Impedance matching method, device and system of telescopic antenna and wireless communication terminal

Abstract

The invention provides an impedance matching method, device and system of a telescopic antenna and a wireless communication terminal, and belongs to the technical field of wireless communication, and the method comprises the steps: determining the real-time length of the telescopic antenna; determining a real-time adjustment parameter of the impedance matching circuit based on the real-time length; and sending a control signal to the impedance matching circuit based on the real-time adjustment parameter, wherein the control signal is used for adjusting the characteristic impedance of the telescopic antenna. The real-time adjustment parameter of the impedance matching circuit is adjusted according to the real-time length of the telescopic antenna, so that the characteristic impedance of the telescopic antenna is adjusted, it is ensured that the characteristic impedance of the telescopic antenna is always matched with the characteristic impedance of a radio frequency system, and the communication effect of the telescopic antenna is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wireless communication, in particular to an impedance matching method, device and system of a pull rod antenna and a wireless communication terminal. BACKGROUND

[0002] In a wireless communication terminal device, an antenna is an important component. In low frequency band communication, a pull rod antenna is a common antenna solution. The pull rod antenna has the advantage of being retractable, so that the user can extend the antenna to obtain better signal transmission and reception performance, and can retract the pull rod antenna to reduce the length for easy carrying of the terminal.

[0003] A conventional pull rod antenna usually needs to be pulled out to the maximum length to achieve the best effect. When the antenna is not at the maximum length, the antenna operating frequency deviates from the original target operating frequency band due to the significant shortening of the antenna length, and the impedance matching between the antenna and the characteristic impedance of the radio frequency system becomes very poor. The transmitted signal will be reflected back to the radio frequency system due to impedance mismatch, affecting the communication performance. In such a case, the antenna communication link has a small margin, and when the length of the antenna changes and causes impedance mismatch, the performance of the antenna will be significantly reduced, affecting the communication effect between the terminal and the satellite, and even unable to communicate, missing the satellite transit communication window period. SUMMARY

[0004] The present application provides an impedance matching method, device and system of a pull rod antenna and a wireless communication terminal, aiming to solve the problem of impedance mismatch caused by the length change of the pull rod antenna, which causes poor communication performance.

[0005] In a first aspect, the present application provides an impedance matching method of a pull rod antenna, comprising: determining the real-time length of the pull rod antenna; determining the real-time adjustment parameter of the impedance matching circuit based on the real-time length; sending a control signal to the impedance matching circuit based on the real-time adjustment parameter, the control signal being used to adjust the characteristic impedance of the pull rod antenna.

[0006] In an embodiment, the real-time length of the pull rod antenna is determined, specifically comprising: receiving the rotation amount of the gear detected by the angle sensor, the gear rotating synchronously with the extension and retraction of the pull rod antenna; determining the real-time length based on the outer circumference of the gear and the rotation amount.

[0007] In an embodiment, the real-time adjustment parameter of the impedance matching circuit is determined based on the real-time length, specifically comprising: determine a length switching gear corresponding to the real-time length, the length switching gear representing a length range of the pull rod antenna; use the adjustment parameter corresponding to the length switching gear as the real-time adjustment parameter.

[0008] In an embodiment, when the length switching gear is not the highest length switching gear, the upper limit value of the length switching gear is determined based on the first original gear length and the second original gear length of the pull rod antenna; when the length switching gear is not the lowest length switching gear, the lower limit value of the length switching gear is determined based on the first original gear length and the third original gear length of the pull rod antenna; Each section of the pull rod antenna corresponds to an original gear length, which represents the length of the pull rod antenna when all sections between the section and the base section are pulled out. The second original gear length, the first original gear length, and the third original gear length gradually decrease.

[0009] In an embodiment, when the length switching gear is not the highest length switching gear, the upper limit value is the first average of the first original gear length and the second original gear length; when the length switching gear is not the lowest length switching gear, the lower limit value is the second average of the first original gear length and the third original gear length.

[0010] In an embodiment, when the pull rod antenna is being stretched: when the real-time length is between the first adjustment lower limit value and the first adjustment upper limit value, the real-time adjustment parameter is adjusted to the adjustment parameter corresponding to the length switching gear one gear higher; when the length switching gear one gear higher is not the highest length switching gear, the first adjustment upper limit value is the sum of the upper limit value of the length switching gear one gear higher and the buffer value; the first adjustment lower limit value is the sum of the lower limit value of the length switching gear one gear higher and the buffer value.

[0011] In an embodiment, when the pull rod antenna is being retracted: when the real-time length is between the second adjustment lower limit value and the second adjustment upper limit value, the real-time adjustment parameter is adjusted to the adjustment parameter corresponding to the length switching gear one gear lower; the second adjustment upper limit value is the difference between the upper limit value of the length switching gear one gear lower and the buffer value; when the length switching gear one gear lower is not the lowest length switching gear, the second adjustment lower limit value is the difference between the lower limit value of the length switching gear one gear lower and the buffer value.

[0012] In a second aspect, the application also provides an impedance matching device for a pull rod antenna, comprising: A real-time length determination module is configured to determine a real-time length of the pull rod antenna. An adjustment parameter determination module is configured to determine a real-time adjustment parameter of the impedance matching circuit based on the real-time length. A control module is configured to send a control signal to the impedance matching circuit based on the real-time adjustment parameter, and the control signal is used to adjust the characteristic impedance of the pull rod antenna.

