Space omnidirectional electric field measurement system and measurement method

Abstract

The invention discloses a spatial omnidirectional electric field measurement system and measurement method, and belongs to the technical field of electromagnetic environment monitoring, a tri-polarized probe is connected with an SP4T switch, the SP4T switch is connected with a radio frequency control module, and the SP4T switch is provided with a radio frequency common port, a radio frequency port and a gating pin; the radio frequency common port is connected with the radio frequency control module, the tri-polarization probe is connected with the radio frequency port, and the radio frequency common port selects the connected radio frequency port through the gating pin; the radio frequency control module is respectively connected with the signal processing instrument and a USB interface of the user computer; the radio frequency control module comprises an MCU and an attitude sensor, the MCU is in communication connection with the attitude sensor, and the MCU controls a gating pin of the SP4T switch to perform channel selection. The three-polarization probe can measure a space omnidirectional electric field, the SP4T switch is used for switching on and off of the three-polarization electric field probe, the attitude sensor can accurately obtain the current probe attitude angle in real time, and the electric field intensity in each direction in the space can be calculated according to the attitude angle.

Description

Technical Field

[0001] The invention belongs to the technical field of electromagnetic environment monitoring, and in particular relates to a spatial omnidirectional electric field measurement system and a measurement method. Background Art

[0002] With the continuous advancement of communication technology and the diversification of electronic devices, the electromagnetic environment in daily life is becoming increasingly complex, and its energy level is also increasing. Although it has promoted the rapid development of the information society and improved the efficiency and quality of information transmission to a certain extent, at the same time, this high-intensity electromagnetic radiation may pose a potential threat to human health and interfere with the normal operation of electronic devices, affecting the smooth and stable operation of society.

[0003] Traditional electric field monitoring equipment usually uses a single-polarized antenna for measurement. This method has obvious limitations, that is, it can only capture electric field information from a specific direction, and cannot fully and accurately reflect the electric field distribution and intensity changes in complex space environments. In order to make up for this shortcoming, traditional methods often require manual rotation of the antenna to perform multi-directional measurements to obtain the overall electric field intensity in space. This operation process is not only time-consuming and labor-intensive, but also inefficient, and it is very easy to introduce errors due to human factors, affecting the accuracy and reliability of the measurement results.

[0004] Therefore, there is an urgent need to develop a measurement method that can automatically and comprehensively collect omnidirectional electric fields in space, which is of great significance for real-time monitoring of electric field strength, warning of potential health risks, and ensuring people's safety. Summary of the invention

[0005] The purpose of the present invention is to overcome the problem that the omnidirectional electric field in space cannot be automatically and comprehensively collected, and a spatial omnidirectional electric field measurement system and a measurement method are proposed.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme: In a first aspect, the present invention provides a spatial omnidirectional electric field measurement system, comprising: a tripolarization probe, an SP4T switch and a radio frequency control module, wherein the tripolarization probe is connected to the SP4T switch, the SP4T switch is connected to the radio frequency control module, and the SP4T switch is provided with a radio frequency common port, a radio frequency port and a gate pin; the radio frequency common port is connected to the radio frequency control module, the tripolarization probe is connected to the radio frequency port, and the radio frequency common port selects the connected radio frequency port through the gate pin; the radio frequency control module is respectively connected to the USB interfaces of a signal processing instrument and a user computer; the radio frequency control module comprises an MCU and a posture sensor, the MCU is communicatively connected to the posture sensor, and the MCU controls the gate pin of the SP4T switch to select a channel.

[0007] Furthermore, the three-polarization probe is connected to the SP4T switch by a coaxial shielded cable, and the SP4T switch is connected to the electromagnetic wave signal of the radio frequency control module by a coaxial shielded cable.

[0008] Furthermore, the tri-polarization probe is three dipole antennas, which are arranged perpendicular to each other in space, and the angle between each dipole antenna and the horizontal direction is 35.26°.

