Dual-frequency antenna working circuit

Abstract

The utility model discloses a dual-frequency antenna working circuit, which is applied to a tire pressure sensor, the dual-frequency antenna working circuit comprises a signal receiving module, a power supply module, a control module and a matching module, the output end of the signal receiving module and the output end of the power supply module are both electrically connected with the control module, and the matching module is electrically connected with the signal receiving module. The input end of the matching module is electrically connected with the control module, the output end of the matching module is electrically connected with an antenna, and the control module comprises a control chip and a crystal oscillator circuit electrically connected with the control chip. Therefore, the matching module outputs impedance matched with the antenna working at the first sending frequency or the second sending frequency. By means of the mode, low-frequency signals are received so that the antenna can send out the first sending frequency or the second sending frequency of the high-frequency model, sending of double-frequency signals is achieved, the tire pressure sensor can be compatible with automobile receiving systems of different brands and models, and the universality of the tire pressure sensor is improved.

Description

Technical Field

[0001] This utility model relates to the field of tire pressure sensor antenna technology, and in particular to a dual-frequency antenna working circuit. Background Technology

[0002] With the increasing prevalence of automobiles and the advancement of automotive digitalization, tire pressure monitoring systems have become standard equipment in vehicles. Currently, the antennas in automotive tire pressure sensors typically operate at either 315MHz or 433MHz. Existing tire pressure sensor antennas only support one of these frequencies and cannot simultaneously support reception at both 315MHz and 433MHz. This necessitates the installation of two different antennas to ensure coverage of the two reception frequencies required by current automotive systems. Utility Model Content

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a dual-frequency antenna working circuit to solve the technical problem that existing tire pressure sensors require the installation of two antennas to meet the coverage of the two receiving frequencies of current automobiles.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] This invention proposes a dual-frequency antenna operating circuit for use in tire pressure sensors. The dual-frequency antenna operating circuit includes a signal receiving module, a power supply module, a control module, and a matching module. The output terminals of the signal receiving module and the power supply module are both electrically connected to the control module. The input terminal of the matching module is electrically connected to the control module, and the output terminal of the matching module is electrically connected to the antenna. The control module includes a control chip and a crystal oscillator circuit electrically connected to the control chip, such that the matching module outputs an impedance that matches the antenna operating at a first transmission frequency or a second transmission frequency.

[0006] In one specific embodiment, the crystal oscillator circuit includes: a crystal oscillator, a seventh capacitor, and an eighth capacitor. The first and third pins of the crystal oscillator are both electrically connected to the control chip. The second and fourth pins of the crystal oscillator are both grounded. One end of the seventh capacitor is connected in parallel with the third pin of the crystal oscillator, and the other end of the seventh capacitor is grounded. One end of the eighth capacitor is connected in parallel with the first pin of the crystal oscillator, and the other end of the eighth capacitor is grounded.

[0007] In one specific embodiment, the signal receiving module includes a signal receiving circuit and a protection circuit, wherein the protection circuit is connected in parallel with the signal receiving circuit, and both ends of the signal receiving circuit are electrically connected to the control chip.

[0008] In one specific embodiment, the signal receiving circuit includes: a first inductor, a second inductor, a third inductor, a fourth inductor, and a fifth inductor. The output terminal of the first inductor is electrically connected to the control chip. The input terminal of the second inductor is connected in series with the output terminal of the first inductor. The output terminal of the second inductor is connected in series with the input terminal of the third inductor. The output terminal of the third inductor is electrically connected to the control chip. The input terminal of the fourth inductor is connected in series with the output terminal of the first inductor. The output terminal of the fourth inductor is connected in series with the output terminal of the fifth inductor. The output terminal of the fifth inductor is grounded.

[0009] In one specific embodiment, the protection circuit includes: a first capacitor, a second capacitor, and a first resistor. One end of the first capacitor is connected in parallel with the output terminal of the third inductor, and the other end of the first capacitor is connected in parallel with the output terminal of the fifth inductor. One end of the second capacitor is connected in parallel with the output terminal of the third inductor, and the other end of the second capacitor is connected in parallel with the output terminal of the fifth inductor. One end of the first resistor is connected in parallel with the output terminal of the third inductor, and the other end of the first resistor is connected in parallel with the output terminal of the fifth inductor.