[0013] In a third aspect, the application further provides an impedance matching system of a pull rod antenna, which comprises a transmission assembly, an angle sensor, a main control unit and an impedance matching circuit. The transmission assembly comprises intermeshing gears and a toothed transmission belt, the gears are rotationally arranged in a main body in which the pull rod antenna is deployed, and one end of the toothed transmission belt is fixed to an outer end of the pull rod antenna and extends into the main body through an inner hole of an innermost segment of the pull rod antenna. The angle sensor is configured to collect the rotation amount of the gears. The main control unit is in signal connection with the angle sensor, and the main control unit is configured to receive the detection information of the angle sensor, determine the real-time length of the pull rod antenna, determine the real-time adjustment parameter of the impedance matching circuit based on the real-time length, and send a control signal to the impedance matching circuit based on the real-time adjustment parameter. One end of the impedance matching circuit is in signal connection with a radio frequency system, and the other end of the impedance matching circuit is connected to a feed point of the pull rod antenna, and the impedance matching circuit is provided with an adjustment element, and the control signal is used to adjust the value of the adjustment element to adjust the characteristic impedance of the pull rod antenna.

[0014] In an embodiment, a first adjustment capacitor and a first fixed inductor are connected in series between the two ends of the impedance matching circuit, one end of the first adjustment capacitor away from the first fixed inductor is connected to a first end of a second fixed inductor, a second end of the second fixed inductor is connected to a first end of a second adjustment capacitor, and a second end of the second adjustment capacitor is grounded. The main control unit controls the capacitance values of the first adjustment capacitor and the second adjustment capacitor through the first control signal and the second control signal respectively.

[0015] In a fourth aspect, the application further provides a wireless communication terminal, which comprises a pull rod antenna and the impedance matching system of the pull rod antenna described above. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0017] Figure 1is one of flow charts of the impedance matching method of the pull rod antenna provided in the present application; Figure 2 is one of flow charts of the impedance matching method of the pull rod antenna provided in the present application; Figure 3 is one of structural schematic diagrams of the impedance matching device of the pull rod antenna provided in the present application; Figure 4 is one of structural schematic diagrams of the impedance matching system of the pull rod antenna provided in the present application; Figure 5 is one of schematic diagrams of the impedance matching circuit of the pull rod antenna provided in the present application; Figure 6 is one of structural schematic diagrams of the pull rod antenna and the transmission assembly provided in the present application; Figure 7 is the result of the reflection coefficient obtained in the original state of the simulation antenna provided in the present application; Figure 8 is the result of the reflection coefficient obtained in the state of the simulation antenna provided in the present application. DETAILED DESCRIPTION

[0018] In order to make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those of ordinary skill in the art without any creative work fall within the scope of protection of the present application.

[0019] It should be noted that in the description of the present application, the terms "comprising", "containing" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or device. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of other identical elements in the process, method, article or device comprising the element. The terms "upper", "lower" and the like indicate the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. Unless otherwise specified and limited, the terms "mounting", "connecting", "connecting" should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0020] The terms "first", "second", and the like used in the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than that illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally a class, and do not limit the number of objects, for example, the first object can be one or more. In addition, "and / or" means at least one of the connected objects, and the character " / ", generally means that the front and rear associated objects are in a "or" relationship.

[0021] The following will be described in conjunction with Figures 1 to 8 The impedance matching method, device, system and wireless communication terminal of the pull rod antenna provided by the present application are described.

[0022] It should be noted that the impedance matching method of the pull rod antenna provided by the embodiments of the present application is realized based on the impedance matching device of the pull rod antenna. The impedance matching method of the pull rod antenna adjusts the characteristic impedance of the pull rod antenna based on the real-time pull-out length of the pull rod antenna, ensures that the characteristic impedance of the pull rod antenna is always matched with the radio frequency system at any stretching length, effectively improves the communication effect of the pull rod antenna, and at the same time, the pull rod antenna can be retracted when not in use, facilitating terminal carrying.

[0023] Figure 1 is one of the flowcharts of the impedance matching method of the pull rod antenna provided by the present application. AsFigure 1 As shown, the method for matching impedance of the pull rod antenna provided by the present application comprises: S110: determining the real-time length of the pull rod antenna.

[0024] The pull rod antenna comprises a plurality of segments, each of which is a hollow cylinder, the diameter of the segments decreases layer by layer, so that the segments are nested layer by layer from the outside to the inside, and the progressive diameter difference fit between the segments ensures the ohmic contact during the telescopic sliding.

[0025] During the process of pulling out or retracting the pull rod antenna, the real-time length of the pull rod antenna can be determined by the length measuring component.

[0026] S120: determining the real-time adjustment parameter of the impedance matching circuit based on the real-time length.

[0027] The impedance matching circuit adjusts the characteristic impedance of the pull rod antenna by adjusting the value of the internal adjustment element, so that the characteristic impedance of the pull rod antenna matches the characteristic impedance of the radio frequency system, and the communication performance of the pull rod antenna is ensured.