[0009] Further, the RF port includes a first RF port, a second RF port, a third RF port and a fourth RF port, and the RF common port is connected to the first RF port, the second RF port, the third RF port or the fourth RF port through a selection pin; The three-polarization probe includes a first probe, a second probe and a third probe, the first RF port is connected to the first probe, the second RF port is connected to the second probe, the third RF port is connected to the third probe, and the fourth RF port is connected to a matching load.

[0010] Further, the enable pin includes a first enable pin and a second enable pin, when the first enable pin and the second enable pin are both at a low level, the RF common port is connected to the first RF port; when the first enable pin is at a low level and the second enable pin is at a high level, the RF common port is connected to the second RF port; when the first enable pin is at a high level and the second enable pin is at a low level, the RF common port is connected to the third RF port; when the first enable pin and the second enable pin are both at a high level, the RF common port is connected to the fourth RF port.

[0011] Furthermore, the angle difference between the PCB boards of each probe of the three-polarization probe is 60°, and the direction of the PCB board of the first probe is the same as the direction of the PCB board of the attitude sensor.

[0012] Furthermore, the radio frequency control module further comprises a first DC step-down module, a second DC step-down module and a low noise amplifier, and the USB interface of the user computer is connected to one end of the first DC step-down module and one end of the second DC step-down module; The first DC step-down module converts the 5V voltage provided by the USB interface of the user's computer into 3.3V, and the other end of the first DC step-down module supplies power to connect the MCU, the attitude sensor and the SP4T switch; The second DC step-down module converts the 5V voltage provided by the USB interface of the user's computer into 4V, the other end of the second DC step-down module is powered and connected to a low-noise amplifier, one end of the low-noise amplifier is connected to an SP4T switch, and the other end of the low-noise amplifier is connected to a signal processing instrument.

[0013] Furthermore, the low noise amplifier is connected to the other end of the second DC buck module through an inductor, and the low noise amplifier adopts a transistor regulation method; a filter circuit is set between the other end of the first DC buck module and the MCU, the posture sensor and the SP4T switch.

[0014] Furthermore, the IIC_SDA pin and the IIC_SCL pin of the MCU are connected to the attitude sensor, the switchA of the MCU is connected to the first enable pin of the SP4T switch, the switchB pin of the MCU is connected to the second enable pin of the SP4T switch, the temp_ADC pin of the MCU is connected to the temperature sensor inside the MCU, and the MCU is connected to the user computer through a USB interface communication.

[0015] In the second aspect, the present invention provides a spatial omnidirectional electric field measurement method, using the described spatial omnidirectional electric field measurement system, including the following steps: placing a spatial omnidirectional electric field measurement system horizontally, initializing the attitude sensor, the attitude sensor transmitting the original angle data to the MCU, the MCU processing the original angle data to obtain the current attitude angle, the current attitude angle includes the pitch angle, the heading angle and the roll angle; according to the current attitude angle, the angle of the three-polarization probe detecting the electric field is calculated to obtain three groups of detection angles, and the three groups of detection angles are used as basis vectors to calculate the electric field strength in any direction in the three-dimensional space.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention proposes a spatial omnidirectional electric field measurement system, which can measure the spatial omnidirectional electric field through a three-polarization probe, and uses an SP4T switch to switch the three-polarization electric field probe on and off. The back end only needs a set of radio frequency modules, i.e., a signal processing instrument, which saves costs and reduces the system volume at the same time. Through the attitude sensor, the current probe attitude angle can be accurately obtained in real time, and the electric field strength in each direction in the space is calculated according to the attitude angle. The conduction state of the switch is controlled or queried through a USB, and the attitude angle data is also sent through the USB, without the need for external protocol conversion, and is easy to use. The present invention utilizes the dual-function characteristics of the USB interface, not only as a signal transmission channel, but also converts the 5V DC power supply it supplies into the working voltage required by each functional module. This integrated power supply solution effectively simplifies the system architecture, enhances the logic and neatness of the internal component layout, thereby greatly facilitating the installation and integration of various components of the system. The present invention has a simple structure but complete functions, and can measure the omnidirectional electric field in the space while keeping the influence on the spatial electric field to a minimum, thereby improving the measurement accuracy. The present invention integrates an MCU control system, and through a carefully designed, simple and easy-to-use operation method, the operation process of the system is simple, thereby improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are for explanation purposes only and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the components in the drawings are only for illustration purposes to help understand the present invention, and are not intended to specifically limit the shapes and proportional dimensions of the components of the present invention. In the drawings: Figure 1 This is the overall structure diagram of a spatial omnidirectional electric field measurement system.

