonant frequency points of the fan-shaped microstrip line structure and its characteristic structural parameters is obtained. The arc span angle is positively correlated with the inductance value and negatively correlated with the capacitance value. The path length is positively correlated with the inductance and capacitance values. Unlike the traditional fan-shaped microstrip line structure with a fixed radius, which only has a single resonant point, the fan-shaped microstrip line structure of this embodiment affects the distribution of the dual resonant frequencies by controlling the value range of the inner radius ri1 and the outer radius ro1, and adjusts the arc span angle to design the equivalent inductance value, thereby determining the value range of the resonant frequency.

[0084] Among them, in the fan-shaped microstrip line, the distance from the crest to the center of the circle is called the outer diameter, the distance from the trough to the center of the circle is called the inner diameter, and the distance from the center of the circle to the connection point between the fan-shaped microstrip line and the external microstrip is called the inner radius.

[0085] As an optional implementation, a fan-shaped microstrip array distribution design can construct multiple resonant units, greatly expanding the circuit's operating bandwidth. New resonant points are introduced through the auxiliary fan-shaped microstrip structure, enabling a multi-resonant array structure design. The appropriate characteristic structural dimensions are designed to distribute the resonant points on either side of the center frequency f0 to achieve broadband design requirements. The radius of the fan-shaped microstrip structure proposed in this embodiment is not a fixed value, and the number and layout of the fan-shaped array units can be designed based on bandwidth requirements, allowing for flexible adjustment of the number and arrangement of the circuit's resonant frequency points.

[0086] In some embodiments, each group of auxiliary fan-shaped microstrip lines includes one auxiliary fan-shaped microstrip line. Since the structures symmetrically distributed on the main fan-shaped microstrip lines are the same, the resonance points provided by each group of auxiliary fan-shaped microstrip lines are the same, so the two groups of auxiliary fan-shaped microstrip lines provide two resonance points.

[0087] In some embodiments, each group of auxiliary fan-shaped microstrip lines includes two or more auxiliary fan-shaped microstrip lines, and each auxiliary fan-shaped microstrip line provides two resonance points. For example, each group of auxiliary fan-shaped microstrip lines includes two auxiliary fan-shaped microstrip lines, and each group of auxiliary fan-shaped microstrip lines can provide 4 resonance points.

[0088] As an optional implementation, the outer arc profile (ie, arc line) of the fan-shaped microstrip line structure may vary according to different design methods, and the design points of the outer arc profile are not limited to a specific connection method.

[0089] In some embodiments, see Figure 3 (b), the outer arc profile is a curve. In other embodiments, see Figure 3 (c) The outer arc contour is a straight line.

[0090] Based on the above-mentioned fan-shaped microstrip line array structure, this embodiment provides a radio frequency bias circuit, which is disposed on a dielectric substrate and includes:

[0091] RF signal transmission microstrip line, used for inputting and outputting RF signals;

[0092] a bias branch microstrip line, one end of which is vertically connected to the RF signal transmission microstrip line, and the other end of which is used to input a DC bias signal;

[0093] The fan-shaped microstrip line array structure as described above is vertically connected to the middle of the bias branch microstrip line.

[0094] As an optional embodiment, the length L2 between one end of the bias branch microstrip line and the fan-shaped microstrip line array structure is designed to be one-quarter of the center frequency to meet bias circuit requirements. Furthermore, the quality factor (Q) should be reduced to achieve bandwidth broadening. Alternatively, increasing the dielectric substrate thickness or reducing the relative dielectric constant of the dielectric substrate can be used to select a suitable dielectric substrate material.

[0095] Based on the above-mentioned fan-shaped microstrip line array structure, this embodiment provides a design method, including the following steps:

[0096] S1. Obtain the center frequency f0.

[0097] A suitable dielectric substrate material is selected according to the center frequency, and the bandwidth requirement is determined. In this embodiment, the wider the bandwidth, the better.