[0028] Specifically, different lengths of the pull rod antenna correspond to different characteristic impedances. The corresponding relationship between different characteristic impedances and the adjustment parameter of the impedance matching circuit, i.e., the corresponding relationship between different lengths and the adjustment parameter of the impedance matching circuit, is calibrated by testing in the research and development stage. Therefore, after the real-time length of the pull rod antenna is determined, the real-time adjustment parameter of the impedance matching circuit can be determined.

[0029] S130: sending a control signal to the impedance matching circuit based on the real-time adjustment parameter, the control signal being used to adjust the characteristic impedance of the pull rod antenna.

[0030] Specifically, the impedance matching circuit adjusts the value of the internal adjustment element based on the control signal to adjust the characteristic impedance of the pull rod antenna.

[0031] The embodiments of the present application adjust the real-time adjustment parameter of the impedance matching circuit according to the real-time length of the pull rod antenna, so as to adjust the characteristic impedance of the pull rod antenna, and ensure that the characteristic impedance of the pull rod antenna always matches the characteristic impedance of the radio frequency system, thereby effectively improving the communication effect of the pull rod antenna.

[0032] In a possible implementation manner, the innermost segments of the pull rod antenna are embedded in the main body (for example, a wireless communication terminal) in which the pull rod antenna is deployed. During the process of stretching or retracting the pull rod antenna, the innermost segments are pulled out or retracted by the same length.

[0033] In such embodiments, in a possible implementation manner, the real-time length is determined based on the detection signal of the angle sensor. As shown in the figure, Figure 2 As shown, the method for matching impedance of the pull rod antenna provided by the present application comprises: S210: receive the rotation amount of the gear detected by the angle sensor. Wherein, the gear rotates synchronously with the telescopic rod antenna (i.e. synchronously with the telescopic rod antenna).

[0034] In a possible implementation, the rotation amount includes the number of rotations and the rotation angle, and the rotation angle is less than 360°. That is, the angle sensor can detect the number of rotations of the gear and the angle less than a full rotation.

[0035] S220: determine the real-time length based on the outer circumference of the gear and the rotation amount.

[0036] It can be understood that the total number of rotations of the gear (which may be a decimal number) can be calculated based on the number of rotations of the gear and the rotation angle after unit conversion, and then the product of the total number of rotations and the outer circumference of the gear is taken as the real-time length.

[0037] S230: determine the real-time adjustment parameter of the impedance matching circuit based on the real-time length. Please refer to step S120.

[0038] S240: send a control signal to the impedance matching circuit based on the real-time adjustment parameter, and the control signal is used to adjust the characteristic impedance of the telescopic rod antenna.

[0039] The embodiment of the present application detects the rotation amount of the gear through the angle sensor, realizes the measurement of the real-time length of the antenna, the gear transmission structure is simple, the measurement is accurate, and the adjustment accuracy of the characteristic impedance of the telescopic rod antenna can be ensured.

[0040] In a possible implementation, in step S120, the real-time adjustment parameter of the impedance matching circuit is determined based on the real-time length, and specifically includes: S1201: determine the length switching gear in which the real-time length is located, and the length switching gear represents a length range of the telescopic rod antenna.

[0041] S1202: take the adjustment parameter corresponding to the length switching gear as the real-time adjustment parameter.

[0042] It can be understood that different antenna lengths correspond to different characteristic impedances, therefore, a plurality of length switching gears need to be divided in the whole length range of the telescopic rod antenna, so as to determine the corresponding adjustment parameter according to different length switching gears.

[0043] In the embodiment of the present application, the antenna lengths in the same length switching gear correspond to the same set of adjustment parameters, which avoids the negative impact of frequent switching of the antenna characteristic impedance on the communication performance of the antenna.

[0044] When determining the length switching gear, theoretically, the upper limit of the length switching gear cannot exceed the maximum length of the rod antenna, i.e. the length of the rod antenna after all the segments are pulled out; the lower limit of the length switching gear cannot be less than the minimum length of the rod antenna, i.e. the length of the outermost segment (base segment) of the rod antenna (at this time all the internal segments are retracted into the base segment).

[0045] On the basis of the above principle, in one possible implementation, when the length switching gear is not the highest length switching gear, the upper limit of the length switching gear is determined based on the first original gear length and the second original gear length of the rod antenna. The upper limit of the highest length switching gear is the first original gear length, i.e. the maximum length of the rod antenna.

[0046] And, when the length switching gear is not the lowest length switching gear, the lower limit of the length switching gear is determined based on the first original gear length and the third original gear length of the rod antenna. The lower limit of the lowest length switching gear is the first original gear length, i.e. the length of the base segment.

[0047] Wherein, the second original gear length, the first original gear length and the third original gear length gradually decrease.

[0048] Wherein, the adjustment parameter corresponding to the antenna length in the length switching gear is the adjustment parameter corresponding to the first original gear length (obtained through testing in the research and development stage).

[0049] Specifically, each segment of the rod antenna corresponds to an original gear length, and the original gear length represents the length of the rod antenna after all the segments between the segment and the base segment are pulled out.

