Automobile key radio frequency impedance adjusting method and device, medium and program product

Abstract

The invention provides an automobile key radio frequency impedance adjusting method and device, a medium and a program product, and relates to the technical field of automobile intelligent keys.The method comprises the steps that input impedance and return loss of a plurality of PCB antennas are measured through a vector network analyzer, and an impedance circuit capable of adjusting impedance is additionally arranged at the input ends of the PCB antennas; adjusting the input impedance to a preset first impedance value by adjusting an impedance matching network of the impedance circuit for the first time; measuring the output impedance of the power amplifier and the impedance circuit through a vector network analyzer; and adjusting the impedance matching network of the impedance circuit for the second time to adjust the output impedance to a preset second impedance value. The problem that radio frequency energy efficiency is low due to the fact that radio frequency impedance is difficult to flexibly adjust in the prior art is solved.

Description

Technical Field

[0001] This invention relates to the field of automotive smart key technology, and in particular to a method, device, medium, and program product for adjusting the radio frequency impedance of an automotive key. Background Technology

[0002] As car keys become smaller and more multifunctional, they need to integrate multiple PCB antennas, such as the LF antenna responsible for wake-up and the radio frequency antenna responsible for remote control command transmission, and be equipped with a radio frequency chip with an integrated power amplifier (PA) to form a complete radio frequency communication link. Precise impedance matching of different radio frequency components in the link is the core prerequisite for maximizing radio frequency energy efficiency.

[0003] Keys often employ frequency modulation (FM) technology to achieve frequency transitions. However, the impedance requirements of antennas and core components differ across frequency bands. Traditional solutions struggle to achieve a full-band 50Ω standard impedance matching, further exacerbating impedance imbalance. Existing technologies mostly utilize fixed impedance matching network designs, achieving only approximate matching within the design frequency band and under ideal operating conditions, resulting in severely insufficient adjustment flexibility. This fixed approach cannot avoid impedance deviations caused by multi-antenna coupling interference, nor can it dynamically adjust the impedance in response to frequency transitions. Summary of the Invention

[0004] The embodiments of the present invention provide a method, device, medium and program product for adjusting the radio frequency impedance of an automobile key, which aims to address the problem of low radio frequency energy efficiency caused by the difficulty in flexibly adjusting radio frequency impedance in the prior art.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a method for adjusting the radio frequency impedance of an automotive key, comprising the following steps: The input impedance and return loss of multiple PCB antennas are measured using a vector network analyzer. An adjustable impedance circuit is added to the input terminal of the multiple PCB antennas. The multiple PCB antennas are disconnected from the power amplifier when measuring the input impedance. By first adjusting the impedance matching network of the impedance circuit, a first impedance value is obtained, which adjusts the input impedance to a predetermined first impedance value; the first impedance value is the impedance value that enables the multiple PCB antennas to achieve maximum radio frequency energy transmission efficiency. The output impedance of the power amplifier and the impedance circuit is measured using a vector network analyzer. When measuring the output impedance, the multiple PCB antennas are disconnected from the impedance circuit, the impedance circuit is connected to a resistor with an impedance value of the first impedance value, and the power amplifier is disconnected from the RF chip. By adjusting the impedance matching network of the impedance circuit a second time, a second impedance value is obtained, which adjusts the output impedance to a predetermined second impedance value; the second impedance value is the impedance value that enables the multiple PCB antennas and the power amplifier to achieve maximum radio frequency energy transmission efficiency.

[0006] Furthermore, the multiple PCB antennas are orthogonally polarized.

[0007] Furthermore, the first impedance value is 50Ω.

[0008] Furthermore, the radio frequency chip is an NCF29A3 radio frequency chip.

[0009] Furthermore, the second impedance value is (50+j115)Ω under the conditions of a radio frequency signal frequency of 434MHz and a power of 10dBm.

[0010] Furthermore, after adjusting the output impedance to the predetermined second impedance value, the impedance matching network output is connected to the spectrum analyzer, and the impedance value of the spectrum analyzer is set to the first impedance value. When the frequency and power of the RF signal are not lower than the predetermined first frequency and first power, respectively, it indicates that the key RF impedance adjustment is complete.

[0011] Secondly, the present invention provides a car key radio frequency impedance adjustment device, including a memory and a processor, wherein the memory stores at least one program, and the at least one program is executed by the processor to implement the car key radio frequency impedance adjustment method as described above.

[0012] Thirdly, the present invention provides a computer-readable storage medium storing at least one program, wherein the at least one program is executed by a processor to implement the car key radio frequency impedance adjustment method as described above.

[0013] Fourthly, the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the car key radio frequency impedance adjustment method as described above.