[0098] S2. Design the first characteristic parameters of the main fan-shaped microstrip line according to the center frequency f0 so that the frequency of the first resonance point generated by the main fan-shaped microstrip line is lower than the center frequency f0; wherein the first characteristic parameters include the angular radian, outer diameter, inner diameter and inner radius of the main fan-shaped microstrip line.

[0099] Specifically, the value range of characteristic parameters that affect the change of the resonance point of the main fan-shaped microstrip line structure is obtained. The structural characteristic parameters include the radian span angle θ1, the outer diameter ro1, the inner diameter ri1, and the inner radius rin1 of the connection point. The design relationship is: the radian span angle Lumped parameter equivalent capacitance The equivalent capacitance is controlled by adjusting the values ​​of the outer diameter ro1 and the inner diameter ri1, thereby determining the distribution of the resonance points f1 and f2 and the appropriate range of the arc span angle. Finally, the structural parameters are optimized according to the dual resonance point definition of the lumped element equivalent circuit model to obtain the design model of the main fan-shaped microstrip structure.

[0100] S3. Design the second characteristic parameters of the auxiliary fan-shaped microstrip line according to the center frequency f0 so that the frequency of the second resonance point generated by the main fan-shaped microstrip line is higher than the center frequency f0; wherein the second characteristic parameters include the angular radian, outer diameter and inner diameter of the auxiliary fan-shaped microstrip line.

[0101] Specifically, the value range of characteristic parameters that affect the change of the auxiliary fan-shaped microstrip line structure resonance point is obtained, and the structural characteristic parameters include the radian span angles θ2 and θ3, the outer diameters ro2 and ro3, ​​and the inner diameters ri2 and ri3. Similarly, the resonance point distribution is calculated according to the lumped element equivalent circuit model to optimize the design of the structural parameters, and the design model of the auxiliary fan-shaped microstrip structure is obtained, so that the resonance point is located on the other side of the center frequency f0 relative to the resonance point of the main fan-shaped structure, and the value range of the bias branch microstrip line structure parameters is obtained according to the resonance point distribution and the medium parameter value.

[0102] As an optional implementation, after step S3, step S4 is also included: designing the outer arc contour connection method of the fan-shaped microstrip line and the bias branch microstrip line, while optimizing the fan-shaped structural parameters, further expanding the bandwidth performance, and designing the final accurate structural parameters.

[0103] Example 2

[0104] This embodiment provides a radio frequency bias circuit, comprising: a fan-shaped microstrip line array structure, a radio frequency signal transmission microstrip line structure, a bias branch microstrip line structure, and a dielectric substrate. The overall circuit structure is as follows: Figure 1 As shown, the main RF signal is input by port 1 (Port 1) and output by port 2 (Port 2), and the DC bias is input by port 3 (Port 3). The bias branch microstrip line is vertically connected to the middle of the RF signal transmission line, and the fan-shaped microstrip line array is laterally connected to the bias branch.

[0105] See also Figure 1 Taking the main fan-shaped microstrip line structure as an example, the inner concave point P3 (i.e., the trough) is located on the θ1 angle bisector, and the outer convex points P1 and P2 (i.e., the two peaks) are symmetrically distributed on the arc span angle quadrant. The distance between the outer convex point and the center of the circle O3 is the outer diameter r01. The connection point where the main fan-shaped microstrip line is connected to the external microstrip is spaced from the center of the circle by the inner radius rin1. The design method of the auxiliary fan-shaped microstrip line structure is consistent with that of the main fan-shaped microstrip line structure.

[0106] Optionally, the dielectric substrate used in the RF bias circuit is Rogers RO4350, the dielectric material thickness is 0.762 mm, the dielectric constant is 3.66, the tangent loss is 0.004, and the copper thickness is 0.035 mm.