[0050] The length switching gear is described as follows with the rod antenna having five segments as an example. In the rod antenna having five segments (base segment, first intermediate segment, second intermediate segment, third intermediate segment and innermost segment), the antenna length is divided into five original gear lengths, i.e. L1, L2, L3, L4, L5 five states. Wherein, L1 is the length of the base segment; L2 is the sum of the lengths of the base segment and the first intermediate segment; L3 is the sum of the lengths of the base segment, the first intermediate segment and the second intermediate segment; L4 is the sum of the lengths of the base segment, the first intermediate segment, the second intermediate segment and the third intermediate segment, and L5 is the sum of the lengths of all the segments, i.e. the maximum length of the rod antenna. The characteristic impedance corresponding to the five original gear lengths is tested in the research and development stage, and the adjustment parameters P1, P2, P3, P4, P5 of the impedance matching circuit are obtained.

[0051] In this embodiment, in impedance matching, the antenna length is divided into five length switching gears, G1, G2, G3, G4, and G5. Among them, G1 is the lowest length switching gear, the first original gear length is L1, the lower limit value is L1 (i.e. the first original gear length of this gear), and the upper limit value is determined by L1 and the second original gear length L2. The adjustment parameter corresponding to the antenna length in this length switching gear is P1. The first original gear length of G2 is L2, the lower limit value is determined by L2 and the third original gear length L1, and the upper limit value is determined by L2 and the second original gear length L3. The adjustment parameter corresponding to the antenna length in this length switching gear is P2. The first original gear length of G3 is L3, the lower limit value is determined by L3 and the third original gear length L2, and the upper limit value is determined by L3 and the second original gear length L4. The adjustment parameter corresponding to the antenna length in this length switching gear is P3. The first original gear length of G4 is L4, the lower limit value is determined by L4 and the third original gear length L3, and the upper limit value is determined by L4 and the second original gear length L5. The adjustment parameter corresponding to the antenna length in this length switching gear is P4. G5 is the highest length switching gear, the first original gear length is L5, the upper limit value is L5 (i.e. the first original gear length of this gear), and the lower limit value is determined by L5 and the third original gear length L4. The adjustment parameter corresponding to the antenna length in this length switching gear is P5.

[0052] The embodiment of the present application determines the switching boundary of the length switching gear based on the original gear length and the adjacent two original gear lengths, and takes the adjustment parameter of the original gear length as the adjustment parameter of the length switching gear. In the case of avoiding frequent switching of antenna characteristic impedance, the adjustment parameter is better adapted to the antenna length in the length switching gear, and the accuracy of the antenna characteristic impedance is ensured.

[0053] On the basis of the above principle, in a possible implementation, in the case that the length switching gear is not the highest length switching gear, the upper limit value is the first average of the first original gear length and the second original gear length; and the upper limit value of the highest length switching gear is the first original gear length of this length switching gear, i.e. the maximum length of the pull rod antenna.

[0054] In addition, in the case that the length switching gear is not the lowest length switching gear, the lower limit value is the second average of the first original gear length and the third original gear length. The lower limit value of the lowest length switching gear is the first original gear length of this length switching gear, i.e. the length of the coxa.

[0055] Taking the pull rod antenna with five segments as an example, in this embodiment, in impedance matching, the antenna length is divided into five length switching gears: G1: L1~(L1+L2) / 2, the gear is the lowest length switching gear, the first original gear length is L1, the second original gear length is L2, the lower limit value is L1, and the adjustment parameter corresponding to the antenna length in the length switching gear is P1; G2: (L1+L2) / 2~(L2+L3) / 2, the first original gear length of the gear is L2, the second original gear length is L3, and the third original gear length is L1, and the adjustment parameter corresponding to the antenna length in the length switching gear is P2; G3: (L2+L3) / 2~(L3+L4) / 2, the first original gear length of the gear is L3, the second original gear length is L4, and the third original gear length is L2, and the adjustment parameter corresponding to the antenna length in the length switching gear is P3; G4: (L3+L4) / 2~(L4+L5) / 2, the first original gear length of the gear is L4, the second original gear length is L5, and the third original gear length is L3, and the adjustment parameter corresponding to the antenna length in the length switching gear is P4; G5: (L4+L5) / 2~L5, the gear is the highest length switching gear, the first original gear length is L5, and the third original gear length is L4, and the upper limit value is L5, and the adjustment parameter corresponding to the antenna length in the length switching gear is P5.

[0056] In the embodiment of the application, the average of the original gear length and the adjacent original gear length is taken as the switching boundary of the length switching gear, and the adjustment parameter of the original gear length is taken as the adjustment parameter of the length switching gear, so that the length switching gear is more balanced, the adjustment parameter is more accurately adapted to the antenna length in the length switching gear, and the accuracy of the antenna characteristic impedance is ensured.

[0057] In a possible implementation, during the stretching of the pull rod antenna: When the real-time length is between the first adjustment lower limit value and the first adjustment upper limit value, the real-time adjustment parameter is adjusted to the adjustment parameter corresponding to the length switching gear of the next higher gear; In the case where the length switching gear of the next higher gear is not the highest length switching gear, the first adjustment upper limit value is the sum of the upper limit value of the length switching gear of the next higher gear and the buffer value, the first adjustment upper limit value of the highest length switching gear is the maximum length L5 of the pull rod antenna, and the first adjustment lower limit value is the sum of the lower limit value of the length switching gear of the next higher gear and the buffer value.