[0018] Figure 2 Schematic diagram of a single probe of a triple polarization probe.

[0019] Figure 3 This is the effect diagram after the three probes of the triple polarization probe are combined.

[0020] Figure 4 Schematic diagram of the structure of the SP4T switch.

[0021] Figure 5 This is the schematic diagram of the low noise amplifier and DC step-down module.

[0022] Figure 6 Schematic diagram of the probe calibration platform.

[0023] Figure 7 It is the electric field spectrum received by the first probe (probe 1) in a certain measurement.

[0024] Figure 8 It is the electric field spectrum received by the second probe (probe 2) in a certain measurement.

[0025] Fig. 9 It is the electric field spectrum received by the third probe (probe 3) in a certain measurement.

[0026] Fig.10 It is the total spatial electric field intensity spectrum calculated in a certain measurement.

[0027] Among them, 1 is a dipole antenna and 2 is a tri-polarized probe. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0029] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only embodiment.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0031] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0032] Embodiment 1 It includes a tri-polarization probe, SP4T switch and RF control module. The RF control module is further divided into four sub-modules: MCU, attitude sensor, first DC buck module, second DC buck module and low noise amplifier.

[0033] The overall structural layout of the system is detailed in Figure 1, which shows in detail the connection relationship and layout configuration between the various components, providing an intuitive reference for the design and implementation of the system. The connection between the tri-polarized antenna and the SP4T (Single-pole Four-throw) switch uses a coaxial shielded cable to ensure the integrity and anti-interference ability of the signal transmission. Similarly, the electromagnetic wave signal transmission between the SP4T switch and the RF control module is also achieved through a coaxial shielded cable. The control signal and power supply are connected through DuPont wires to ensure stable signal transmission and reliable power supply. Communication between RF control modules is achieved through USB cables, and the connection with the electromagnetic signal processing equipment again uses coaxial shielded cables to maintain high-quality signal transmission.

[0034] The tri-polarized probe consists of three dipole antennas. See the schematic diagram for details. Figure 2 The design feature of this probe is that the three antennas are arranged perpendicular to each other in space. The specific spatial combination effect is shown in Figure 3 .in accordance with Figure 2 As shown in the figure, the antennas used are all dipole type, and the angle between each antenna and the horizontal direction is precisely set to 35.26°. This angle configuration ensures that when the three antennas are used in combination, the electric field components from different directions can be effectively received. Since the three probes maintain consistency in structural design, their response characteristics to signals are also consistent, which is crucial for accurately restoring the spatial electric field distribution from the measured signal.

[0035] In the signal transmission link, the dipole probe is fed by a balanced differential transmission line. To ensure compatibility with unbalanced transmission systems, the balanced signal must be converted to an unbalanced signal through a balun. After the signal conversion is completed, the signal is transmitted to the SP4T power divider through the SMA connector to achieve effective signal distribution and processing.