[0107] See also Figure 3 (a) The arc span angle θ of the traditional fixed-radius fan-shaped microstrip line structure is 75°, the radius length is 14.8mm, the center frequency f0 is 2.05GHz, the RF signal transmission microstrip line length L1 is 60mm, the width W1 is 1.5mm, the offset branch microstrip line length L2 is 6mm, L3 is 48mm, and the width W2 is 1.2mm. Figure 1The fan-shaped outer contour of the fan-shaped microstrip line array structure of this embodiment uses a smooth curve similar to a sine function to connect the design points. At the same time, the structural parameters such as the arc span angle, inner and outer diameter lengths are optimized according to the design method to expand its operating bandwidth. The arc span angle θ1 of the main fan-shaped structure is 85°, the outer diameter ro1 is 22.5mm, the inner diameter ri1 is 13mm, and the inner radius rin1 is 1.5mm. The parameters of the two auxiliary fan-shaped microstrip line structures are consistent, the fan-shaped edge lines on both sides of the spacing are kept parallel, the spacing d1=d2=1mm, the fan-shaped structure arc span angle θ2 is 30°, the outer diameter ro2 is 20.2mm, and the inner diameter ri1 is 15.3mm. The other auxiliary fan-shaped microstrip line structure is symmetrically distributed about the center line O1O3. The length L1 of the RF signal transmission microstrip line is 60mm, the width W1 is 1.5mm, the length L2 of the bias branch microstrip line is 19.5mm, L3 is 34.5mm, and the width W2 is 0.6mm. The two auxiliary fan-shaped microstrip line structures are consistent. It can be obtained that there are four resonant frequency points in this embodiment, among which the main fan-shaped microstrip line structure provides resonant frequency points at 1.45GHz and 1.9GHz, and the auxiliary fan-shaped microstrip line structure provides resonant frequency points at 2.15GHz and 3.35GHz, which are distributed on both sides of the center frequency f0.

[0108] This embodiment is modeled and simulated in the electromagnetic simulation software ANSYS HFSS 18.2. Figure 4 This is the Smith impedance circle result of the traditional fan-shaped structure S31 parameter. The normalized impedance at the resonant frequency point is 0.997+0.007iΩ. Figure 5 The Smith impedance circle results of the S31 parameter of the sector-shaped microstrip line array structure of this embodiment are shown. The normalized impedances at the resonant frequency points are 1-0.0008iΩ, 0.9846+0.0077iΩ, 0.9942+0.0148iΩ, and 0.9699-0.1725iΩ, respectively. This indicates that the corresponding frequency points are in the circuit resonant state and have a good matching effect. Figure 7 and Figure 8 This is the parameter simulation result of S21 and S33 in this embodiment, which also shows that the attenuation of the RF signal is very small when passing through the bias branch node, and the signal transmission of the main path is better achieved. Figure 9 The simulation results for the S31 parameter of this embodiment show that when S31 is less than -10dB, the circuit bandwidth (BW1) corresponding to the fan-shaped microstrip array structure is 3.27GHz (154.6%), while the circuit bandwidth (BW2) corresponding to the traditional fan-shaped structure is 2.4GHz (104.3%). The fan-shaped microstrip structure improves the operating bandwidth by 50.3%. Therefore, the comparative analysis of the above results shows that the fan-shaped microstrip array structure design of this embodiment significantly expands the operating bandwidth of the traditional fan-shaped structure.

[0109] Example 3

[0110] The design parameters of the radio frequency bias circuit of this embodiment, except for the sector-shaped microstrip line array structure, are exactly the same as those of the second embodiment, and the designed center frequency f0 is 2.05 GHz. The outer contour of a fan-shaped microstrip line structure of the present embodiment uses multiple broken lines to connect the design points, wherein the main fan-shaped structure has an arc span angle θ1 of 85°, an outer diameter ro1 of 17.7 mm, an inner diameter ri1 of 9.5 mm, and an inner radius rin1 of the connection point of 1.5 mm. The parameters of the two auxiliary fan-shaped microstrip line structures are consistent, the fan-shaped edge lines on both sides of the spacing remain parallel, the spacing d1 = d2 = 1 mm, the fan-shaped structure has an arc span angle θ2 of 30°, an outer diameter ro2 of 15.2 mm, and an inner diameter ri1 of 10.3 mm. The other auxiliary fan-shaped microstrip line structure is symmetrically distributed about the center line O1O3. Since the two auxiliary fan-shaped microstrip line structures are consistent, there are four resonant frequency points in the present embodiment. The main fan-shaped microstrip line structure provides resonant frequency points at 1.5 GHz and 2.05 GHz, and the auxiliary fan-shaped microstrip line structure provides resonant frequency points at 2.2 GHz and 3.3 GHz, which are distributed on both sides of the center frequency f0.

