Antenna, radio frequency antenna link, impedance tuning method thereof and electronic device

Abstract

The application relates to an antenna, a radio frequency antenna link, an impedance tuning method thereof and an electronic device, the antenna comprising a radiator in a strip-shaped structure, the radiator being provided with a feed end and a ground end which are spaced apart at one end in a first direction, the first direction being the length direction of the radiator; and a first slot body being formed in the radiator along the first direction and being arranged at a position close to the feed end. The first slot body is formed in the radiator of the designed antenna along the first direction, the first slot body is arranged close to the feed end and extends along the first direction, so that the impedance of the antenna is changed, the existing load impedance circle of the antenna rotates and moves around the equal-reflection-coefficient circle, the quadrant rotation of the load impedance of the antenna is realized, the load impedance circle of the antenna and the maximum power impedance point of the radio frequency power amplifier chip are in the same quadrant, the best matching point of the load impedance circle of the antenna and the impedance of the radio frequency power amplifier chip is found, and the maximum power output of the radio frequency antenna is realized.

Description

Technical Field

[0001] This application relates to the field of wireless communication technology, and in particular to an antenna, a radio frequency antenna link, an impedance tuning method thereof, and an electronic device. Background Technology

[0002] In the field of passive antenna design, a typical transmitter RF-antenna link consists of an RF power amplifier chip, a transmission line, a matching circuit, and an antenna. The RF power amplifier chip transmits the power signal through the transmission line and matches the power signal to the antenna through the matching circuit.

[0003] However, because the load impedance of the antenna cannot be optimally matched with the impedance of the RF power amplifier chip, the RF antenna cannot achieve maximum power output. Summary of the Invention

[0004] The purpose of this application is to provide an antenna, a radio frequency antenna link, its impedance tuning method, and an electronic device, wherein the load impedance circle of the antenna and the maximum power impedance point of the radio frequency power amplifier chip are in the same quadrant, so that the load impedance circle of the antenna and the impedance of the radio frequency power amplifier chip reach the optimal matching point, thereby maximizing the power output of the radio frequency antenna.

[0005] In a first aspect, embodiments of this application propose an antenna, comprising: a radiator having an elongated strip-shaped structure, wherein a feed end and a ground end are provided at intervals along a first direction, the first direction being the length direction of the radiator; and a first slot formed in the radiator along the first direction, wherein the first slot is positioned near the feed end.

[0006] According to one embodiment of this application, the length dimension L1 of the first groove along the first direction is in the range of: L1 > 25 mm; and / or, the width dimension D1 of the first groove is in the range of: D1 ≤ 0.8 mm.

[0007] According to one embodiment of this application, the power supply terminal and the grounding terminal extend along a second direction, which is the width direction of the radiator; a second groove is formed between the power supply terminal and the grounding terminal, and the first groove and the second groove are separated from each other by the power supply terminal.

[0008] According to one embodiment of this application, the width dimension D2 of the second groove along the first direction is in the range of: D2≤1mm; and / or, the length dimension L2 of the second groove along the second direction is in the range of: L2>4mm.

[0009] According to one embodiment of this application, the dimension L1 of the first groove along the first direction and the dimension L2 of the second groove along the second direction must satisfy the following condition: L1 > L2.

[0010] According to one embodiment of this application, the first groove has a first side and a second side extending along the first direction and disposed opposite to each other. The power supply end and the grounding end are formed extending from one end of the first side along the first direction. Both the power supply end and the grounding end extend in a direction away from the second side, and the power supply end is located on the side of the grounding end facing the center of the radiator. The first groove is formed on the side of the power supply end away from the grounding end. The second groove is formed along the second direction on the side of the power supply end facing the grounding end.

[0011] Secondly, embodiments of this application provide a radio frequency antenna link, including: an antenna as described in any of the first aspects; and a radio frequency power amplifier chip, wherein the radio frequency power amplifier chip transmits a power signal through a transmission line and matches the power signal to the antenna through a matching circuit.

[0012] Thirdly, embodiments of this application provide an impedance tuning method for a radio frequency antenna link as described in the second aspect, comprising:

[0013] A first slot is formed on the radiator of the antenna. The radiator has a long strip structure. One end of the radiator along a first direction is provided with a feed terminal and a ground terminal that are spaced apart. The first direction is the length direction of the radiator. The first slot extends from a position near the feed terminal along the first direction of the radiator.

[0014] The first slot is used to rotate the impedance circle of the antenna around the circle with equal reflection coefficient to perform quadrant matching, so as to achieve the matching of the load impedance of the antenna with the maximum power impedance point of the RF power amplifier chip.