[0058] Taking the pull rod antenna with five segments as an example, in the embodiment, during the stretching of the pull rod antenna, the switching points of the five length switching gears are provided with a buffer value LX. Specifically, with the change of the real-time length L0 of the antenna, the switching time is as follows: L1≤L0<(L1+L2) / 2+LX, the adjusting parameter is P1, wherein (L1+L2) / 2+LX is the first adjusting upper limit value, and L1 is the first adjusting lower limit value; (L1+L2) / 2+LX<L0<(L2+L3) / 2+LX, the adjusting parameter is P2, wherein (L2+L3) / 2+LX is the first adjusting upper limit value, and (L1+L2) / 2+LX is the first adjusting lower limit value; (L2+L3) / 2+LX<L0<(L3+L4) / 2+LX, the adjusting parameter is P3, wherein (L3+L4) / 2+LX is the first adjusting upper limit value, and (L2+L3) / 2+LX is the first adjusting lower limit value; (L3+L4) / 2+LX<L0<(L4+L5) / 2+LX, the adjusting parameter is P4, wherein (L4+L5) / 2+LX is the first adjusting upper limit value, and (L3+L4) / 2+LX is the first adjusting lower limit value; (L4+L5) / 2+LX<L0<L5, the adjusting parameter is P5, wherein L5 is the first adjusting upper limit value, and (L4+L5) / 2+LX is the first adjusting lower limit value.

[0059] In the embodiment, each length switching gear has a buffer space determined by the buffer value LX. When the growth of the antenna length exceeds the buffer space, the adjusting parameter is adjusted to the adjusting parameter corresponding to the length switching gear of the next higher gear, so as to avoid the impedance mismatch caused by the false switching of the characteristic impedance of the antenna due to the length detection error or the slight change of the antenna length.

[0060] In a possible implementation, during the retracting of the pull rod antenna: when the real-time length is between the second adjusting lower limit value and the second adjusting upper limit value, the real-time adjusting parameter is adjusted to the adjusting parameter corresponding to the length switching gear of the next lower gear; the second adjusting upper limit value is the difference between the upper limit value of the length switching gear of the next lower gear and the buffer value. In the case that the length switching gear is not the lowest length switching gear, the second adjusting lower limit value is the difference between the lower limit value of the length switching gear of the next lower gear and the buffer value; and the lower limit value of the lowest length switching gear is the length L1 of the base section.

[0061] Taking the pull rod antenna with five sections as an example, during the retracting of the pull rod antenna, the buffer value LX is set at the switching points of the five length switching gears. Specifically, with the change of the real-time length L0 of the antenna, the switching time is as follows: (L4+L5) / 2-LX<L0<L5, the adjusting parameter is P5, wherein L5 is a second adjusting upper limit value, (L4+L5) / 2-LX is a second adjusting lower limit value; (L3+L4) / 2-LX<L0<(L4+L5) / 2-LX, the adjusting parameter is P4, wherein (L4+L5) / 2-LX is a second adjusting upper limit value, (L3+L4) / 2-LX is a second adjusting lower limit value; (L2+L3) / 2-LX<L0<(L3+L4) / 2-LX, the adjusting parameter is P3, wherein (L3+L4) / 2-LX is a second adjusting upper limit value, (L2+L3) / 2-LX is a second adjusting lower limit value; (L1+L2) / 2-LX<L0<(L2-L3) / 2-LX, the adjusting parameter is P2, wherein (L1+L2) / 2-LX is a second adjusting upper limit value, (L2-L3) / 2-LX is a second adjusting lower limit value; L1≤L0<(L1+L2) / 2-LX, the adjusting parameter is P1, wherein (L1+L2) / 2-LX is a second adjusting upper limit value, L1 is a second adjusting lower limit value.

[0062] In the embodiments of the present application, each length switching gear has a buffer space determined by a buffer value LX. When the shortening of the antenna length exceeds the buffer space, the adjusting parameter is adjusted to the adjusting parameter corresponding to the length switching gear of the lower gear, so as to avoid the impedance mismatch caused by the false switching of the characteristic impedance of the antenna due to the length detection error or the slight change of the antenna length.

[0063] Based on the above, the present application further provides an impedance matching device of a pull rod antenna. The impedance matching device of the pull rod antenna can be correspondingly referred to the impedance matching method of the pull rod antenna.

[0064] As an embodiment, as shown in Figure 3 The impedance matching device of the pull rod antenna comprises: A real-time length determination module 310 is configured to determine the real-time length of the pull rod antenna; An adjusting parameter determination module 320 is configured to determine the real-time adjusting parameter of the impedance matching circuit based on the real-time length; A control module 330 is configured to send a control signal to the impedance matching circuit based on the real-time adjusting parameter, and the control signal is used to adjust the characteristic impedance of the pull rod antenna.

[0065] The embodiments of the present application adjust the real-time adjusting parameter of the impedance matching circuit according to the real-time length of the pull rod antenna, so as to adjust the characteristic impedance of the pull rod antenna, and ensure that the characteristic impedance of the pull rod antenna is always matched with the characteristic impedance of the radio frequency system, thereby effectively improving the communication effect of the pull rod antenna.

[0066] In a possible implementation, the real-time length determination module 310 is specifically configured to: receive the rotation amount of the gear detected by the angle sensor, the gear rotating synchronously with the extension and retraction of the pull rod antenna; determine the real-time length based on the outer circumference of the gear and the rotation amount.