[0036] SP4T switch structure Figure 4As shown. The SP4T switch is a single-pole four-throw switch, which is a switch with a common input or output terminal and four selectable input or output terminals. The SP4T switch is configured with five RF ports, as follows: the RF common port, as the central node of the switch, is used to establish a connection with any of the other four ports, the first RF port (RF port 1), the second RF port (RF port 2), the third RF port (RF port 3), and the fourth RF port (RF port 4). In this embodiment, the RF common port is connected to the RF control module; the first RF port is connected to the first probe (probe 1); the second RF port is connected to the second probe (probe 2); and the third RF port is connected to the third probe (probe 3). Given that the three-polarization probe only contains three RF ports, and the SP4T switch is equipped with four RF ports, there will be an additional RF port, namely the fourth RF port, which remains unconnected in this solution. In order to ensure signal integrity and reduce interference, the fourth RF port will be connected to a matching load. The matching load is designed to completely absorb the signal from the fourth RF port and prevent the signal from reflecting back to the SP4T switch, thereby avoiding interference with the signals of other ports.

[0037] The operation of the strobe pins of the SP4T switch is controlled by the MCU. When the first strobe pin (select pin A) is low and the second strobe pin (select pin B) is low, the RF common port is connected to the first RF port, and the signal on the first probe is drawn out; when the first strobe pin (select pin A) is low and the second strobe pin (select pin B) is high, the RF common port is connected to the second RF port, and the signal on the second probe is drawn out; when the first strobe pin (select pin A) is high and the second strobe pin (select pin B) is low, the RF common port is connected to the third RF port, and the signal on the third probe is drawn out; when the first strobe pin (select pin A) is high and the second strobe pin (select pin B) is high, the RF common port is connected to the matching load, and there is no signal.

[0038] By integrating the SP4T switch, the amplification processing of the probe receiving signal can be achieved using only one set of low-noise amplifiers, which effectively reduces the size of the system and reduces costs. The application of the SP4T switch further optimizes the signal transmission path, allowing the measured spatial three-dimensional electric field data to be output through a single SMA interface, thereby avoiding the complexity of three independent signal processing devices required at the back end. This design not only improves the system integration, but also simplifies the complexity of back-end signal processing, providing a more efficient and economical solution for electric field measurement.

[0039] The USB interface is selected because it has the dual functions of data communication and power transmission. The interface can provide a stable 5V voltage source. For the USB 2.0 standard, its maximum output power can reach 2.5 watts, which is enough to meet the overall power consumption requirements of this system. Therefore, this system uses the USB interface as a power source, and no additional power supply equipment is required.

[0040] In order to adapt to the working voltage requirements of most chips, this system converts the 5V voltage provided by the USB interface into 3.3V through an integrated chip. Subsequently, the filter circuit further removes the noise interference that may exist in the 3.3V voltage to ensure the quality and stability of the output power. This design helps to simplify the interface configuration, improve the integration of the system, and reduce the interference with the external electromagnetic field, thereby improving the overall performance and reliability of the system.

[0041] Considering the size limitation of the probe and the low gain of the selected dipole antenna, the signal strength received by the probe is weak. Therefore, the signal must be pre-enhanced before being transmitted to the back-end signal processing device. To this end, this embodiment uses LNA (Low Noise Amplifier) ​​to enhance the signal. The low noise amplifier maintains low noise characteristics while providing the required gain, which helps to minimize the introduction of noise, thereby ensuring the integrity and signal-to-noise ratio of the signal, which is crucial to maintaining the purity and reliability of the received spatial signal.

[0042] This system is powered by a USB interface with a power supply voltage of 5V. Since low-noise amplifiers usually have specific power supply voltage requirements, the power supply voltage needs to be appropriately stepped down or stepped up to meet the working voltage requirements of the low-noise amplifier. In this solution, the working voltage of the low-noise amplifier is 4V, and the 5V power supply voltage is converted to 4V through transistor regulation to ensure the stable operation of the low-noise amplifier. The use of transistors is conducive to improving the accuracy and stability of power supply. In order to reduce the interference of RF signals on the power supply signal, the power supply circuit and the low-noise amplifier are connected through an inductor. For a detailed schematic diagram of the low-noise amplifier and its DC step-down module, see Figure 5 .