[0015] The step of rotating the antenna's impedance circle around a circle with equal reflection coefficients via the first slot for quadrant matching includes:

[0016] The load impedance circle of the antenna rotates cyclically in a clockwise direction, so that the load impedance circle of the antenna rotates sequentially from the initial first quadrant to the fourth quadrant, the third quadrant, and the second quadrant.

[0017] The maximum power impedance point of the RF power amplifier chip is located in the second quadrant. When the load impedance of the antenna is rotated to the second quadrant, the load impedance of the antenna is matched with the maximum power impedance point of the RF power amplifier chip.

[0018] Fourthly, embodiments of this application provide an electronic device including the antenna as described above.

[0019] According to the antenna, RF antenna link, impedance tuning method, and electronic equipment provided in the embodiments of this application, a first slot is formed on the radiator of the pre-designed antenna along a first direction (i.e., the radiator is a long strip structure, and the first direction is its length direction). The first slot is set close to the feed end and extends along the first direction, which changes the impedance of the antenna. The existing load impedance circle of the antenna rotates and moves around the circle of equal reflection coefficient, realizing quadrant rotation of the antenna load impedance until the load impedance circle of the antenna and the maximum power impedance point of the RF power amplifier chip are in the same quadrant. The optimal matching point between the load impedance circle of the antenna and the impedance of the RF power amplifier chip is found, thereby maximizing the power output of the RF antenna. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In addition, in the drawings, the same parts use the same reference numerals, and the drawings are not drawn to scale.

[0021] Figure 1 A schematic diagram of the radio frequency antenna link provided in the embodiments of this application;

[0022] Figure 2 This is a schematic diagram of the structure of the radiator of the antenna provided in an embodiment of this application;

[0023] Figure 3 For based on Figure 1 The power-added efficiency diagram of the RF power amplifier chip;

[0024] Figure 4 For based on Figure 2 A schematic diagram showing the load impedance circle of the antenna located in the first quadrant;

[0025] Figure 5 For based on Figure 2 A schematic diagram showing the load impedance of the antenna rotated to the fourth quadrant;

[0026] Figure 6 For based on Figure 2 A schematic diagram showing the load impedance of the antenna rotated to the third quadrant;

[0027] Figure 7 For based on Figure 2 A schematic diagram showing the load impedance of the antenna rotated to the second quadrant.

[0028] Explanation of reference numerals in the attached figures:

[0029] 100. Radiator; 11. First side; 12. Second side; 13. Feed terminal; 14. Grounding terminal; 15. First tank; 16. Second tank;

[0030] 200. Radio frequency power amplifier chip;

[0031] 300. Transmission line;

[0032] 400. Matching circuit;

[0033] 10. Load impedance circle; 20. Maximum power impedance point; 30. Circle with equal reflection coefficient; Q1. First quadrant; Q2. Second quadrant; Q3. Third quadrant; Q4. Fourth quadrant;

[0034] A. First direction; B. Second direction. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0036] This embodiment provides an electronic device, which can be a mobile phone, smart home device, smart industry device, or smart device, etc.

[0037] Figure 1 This is a schematic diagram of the radio frequency antenna link provided in the embodiments of this application.

[0038] Please see Figure 1 As shown, the electronic device provided in this embodiment has a radio frequency antenna link, which includes an antenna and a radio frequency power amplifier chip 200. The radio frequency power amplifier chip 200 transmits a power signal through a transmission line 300 and matches the power signal to the antenna through a matching circuit 400.

[0039] In the field of passive antenna design, different antenna radiators 100 are often designed to meet the S-parameter (input return loss) requirements based on the antenna's resonant frequency and bandwidth. The aim is to maximize the S-parameters of the antenna load and optimize the power transmission efficiency from the power amplifier output to the antenna. S-parameters are network parameters based on the relationship between incident and reflected waves, suitable for microwave circuit analysis. They describe the circuit network using the reflected signal at the device port and the signal transmitted from one port to another. S-parameters refer to the port's reflection coefficient (input return loss), and are often simplified as the ratio of the equivalent reflected voltage to the equivalent incident voltage.

[0040] Due to the parasitic load-pull effect of the RF power amplifier chip 200, the influence of the transmission line 300 and the matching network, the load-pull (transistor output plane) given in the datasheet of the RF power amplifier chip 200 often differs from that observed at the actual antenna port. To achieve maximum power matching, i.e., optimal load matching, the maximum power impedance point 20 of the RF power amplifier chip 200 and the antenna load impedance must be optimally matched.