[0010] In one specific embodiment, the power module includes a battery connector and an input filter circuit. The positive terminal of the battery connector is electrically connected to the control chip, the negative terminal of the battery connector is grounded, and the input filter circuit is connected in parallel with the positive terminal of the battery connector.

[0011] In one specific embodiment, the input filtering circuit includes a third capacitor, a fourth capacitor, a fifth capacitor, and a sixth capacitor. One end of the third capacitor is connected in parallel with the positive terminal of the battery connector, and the other end of the third capacitor is grounded. One end of the fourth capacitor is connected in parallel with the positive terminal of the battery connector, and the other end of the fourth capacitor is grounded. One end of the fifth capacitor is connected in parallel with one end of the fifth capacitor, and the other end of the sixth capacitor is grounded.

[0012] In one specific embodiment, the matching module includes an output circuit and a protection circuit. One end of the output circuit is electrically connected to the output terminal of the control chip, and the other end of the output circuit is electrically connected to the antenna. One end of the protection circuit is connected in parallel with the output circuit, and the other end of the protection circuit is grounded.

[0013] In one specific embodiment, the output circuit includes: a seventh inductor, a thirteenth capacitor, a fourteenth capacitor, a third resistor, a fifteenth capacitor, an eighth inductor, and a fourth resistor. One end of the seventh inductor is electrically connected to the control chip, and the other end of the seventh inductor is electrically connected to the antenna. One end of the thirteenth capacitor is electrically connected to the seventh inductor, and the other end of the thirteenth capacitor is electrically connected to the antenna. One end of the fourteenth capacitor is electrically connected to the thirteenth capacitor, and the other end of the fourteenth capacitor is grounded. One end of the third resistor is electrically connected to the thirteenth capacitor, and the other end of the third resistor is electrically connected to the antenna. One end of the fifteenth capacitor is electrically connected to the third resistor, and the other end of the fifteenth capacitor is electrically connected to one end of the eighth inductor, and the other end of the eighth inductor is grounded. One end of the fourth resistor is electrically connected to one end of the third resistor, and the other end of the fourth resistor is electrically connected to the antenna.

[0014] In one specific embodiment, the protection circuit includes: a tenth capacitor, an eleventh capacitor, a second resistor, a sixth inductor, and a twelfth capacitor. One end of the twelfth capacitor is electrically connected to the control chip, and the other end of the twelfth capacitor is grounded. One end of the sixth inductor is connected in parallel with the twelfth capacitor, and the other end of the sixth inductor is connected in parallel with one end of the second resistor. The other end of the second resistor is connected in parallel with one end of the eleventh capacitor. One end of the eleventh capacitor is connected in series with one end of the tenth capacitor and then grounded. The other end of the tenth capacitor is connected in parallel with the seventh inductor.

[0015] The beneficial effects of this utility model are:

[0016] Compared with the prior art, the dual-frequency antenna working circuit proposed in this utility model realizes the transmission of dual-frequency signals by receiving low-frequency signals and then transmitting them at a first or second high-frequency transmission frequency. This enables the tire pressure sensor to be compatible with different brands and models of automotive receiving systems, improving the versatility of the tire pressure sensor. Furthermore, by achieving communication between the two frequencies through a single dual-frequency antenna working circuit, the number of antennas is reduced, and the physical size of the tire pressure sensor is lowered.