[0043] The attitude sensor is responsible for obtaining the dynamic attitude angle of the system in real time and is powered by a 3.3V voltage. Before taking measurements, the system needs to be laid flat to initialize the attitude sensor. After initialization, the attitude sensor will continuously transmit angle raw data. By processing these raw data, the current attitude angle of the sensor can be determined.

[0044] The MCU (Micro Controller Unit) is responsible for the control function of the system and is powered by a 3.3 V voltage. The selected MCU has an integrated USB function that can be enabled through software configuration, and no additional protocol conversion is required when communicating with the user's computer, thereby simplifying the system design and reducing the size.

[0045] The MCU has two core responsibilities: one is to control the channel selection of the SP4T switch; the other is to monitor the system status. The five specific pins of the MCU are marked as IIC_SDA, IIC_SCL, switchA, switchB and temp_ADC. Among them, the IIC_SDA and IIC_SCL pins are connected to the attitude sensor, and the attitude angle data is acquired through the I2C communication protocol. The switchA and switchB pins are connected to the first selection pin A and the second selection pin B of the SP4T switch respectively, which are used to control the channel selection of the SP4T switch. In the default state, switchA and switchB output high level, indicating no signal output. The temp_ADC pin is connected to the temperature sensor inside the MCU for real-time monitoring of the ambient temperature.

[0046] The communication between MCU and user's computer is realized through serial interface. The following is the specific instruction set to control the SP4T switch channel selection: ① The user computer sends the command "channel 1" to the MCU. The MCU responds by setting switchA and switchB to low level to select RF port 1. At this time, the signal from the first probe is output.

[0047] ② The user computer sends the command "channel 2" to the MCU. The MCU responds by setting switchA to a low level and switchB to a high level to select RF port 2. At this time, the signal from the second probe is output.

[0048] ③ The user computer sends the command "channel 3" to the MCU. The MCU responds by setting switchA to a high level and switchB to a low level to select RF port 3. At this time, the signal from the third probe is output.

[0049] ④ The user computer sends the command "channel 0" to the MCU. The MCU responds by setting both switchA and switchB to high levels to select RF port 4. At this time, no signal is output.

[0050] After the channel selection is completed, the MCU sends a confirmation command "set channel X" to the user computer, where "X" represents the selected port number to indicate that the setting has been successfully executed.

[0051] The following are the specific instructions for obtaining system status: ① When the current system attitude angle needs to be obtained, the user computer sends the command "get angle" to the MCU, and the MCU responds by sending the current system attitude angle data "(θpitch, θyaw, θroll)", where θpitch, θyaw, and θroll represent the pitch angle, heading angle, and roll angle, respectively.

[0052] ②When the current temperature needs to be obtained, the user computer sends the command "get temperature" to the MCU, and the MCU responds by sending the current temperature data "temperature: X", where "X" represents the actual temperature value.

[0053] ③When the current selected channel needs to be obtained, the user computer sends the command "get channel" to the MCU, and the MCU responds by sending the current selected channel data "channel: X", where "X" represents the currently selected RF port number.

[0054] In this embodiment, the original signal is amplified and directly exported through the SMA interface, and can be connected to any external signal processing instrument for processing according to user needs. The tripolarization probe in this embodiment is composed of three consistent dipole probes, and these probes are arranged vertically in pairs. Their response characteristics to the signal are consistent, and the electric field measured by them can be used as the basis vector to deduce the electric field strength in any direction in space, thereby improving the accuracy and reliability of the measurement.