[0041] Meanwhile, the circuit board with the RF power amplifier chip 200 is often determined in advance, and the only thing that can be modified and optimized is the antenna itself. At this time, it is necessary to design and optimize the optimal load impedance of the antenna. After the antenna is designed to resonate, its load impedance circle 10 will often fall on a certain quadrant of the Smith chart (efficiency chart), which may not match the maximum power impedance point 20 of the RF power amplifier chip 200. In this case, quadrant matching is required to achieve the optimal match between the maximum power impedance point 20 of the RF power amplifier chip 200 and the antenna load impedance circle 10, thereby achieving maximum power transmission.

[0042] Figure 2 This is a schematic diagram of the structure of the radiator 100 of the antenna provided in an embodiment of this application.

[0043] Therefore, please see Figure 2 As shown, this embodiment proposes an antenna, including: a radiator 100, which has an elongated structure, and a feed terminal 13 and a ground terminal 14 are provided at one end of the radiator 100 along a first direction A, wherein the first direction A is the length direction of the radiator 100; and a first slot 15, which is formed in the radiator 100 along the first direction A, and the first slot 15 is located near the feed terminal 13.

[0044] A first slot 15 is formed on the radiator 100 of the pre-designed antenna along the first direction A (i.e., the radiator 100 is a long strip structure, and the first direction A is its length direction). The first slot 15 is set close to the feed end 13 and extends along the first direction A, which changes the impedance of the antenna. The existing load impedance circle 10 of the antenna rotates and moves around the equal reflection coefficient circle 30 to realize the quadrant rotation of the antenna load impedance until the load impedance circle 10 of the antenna and the maximum power impedance point 20 of the RF power amplifier chip 200 are in the same quadrant. The optimal matching point between the load impedance circle 10 of the antenna and the impedance of the RF power amplifier chip 200 is found, thereby maximizing the power output of the RF antenna.

[0045] Regarding the specific dimensions of the first slot 15, the length L1 of the first slot 15 along the first direction A ranges from L1 > 25 mm; and / or, the width D1 of the first slot 15 ranges from D1 ≤ 0.8 mm. By setting the first slot 15 to an elongated shape, the load impedance circle 10 of the antenna rotates around the equal reflection coefficient circle 30, thereby placing it in the same quadrant as the maximum power impedance point 20 of the RF power amplifier chip 200, thus maximizing the power output of the RF antenna.

[0046] In addition, the power supply terminal 13 and the grounding terminal 14 extend along a second direction, which is the width direction of the radiator 100; a second groove 16 is formed between the power supply terminal 13 and the grounding terminal 14, and the first groove 15 and the second groove 16 are separated from each other by the power supply terminal 13.

[0047] The first slot 15 is used to control the phase change of the radiator 100 while ensuring that the wavelength resonant impedance of the antenna remains unchanged. The second slot 16 is used to control the changes in the wavelength resonant impedance of the antenna. It can be understood that the first slot 15 controls the rotation of the antenna's load impedance circle 10 around the equal reflection coefficient circle 30, while the second slot 16 determines the antenna's S-parameters and other performance characteristics. Without changing the parameters of the second slot 16 and under the premise that the second slot 16 and the first slot 15 are isolated from each other, by opening the first slot 15 only along the first direction A of the radiator 100, the existing load impedance circle 10 of the antenna can be rotated around the equal reflection coefficient circle 30. In this way, while keeping the wavelength resonant impedance of the antenna basically unchanged, the quadrant rotation of the antenna load impedance circle 10 is achieved, and the optimal match with the maximum power impedance point 20 of the RF power amplifier chip 200 is found, thereby maximizing the power output of the RF antenna.

[0048] In other words, on an antenna that has already been designed and debugged, by opening a first slot 15 along the first direction A on the radiator 100 near the feed end 13, the antenna impedance is changed, but the S-coefficient of the antenna is not changed, that is, the standing wave of the antenna itself is not changed. The change in antenna impedance can cause the load impedance circle 10 of the antenna to move around the circle of equal emission coefficient, thereby changing the quadrant position of the antenna load impedance circle 10, maximizing its matching with the maximum power impedance point 20 of the RF power amplifier chip 200, and realizing the maximum power output of the RF antenna.

[0049] Specifically, the width dimension D2 of the second slot 16 along the first direction A is in the range of D2≤1mm; and / or the length dimension L2 of the second slot 16 along the second direction is in the range of L2>4mm. When the parameters of the second slot 16 are set as described above, the wavelength resonant impedance and other parameters of the antenna are within a suitable range, thereby maximizing the power output of the radio frequency antenna by changing the antenna impedance.