[0017] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model, it can be implemented according to the contents of the specification. In order to make the above and other objects, features and advantages of this utility model more obvious and easy to understand, the following are preferred embodiments, which are described in detail below. Attached Figure Description

[0018] Figure 1 This is a structural block diagram of a dual-frequency antenna operating circuit proposed in an embodiment of the present invention;

[0019] Figure 2A circuit diagram of the signal receiving module in a dual-frequency antenna operating circuit proposed in this embodiment of the present invention;

[0020] Figure 3 A circuit diagram of the power supply module in a dual-frequency antenna operating circuit proposed in this embodiment of the present invention;

[0021] Figure 4 A circuit diagram of the matching module in a dual-frequency antenna operating circuit proposed in this embodiment of the present invention;

[0022] Figure 5 This is a circuit diagram of the control module in a dual-frequency antenna operating circuit proposed in an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures:

[0024] 10. Signal receiving module; 20. Power supply module; 30. Control module; 40. Matching module. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0027] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0028] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0029] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0030] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0031] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0032] Example

[0033] Please see Figures 1 to 5This utility model proposes a dual-frequency antenna working circuit for use in tire pressure sensors. The dual-frequency antenna working circuit includes: a signal receiving module 10, a power supply module 20, a control module 30, and a matching module 40. The output terminals of the signal receiving module 10 and the power supply module 20 are both electrically connected to the control module 30. The input terminal of the matching module 40 is electrically connected to the control module 30, and the output terminal of the matching module 40 is electrically connected to the antenna. The control module 30 includes: a control chip and a crystal oscillator Y1 circuit electrically connected to the control chip, so that the matching module 40 outputs the impedance of the matching antenna when it operates at the first transmission frequency or the second transmission frequency.

[0034] In practical applications, the power module 20 starts up, providing a stable power supply to the dual-band antenna operating circuit. The signal receiving module 10 receives the low-frequency signal of tire pressure data detected by the tire pressure sensor and transmits it to the control module 30. After receiving the signal, the control chip in the control module 30 processes the low-frequency signal according to the preset program and logic, amplifying the low frequency to generate a high-frequency signal. At the same time, the crystal oscillator Y1 circuit provides a precise clock signal to the control chip, ensuring the accuracy and stability of the signal processing. Based on the processing result, the control chip sends a control signal to the matching module 40, causing the matching module 40 to adjust the impedance of the antenna so that the antenna operates at the first transmission frequency or the second transmission frequency, thereby realizing communication with the vehicle's receiving system.

[0035] The dual-frequency antenna circuit proposed in this embodiment enables the antenna to transmit at a first or second high-frequency signal after receiving a low-frequency signal, thus achieving dual-frequency signal transmission. This allows the tire pressure sensor to be compatible with different brands and models of automotive receiving systems, improving the versatility of the tire pressure sensor. Furthermore, by achieving communication between two frequencies through a single dual-frequency antenna circuit, the number of antennas is reduced, thus lowering the physical size of the tire pressure sensor.

[0036] Please see Figure 4 The crystal oscillator Y1 circuit includes: crystal oscillator Y1, seventh capacitor C7 and eighth capacitor C8. The first and third pins of crystal oscillator Y1 are electrically connected to the control chip. The second and fourth pins of crystal oscillator Y1 are grounded. One end of the seventh capacitor C7 is connected in parallel with the third pin of crystal oscillator Y1, and the other end of the seventh capacitor C7 is grounded. One end of the eighth capacitor C8 is connected in parallel with the first pin of crystal oscillator Y1, and the other end of the eighth capacitor C8 is grounded.

[0037] Specifically, the first pin of crystal oscillator Y1 is electrically connected to the XIN pin of the control chip, and the third pin of crystal oscillator Y1 is electrically connected to the XOUT pin of the control chip. The oscillation signal generated by crystal oscillator Y1 is transmitted to the XIN pin of the control chip through the first pin, providing a clock reference for the control chip. The control chip is connected to the third pin of crystal oscillator Y1 through the XOUT pin to adjust the oscillation of crystal oscillator Y1 to ensure the stability and accuracy of the oscillation. At the same time, the seventh capacitor C7 and the eighth capacitor C8 are used to fine-tune the load capacitance of crystal oscillator Y1 to improve the stability of the clock signal.

[0038] Please see Figure 2 The signal receiving module 10 includes a signal receiving circuit and a protection circuit. The protection circuit is connected in parallel with the signal receiving circuit, and both ends of the signal receiving circuit are electrically connected to the control chip.

