Output impedance calculation device

Abstract

This invention provides an output impedance calculation device, which includes: a control unit, an adjustment unit, a LORA transmitting unit, a first impedance calculation unit, a second impedance calculation unit, a matching unit, and a transmitting antenna. The control unit is used to transmit wireless signals; the LORA transmitting unit is used to convert wireless signals into LORA signals; the first impedance calculation unit is used to calculate the input impedance based on the LORA signals; the second impedance calculation unit is used to calculate the output impedance based on the LORA signals; the control unit is used to calculate the reflection coefficient based on the input and output impedances, and to calculate the standing wave ratio based on the transmission coefficient; the adjustment unit is used to adjust the impedance in the circuit based on the standing wave ratio and the reflection coefficient, thereby achieving impedance matching and balance between the input and output terminals of the line, improving the output quality of radio signals, reducing the overall output power consumption, and reducing harmonic interference.

Description

Technical Field

[0001] This invention relates to the field of wireless radio frequency technology, and in particular to a device for calculating output impedance. Background Technology

[0002] In high-speed network signals, impedance matching is mainly used on transmission lines to ensure that both high-frequency and microwave signals can be transmitted to the load point with minimal signal reflection back to the source, thereby improving the circuit's energy efficiency. Impedance matching occurs when the internal resistance of the signal source is equal in magnitude and phase to the characteristic impedance of the connected transmission line, or when the characteristic impedance of the transmission line is equal in magnitude and phase to the impedance of the connected load. This is referred to as impedance matching at the input or output of the transmission line.

[0003] Currently, the main approach to impedance matching design is to calculate impedance and antenna parameters in advance during the circuit design process. After actual production, the parameters of various components used in the matching circuit design at the wireless output backend are adjusted according to the specific board test parameters. Through multiple impedance tests and adjustments of matching parameters, the input and output impedance are matched.

[0004] Since the impedance design has been calculated and adjusted in the early and middle stages of production, and the hardware design is fixed, the entire system cannot dynamically adjust the impedance parameters when the antenna ages or the parameters are changed. When the antenna parameters are changed later, the circuit cannot effectively identify and adjust the impedance parameters of the LORAWAN output signal. Summary of the Invention

[0005] In view of the above problems, embodiments of the present invention are proposed to provide an output impedance calculation device that overcomes or at least partially solves the above problems.

[0006] This invention provides an output impedance calculation device, which includes: a control unit, an adjustment unit, a LORA transmitting unit, a first impedance calculation unit, a second impedance calculation unit, a matching unit, and a transmitting antenna. The control unit is connected to the LORA transmitting unit, the first impedance calculation unit, the second impedance calculation unit, and the adjustment unit. The LORA transmitting unit is connected to the first impedance calculation unit and the matching unit. The matching unit is connected to the transmitting antenna through the second impedance calculation unit.

[0007] The control unit is used to transmit wireless signals;

[0008] The LORA transmitting unit is used to convert the wireless signal into a LORA signal;

[0009] The first impedance calculation unit is used to calculate the input impedance based on the LORA signal;

[0010] The second impedance calculation unit is used to calculate the output impedance based on the LORA signal;

[0011] The control unit is used to calculate the reflection coefficient based on the input impedance and the output impedance, and to calculate the standing wave coefficient based on the emission coefficient;

[0012] The adjustment unit is used to adjust the impedance in the circuit according to the standing wave coefficient and the reflection coefficient.

[0013] Optionally, the first impedance calculation unit is used to calculate the input impedance based on the LORA signal using a genetic algorithm and a closed-loop algorithm.

[0014] Optionally, the second impedance calculation unit is used to calculate the output impedance based on the LORA signal using a genetic algorithm and a closed-loop algorithm.

[0015] Optionally, the control unit is used to calculate the reflection coefficient according to the following formula, specifically including:

[0016] R = (Z1 - Z2 / Z1 + Z2), where R is the reflection coefficient, Z1 is the input impedance, and Z2 is the output impedance.

[0017] Optionally, the control unit is used to calculate the standing wave ratio based on the emission coefficient, specifically including:

[0018] VSWR = (1+R) / (1-R), where VSWR is the standing wave coefficient.

