Directional antenna for Internet of Things communication and Internet of Things communication device

Abstract

The utility model relates to the radio antenna technology, and discloses a directional antenna for Internet of Things communication and an Internet of Things communication device, the directional antenna comprises an artificial magnetic conductor reflecting surface located at the upper layer and a gradient metamaterial layer located at the lower layer, and the artificial magnetic conductor reflecting surface comprises metamaterial units arranged in a 5 * 5 array; in each metamaterial unit, the upper layer is a metamaterial patch covering the 2.4 GHz frequency band, the lower layer is a slot coupling antenna covering the Sub-1GHz frequency band, and the central axis of the central aperture of the fractal split resonant ring on the upper layer coincides with the central axis of the central aperture of the nested hexagonal ring on the lower layer. The utility model aims to provide a directional antenna which is low in power consumption and strong in interference resistance and can be used for long-distance and high-penetration communication of the Internet of Things.

Description

Technical Field

[0001] This utility model relates to the field of radio antenna technology, and in particular to a directional antenna and an IoT communication device for Internet of Things (IoT) communication. Background Technology

[0002] Currently, in IoT communication, omnidirectional antennas are generally used to provide wide-area signal coverage in order to ensure accurate transmission and reception of wireless signals.

[0003] However, due to the low radiation efficiency of omnidirectional antennas, a lot of energy needs to be consumed to ensure sufficient signal coverage, which directly leads to a shortened battery life of IoT communication devices. Furthermore, in complex electromagnetic environments, omnidirectional antennas are susceptible to multipath effects and co-channel interference (multipath effects cause signals to reach the receiver through different paths, resulting in signal fading and distortion; co-channel interference will superimpose with the useful signal, reducing signal quality). In addition, omnidirectional antennas use a non-directional transmission method, which makes it difficult to meet the communication needs of long-distance and high-penetration scenarios (such as the need for signal coverage of large areas of farmland in smart agriculture, and the need for signals to penetrate pipe walls in underground pipeline monitoring).

[0004] The above content is only used to help understand the technical solution of this utility model and does not represent an admission that the above content is prior art. Utility Model Content

[0005] This invention proposes a directional antenna and an IoT communication device, aiming to provide a low-power, high-interference, and long-distance, high-penetration directional antenna for IoT communication.

[0006] To achieve the above objectives, this utility model proposes a directional antenna for Internet of Things (IoT) communication. The directional antenna includes an artificial magnetic conductor reflector on the upper layer and a gradient metamaterial layer on the lower layer. The artificial magnetic conductor reflector includes metamaterial units arranged in a 5×5 array.

[0007] In each metamaterial unit, the upper layer is a metamaterial patch covering the 2.4 GHz frequency band, and the lower layer is a slot-coupled antenna covering the Sub-1 GHz frequency band. The central axis of the central aperture of the upper fractal open resonant ring coincides with the central axis of the central aperture of the lower nested hexagonal ring.

[0008] Optionally, the metamaterial patch is a fractal open resonant ring.

[0009] Optionally, the slot-coupled antenna is a nested hexagonal ring.

[0010] This utility model further proposes an Internet of Things (IoT) communication device, including a main control module and a radio frequency (RF) module; the RF module includes a directional antenna and a feed network, and the directional antenna is electrically connected to the main control module via the feed network;

[0011] The directional antenna is the same as the directional antenna used for IoT communication as described above.

[0012] Optionally, the power supply network integrates a duplex filter adapted to the 2.4GHz band and the Sub-1GHz band.

[0013] Optionally, the directional antenna is electrically connected to the feed network via a Sub-1GHz front-end, and the Sub-1GHz front-end integrates an SX1262 chip.

[0014] Optionally, the radio frequency module may also include an NB-IoT module.

[0015] Optionally, the radio frequency module adopts an integrated module design, which integrates a noise amplifier and a power amplifier.

[0016] Optionally, the main control module is configured with an nRF9160 chip as its main control chip.

[0017] The beneficial effects of this utility model are as follows: the directional antenna adopts a unique design with an upper artificial magnetic conductor reflector and a lower gradient metamaterial layer, which greatly improves the radiation efficiency and enables accurate transmission and reception of wireless signals. Compared with omnidirectional antennas, it can effectively reduce energy consumption in the IoT communication process and significantly extend the battery life. In terms of anti-interference performance, it avoids the problems of multipath effect and co-channel interference that omnidirectional antennas are susceptible to, which greatly improves the signal quality of IoT communication. In terms of scenario applicability, IoT communication based on directional antennas can well meet the communication needs of long-distance and high-penetration scenarios due to its directional transmission method. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the architecture of a directional antenna in one embodiment of this application;

[0019] Figure 2 This is a side view of the metamaterial unit in one embodiment of this application.

[0020] Figure 3 This is a comparison diagram of the absorption spectrum of a square resonant ring based on FDTD simulation and different magnetic field distributions in one embodiment of this application;

[0021] Figure 4 This is a top view of a shared aperture architecture of nested hexagonal rings and square resonant rings in one embodiment of this application;

[0022] Figure 5This is a schematic diagram of the architecture of an Internet of Things (IoT) communication device in one embodiment of this application.

[0023] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0024] The solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0025] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this utility model are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0026] It should also be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component present. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component present.

[0027] Furthermore, descriptions involving terms such as "first" and "second" in this utility model are for descriptive purposes only (e.g., to distinguish identical or similar elements) and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" and "second" may explicitly or implicitly include at least one of those features. Additionally, technical solutions from different embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If a combination of technical solutions is contradictory or impossible to implement, such a combination should be considered nonexistent and not within the scope of protection claimed by this utility model.