[0067] The embodiment of the application realizes the measurement of the real-time length of the antenna by detecting the rotation amount of the gear through the angle sensor, has a simple structure, is accurate in measurement, and ensures the accuracy of the adjustment of the characteristic impedance of the pull rod antenna.

[0068] In a possible implementation, the adjustment parameter determination module 320 is specifically configured to: determine a length switching gear in which the real-time length is located, the length switching gear representing a length range of the pull rod antenna; use the adjustment parameter corresponding to the length switching gear as the real-time adjustment parameter.

[0069] In the embodiment of the application, the antenna length in the same length switching gear corresponds to the same set of adjustment parameters, thereby avoiding the negative impact of the frequent switching of the antenna characteristic impedance on the communication performance of the antenna.

[0070] Based on the above, the application further provides an impedance matching system of a pull rod antenna. As shown in Figure 4 , the impedance matching system of the pull rod antenna includes a transmission assembly, an angle sensor, a main control unit, and an impedance matching circuit. The transmission assembly and the angle sensor are made of non-metallic materials to avoid affecting the antenna.

[0071] Please refer to Figure 6 , the transmission assembly includes a gear 640 and a toothed transmission belt 650 that are engaged with each other. The gear 640 is rotationally arranged in a main body 610 in which the pull rod antenna 620 is deployed. One end of the toothed transmission belt 650 is fixed to an outer end portion 6201 of the pull rod antenna 620, extends into the main body 610 through an inner hole of an innermost segment of the pull rod antenna 620, and is engaged with the gear 640. Specifically, the main body 610 is provided with a guide rail for guiding the toothed transmission belt 650 to prevent the toothed transmission belt 650 from deviating. The guide rail can extend along multiple adjacent sides of the main body 610 to form a U-shaped guide rail to accommodate a longer toothed transmission belt 650 to adapt to the case where the length of the toothed transmission belt 650 is greater than the height of the main body 610. The angle sensor 630 is used to collect the rotation amount of the gear 640, such as the number of rotation circles and the rotation angle. In this way, during the process of the user stretching or retracting the pull rod antenna, the gear rotates synchronously with the stretching or retraction of the pull rod antenna.

[0072] In a possible implementation, the angle sensor is mounted on the gear shaft, and when the gear rotates synchronously with the stretching or retracting of the pull rod antenna, the angle sensor rotates with the gear to collect the rotation amount of the gear.

[0073] The main control unit is connected with the angle sensor, and the main control unit is configured to receive the detection information of the angle sensor (i.e., the rotation amount of the gear), determine the real-time length of the pull rod antenna based on the detection information, determine the real-time adjustment parameter of the impedance matching circuit based on the real-time length, and send the control signal to the impedance matching circuit based on the real-time adjustment parameter.

[0074] Please refer to Figure 5 , one end of the impedance matching circuit is connected with the signal of the radio frequency system, the other end of the impedance matching circuit is connected with the feed point of the pull rod antenna, the impedance matching circuit is provided with an adjustment element, and the control signal is used to adjust the value of the adjustment element, so as to adjust the characteristic impedance of the pull rod antenna, so as to match the characteristic impedance of the radio frequency system, and ensure the signal transmission performance and signal receiving performance of the radio frequency system.

[0075] The embodiment of the present application sets the toothed transmission belt on the pull rod antenna, and the meshing of the gear and the toothed transmission belt enables the angle sensor to collect the rotation amount of the gear, so as to realize the measurement of the real-time length of the antenna, and determine the real-time adjustment parameter of the impedance matching circuit according to the length of the antenna, so as to adjust the characteristic impedance of the pull rod antenna, so as to always match the radio frequency system, and effectively improve the communication effect of the pull rod antenna.

[0076] In a possible implementation, as shown in Figure 5 , the first adjustment capacitor C1 (adjustment element) and the first fixed inductor L1 are connected in series between the two ends of the impedance matching circuit, one end of the first adjustment capacitor C1 away from the first fixed inductor L1 is connected with the first end of the second fixed inductor L2, the second end of the second fixed inductor L2 is connected with the first end of the second adjustment capacitor C2 (adjustment element), and the second end of the second adjustment capacitor C2 is grounded.

[0077] As shown in Figure 5 , the main control unit controls the capacitance values of the first adjustment capacitor C1 and the second adjustment capacitor C2 through the first control signal and the second control signal respectively.

[0078] In the embodiment of the present application, one adjustment element is arranged on the series branch and the parallel branch of the impedance matching circuit respectively, and the characteristic impedance of the pull rod antenna is changed by adjusting the values of the two adjustment elements. Compared with the scheme with one adjustment element, the scheme with two adjustment elements improves the flexibility of adjustment, thereby improving the accuracy of adjustment.

[0079] It should be noted that the main control unit can execute all the embodiments of the impedance matching method of the pull rod antenna described above.

[0080] The following is an example of the above-described five-segment pull rod antenna. The adjustment parameters of the length switching gear are described in combination with the above-described impedance matching circuit. In the five-segment pull rod antenna, the antenna length is divided into five original gear lengths, i.e., L1, L2, L3, L4, and L5. The characteristic impedance corresponding to the five original gear lengths is tested in the research and development stage, and five sets of adjustment parameters of the first adjustment capacitor and the second adjustment capacitor in the impedance matching circuit are obtained: (C 11 , 21 ), (C 12 , 22 ), (C 13 , 23 ), (C 14 , 24 ), and (C 15 , 25 ).