[0019] Optionally, the adjustment unit is used to adjust the LCR impedance parameters of the circuit, calculate the LCR parameter values ​​when the emission coefficient R=0 and the standing wave coefficient VSWR=1, adjust and calculate the impedance value of the circuit until the measured reflection coefficient R=0 and the standing wave coefficient VSWR=1, and then perform impedance matching of the circuit.

[0020] Optionally, the first impedance calculation unit is further used to calculate the PCB line terminal impedance, specifically including:

[0021] ,in:

[0022] Z0: Line impedance;

[0023] t: Copper thickness of a single-ended microstrip line;

[0024] h: Thickness of the single-ended microstrip line to the reference ground;

[0025] Eε: Dielectric constant of the medium from the microstrip line to the reference formation.

[0026] Optionally, the first impedance calculation unit is used to calculate the input impedance based on the LORA signal, specifically including:

[0027] Where Z1 is the input impedance, R1 is the resistance, C2 is the capacitance, and L1 is the inductance.

[0028] Optionally, the second impedance calculation unit is used to calculate the output impedance based on the LORA signal, specifically including:

[0029] ;

[0030] Where Z0 is the line impedance; R r Z is the antenna radiation impedance; Z is the total impedance.

[0031] Optionally, the wireless signal is a variable frequency, constant power wireless test signal with a wireless frequency in the range of 470-510MHz.

[0032] The embodiments of the present invention have the following advantages:

[0033] The output impedance calculation device provided in this embodiment of the invention includes: a control unit, an adjustment unit, a LORA transmitting unit, a first impedance calculation unit, a second impedance calculation unit, a matching unit, and a transmitting antenna. The control unit is connected to the LORA transmitting unit, the first impedance calculation unit, the second impedance calculation unit, and the adjustment unit. The LORA transmitting unit is connected to the first impedance calculation unit and the matching unit. The matching unit is connected to the transmitting antenna through the second impedance calculation unit. The control unit transmits wireless signals. The LORA transmitting unit converts the wireless signals into LORA signals. The first impedance calculation unit calculates the input impedance based on the LORA signals. The second impedance calculation unit calculates the output impedance based on the LORA signals. The control unit calculates the reflection coefficient based on the input and output impedances and calculates the standing wave ratio (SWR) based on the transmission coefficient. The adjustment unit adjusts the impedance in the circuit based on the SWR and reflection coefficients. This achieves the calculation and automatic impedance parameter adjustment of the wireless network output impedance in LORAWAN wireless network applications, thereby achieving impedance matching balance between the input and output ends of the line, improving the output quality of the radio signal, reducing the overall output power consumption, and minimizing harmonic interference. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of an embodiment of the output impedance calculation device of the present invention;

[0035] Figure 2This is a schematic diagram of the structure of another embodiment of the output impedance calculation device of the present invention;

[0036] Figure 3 This is a schematic diagram illustrating the calculation of PCB line terminal impedance according to the present invention;

[0037] Figure 4 This is a schematic diagram illustrating the calculation of the matching circuit impedance of the present invention;

[0038] Figure 5 This is a schematic diagram of another embodiment of the output impedance calculation device of the present invention. Detailed Implementation

[0039] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Reference Figure 1 The diagram illustrates an embodiment of an output impedance calculation device according to the present invention. The output impedance calculation device includes: a control unit 101, an adjustment unit 102, a LORA transmission unit 103, a first impedance calculation unit 104, a second impedance calculation unit 105, a matching unit 106, and a transmitting antenna 107. The control unit is connected to the LORA transmission unit, the first impedance calculation unit, the second impedance calculation unit, and the adjustment unit, respectively. The LORA transmission unit is connected to the first impedance calculation unit and the matching unit, respectively. The matching unit is connected to the transmitting antenna through the second impedance calculation unit.

[0041] The control unit is used to transmit wireless signals;

[0042] The LORA transmitter unit is used to convert wireless signals into LORA signals;

[0043] The first impedance calculation unit is used to calculate the input impedance based on the LORA signal;

[0044] The second impedance calculation unit is used to calculate the output impedance based on the LORA signal;

[0045] The control unit is used to calculate the reflection coefficient based on the input impedance and output impedance, and to calculate the standing wave coefficient based on the emission coefficient;

[0046] The adjustment unit is used to adjust the impedance in the circuit based on the standing wave coefficient and the reflection coefficient.