[0055] Embodiment 2 A spatial omnidirectional electric field measurement method uses a spatial omnidirectional electric field measurement system of embodiment 1, comprising the following steps: placing a spatial omnidirectional electric field measurement system horizontally, initializing a posture sensor, the posture sensor transmitting angle raw data to an MCU, the MCU processing the angle raw data to obtain a current posture angle, the current posture angle comprising a pitch angle, a heading angle and a roll angle; calculating the angle of a tri-polarized probe detecting an electric field according to the current posture angle to obtain three groups of detection angles, and using the three groups of detection angles as basis vectors to calculate the electric field strength in any direction in the three-dimensional space.

[0056] Specifically, θ pitch Represents the pitch angle, that is, the rotation angle of the sensor around the X axis; θ yaw Represents the heading angle, that is, the rotation angle of the sensor around the Y axis; θ roll represents the roll angle, that is, the rotation angle of the sensor around the Z axis. Therefore, the attitude of the attitude sensor at any time can be expressed as (θ pitch , θ yaw , θ roll ).

[0057] The design direction of the PCB (Printed Circuit Board) of the first probe is consistent with the PCB direction of the attitude sensor. Therefore, for the first probe, the angle of its detection electric field can be expressed as (θ pitch , θ yaw +54.74°, θ roll ). Given that the angle difference between the PCB boards of each probe in the tri-polarized probe is 60°, the angles of the electric field detected by the second and third probes can be deduced. The electric field detection angle of the second probe is (θ pitch , θ yaw + 54.74°,θ roll + 60°), and the detection electric field angle of the third probe is (θ pitch , θ yaw + 54.74°, θ roll - 60°). These three sets of angles are orthogonal to each other and can be used as basis vectors to calculate the electric field strength in any direction in three-dimensional space.

[0058] This embodiment provides a calibration method for an omnidirectional electric field measurement system. In order to achieve accurate measurement of the omnidirectional electric field in space, the probe must be calibrated before measurement. The probe calibration process is carried out on a calibration platform as shown in FIG6 . The measurement part of the calibration platform is located in a microwave darkroom. The measurement device used in this scheme is a two-port vector network analyzer, which can transmit signals and enhance the signal strength through a power amplifier, and then radiate into space by a standard antenna. In this embodiment, the antenna to be tested is a standard gain horn and a three-polarization probe, which is responsible for receiving electromagnetic signals in space. The received signal is first subjected to noise reduction and amplification processing by a low-noise amplifier, and then transmitted back to the vector network analyzer. To ensure the accuracy of the measurement, the standard antenna and the antenna to be tested must be facing each other and maintain polarization consistency. The vector network analyzer has the function of automatically measuring the transmission coefficient.

[0059] During the calibration process, the standard gain horn is first fixed on the low-scattering bracket at the receiving end, and the transmission coefficient at this time is measured by the vector network analyzer, which is recorded as S1. Subsequently, one of the three-polarization probes is installed on the low-scattering bracket, and the transmission coefficient is measured again using the vector network analyzer, which is recorded as S2. The correction factor η is defined, and its calculation formula is η = S1÷S2. In actual measurement, if the frequency amplitude curve obtained using the probe is f(V), the actual frequency curve adjusted by the correction factor η is η×f(V).

[0060] This embodiment provides a method for using an omnidirectional electric field measurement system. Two methods for operating the omnidirectional electric field measurement system are given below to achieve omnidirectional measurement of the electric field.

[0061] Method 1: Manual control The user can manually select a specific channel of the SP4T switch for signal conduction and use the system as a regular environmental measurement probe. In this mode, the user can select any channel for measurement as needed.

