Calibration structure for RF transmitting power and receiving sensitivity

Abstract

The utility model discloses a calibration structure for RF transmitting power and receiving sensitivity, which comprises a calibrated module, a calibrated module, an MCU board and a PC, the MCU board is provided with two groups of attenuators with adjustable power and two groups of radio frequency electronic switches used for switching the attenuators, the two groups of attenuators are respectively an adjustable attenuator I and an adjustable attenuator II, and the adjustable attenuator I and the adjustable attenuator II are connected with the PC. The two groups of radio frequency electronic switches are respectively SPDT1 and SPDT2, an MCU main body is arranged on the MCU board and is used for controlling the radio frequency electronic switches to switch attenuators through I / O serial ports, and the PC, the calibrated module and the calibrated module are connected with the MCU main body through UART serial ports and are used for information interaction. According to the utility model, two groups of calibration loops are formed through a simple structure, and the transmitting power and the receiving sensitivity of the RF can be effectively calibrated, so that the transmitting power and the receiving sensitivity of the RF are in a controllable state, and the communication quality of the RF is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of micro-power wireless communication, in particular to a calibration structure for RF transmission power and receiving sensitivity. Background Art

[0002] The evolution of traditional power grids to new power systems has brought about rapid development in the intelligence of power equipment and communication networking. Among them, RF communication has been widely used in low-voltage distribution network communication systems due to its convenient access method and mature technology. At the same time, with the development of technology, dual-mode communication modules have gradually increased in actual market applications. When the number reaches a huge level, the communication quality of the communication module is crucial to ensure the safe and reliable operation of the entire communication network, which puts higher requirements on the transmission power and receiving sensitivity of the RF circuit.

[0003] At present, most communication module manufacturers use special equipment such as logic analyzers, wireless network testers, and integrated testers to test the RF part, but these devices can only test the RF transmission power but not the receiving sensitivity. At the same time, these devices are expensive and large in size. During mass production, they are difficult to use on the production line due to factors such as site, technology, and cost.

[0004] Due to the above reasons, many module manufacturers only limit RF testing to normal communication and are unable to control RF transmission power and receiving sensitivity, which poses a hidden danger to the actual on-site application of the module.

[0005] To this end, the present application specifically proposes a calibration structure for RF transmission power and receiving sensitivity to solve the above technical problems. Utility Model Content

[0006] The main purpose of the utility model is to provide a calibration structure for RF transmission power and receiving sensitivity, which can utilize a calibrated module of RF communication, a radio frequency electronic switch, an adjustable attenuator, an MCU board, and a PC to realize the calibration of the transmission power and receiving sensitivity of the RF communication circuit in a dual-mode communication calibrated module.

[0007] In order to solve the above technical problems, the utility model provides a calibration structure for RF transmission power and receiving sensitivity, including a calibrated module, a module to be calibrated, an MCU board and a PC, wherein the MCU board is provided with two groups of power-adjustable attenuators and two groups of radio frequency electronic switches for switching attenuators, the two groups of attenuators are adjustable attenuator 1 and adjustable attenuator 2, respectively, the two groups of radio frequency electronic switches are SPDT1 and SPDT2, an MCU body is provided on the MCU board, which is used to control the radio frequency electronic switch to switch the attenuator through an I / O serial port, and the PC, the calibrated module and the module to be calibrated are all connected to the MCU body through a UART serial port for information interaction.

[0008] Furthermore, the calibrated module is sequentially connected to the SPDT2, the adjustable attenuator 1, and the SPDT1 to the calibrated module via a radio frequency connection line to form a transmission power calibration loop.

[0009] Furthermore, the two groups of I / O serial ports of the MCU board connected to SPDT1 and SPDT2 are both set to level H, and the SPDT1 and SPDT2 are used to connect the adjustable attenuator 1 to the test loop.

[0010] Furthermore, the calibrated module is sequentially connected to SPDT1, adjustable attenuator 2, SPDT2 and the calibrated module through a radio frequency connection line to form a receiving sensitivity calibration loop.

[0011] Furthermore, the two groups of I / O serial ports of the MCU board connected to SPDT1 and SPDT2 are both set to level L, and the SPDT1 and SPDT2 are used to connect the adjustable attenuator 2 to the test loop.

[0012] The beneficial effects of the utility model are embodied in:

[0013] 1. The utility model forms two sets of calibration loops through a simple structure. Only by switching two sets of attenuators, the RF transmission power and receiving sensitivity can be simply and effectively calibrated, so that the RF transmission power and receiving sensitivity are in a controllable state, ensuring the communication quality of RF, and solving the problem that the transmission power and receiving sensitivity cannot be accurately controlled during the mass production of RF communication modules; there is no need to use expensive special detection equipment, which reduces production costs; and simplifies the production line process and calibration process. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The drawings constituting part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0015] Figure 1 It is a schematic diagram of the structural connection of the utility model. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. In the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0017] In the embodiment, see Figure 1 .