[0047] Optionally, the first impedance calculation unit is used to calculate the input impedance based on the LORA signal using a genetic algorithm and a closed-loop algorithm.

[0048] Optionally, the second impedance calculation unit is used to calculate the output impedance based on the LORA signal using a genetic algorithm and a closed-loop algorithm.

[0049] Optionally, the control unit is used to calculate the reflection coefficient according to the following formula, specifically including:

[0050] R = (Z1 - Z2 / Z1 + Z2), where R is the reflection coefficient, Z1 is the input impedance, and Z2 is the output impedance.

[0051] Optionally, the control unit is used to calculate the standing wave ratio based on the emission coefficient, specifically including:

[0052] VSWR = (1+R) / (1-R), where VSWR is the standing wave coefficient.

[0053] Optionally, the adjustment unit is used to adjust the LCR impedance parameters of the circuit, calculate the LCR parameter values ​​when the emission coefficient R=0 and the standing wave coefficient VSWR=1, adjust and calculate the impedance value of the circuit until the measured reflection coefficient R=0 and the standing wave coefficient VSWR=1, and then perform impedance matching of the circuit.

[0054] Figure 3 This is a schematic diagram illustrating the calculation of PCB line terminal impedance according to the present invention. The first impedance calculation unit is also used to calculate the PCB line terminal impedance, that is, to calculate the input impedance of the single-ended microstrip line on the PCB.

[0055] ,in:

[0056] Z0: Line impedance;

[0057] t: Copper thickness of a single-ended microstrip line;

[0058] h: Thickness of the single-ended microstrip line to the reference ground;

[0059] Eε: Dielectric constant of the medium from the microstrip line to the reference formation.

[0060] Figure 4 This is a schematic diagram of the impedance calculation for the matching circuit of the present invention. The first impedance calculation unit is used to calculate the input impedance based on the LORA signal, that is, to perform input impedance calculation for the matching circuit:

[0061] Where Z1 is the input impedance, R1 is the resistance, c2 is the capacitor, L1 is the inductance, and f is the input LORA wireless information frequency.

[0062] Optionally, the second impedance calculation unit is used to calculate the output impedance based on the LORA signal, specifically including:

[0063] ;

[0064] Where Z0 is the line impedance; R rZ is the antenna radiation impedance; Z is the total impedance.

[0065] Specifically, the calculation of wireless radiated power and antenna radiation resistance:

[0066] Total radiated power is ;

[0067] by Substituting the values ​​into the calculation, we get:

[0068] ;

[0069] in ;

[0070] Therefore, after substituting the values, the total radiated power can be calculated as follows:

[0071] ;

[0072] By definition, radiation resistance is the radiation power divided by the square of the current. Therefore, the general formula for radiation resistance impedance is:

[0073] ;

[0074] In summary, the total impedance of the line after connecting the antenna is:

[0075] ;

[0076] Wherein, Z0 (line impedance) and R r (Antenna radiation impedance) is the design impedance, meaning that the relevant impedance parameters are set at the factory and cannot be adjusted. Z1 is the line matching impedance, which can be adjusted by adjusting the parameters of relevant components such as resistors, capacitors, and inductors in the circuit.

[0077] When the output impedance Z of the radio frequency circuit out When the voltage is equal to Z, the output power of the entire circuit reaches impedance matching.

[0078] Optionally, the wireless signal is a variable frequency, constant power wireless test signal in the frequency range of 470-510MHz.

[0079] Figure 2 This is a schematic diagram of the structure of another embodiment of the output impedance calculation device of the present invention, as shown below. Figure 2 As shown, the device for calculating the output impedance includes:

[0080] Control unit: The core control area of ​​the system;

[0081] LORA Transmitting Unit: Through the control and scheduling of the control unit, it transmits and receives LORA signals in the form of a LORA wireless network, transmitting and receiving information from the control unit.

[0082] Impedance calculation: This includes a first impedance calculation unit and a second impedance calculation unit. Each independent calculation unit is responsible for collecting load information on the line and calculating the impedance value of the line.

[0083] Matching circuit (matching unit): It consists of fixed resistors, inductors, capacitors and PCB lines, and the relevant parameters are fixed during the design and production and cannot be changed.