[0039] Specifically, one end of the signal receiving circuit is electrically connected to the LFP terminal of the control chip, and the other end is electrically connected to the LFN terminal of the control chip. The received differential low-frequency signal is transmitted to the control chip. When the signal receiving circuit is working, the protection circuit is also in standby mode. When abnormal voltage fluctuations occur in the circuit, such as interference from external electrostatic discharge or instantaneous overvoltage in the automotive electrical system, the protection circuit will respond immediately to protect the signal receiving circuit from damage. The signal receiving circuit and the protection circuit work together to remove noise and interference.

[0040] Please refer to it again. Figure 2 The signal receiving circuit includes: a first inductor L1, a second inductor L2, a third inductor L3, a fourth inductor L4, and a fifth inductor L5. The output terminal of the first inductor L1 is electrically connected to the control chip. The input terminal of the second inductor L2 is connected in series with the output terminal of the first inductor L1. The output terminal of the second inductor L2 is connected in series with the input terminal of the third inductor L3. The output terminal of the third inductor L3 is electrically connected to the control chip. The input terminal of the fourth inductor L4 is connected in series with the output terminal of the first inductor L1. The output terminal of the fourth inductor L4 is connected in series with the output terminal of the fifth inductor L5. The output terminal of the fifth inductor L5 is grounded.

[0041] Specifically, one output terminal of the first inductor L1 is electrically connected to the LFP terminal of the control chip, and the other output terminal of the first inductor L1 is electrically connected to the LFN terminal of the control chip, ensuring that the signal can be transmitted to the control chip. In this example, the first inductor L1 is a filter inductor, which uses the impedance characteristics of the filter inductor to signals of different frequencies to achieve filtering. The filter inductor presents high impedance to high-frequency signals and low impedance to low-frequency signals, thus blocking high-frequency noise and interference signals from passing through, while allowing low-frequency tire pressure data signals to pass through smoothly, thereby improving the accuracy of the signal; the second inductor L2, the third inductor L3, the fourth inductor L4, and the fifth inductor L5 are connected in series to form a signal processing circuit to ensure the stability of the signal during transmission.

[0042] Please refer to it again. Figure 2 The protection circuit includes: a first capacitor C1, a second capacitor C2, and a first resistor R1. One end of the first capacitor C1 is connected in parallel with the output terminal of the third inductor L3, and the other end of the first capacitor C1 is connected in parallel with the output terminal of the fifth inductor L5. One end of the second capacitor C2 is connected in parallel with the output terminal of the third inductor L3, and the other end of the second capacitor C2 is connected in parallel with the output terminal of the fifth inductor L5. One end of the first resistor R1 is connected in parallel with the output terminal of the third inductor L3, and the other end of the first resistor R1 is connected in parallel with the output terminal of the fifth inductor L5.

[0043] Specifically, the first capacitor C1 and the second capacitor C2 are used for filtering and decoupling to remove high-frequency noise from the signal and ensure signal accuracy. The first resistor R1 is used to limit the current and prevent excessive current from damaging the circuit. The first capacitor C1, the second capacitor C2 and the first resistor R1 are connected in parallel between the output terminals of the third inductor L3 and the fifth inductor L5 to ensure the stability of the signal during transmission.

[0044] Please see Figure 3 The power module 20 includes a battery connector J1 and an input filter circuit. The positive terminal of the battery connector J1 is electrically connected to the control chip, the negative terminal of the battery connector J1 is grounded, and the input filter circuit is connected in parallel with the positive terminal of the battery connector J1.

[0045] Specifically, battery connector J1 is used to connect an external battery to provide a stable DC power supply to the circuit. The positive terminal of battery connector J1 is electrically connected to the control chip to ensure that power can be directly transmitted to the control chip; the input filter circuit is connected in parallel with the positive terminal of battery connector J1 to remove high-frequency noise and interference in the power supply and ensure the stability of the power output.