[0018] like Figure 1 As shown, the utility model provides a calibration structure for RF transmission power and receiving sensitivity, including a calibrated module, a module to be calibrated, an MCU board and a PC. The MCU board is provided with two groups of power-adjustable attenuators and two groups of RF electronic switches for switching attenuators, the two groups of attenuators are adjustable attenuator 1 and adjustable attenuator 2, respectively, the two groups of RF electronic switches are SPDT1 and SPDT2, the MCU board is provided with an MCU body for connecting the RF electronic switch through an I / O serial port, and the PC, the calibrated module and the module to be calibrated are all connected to the MCU body through a UART serial port.

[0019] Specifically, the calibrated module is a calibrated RF communication module, and the calibrated module is a calibrated RF communication module.

[0020] Therefore, in a specific embodiment, the functions of the calibrated module, the RF electronic switch SPDT1, the RF electronic switch SPDT1, the attenuator, the MCU board, the PC and the calibrated module in the application include:

[0021] Calibrated module: a communication module that has been calibrated and meets the requirements for RF transmit power and receive sensitivity. In the actual use of this application, the transmit power is calibrated to 13dBm, and the receive sensitivity is more than 90% successful when receiving -115dBm signals;

[0022] Calibrated module: internal transmit power is adjustable (11dBm ~ 15dBm), receive signal attenuation is configurable. In the actual use of this application, the transmit power defaults to 13dBm, the internal receive attenuator defaults to 40dB, and the adjustable range is 40dB ~ 45dB;

[0023] RF electronic switch: SPDT1 and SPDT1 are both controlled by the MCU body and are used to switch the attenuator;

[0024] Attenuator: The attenuation value of adjustable attenuator 1 is adjustable and the default value is 128dB, and the attenuation value of adjustable attenuator 2 is adjustable and the default value is 88dB;

[0025] MCU board: controls the switching of RF electronic switches SPDT1 and SPDT2 through the I / O serial port, and connects the marked module, the calibrated module, and the PC through the UART serial port for information exchange;

[0026] PC: It has calibration software installed inside, which is used to start calibration and determine the results after information exchange with MCU.

[0027] In the specific implementation process, the PC is connected to the MCU board through a serial communication port, and the PC is installed with calibration software to control the entire calibration process.

[0028] At the same time, when the MCU board controls the switching of the RF electronic switches SPDT1 and SPDT2 through two I / O serial ports, the levels of the two sets of I / O serial ports will switch between H and L.

[0029] Further, the module to be calibrated is connected to SPDT2, adjustable attenuator 1, SPDT1 in sequence to the calibrated module through RG316 RF connection line to form a transmission power calibration loop;

[0030] At this time, the two I / O serial ports of the MCU board connected to SPDT1 and SPDT2 are set to level H. SPDT1 and SPDT2 are used to connect the adjustable attenuator 1 to the test loop. At this time, it is the transmission power calibration;

[0031] It should be noted that due to the existence of insertion loss and line loss, the attenuation value of adjustable attenuator 1 is adjusted so that the attenuation value between the RF connecting line, SPDT2, adjustable attenuator 1, and SPDT1, that is, the attenuation value between the module under test and the calibrated module is 128dB. This loop attenuation value needs to be calibrated by a vector network analyzer.

[0032] Further, the calibrated module is sequentially connected to SPDT1, adjustable attenuator 2, and SPDT2 to the calibrated module through RG316 RF connection line to form a receiving sensitivity calibration loop;

[0033] At this time, the two I / O serial ports of the MCU board connected to SPDT1 and SPDT2 are set to level L. SPDT1 and SPDT2 are used to connect the adjustable attenuator 2 to the test loop. At this time, the receiving sensitivity is calibrated;

[0034] It should be noted that due to the existence of insertion loss and line loss, the adjustable attenuator 2 is adjusted so that the attenuation value between the RF connecting line, SPDT1, adjustable attenuator 2, and SPDT2, that is, the attenuation value between the calibrated module and the module under test is 88dB. This loop attenuation value needs to be calibrated by a vector network analyzer.

[0035] In summary, the present application utilizes a calibrated RF communication module, a radio frequency electronic switch, an adjustable attenuator, an MCU board, a PC and its supporting software to form two sets of calibration loops through a simple structure. Only by switching the two sets of attenuators, the calibration of the transmitting power and receiving sensitivity of the RF communication circuit in the dual-mode communication module can be realized. The RF transmitting power and receiving sensitivity are calibrated in the simplest and most effective way, so that the RF transmitting power and receiving sensitivity are in a controllable state, ensuring the communication quality of RF, and solving the problem that the transmitting power and receiving sensitivity cannot be accurately controlled during mass production of RF communication modules.