[0081] Taking the embodiment provided with the buffer value LX as an example, during the process in which the user stretches the pull rod antenna, the switching timing is as follows with the real-time change of the antenna length L0: When the user stretches the pull rod antenna to L1≤L0<(L1+L2) / 2, the main control unit controls the capacitance value of the first adjustment capacitor C1 to be adjusted to C 11 by the first control signal, controls the capacitance value of the second adjustment capacitor C2 to be adjusted to C 21 by the second control signal, and ensures that the characteristic impedance of the antenna is completely matched with the characteristic impedance of the radio frequency system at this time; when the user stretches the pull rod antenna to (L1+L2) / 2≤L0<(L1+L2) / 2+LX, the antenna length is in the buffer zone, the capacitance value of the first adjustment capacitor C1 is still maintained at C 11 , the capacitance value of the second adjustment capacitor C2 is still maintained at C 21 , and the subsequent analogy is performed; when the user stretches the pull rod antenna to (L1+L2) / 2+LX<L0<(L2+L3) / 2+LX, the main control unit controls the capacitance value of the first adjustment capacitor C1 to be adjusted to C 12 by the first control signal, controls the capacitance value of the second adjustment capacitor C2 to be adjusted to C 22 by the second control signal, and ensures that the characteristic impedance of the antenna is completely matched with the characteristic impedance of the radio frequency system at this time; when the user stretches the pull rod antenna to (L2+L3) / 2+LX<L0<(L3+L4) / 2+LX, the main control unit controls the capacitance value of the first adjustment capacitor C1 to be adjusted to C 13 by the first control signal, controls the capacitance value of the second adjustment capacitor C2 to be adjusted to C 23, the characteristic impedance of the antenna is completely adapted to the characteristic impedance of the radio frequency system; when the user stretches the pull rod antenna to (L3+L4) / 2+LX 14 , the main control unit controls the second adjusting capacitor C2 to adjust the capacitance value to C 24 , the characteristic impedance of the antenna is completely adapted to the characteristic impedance of the radio frequency system; when the user stretches the pull rod antenna to (L4+L5) / 2+LX 15 , the main control unit controls the second adjusting capacitor C2 to adjust the capacitance value to C 25 , the characteristic impedance of the antenna is completely adapted to the characteristic impedance of the radio frequency system.

[0082] During the process of the user retracting the pull rod antenna, with the change of the real-time length L0 of the antenna, the switching time is as follows: If (L4+L5) / 2+LX 15 , the second adjusting capacitor C2 keeps the capacitance value at C 25 , the characteristic impedance of the antenna is completely adapted to the characteristic impedance of the radio frequency system. When the user retracts the pull rod antenna to (L4+L5) / 2-LX 15 , the second adjusting capacitor C2 keeps the capacitance value at C 25 , the subsequent analogy; when the user retracts the pull rod antenna to (L3+L4) / 2-LX 14 , the main control unit controls the second adjusting capacitor C2 to adjust the capacitance value to C 24 , the characteristic impedance of the antenna is completely adapted to the characteristic impedance of the radio frequency system; when the user retracts the pull rod antenna to (L2+L3) / 2-LX 13 , the main control unit controls the second adjusting capacitor C2 to adjust the capacitance value to C 23, the characteristic impedance of the antenna is completely adapted to the characteristic impedance of the radio frequency system; when the user retracts the pull rod antenna to L1≤L0<(L1+L2) / 2-LX, the main control unit controls the first adjusting capacitor C1 to adjust the capacitance value to C 12 , controls the second adjusting capacitor C2 to adjust the capacitance value to C 22 , the characteristic impedance of the antenna is completely adapted to the characteristic impedance of the radio frequency system; when the user retracts the pull rod antenna to L1≤L0<(L1+L2) / 2-LX, the main control unit controls the first adjusting capacitor C1 to adjust the capacitance value to C 11 , controls the second adjusting capacitor C2 to adjust the capacitance value to C 21 , the characteristic impedance of the antenna is completely adapted to the characteristic impedance of the radio frequency system.

[0083] The technical effects of the present application are illustrated by an example as follows: A model is established by using an antenna three-dimensional electromagnetic simulation software, and the reflection coefficient S(1, 1) results of different original gear lengths of the antenna in the original state are simulated according to the antenna lengths of 50 / 80 / 110 / 140 / 170 (unit: millimeter) five original gear lengths. S(1, 1) reflects whether the characteristic impedance of the pull rod antenna is adapted to the characteristic impedance of the radio frequency system. The more adapted the characteristic impedance of the pull rod antenna is to the characteristic impedance of the radio frequency system, the smaller S(1, 1) is; otherwise, the larger S(1, 1) is. The reflection coefficient S(1, 1) obtained by simulating the original state of the antenna is shown in Table 1. Figure 7 According to the present application, the capacitance values of the two adjusting capacitors in the impedance matching circuit are controlled after detecting the real-time length of the antenna, so as to ensure that the antenna is matched to the consistent characteristic impedance of the radio frequency system, so that S(1, 1) becomes smaller. It has been verified that, based on the present application, after matching the five states by adjusting the capacitance values of the two adjusting capacitors, the simulation results show that the antenna impedance and the radio frequency system impedance are very close in the five states of the antenna lengths of 50 / 80 / 110 / 140 / 170 (unit: millimeter), the matched S(1, 1) results are shown in Table 2, and the performance is obviously optimized, which can improve the communication performance of the pull rod antenna when used in the wireless communication terminal. Figure 8

[0084] Based on the above, the present application also provides a wireless communication terminal, which comprises a pull rod antenna and the impedance matching system of the pull rod antenna.