[0111] This embodiment is modeled and simulated in the electromagnetic simulation software ANSYS HFSS 18.2. Figure 4 This is the Smith impedance circle result of the traditional fan-shaped structure S31 parameter. The normalized impedance at the resonant frequency point is 0.997+0.007iΩ. Figure 6 The Smith impedance circle results of the S31 parameter of the sector-shaped microstrip line array structure of this embodiment are shown. The normalized impedances at the resonant frequency points are 0.9998-0.0008iΩ, 0.9674+0.0266iΩ, 1.0256-0.0055iΩ, and 0.9814-0.1384iΩ, respectively. This indicates that the corresponding frequency points are in the circuit resonance state and have a good matching effect. Figure 10 and Figure 11 This is the parameter simulation result of S21 and S33 in this embodiment, which also shows that the attenuation of the RF signal is very small when passing through the bias branch node, and the signal transmission of the main path is better achieved. Figure 12 The S31 parameter simulation results for this embodiment show that when S31 is less than -10dB, the circuit bandwidth (BW1) corresponding to the fan-shaped microstrip array structure is 3.3GHz (154.9%), while the circuit bandwidth (BW2) corresponding to the traditional fan-shaped structure is 2.4GHz (104.3%). The fan-shaped microstrip structure improves the operating bandwidth by 50.6%. The comparative analysis of the above results shows that the fan-shaped microstrip array structure design of this embodiment significantly expands the operating bandwidth of the traditional fan-shaped structure.

[0112] In summary, compared with the prior art, the present invention has at least the following advantages: the fan-shaped microstrip line array structure of the present invention expands the operating bandwidth of the radio frequency circuit through multiple resonant units, expands its scope of application, and has high implementation flexibility. The radius variability of the fan-shaped structure facilitates technicians to design different fan-shaped structures using different dielectric substrate materials according to specific index requirements, and is applied to multiple frequency band scenarios.

[0113] In the above description of this specification, reference to the terms "one embodiment / example," "another embodiment / example," or "certain embodiments / examples" 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 suitable manner in any one or more embodiments or examples.

[0114] While 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 invention, and that the scope of the invention is defined by the claims and their equivalents.

[0115] The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A fan-shaped microstrip line array structure, characterized in that: include: A main fan-shaped microstrip line, used for providing two first resonance points; Two groups of auxiliary fan-shaped microstrip lines, the two groups of auxiliary fan-shaped microstrip lines have the same structure and are symmetrically arranged on both sides of the main fan-shaped microstrip line, the auxiliary fan-shaped microstrip lines are used to provide multiple second resonance points; The arcs of the main fan-shaped microstrip line and the auxiliary fan-shaped microstrip line are both designed in a shape similar to a sine function; The frequencies of the two first resonance points and the frequencies of the plurality of second resonance points are respectively distributed on both sides of a preset center frequency; The frequencies of the two first resonance points are lower than the center frequency, and the frequencies of the plurality of second resonance points are higher than the center frequency; The sum of the angular radians of the main sector-shaped microstrip line and the angular radians of the two groups of auxiliary sector-shaped microstrip lines is less than 180°.

2. The fan-shaped microstrip line array structure according to claim 1, characterized in that: The arc of the main fan-shaped microstrip line includes two crests and one trough; Among them, the frequency of a first resonance point is: The frequency of the other first resonance point is: Wherein, L11 is the first equivalent inductance of the main fan-shaped microstrip line, L12 is the second equivalent inductance of the main fan-shaped microstrip line, C11 is the first equivalent capacitance of the main fan-shaped microstrip line, and C12 is the second equivalent capacitance of the main fan-shaped microstrip line; the frequencies of the two first resonance points are both less than the center frequency; The equivalent inductance is related to the outer diameter, inner radius and angular radian of the main fan-shaped microstrip line, and the equivalent capacitance is related to the inner diameter, outer diameter and angular radian of the main fan-shaped microstrip line; among them, in the fan-shaped microstrip line, the distance from the crest to the center of the circle is called the outer diameter, the distance from the trough to the center of the circle is called the inner diameter, and the distance from the center of the circle to the connection point between the fan-shaped microstrip line and the external microstrip is called the inner radius.