[0014] The above technical solution has the following technical effects: The input impedance and return loss of multiple PCB antennas are measured using a vector network analyzer. An adjustable impedance circuit is added to the input terminals of each PCB antenna. The impedance matching network of the impedance circuit is adjusted first to a predetermined first impedance value, which maximizes the RF energy transmission efficiency of the multiple PCB antennas. The output impedance of the power amplifier and the impedance circuit is measured using the vector network analyzer. The impedance matching network of the impedance circuit is then adjusted second to a predetermined second impedance value, which maximizes the RF energy transmission efficiency of both the multiple PCB antennas and the power amplifier. This invention solves the problem of low RF energy efficiency caused by the difficulty in flexibly adjusting RF impedance in existing technologies.

[0015] In summary, the embodiments of the present invention adjust the radio frequency impedance of the car key by adding an adjustable impedance circuit. The first adjustment enables multiple PCB antennas to reach the maximum radio frequency energy transmission efficiency, and the second adjustment, based on the multiple PCB antennas reaching the maximum radio frequency energy transmission efficiency, enables the multiple PCB antennas and the power amplifier to simultaneously reach the maximum radio frequency energy transmission efficiency. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating a method for adjusting the radio frequency impedance of a car key according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of a car key radio frequency impedance adjustment device according to an embodiment of the present invention. Detailed Implementation

[0017] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention, primarily used to illustrate the embodiments and to explain the operating principles of the embodiments in conjunction with the relevant descriptions in the specification. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. Components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0018] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0019] Example 1: Figure 1 This is a flowchart illustrating a method for adjusting the radio frequency impedance of a car key according to an embodiment of the present invention, as shown below. Figure 1 As shown, the method of this embodiment includes the following steps: The input impedance and return loss of multiple PCB antennas are measured using a vector network analyzer. An adjustable impedance circuit is added to the input terminals of each PCB antenna. In one specific implementation, the multiple PCB antennas are disconnected from the power amplifier during input impedance measurement to prevent interference signals from the power amplifier (PA) from being conducted to the antennas. The return loss data is used to determine the degree of impedance deviation from the standard. In this embodiment, the required input impedance of the PCB antenna is 50Ω. Due to the limitations of the car key antenna layout, without changing the antenna length or other factors affecting impedance, an impedance circuit is added to the antenna input terminals, and the adjustment device is optimized to make the antenna input impedance meet the design requirements.

[0020] The impedance matching network of the impedance circuit is adjusted in the first step to obtain the impedance value of the first impedance circuit, so that the input impedance is adjusted to the predetermined first impedance value; in a specific implementation, the first impedance value is the impedance value that makes the corresponding antenna achieve the maximum radio frequency energy transmission efficiency, and it is adjusted using the Smith chart tool. The output impedance of the power amplifier and the impedance circuit is measured by a vector network analyzer. In one specific implementation, when measuring the output impedance, multiple PCB antennas are disconnected from the impedance circuit, the impedance circuit is connected to a resistor with an impedance value of the first impedance value, and the power amplifier is disconnected from the RF chip. The impedance matching network of the second impedance adjustment circuit is used to obtain the impedance value of the second impedance circuit, so that the output impedance is adjusted to the predetermined second impedance value; in a specific implementation, the second impedance value is the impedance value that enables multiple PCB antennas and power amplifiers to achieve maximum radio frequency energy transmission efficiency.

[0021] In one specific implementation, the first impedance value is 50Ω.

[0022] In one specific implementation, the second impedance value is (50 + j115) Ω under the conditions of a radio frequency signal frequency of 434 MHz and a power of 10 dBm. This value represents the required impedance of the radio frequency chip at a specific frequency, used to transform the 50 Ω impedance of the antenna into the impedance required by the chip; this value is expressed in complex form: Z = R + jX, where: R is the real part: it refers to resistance, the part of the circuit that loses energy.

[0023] X represents the imaginary part; it refers to reactance, with positive values ​​representing inductive reactance and negative values ​​representing capacitive reactance, corresponding to the effects of inductance and capacitance.

[0024] In one specific implementation, multiple PCB antennas are orthogonally polarized. The smart key needs to integrate multiple antennas, with low-frequency antennas preferentially employing orthogonal polarization, ensuring the polarization directions of two antennas are perpendicular to each other. This reduces interference between antennas in car keys without requiring additional circuitry.

[0025] In one specific implementation, the radio frequency chip is the NCF29A3 radio frequency chip.

[0026] In one specific implementation, after adjusting the output impedance to a predetermined second impedance value, the output terminal of the impedance matching network is connected to a spectrum analyzer, and the impedance value of the spectrum analyzer is set to the first impedance value. When the frequency and power of the RF signal are not lower than the predetermined first frequency and first power, respectively, it indicates that the RF impedance adjustment of the key is complete.