[0036] At the same time, in actual use, there is no need to use expensive special testing equipment, which reduces production costs and simplifies the production line process and calibration process.

[0037] At the same time, in actual use, due to the overall simplicity of the structure and the small size of the equipment, it is suitable for use on the production line.

[0038] In a specific embodiment, the RF transmission power calibration principle is expressed as follows:

[0039] The RF transmitter of the module being calibrated transmits signals at the default transmit power of 13dBm. After the signal is attenuated by 128dB through SPDT2, adjustable attenuator 1, SPDT1 and RF connecting line, the signal strength reaching the calibrated module should meet -115dBm; otherwise, the transmit power of the RF transmitter of the module being calibrated needs to be increased or decreased until the signal strength received by the calibrated module meets -115dBm.

[0040] At this time, the RF transmission power calibration process is expressed as:

[0041] S1. PC starts RF transmission power calibration command;

[0042] S2.MCU switches the RF electronic switch to the adjustable attenuator 1;

[0043] S3. The calibrated module starts a signal transmission at the default power value;

[0044] S4. MCU reads the received signal strength of the calibrated module and converts the value to send to the calibrated module;

[0045] S5. The calibrated module autonomously determines to increase or decrease the transmission power according to the received signal strength value, stepping by 0.1dBm, and restarts the signal transmission;

[0046] Repeat steps S4 and S5 until the signal strength received by the calibration module meets the established parameter requirements; the calibrated module saves the transmit power parameter at this time as the transmit power parameter during normal communication.

[0047] In a specific embodiment, the RF receiving sensitivity calibration principle is expressed as follows:

[0048] The calibrated module RF transmitter transmits a 13dBm standard power signal. The signal is attenuated by 88dB through SPDT1, adjustable attenuator 2, SPDT2 and RF connecting line before reaching the module under test (there is 40dB attenuation inside the module under test). At this time, the internal attenuator of the module under test needs to be adjusted so that the success rate of the module under test receiving the signal is above 90% (the communication success rate A is calculated for 500 times).

[0049] At this time, the RF receiving sensitivity calibration process is expressed as:

[0050] L1. PC starts RF receiving sensitivity calibration command;

[0051] L2.MCU switches the RF electronic switch to the adjustable attenuator 2;

[0052] L3. The calibrated module starts signal transmission at the calibrated transmission power;

[0053] L4. The module being calibrated counts the success rate of signal reception. If the success rate of signal reception is higher than 90%, the calibration is completed. Otherwise, the attenuation value of the internal attenuator of the module being tested is reduced by 0.1dB, and the calibrated module is notified by the MCU to restart transmission.

[0054] Repeat steps L3 and L4 until the packet receiving success rate reaches 90%, and save the current attenuation value of the module under test as a standard parameter.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0056] In addition, it should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0057] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or schemes that A and B meet at the same time. In addition, in the embodiments of the utility model, "multiple" refers to more than two. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

Claims

1. A calibration structure for RF transmission power and receiving sensitivity, characterized in that: The invention comprises a calibrated module, a module to be calibrated, an MCU board and a PC. The MCU board is provided with two groups of power-adjustable attenuators and two groups of radio frequency electronic switches for switching attenuators. The two groups of attenuators are adjustable attenuator 1 and adjustable attenuator 2 respectively. The two groups of radio frequency electronic switches are SPDT1 and SPDT2 respectively. The MCU board is provided with an MCU body for controlling the radio frequency electronic switch to switch the attenuator through an I / O serial port. The PC, the calibrated module and the module to be calibrated are all connected to the MCU body through a UART serial port for information interaction.

2. The calibration structure for RF transmission power and receiving sensitivity as claimed in claim 1, characterized in that: The module to be calibrated is connected to SPDT2, adjustable attenuator 1, SPDT1 in sequence to the calibrated module through a radio frequency connection line to form a transmission power calibration loop; The two I / O serial ports of the MCU board connected to SPDT1 and SPDT2 are both set to level H. The SPDT1 and SPDT2 are used to connect the adjustable attenuator 1 to the test loop.

3. The calibration structure for RF transmission power and receiving sensitivity as claimed in claim 1, characterized in that: The calibrated module is connected to SPDT1, adjustable attenuator 2, SPDT2 in sequence to the calibrated module through a radio frequency connection line to form a receiving sensitivity calibration loop; The two I / O serial ports of the MCU board connected to SPDT1 and SPDT2 are both set to level L, and the SPDT1 and SPDT2 are used to connect the adjustable attenuator 2 to the test loop.

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