[0046] Please refer to it again. Figure 3 The input filter circuit includes: a third capacitor, a fourth capacitor, a fifth capacitor (C5), and a sixth capacitor (C6). One end of the third capacitor is connected in parallel with the positive terminal of the battery connector J1, and the other end of the third capacitor is grounded. One end of the fourth capacitor is connected in parallel with the positive terminal of the battery connector J1, and the other end of the fourth capacitor is grounded. One end of the fifth capacitor (C5) is connected in parallel with the positive terminal of the battery connector J1, and the other end of the fifth capacitor (C5) is grounded. One end of the sixth capacitor (C6) is connected in parallel with one end of the fifth capacitor (C5), and the other end of the sixth capacitor (C6) is grounded.

[0047] Specifically, the third, fourth, and fifth capacitors (C5 and C6) are connected in parallel between the positive terminal of the battery connector J1 and ground, forming a multi-stage filter to improve the filtering effect and ensure the stability of the power supply.

[0048] Please see Figure 5 The matching module 40 includes an output circuit and a protection circuit. One end of the output circuit is electrically connected to the output terminal of the control chip, and the other end of the output circuit is electrically connected to the antenna. One end of the protection circuit is connected in parallel with the output circuit, and the other end of the protection circuit is grounded.

[0049] Specifically, the input terminal of the output circuit is electrically connected to the PAOUT terminal of the control chip, and the output terminal of the output circuit is electrically connected to the antenna. One end of the protection circuit is connected in parallel with the output circuit, and the other end of the protection circuit is electrically connected to the VDDPA terminal of the control chip and then grounded. The control chip outputs an RF signal through the PAOUT terminal. This signal undergoes impedance transformation and processing by the output circuit to match the impedance of the signal with the input impedance of the antenna. When a transient overvoltage or overcurrent occurs in the circuit, the components in the protection circuit will exhibit low impedance characteristics, guiding the overvoltage or overcurrent to ground or the components of the protection circuit, thereby limiting the voltage and current across each component in the circuit and keeping them within a safe range, thus preventing damage to the control chip and antenna due to overvoltage or overcurrent.

[0050] Please refer to it again. Figure 5 The output circuit includes: a seventh inductor L7, a thirteenth capacitor C13, a fourteenth capacitor C14, a third resistor R3, a fifteenth capacitor C15, an eighth inductor L8, and a fourth resistor R4. One end of the seventh inductor L7 is electrically connected to the control chip, and the other end of the seventh inductor L7 is electrically connected to the antenna. One end of the thirteenth capacitor C13 is electrically connected to the seventh inductor L7, and the other end of the thirteenth capacitor C13 is electrically connected to the antenna. One end of the fourteenth capacitor C14 is electrically connected to the thirteenth capacitor C13, and the other end of the fourteenth capacitor C14 is grounded. One end of the third resistor R3 is electrically connected to the thirteenth capacitor C13, and the other end of the third resistor R3 is electrically connected to the antenna. One end of the fifteenth capacitor C15 is electrically connected to the third resistor R3, and the other end of the fifteenth capacitor C15 is electrically connected to one end of the eighth inductor L8, and the other end of the eighth inductor L8 is grounded. One end of the fourth resistor R4 is electrically connected to one end of the third resistor R3, and the other end of the fourth resistor R4 is electrically connected to the antenna.

[0051] Specifically, the seventh inductor L7 is electrically connected to the PAOUT terminal of the control chip, and the output terminal of the seventh inductor L7 is electrically connected to the antenna. The seventh inductor L7 is connected in series between the control chip and the antenna to perform appropriate phase adjustment and impedance transformation on the signal output by the control chip to adapt to the input characteristics of the antenna. The eighth inductor L8 and the fifteenth capacitor C15 form an LC circuit, which plays a filtering role, attenuating or enhancing signals of specific frequencies to improve the spectral characteristics of the signal. The fourth resistor R4 is used to limit the current and prevent excessive current from damaging the circuit.