[0085] ​Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the same; although the present application has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An impedance matching method for a telescopic antenna, characterized in that, include: Determine the real-time length of the telescopic antenna; The real-time adjustment parameters of the impedance matching circuit are determined based on the real-time length. Based on the real-time adjustment parameters, a control signal is sent to the impedance matching circuit, and the control signal is used to adjust the characteristic impedance of the telescopic antenna.

2. The impedance matching method for a telescopic antenna according to claim 1, characterized in that, Determining the real-time length of the telescopic antenna specifically includes: The rotation of the gear is detected by the angle sensor, and the gear rotates synchronously with the extension and retraction of the telescopic antenna; The real-time length is determined based on the outer circumference of the gear and the amount of rotation.

3. The impedance matching method for a telescopic antenna according to claim 1, characterized in that, The determination of the real-time adjustment parameters of the impedance matching circuit based on the real-time length specifically includes: Determine the length switching gear where the real-time length is located, where the length switching gear represents a length range of the telescopic antenna; The adjustment parameter corresponding to the length switching gear is used as the real-time adjustment parameter.

4. The impedance matching method for a telescopic antenna according to claim 3, characterized in that, When the length switching position is not the highest length switching position, the upper limit of the length switching position is determined based on the first original position length and the second original position length of the telescopic antenna. If the length switching position is not the lowest length switching position, the lower limit of the length switching position is determined based on the first original position length and the third original position length of the telescopic antenna. Each segment on the telescopic antenna corresponds to an initial span length, which represents the length of the telescopic antenna after all segments between the segment and the base segment have been pulled out; the second initial span length, the first initial span length, and the third initial span length gradually decrease.

5. The impedance matching method for a telescopic antenna according to claim 4, characterized in that, When the length switching gear is not the highest length switching gear, the upper limit value is the first average value of the first original gear length and the second original gear length; When the length switching gear is not the lowest length switching gear, the lower limit value is the second average of the first original gear length and the third original gear length.

6. The impedance matching method for a telescopic antenna according to claim 5, characterized in that, During the stretching process of the telescopic antenna: When the real-time length is between the first lower adjustment limit and the first upper adjustment limit, the real-time adjustment parameter is adjusted to the adjustment parameter corresponding to the next higher length switching level. If the next higher length switching gear is not the highest length switching gear, the first adjustment upper limit value is the sum of the upper limit value of the next higher length switching gear and the buffer value. The first adjustment lower limit value is the sum of the lower limit value of the next higher length switching gear and the buffer value.

7. The impedance matching method for a telescopic antenna according to claim 5, characterized in that, During the retraction of the telescopic antenna: When the real-time length is between the second lower adjustment limit and the second upper adjustment limit, the real-time adjustment parameter is adjusted to the adjustment parameter corresponding to the lower length switching level. The second adjustment upper limit value is the difference between the upper limit value of the lower length switching gear and the buffer value; If the length switching position is not the lowest length switching position, the second adjustment lower limit value is the difference between the lower limit value of the next lower length switching position and the buffer value.

8. An impedance matching device for a telescopic antenna, characterized in that, include: The real-time length determination module is used to determine the real-time length of the telescopic antenna. The adjustment parameter determination module is used to determine the real-time adjustment parameters of the impedance matching circuit based on the real-time length. The control module is used to send control signals to the impedance matching circuit based on the real-time adjustment parameters, and the control signals are used to adjust the characteristic impedance of the telescopic antenna.

9. An impedance matching system for a telescopic antenna, characterized in that, This includes the transmission components, angle sensor, main control unit, and impedance matching circuit; The transmission assembly includes meshing gears and a toothed transmission belt; the gears are rotatably disposed within the main body of the deployed telescopic antenna; one end of the toothed transmission belt is fixed to the outer end of the telescopic antenna and extends into the main body through the innermost segment of the telescopic antenna. The angle sensor is used to collect the rotation amount of the gear; The main control unit is signal-connected to the angle sensor. The main control unit is used to receive the detection information from the angle sensor; determine the real-time length of the telescopic antenna; determine the real-time adjustment parameters of the impedance matching circuit based on the real-time length; and send control signals to the impedance matching circuit based on the real-time adjustment parameters. One end of the impedance matching circuit is connected to the radio frequency system signal, and the other end of the impedance matching circuit is connected to the feed point of the telescopic antenna. The impedance matching circuit is provided with an adjustment element, and the control signal is used to adjust the characteristic impedance of the telescopic antenna by adjusting the value of the adjustment element.

10. A wireless communication terminal, characterized in that, Includes a telescopic antenna and an impedance matching system for the telescopic antenna as described in claim 9.

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