[0050] Furthermore, the dimension L1 of the first slot 15 along the first direction A and the dimension L2 of the second slot 16 along the second direction must satisfy the following condition: L1 > L2. To ensure that the length of the first slot 15 is longer than the length of the second slot 16 (i.e., the first slot 15 is a long slot and the second slot 16 is a short slot), it is necessary to ensure that, without changing the S-coefficient, the antenna's load impedance circle 10 continuously rotates around the equal emission coefficient circle by changing the antenna's impedance. This allows the antenna's load impedance circle 10 to continuously match the maximum power impedance point 20 of the RF power amplifier chip 200, maximizing the power output of the RF antenna.

[0051] Please continue reading Figure 1 As shown, the first groove 15 has a first side 11 and a second side 12 that extend along the first direction A and are arranged opposite to each other. That is, the first side 11 and the second side 12 are both long sides of the radiator 100. Since the radiator 100 is long and narrow, the other two sides, namely the third side and the fourth side that are arranged opposite to each other and extend along the second direction, are short sides. Thus, in the counterclockwise direction, the first side 11, the third side, the fourth side and the second side 12 are connected end to end to form a closed long and narrow structure.

[0052] Furthermore, the feed terminal 13 and the ground terminal 14 extend from one end of the first side 11 along the first direction A. Both the feed terminal 13 and the ground terminal 14 extend in a direction away from the second side 12, and the feed terminal 13 is located on the side of the ground terminal 14 facing the center of the radiator 100. The feed terminal 13 and the ground terminal 14 both extend from the first side 11 along the second direction, and both extend away from the radiator 100. The extended feed terminal 13 and the ground terminal 14 are isolated from each other to prevent conduction. The first slot 15 is formed on the side of the feed terminal 13 away from the ground terminal 14, that is, the first slot 15 is close to the feed terminal 13 and adjacent to the first side 11, and extends along the first direction A, thereby causing a change in antenna impedance. The second slot 16 is formed along the second direction on the side of the feed terminal 13 facing the ground terminal 14. The second slot 16 is used to control the changes in the wavelength resonance impedance of the antenna, and the second slot 16 serves to isolate the ground terminal 14 and the feed terminal 13.

[0053] Figure 3 For based on Figure 1 Power-added efficiency diagram of RF power amplifier chip 200; Figure 4 For based on Figure 2 A schematic diagram showing the load impedance circle of the antenna located in the first quadrant; Figure 5 For based on Figure 2 A schematic diagram showing the load impedance of the antenna rotated to the fourth quadrant; Figure 6 For based on Figure 2 A schematic diagram showing the load impedance of the antenna rotated to the third quadrant; Figure 7 For based on Figure 2 A schematic diagram showing the load impedance of the antenna rotated to the second quadrant.

[0054] Please also see Figure 3 - Figure 7 As shown, this embodiment also provides an impedance tuning method for a radio frequency antenna link, including:

[0055] A first slot 15 is formed on the radiator 100 of the antenna. The radiator 100 has a long strip structure. One end of the radiator 100 along a first direction A is provided with a feed terminal 13 and a ground terminal 14 that are spaced apart. The first direction A is the length direction of the radiator 100. The first slot 15 extends from a position near the feed terminal 13 along the first direction A of the radiator 100.

[0056] The first slot 15 is used to rotate the impedance circle of the antenna around the equal reflection coefficient circle 30 to perform quadrant matching, so as to achieve the matching of the load impedance of the antenna with the maximum power impedance point 20 of the RF power amplifier chip 200.

[0057] The quadrant matching process, which involves rotating the antenna's impedance circle around the equal reflection coefficient circle 30 via the first slot 15, specifically includes:

[0058] The load impedance circle 10 of the antenna rotates cyclically in a clockwise direction, as shown in the figure. Figure 4 - Figure 7 The position is rotated clockwise around the equal reflection coefficient circle 30, and the load impedance circle 10 of the antenna is moved from the initial first quadrant Q1 (see continue to the previous section). Figure 4 (As shown) Rotate sequentially to the fourth quadrant Q4 (please continue to see) Figure 5 As shown), the third quadrant Q3 (please continue to see) Figure 6 (as shown) and the second quadrant Q2 (please continue to see) Figure 7 (as shown);

[0059] Please continue reading Figure 7As shown, the maximum power impedance point 20 of the RF power amplifier chip 200 is located in the second quadrant Q2. When the load impedance circle 10 of the antenna is rotated to the second quadrant Q2, the load impedance circle 10 of the antenna and the maximum power impedance point 20 of the RF power amplifier chip 200 are located in the same quadrant, thereby achieving the matching of the load impedance of the antenna with the maximum power impedance point 20 of the RF power amplifier chip 200.