3. The fan-shaped microstrip line array structure according to claim 2, characterized in that: The trough is located at the midpoint of the arc of the main sector-shaped microstrip line, and the two crests are symmetrically arranged on both sides of the trough; the three line segments connecting the trough, the two crests and the center of the circle respectively divide the angular arc of the main sector-shaped microstrip line into four equal parts; The line segment between the trough and the crest is a curve or a straight line.

4. The fan-shaped microstrip line array structure according to claim 2, characterized in that: The angular radian θ1 of the main sector microstrip line is calculated as follows: Among them, ro1 is the outer diameter of the main sector-shaped microstrip line, rin1 is the inner radius of the main sector-shaped microstrip line, c is the speed of light, and h is the thickness of the dielectric substrate.

5. The fan-shaped microstrip line array structure according to claim 1, characterized in that: Each group of auxiliary fan-shaped microstrip lines includes an auxiliary fan-shaped microstrip line, and the arc of the auxiliary fan-shaped microstrip line includes two peaks and one trough; the two groups of auxiliary fan-shaped microstrip lines provide two second resonance points, and the frequencies of the two second resonance points are greater than the center frequency.

6. The fan-shaped microstrip line array structure according to claim 1, characterized in that: Each group of the main fan-shaped microstrip lines includes two or more auxiliary fan-shaped microstrip lines, and one auxiliary fan-shaped microstrip line provides two resonance points.

7. A radio frequency bias circuit, characterized in that: Set on a dielectric substrate, including: RF signal transmission microstrip line, used for inputting and outputting RF signals; a bias branch microstrip line, one end of which is vertically connected to the RF signal transmission microstrip line, and the other end of which is used to input a DC bias signal; The fan-shaped microstrip line array structure according to any one of claims 1 to 6, vertically connected to the middle of the bias branch microstrip line.

8. The radio frequency bias circuit according to claim 7, characterized in that: The length L2 between one end of the bias branch microstrip line and the fan-shaped microstrip line array structure is designed to be a quarter wavelength of the center frequency; The specifications of the dielectric substrate are selected according to the operating frequency band.

9. A method for designing a fan-shaped microstrip line array structure according to any one of claims 1 to 6, characterized in that: The following steps are involved: Get the center frequency f0; Designing first characteristic parameters of the main sector-shaped microstrip line according to the center frequency f0 so that the frequency of the first resonance point generated by the main sector-shaped microstrip line is lower than the center frequency f0; wherein the first characteristic parameters include the angular radian, outer diameter, inner diameter and inner radius of the main sector-shaped microstrip line; The second characteristic parameters of the auxiliary fan-shaped microstrip line are designed according to the center frequency f0 so that the frequency of the second resonance point generated by the main fan-shaped microstrip line is higher than the center frequency f0; wherein the second characteristic parameters include the angular radian, outer diameter and inner diameter of the auxiliary fan-shaped microstrip line.

10. A design method according to claim 9, characterized in that: The first characteristic parameter is designed in the following way: Based on the calculation formula of the angular radian of the main sector microstrip line, the value of the outer diameter ro1 and the inner diameter ri1 are adjusted to control the size of the equivalent capacitance, thereby determining the frequency distribution of the resonance points f1 and f2 and the value range of the angular radian; Optimizing the first characteristic parameter to obtain a final first characteristic parameter; The calculation formula for the angular radian θ1 is: Where ro1 is the outer diameter of the main sector-shaped microstrip line, rin1 is the inner radius of the main sector-shaped microstrip line, c is the speed of light, and h is the thickness of the dielectric substrate.

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