[0062] Method 2: Automatic collection The omnidirectional electric field measurement system has digital control function and can work with signal processing equipment with digital control capability to form an automated data acquisition system. In a single data acquisition process, the user computer first sends a "get angle" command to the omnidirectional electric field measurement system to obtain the current attitude angle of the sensor. Subsequently, the user computer instructs the omnidirectional electric field measurement system to turn on RF port 1, RF port 2, and RF port 3 in turn, and saves the data collected each time, thereby completing a single omnidirectional electric field measurement. The user can determine the total electric field strength in space by calculating the Euclidean norm of the amplitude of these three sets of electric field data; or calculate the electric field strength in any direction based on the attitude angle of the sensor. The duration of a single acquisition is mainly determined by the data storage time, which is usually at the millisecond level. Therefore, if the movement speed of the omnidirectional electric field measurement system is not too high, it can be assumed that the system remains stationary during a single measurement, and the signals collected by the tripolarization probe represent the electric fields in different directions at the same position.

[0063] The omnidirectional electric field measurement system can be installed on various vehicles, such as hanging under a drone, to collect data on the environmental electric field. The system supports timed triggering to achieve a continuous data collection process, or triggering collection at a specific location to collect fixed-point data at each target location.

[0064] The automatic acquisition function allows the formation of an automatic acquisition system with a signal processing instrument with numerical control function, achieving fast and continuous data acquisition and improving measurement efficiency. At the same time, the manual control function of the system provides flexibility, allowing users to select specific measurement channels as needed to adapt to different measurement scenarios and requirements.

[0065] In addition, in one embodiment, in a certain measurement of the environmental electric field, the spectrum measured by the first probe is as follows: Figure 7 As shown, the spectrum measured by the second probe is as follows Figure 8 As shown, the spectrum measured by the third probe is as follows Fig. 9As shown in Figure 10. From the spectrum measured by the three probes, we can clearly see the various frequency components in the space and the amplitudes of each frequency component in the three-dimensional orthogonal direction, which is impossible to achieve with the traditional detection-type electric field detection method. The total electric field strength in the space can also be determined by calculating the Euclidean norm of the amplitudes of the three sets of electric field data, as shown in Figure 10. If necessary, the direction vectors of the three probes can be used as basis vectors to calculate the electric field strength in any direction in the three-dimensional space based on the data measured by the three probes.

[0066] In addition, in one embodiment, the three-polarization probe uses other types of antennas.

[0067] In addition, in one embodiment, no switch is used, and the data collected by each probe is directly connected to the outside world after passing through a separate low-noise amplifier.

[0068] In addition, in one embodiment, a combination of an adjustable attenuator and a low noise amplifier is used instead of the low noise amplifier to achieve variable gain.

[0069] In addition, in one embodiment, an MCU is used to implement automated control of external signal processing devices on behalf of a user computer.

[0070] In addition, in one embodiment, switches of other specifications are used, such as a one-to-three switch.

[0071] In addition, in one embodiment, other methods are used to achieve voltage reduction.

[0072] Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the preceding claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to be a disclaimer of such subject matter, nor should it be considered that the applicants did not consider such subject matter to be part of the disclosed inventive subject matter.

[0073] The above content is a further detailed description of the present invention. It cannot be determined that the specific implementation methods of the present invention are limited to these. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, they can also make several simple deductions or substitutions, which should be regarded as belonging to the protection scope of the present invention determined by the submitted claims.

Claims

1. A spatial omnidirectional electric field measurement system, characterized in that: include: A tripolarization probe, an SP4T switch and a radio frequency control module, wherein the tripolarization probe is connected to the SP4T switch, the SP4T switch is connected to the radio frequency control module, and the SP4T switch is provided with a radio frequency common port, a radio frequency port and a gate pin; the radio frequency common port is connected to the radio frequency control module, the tripolarization probe is connected to the radio frequency port, and the radio frequency common port selects the connected radio frequency port through the gate pin; the radio frequency control module is respectively connected to the USB interfaces of a signal processing instrument and a user's computer; the radio frequency control module comprises an MCU and a posture sensor, the MCU is communicatively connected to the posture sensor, and the MCU controls the gate pin of the SP4T switch to select a channel.