[0052] Please refer to it again. Figure 5The protection circuit includes: a tenth capacitor C10, an eleventh capacitor C11, a second resistor R2, a sixth inductor L6, and a twelfth capacitor C12. One end of the twelfth capacitor C12 is electrically connected to the control chip, and the other end of the twelfth capacitor C12 is grounded. One end of the sixth inductor L6 is connected in parallel with the twelfth capacitor C12, and the other end of the sixth inductor L6 is connected in parallel with one end of the second resistor R2. The other end of the second resistor R2 is connected in parallel with one end of the eleventh capacitor C11, and one end of the eleventh capacitor C11 is connected in series with one end of the tenth capacitor and then grounded. The other end of the tenth capacitor C10 is connected in parallel with the seventh inductor L7.

[0053] Specifically, one end of the twelfth capacitor C12 is connected to the VDDPA terminal of the control chip, and the other end of the twelfth capacitor C12 is grounded, so that both the twelfth capacitor C12 and the tenth capacitor C10 are used for filtering. Through their low impedance characteristics to high-frequency signals, they attenuate high-frequency noise and remove high-frequency noise in the power supply. The sixth inductor L6 and the second resistor R2 are used to limit the current and prevent excessive current from damaging the circuit. The eleventh capacitor C11 is used for decoupling. Through its low impedance characteristics to high-frequency signals, it bypasses high-frequency noise to ground.

[0054] Please refer to it again. Figure 5 In this embodiment, the CNDD terminal of the control chip is grounded to provide a stable reference ground potential and ensure the stable operation of the internal circuitry of the chip.

[0055] Please refer to it again. Figure 5 In this embodiment, the dual-band antenna working circuit also includes a ninth capacitor C9. One end of the ninth capacitor C9 is electrically connected to the VREG terminal of the control chip, and the other end of the ninth capacitor C9 is grounded to filter the power supply and remove high-frequency noise from the power supply.

[0056] Compared with the prior art, the dual-frequency antenna working circuit proposed in this utility model realizes the transmission of dual-frequency signals by receiving low-frequency signals and then transmitting them at a first or second high-frequency transmission frequency. This enables the tire pressure sensor to be compatible with different brands and models of automotive receiving systems, improving the versatility of the tire pressure sensor. Furthermore, by achieving communication between the two frequencies through a single dual-frequency antenna working circuit, the number of antennas is reduced, and the physical size of the tire pressure sensor is lowered.

[0057] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A dual-frequency antenna operating circuit, applied to a tire pressure sensor, characterized in that, The dual-band antenna operating circuit includes: a signal receiving module, a power supply module, a control module, and a matching module. The output terminals of the signal receiving module and the power supply module are both electrically connected to the control module. The input terminal of the matching module is electrically connected to the control module, and the output terminal of the matching module is electrically connected to the antenna. The control module includes: a control chip and a crystal oscillator circuit electrically connected to the control chip, such that the matching module outputs an impedance that matches the antenna operating at a first transmission frequency or a second transmission frequency.

2. The dual-frequency antenna operating circuit according to claim 1, characterized in that, The crystal oscillator circuit includes a crystal oscillator, a seventh capacitor, and an eighth capacitor. The first and third pins of the crystal oscillator are electrically connected to the control chip. The second and fourth pins of the crystal oscillator are grounded. One end of the seventh capacitor is connected in parallel with the third pin of the crystal oscillator, and the other end of the seventh capacitor is grounded. One end of the eighth capacitor is connected in parallel with the first pin of the crystal oscillator, and the other end of the eighth capacitor is grounded.

3. The dual-frequency antenna operating circuit according to claim 1, characterized in that, The signal receiving module includes a signal receiving circuit and a protection circuit. The protection circuit is connected in parallel with the signal receiving circuit, and both ends of the signal receiving circuit are electrically connected to the control chip.