[0084] Transmitting antenna: The load antenna, responsible for signal transmission and reception;

[0085] Adjustment circuit (adjustment unit): It is combined with the matching circuit in series and parallel to adjust the output line impedance. It is directly controlled by the control unit and mainly consists of variable capacitors, variable resistors, variable inductors, varactor diodes, etc.

[0086] Switch: The control unit controls the connection between the matching circuit unit and the impedance measurement unit and the transmitting antenna unit.

[0087] Figure 5 This is a schematic diagram of another embodiment of the output impedance calculation device of the present invention, as shown below. Figure 5 As shown, the LoRaWAN network uses multiple fixed-frequency radio frequencies within the 470MHz-510MHz band to transmit relevant data.

[0088] The LORA transmitting unit is controlled by the control unit to transmit a fixed-frequency, fixed-power wireless test signal with a wireless frequency of f=470MHz.

[0089] The control unit controls the switching switch-1 to connect the output terminal of the LORA transmitter to the impedance calculation terminal (first impedance calculation unit). Through the genetic algorithm and closed-loop algorithm of the impedance calculation unit (first impedance calculation unit), the transmit power and output matching impedance Z1 of the LORA transmitter are calculated, and the corresponding calculation results are fed back to the control unit.

[0090] The control unit controls the switching switch-2 to connect the output of the LORA transmitting unit to the matching circuit, and then connects the output of the matching circuit to the transmitting antenna. The actual output impedance Z2 of the load circuit is calculated by the genetic algorithm and closed-loop algorithm of the second impedance calculation unit, and the result is fed back to the control unit.

[0091] The control unit calculates the difference between the input impedance Z1 and the output impedance Z2, and calculates the reflection coefficient R = (Z1-Z2 / Z1+Z2). From this, the standing wave ratio VSWR = (1+R) / (1-R) ​​is obtained. The closer the value of VSWR is to 1, the better the impedance matching of the circuit.

[0092] The control unit controls the LCR impedance parameter of the adjustment circuit, calculates the LCR parameter value when the emission coefficient R=0 and the standing wave coefficient VSWR=1, adjusts and calculates the impedance value of the circuit until the measured reflection coefficient R=0 and the standing wave coefficient VSWR=1, thus achieving impedance matching of the circuit, and records the adjustment parameter value of the circuit in the linked list unit of the control unit.

[0093] The LORA transmitting unit is controlled by the control unit to transmit a variable frequency and constant power wireless test signal in the 470-510MHz frequency range. The impedance matching parameters at different frequencies are obtained according to the above steps, and the relevant configuration parameters are saved in the database.

[0094] When the control unit needs to transmit a radio frequency signal of a wireless LORA at a specified frequency or frequency modulation, the output impedance can be adjusted simply by modifying the relevant adjustment circuit parameters through software.

[0095] Adjusting circuit components, matching circuit components and PCB lines, and other related parameters can lead to component parameter attenuation or convexity after a certain number of years of use or after exposure to external environmental interference. In this case, by periodically performing circuit self-tests and recording the relevant impedance adjustment parameters, the impedance matching function of the load line can be achieved.

[0096] Through the embodiments of the present invention, the input and output impedances in the circuit can be accurately calculated, and through related circuit design, the circuit can be dynamically adjusted by adjusting the parameters, and the impedance can also be dynamically matched.

[0097] The output impedance calculation device provided in this embodiment of the invention includes: a control unit, an adjustment unit, a LORA transmitting unit, a first impedance calculation unit, a second impedance calculation unit, a matching unit, and a transmitting antenna. The control unit is connected to the LORA transmitting unit, the first impedance calculation unit, the second impedance calculation unit, and the adjustment unit. The LORA transmitting unit is connected to the first impedance calculation unit and the matching unit. The matching unit is connected to the transmitting antenna through the second impedance calculation unit. The control unit transmits wireless signals. The LORA transmitting unit converts the wireless signals into LORA signals. The first impedance calculation unit calculates the input impedance based on the LORA signals. The second impedance calculation unit calculates the output impedance based on the LORA signals. The control unit calculates the reflection coefficient based on the input and output impedances and calculates the standing wave ratio (SWR) based on the transmission coefficient. The adjustment unit adjusts the impedance in the circuit based on the SWR and reflection coefficients. This achieves the calculation and automatic impedance parameter adjustment of the wireless network output impedance in LORAWAN wireless network applications, thereby achieving impedance matching balance between the input and output ends of the line, improving the output quality of the radio signal, reducing the overall output power consumption, and minimizing harmonic interference.