[0060] It should be noted that since the load impedance circle 10 of the antenna rotates cyclically in a clockwise direction, when the maximum power impedance point 20 of the RF power amplifier chip 200 is located in the second quadrant Q2, the load impedance circle 10 of the antenna can rotate continuously to pass through the second quadrant Q2 multiple times, so as to achieve multiple matching between the load impedance circle 10 of the antenna and the maximum power impedance point 20 of the RF power amplifier chip 200, thereby maximizing the power output of the RF antenna.

[0061] It should be noted that the terms "one embodiment," "embodiment," "exemplary embodiment," "some embodiments," etc., mentioned in the specification indicate that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0062] It should be readily understood that the terms “on,” “above,” and “on top of” in this disclosure should be interpreted in the broadest possible sense, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on top of something” but also “on top of something” without an intermediate feature or layer therebetween (i.e., directly on something).

[0063] Furthermore, for ease of explanation, spatially relative terms such as "below," "below," "under," "above," and "above" may be used to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation other than those shown in the figures. The device may have other orientations (rotated 90 degrees or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.

[0064] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An antenna, characterized in that, include: The radiator has a long strip-shaped structure, and one end of the radiator along a first direction is provided with a feed terminal and a ground terminal that are spaced apart. The first direction is the length direction of the radiator. as well as A first groove is formed in the radiator along the first direction, and the first groove is positioned near the feed end; the sidewalls of the first groove are connected end to end in a ring shape, and the first groove is used to control the phase change of the radiator. The power supply terminal and the grounding terminal extend along a second direction, which is the width direction of the radiator; A second groove is formed between the power supply terminal and the grounding terminal, and the first groove and the second groove are isolated from each other by the power supply terminal; The dimensions L1 of the first tank along the first direction and the dimensions L2 of the second tank along the second direction must satisfy the following condition: L1 > L2.

2. The antenna according to claim 1, characterized in that, The length dimension L1 of the first groove along the first direction is in the range of L1 > 25 mm; and / or the width dimension D1 of the first groove is in the range of D1 ≤ 0.8 mm.

3. The antenna according to claim 1, characterized in that, The width dimension D2 of the second groove along the first direction is in the range of D2≤1mm; and / or the length dimension L2 of the second groove along the second direction is in the range of L2>4mm and L2<L1.

4. The antenna according to claim 1, characterized in that, The first tank has a first side and a second side extending along the first direction and arranged opposite to each other. The power supply end and the grounding end are formed extending from one end of the first side along the first direction. Both the power supply end and the grounding end extend in a direction away from the second side, and the power supply end is located on the side of the grounding end facing the center of the radiator. The first slot is located on the side of the power supply terminal away from the grounding terminal; The second groove is formed along the second direction on the side of the power supply terminal facing the ground terminal.

5. A radio frequency antenna link, characterized in that, include: The antenna as described in any one of claims 1 to 4; as well as The radio frequency power amplifier chip transmits power signals through a transmission line and matches the power signals to the antenna through a matching circuit.

6. An impedance tuning method for a radio frequency antenna link as described in claim 5, characterized in that, include: A first slot is formed on the radiator of the antenna. The radiator has a long strip structure. One end of the radiator along a first direction is provided with a feed terminal and a ground terminal that are spaced apart. The first direction is the length direction of the radiator. The first slot extends from a position near the feed terminal along the first direction of the radiator. The first slot is used to rotate the impedance circle of the antenna around the circle with equal reflection coefficient to perform quadrant matching, so as to achieve the matching of the load impedance of the antenna with the maximum power impedance point of the RF power amplifier chip.

7. The impedance tuning method according to claim 6, characterized in that, The step of rotating the antenna's impedance circle around a circle with equal reflection coefficients via the first slot for quadrant matching includes: The load impedance circle of the antenna rotates cyclically in a clockwise direction, so that the load impedance circle of the antenna rotates sequentially from the initial first quadrant to the fourth quadrant, the third quadrant, and the second quadrant. The maximum power impedance point of the RF power amplifier chip is located in the second quadrant. When the load impedance of the antenna is rotated to the second quadrant, the load impedance of the antenna is matched with the maximum power impedance point of the RF power amplifier chip.

8. An electronic device, characterized in that, Including the antenna as described in any one of claims 1-4.

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