4. The dual-frequency antenna operating circuit according to claim 3, characterized in that, The signal receiving circuit includes a first inductor, a second inductor, a third inductor, a fourth inductor, and a fifth inductor. The output terminal of the first inductor is electrically connected to the control chip. The input terminal of the second inductor is connected in series with the output terminal of the first inductor. The output terminal of the second inductor is connected in series with the input terminal of the third inductor. The output terminal of the third inductor is electrically connected to the control chip. The input terminal of the fourth inductor is connected in series with the output terminal of the first inductor. The output terminal of the fourth inductor is connected in series with the output terminal of the fifth inductor. The output terminal of the fifth inductor is grounded.

5. The dual-frequency antenna operating circuit according to claim 4, characterized in that, The protection circuit includes: a first capacitor, a second capacitor, and a first resistor. One end of the first capacitor is connected in parallel with the output terminal of the third inductor, and the other end of the first capacitor is connected in parallel with the output terminal of the fifth inductor. One end of the second capacitor is connected in parallel with the output terminal of the third inductor, and the other end of the second capacitor is connected in parallel with the output terminal of the fifth inductor. One end of the first resistor is connected in parallel with the output terminal of the third inductor, and the other end of the first resistor is connected in parallel with the output terminal of the fifth inductor.

6. The dual-frequency antenna operating circuit according to claim 1, characterized in that, The power module includes a battery connector and an input filter circuit. The positive terminal of the battery connector is electrically connected to the control chip, the negative terminal of the battery connector is grounded, and the input filter circuit is connected in parallel with the positive terminal of the battery connector.

7. The dual-frequency antenna operating circuit according to claim 6, characterized in that, The input filtering circuit includes a third capacitor, a fourth capacitor, a fifth capacitor, and a sixth capacitor. One end of the third capacitor is connected in parallel with the positive terminal of the battery connector, and the other end of the third capacitor is grounded. One end of the fourth capacitor is connected in parallel with the positive terminal of the battery connector, and the other end of the fourth capacitor is grounded. One end of the fifth capacitor is connected in parallel with one end of the fifth capacitor, and the other end of the sixth capacitor is grounded.

8. The dual-frequency antenna operating circuit according to claim 1, characterized in that, The matching module includes an output circuit and a protection circuit. One end of the output circuit is electrically connected to the output terminal of the control chip, and the other end of the output circuit is electrically connected to the antenna. One end of the protection circuit is connected in parallel with the output circuit, and the other end of the protection circuit is grounded.

9. The dual-frequency antenna operating circuit according to claim 8, characterized in that, The output circuit includes: a seventh inductor, a thirteenth capacitor, a fourteenth capacitor, a third resistor, a fifteenth capacitor, an eighth inductor, and a fourth resistor. One end of the seventh inductor is electrically connected to the control chip, and the other end of the seventh inductor is electrically connected to the antenna. One end of the thirteenth capacitor is electrically connected to the seventh inductor, and the other end of the thirteenth capacitor is electrically connected to the antenna. One end of the fourteenth capacitor is electrically connected to the thirteenth capacitor, and the other end of the fourteenth capacitor is grounded. One end of the third resistor is electrically connected to the thirteenth capacitor, and the other end of the third resistor is electrically connected to the antenna. One end of the fifteenth capacitor is electrically connected to the third resistor, and the other end of the fifteenth capacitor is electrically connected to one end of the eighth inductor, and the other end of the eighth inductor is grounded. One end of the fourth resistor is electrically connected to one end of the third resistor, and the other end of the fourth resistor is electrically connected to the antenna.

10. The dual-frequency antenna operating circuit according to claim 9, characterized in that, The protection circuit includes: a tenth capacitor, an eleventh capacitor, a second resistor, a sixth inductor, and a twelfth capacitor. One end of the twelfth capacitor is electrically connected to the control chip, and the other end of the twelfth capacitor is grounded. One end of the sixth inductor is connected in parallel with the twelfth capacitor, and the other end of the sixth inductor is electrically connected to one end of the second resistor. The other end of the second resistor is electrically connected to one end of the eleventh capacitor. One end of the eleventh capacitor is connected in series with one end of the tenth capacitor and then grounded. The other end of the tenth capacitor is connected in parallel with the seventh inductor.

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