2. A spatial omnidirectional electric field measurement system according to claim 1, characterized in that: The three-polarization probe is connected to the SP4T switch by a coaxial shielded cable, and the SP4T switch is connected to the electromagnetic wave signal of the radio frequency control module by a coaxial shielded cable.

3. A spatial omnidirectional electric field measurement system according to claim 1, characterized in that: The tri-polarization probe is three dipole antennas, which are arranged perpendicular to each other in space, and the angle between each dipole antenna and the horizontal direction is 35.26°.

4. A spatial omnidirectional electric field measurement system according to claim 1, characterized in that: The radio frequency port includes a first radio frequency port, a second radio frequency port, a third radio frequency port and a fourth radio frequency port, and the radio frequency common port selects to connect to the first radio frequency port, the second radio frequency port, the third radio frequency port or the fourth radio frequency port through a selection pin; The three-polarization probe includes a first probe, a second probe and a third probe, the first RF port is connected to the first probe, the second RF port is connected to the second probe, the third RF port is connected to the third probe, and the fourth RF port is connected to a matching load.

5. A spatial omnidirectional electric field measurement system according to claim 4, characterized in that: The enable pins include a first enable pin and a second enable pin. When the first enable pin and the second enable pin are both at a low level, the RF common port is connected to the first RF port; when the first enable pin is at a low level and the second enable pin is at a high level, the RF common port is connected to the second RF port; when the first enable pin is at a high level and the second enable pin is at a low level, the RF common port is connected to the third RF port; when the first enable pin and the second enable pin are both at a high level, the RF common port is connected to the fourth RF port.

6. A spatial omnidirectional electric field measurement system according to claim 4, characterized in that: The angle difference between the PCB boards of each probe of the three-polarization probe is 60°, and the direction of the PCB board of the first probe is the same as the direction of the PCB board of the attitude sensor.

7. The spatial omnidirectional electric field measurement system according to claim 1, characterized in that: The radio frequency control module also includes a first DC step-down module, a second DC step-down module and a low noise amplifier, and the USB interface of the user computer is connected to one end of the first DC step-down module and one end of the second DC step-down module; The first DC step-down module converts the 5V voltage provided by the USB interface of the user's computer into 3.3V, and the other end of the first DC step-down module supplies power to connect the MCU, the attitude sensor and the SP4T switch; The second DC step-down module converts the 5V voltage provided by the USB interface of the user's computer into 4V, the other end of the second DC step-down module is powered and connected to a low-noise amplifier, one end of the low-noise amplifier is connected to an SP4T switch, and the other end of the low-noise amplifier is connected to a signal processing instrument.

8. A spatial omnidirectional electric field measurement system according to claim 7, characterized in that: The low noise amplifier is connected to the other end of the second DC buck module through an inductor, and the low noise amplifier adopts a transistor regulation method; a filter circuit is set between the other end of the first DC buck module and the MCU, the posture sensor and the SP4T switch.

9. The spatial omnidirectional electric field measurement system according to claim 1, characterized in that: The IIC_SDA pin and the IIC_SCL pin of the MCU are connected to the attitude sensor, the switchA of the MCU is connected to the first enable pin of the SP4T switch, the switchB pin of the MCU is connected to the second enable pin of the SP4T switch, the temp_ADC pin of the MCU is connected to the temperature sensor inside the MCU, and the MCU is connected to the user's computer through a USB interface communication connection.

10. A spatial omnidirectional electric field measurement method, using a spatial omnidirectional electric field measurement system as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: A spatial omnidirectional electric field measurement system is placed horizontally, and the attitude sensor is initialized. The attitude sensor transmits the original angle data to the MCU, and the MCU processes the original angle data to obtain the current attitude angle. The current attitude angle includes the pitch angle, the heading angle and the roll angle. The angle of the three-polarization probe detecting the electric field is calculated according to the current attitude angle to obtain three groups of detection angles, and the three groups of detection angles are used as basis vectors to calculate the electric field strength in any direction in the three-dimensional space.

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