[0027] Example 2: Figure 2 This is a schematic diagram of the structure of a smart toothbrush according to an embodiment of the present invention, as shown below. Figure 2 As shown, the device includes a processor 201, a memory 202, a bus 203, and a computer program stored in the memory 202 and executable on the processor 201. The processor 201 includes one or more processing cores. The memory 202 is connected to the processor 201 via the bus 203. The memory 202 is used to store program instructions. When the processor executes the computer program, it implements the steps in the above-described method embodiment of Embodiment 1 of the present invention.

[0028] Furthermore, as an executable solution, the smart toothbrush can be a computer unit, which can be a desktop computer, laptop, handheld computer, or cloud server, etc. The computer unit may include, but is not limited to, a processor and memory. Those skilled in the art will understand that the above-described structure of the computer unit is merely an example and does not constitute a limitation on the computer unit. It may include more or fewer components, or combine certain components, or use different components. For example, the computer unit may also include input / output devices, network access devices, buses, etc., and this embodiment of the invention does not limit this.

[0029] Furthermore, as an executable solution, the processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc. The processor is the control center of the computer unit, connecting various parts of the entire computer unit via various interfaces and lines.

[0030] The memory can be used to store the computer programs and / or modules. The processor implements various functions of the computer unit by running or executing the computer programs and / or modules stored in the memory and by calling data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a function; the data storage area may store data created based on the use of the mobile phone, etc. In addition, the memory may include high-speed random access memory and may also include non-volatile memory, such as hard disk, RAM, plug-in hard disk, smart media card (SMC), secure digital card (SD card), flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0031] Example 3: The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the method described in the embodiments of the present invention.

[0032] If the modules / units integrated in the computer unit are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), and software distribution media, etc. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction.

[0033] Example 4: The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the car key radio frequency impedance adjustment method as described above.

[0034] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. A method for adjusting the radio frequency impedance of a car key, characterized in that, Includes the following steps: The input impedance and return loss of multiple PCB antennas are measured using a vector network analyzer. An adjustable impedance circuit is added to the input terminal of the multiple PCB antennas. The multiple PCB antennas are disconnected from the power amplifier when measuring the input impedance. By first adjusting the impedance matching network of the impedance circuit, the impedance value of the first impedance circuit is obtained, and the impedance value of the first impedance circuit adjusts the input impedance to a predetermined first impedance value. The first impedance value is the impedance value that enables the plurality of PCB antennas to achieve maximum radio frequency energy transmission efficiency; The output impedance of the power amplifier and the impedance circuit is measured using a vector network analyzer. When measuring the output impedance, the multiple PCB antennas are disconnected from the impedance circuit, the impedance circuit is connected to a resistor with an impedance value of the first impedance value, and the power amplifier is disconnected from the RF chip. By adjusting the impedance matching network of the impedance circuit a second time, the impedance value of the second impedance circuit is obtained, and the output impedance is adjusted to a predetermined second impedance value. The second impedance value is the impedance value that enables the multiple PCB antennas and the power amplifier to achieve maximum radio frequency energy transmission efficiency.

2. The method for adjusting the radio frequency impedance of a car key according to claim 1, characterized in that, The multiple PCB antennas are orthogonally polarized.

3. The method for adjusting the radio frequency impedance of a car key according to claim 1, characterized in that, The first impedance value is 50Ω.

4. The method for adjusting the radio frequency impedance of a car key according to claim 1, characterized in that, The radio frequency chip is an NCF29A3 radio frequency chip.

5. The method for adjusting the radio frequency impedance of a car key according to claim 1, characterized in that, The second impedance value is (50+j115)Ω under the conditions of a radio frequency signal frequency of 434MHz and a power of 10dBm.

6. The method for adjusting the radio frequency impedance of a car key according to claim 1, characterized in that, After adjusting the output impedance to the predetermined second impedance value, the impedance matching network output is connected to the spectrum analyzer, and the impedance value of the spectrum analyzer is set to the first impedance value. When the frequency and power of the RF signal are not lower than the predetermined first frequency and first power, respectively, it indicates that the key RF impedance adjustment is complete.

7. A car key radio frequency impedance adjustment device, characterized in that, The device includes a memory and a processor, the memory storing at least one program, which is executed by the processor to implement the car key radio frequency impedance adjustment method as described in any one of claims 1-6.

8. A computer-readable storage medium, characterized in that, The storage medium stores at least one program, which is executed by a processor to implement the car key radio frequency impedance adjustment method as described in any one of claims 1-6.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the car key radio frequency impedance adjustment method as described in any one of claims 1-6.

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