[0098] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0099] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, apparatus, or computer program products. Therefore, embodiments of the present invention can take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware aspects. Furthermore, embodiments of the present invention can take the form of computer program products implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0100] Embodiments of the present invention are described with reference to flowchart illustrations and / or block diagrams of methods, electronic devices (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing electronic device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing electronic device, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1A device that provides the functions specified in one or more boxes.

[0101] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing electronic device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0102] These computer program instructions can also be loaded onto a computer or other programmable data processing electronic device to cause a series of operational steps to be performed on the computer or other programmable electronic device to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable electronic device for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0103] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present invention.

[0104] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or electronic device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or electronic device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or electronic device that includes the element.

Claims

1. A device for calculating output impedance, characterized in that, The output impedance calculation device includes: a control unit, an adjustment unit, a LORA transmission unit, a first impedance calculation unit, a second impedance calculation unit, a matching unit, and a transmitting antenna, wherein: the control unit is connected to the LORA transmission unit, the first impedance calculation unit, the second impedance calculation unit, and the adjustment unit respectively; the LORA transmission unit is connected to the first impedance calculation unit and the matching unit respectively; and the matching unit is connected to the transmitting antenna through the second impedance calculation unit. The control unit is used to transmit wireless signals; The LORA transmitting unit is used to convert the wireless signal into a LORA signal; The first impedance calculation unit is used to calculate the input impedance based on the LORA signal; The second impedance calculation unit is used to calculate the output impedance based on the LORA signal; The control unit is used to calculate the reflection coefficient based on the input impedance and the output impedance, and to calculate the standing wave coefficient based on the emission coefficient; The adjustment unit is used to adjust the impedance in the circuit according to the standing wave coefficient and the reflection coefficient; the first impedance calculation unit is used to calculate the input impedance according to the LORA signal, specifically including: Where Z1 is the input impedance, R1 is the resistance, c2 is the capacitor, L1 is the inductance, and f is the input LORA wireless information frequency. The second impedance calculation unit is used to calculate the output impedance based on the LORA signal, specifically including: ； Where Z0 is the line impedance; R r Z is the antenna radiation impedance; Z is the total impedance.

2. The output impedance calculation device according to claim 1, characterized in that, The first impedance calculation unit is used to calculate the input impedance based on the LORA signal using a genetic algorithm and a closed-loop algorithm.

3. The output impedance calculation device according to claim 1, characterized in that, The second impedance calculation unit is used to calculate the output impedance based on the LORA signal using a genetic algorithm and a closed-loop algorithm.

4. The output impedance calculation device according to claim 3, characterized in that, The control unit is used to calculate the reflection coefficient according to the following formula, specifically including: R = (Z1 - Z2 / Z1 + Z2), where R is the reflection coefficient, Z1 is the input impedance, and Z2 is the output impedance.

5. The output impedance calculation device according to claim 4, characterized in that, The control unit is used to calculate the standing wave ratio based on the emission coefficient, specifically including: VSWR = (1+R) / (1-R), where VSWR is the standing wave coefficient.

6. The output impedance calculation device according to claim 3, characterized in that, The adjustment unit is used to adjust the LCR impedance parameters of the circuit, calculate the LCR parameter values ​​when the emission coefficient R=0 and the standing wave coefficient VSWR=1, adjust and calculate the impedance value of the circuit until the measured reflection coefficient R=0 and the standing wave coefficient VSWR=1, and then perform impedance matching of the circuit.

7. The output impedance calculation device according to claim 1, characterized in that, The first impedance calculation unit is also used to calculate the impedance of PCB trace terminals, specifically including: ,in: Z0: Line impedance; t: Copper thickness of a single-ended microstrip line; h: Thickness of the single-ended microstrip line to the reference ground; Eε: Dielectric constant of the medium from the microstrip line to the reference formation.

8. The output impedance calculation device according to claim 1, characterized in that, The wireless signal is a variable frequency, constant power wireless test signal with a wireless frequency range of 470-510MHz.

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