[0028] This utility model proposes a directional antenna for Internet of Things (IoT) communication, referring to... Figure 1 and Figure 2 The directional antenna for this Internet of Things communication includes an artificial magnetic conductor reflector on the upper layer and a gradient metamaterial layer on the lower layer. The artificial magnetic conductor reflector includes metamaterial units arranged in a 5×5 array.

[0029] In each metamaterial unit, the upper layer is a metamaterial patch covering the 2.4 GHz frequency band, and the lower layer is a slot-coupled antenna covering the Sub-1 GHz frequency band. The central axis of the central aperture of the upper fractal open resonant ring coincides with the central axis of the central aperture of the lower nested hexagonal ring.

[0030] In this embodiment, the directional antenna employs a special layered design, including an upper artificial magnetic conductor reflector and a lower gradient metamaterial layer. This layered structure optimizes antenna performance, improving signal directivity and gain. The artificial magnetic conductor reflector enhances the antenna's forward radiation efficiency, while the gradient metamaterial layer provides phase compensation, enabling beam focusing and resulting in a directional gain greater than 8 dBi and a 30% increase in coverage distance.

[0031] It should be noted that an artificial magnetic conductor (AMC) is an artificially designed electromagnetic material that can exhibit properties similar to an ideal magnetic conductor within a specific frequency range (i.e., it has high surface impedance and zero phase when reflecting electromagnetic waves); a gradient metamaterial layer is an artificially designed metamaterial layer characterized by its internal structural parameters (such as dielectric constant and permeability) varying in a gradient along a specific direction. This gradient variation is carefully designed to achieve specific control over electromagnetic waves.

[0032] Optionally, the gradient metamaterial layer can be a gradient refractive index lens, because a gradient refractive index lens can achieve different focusing effects and beam characteristics by precisely designing the internal refractive index distribution.

[0033] The artificial magnetic conductor reflector is composed of metamaterial units arranged in a 5×5 array. This array structure can enhance the antenna's radiation characteristics, making the signal more concentrated in a specific direction.

[0034] Each metamaterial unit also has a unique two-layer structure: the upper layer is a metamaterial patch covering the 2.4 GHz band, which is specifically designed for the 2.4 GHz band and can effectively transmit and receive signals in this band; the lower layer is a slot-coupled antenna covering the Sub-1 GHz band, which is suitable for communication in the lower frequency Sub-1 GHz band.

[0035] Among them, the slot-coupled antenna is a type of antenna based on a slot structure. Its working principle is to create a slot on the surface of a conductor. When an alternating current passes through the conductor, a radiated electromagnetic field is generated around the slot, thereby realizing the transmission and reception of signals.

[0036] Both the upper metamaterial patch and the lower slot-coupled antenna have apertures at their centers, and the central axis of the central aperture of the upper metamaterial patch coincides with the central axis of the central aperture of the lower slot-coupled antenna. This shared aperture design can avoid mutual interference between signals of different frequency bands, ensure the effective transmission and coupling of signals of different frequency bands, and thus improve the overall performance of the antenna.

[0037] In one embodiment, the directional antenna employs a unique design with an upper artificial magnetic conductor reflector and a lower gradient metamaterial layer, which greatly improves radiation efficiency and enables precise transmission and reception of wireless signals. Compared with omnidirectional antennas, it can effectively reduce energy consumption during IoT communication and significantly extend battery life. Furthermore, in terms of anti-interference performance, it avoids the problems of multipath effects and co-channel interference that omnidirectional antennas are susceptible to, resulting in a significant improvement in the signal quality of IoT communication. In terms of scenario applicability, IoT communication based on directional antennas, with its directional transmission method, can well meet the communication needs of long-distance and high-penetration scenarios.

[0038] In one embodiment, based on the above embodiments, the metamaterial patch is a fractal open-ended resonant ring.

[0039] In this embodiment, the fractal split-ring resonator (FSRR) is an artificial electromagnetic material unit that combines fractal geometry and the structure of a split-ring resonator (SRR), and has advantages such as multi-band response, miniaturization and tunable electromagnetic properties.

[0040] When electromagnetic waves strike a fractal open-circuit resonator, its unique fractal structure and open design induce currents within the ring. These currents generate a magnetic field that interacts with the incident electromagnetic waves, causing the fractal open-circuit resonator to resonate at a specific frequency. Near the resonant frequency, the fractal open-circuit resonator exhibits unique electromagnetic properties, such as strong absorption, reflection, or transmission of electromagnetic waves, and alteration of the propagation direction of electromagnetic waves.

[0041] Designing metamaterial patches as fractal open resonant rings can enhance the antenna's response to electromagnetic waves in specific frequency bands (such as 2.4GHz), improve the antenna's radiation efficiency and performance, and thus enhance the signal transmission and reception quality and communication effect of the entire IoT communication device.

[0042] Optionally, the fractal open resonant ring is a square resonant ring with two layers of openings facing different directions.

[0043] This fractal open-loop resonator structure consists of two layers of square resonator rings, each with an opening. However, the openings of the two layers face different directions, and the overlap of the centers of the openings forms the corresponding central aperture. In terms of electromagnetic principles, when external electromagnetic waves are incident, the double-layer structure creates a more complex current distribution and magnetic field interaction. The different opening orientations cause the two resonator rings to respond differently to electromagnetic waves, thus producing resonance effects in multiple frequency bands.

[0044] Optionally, a square resonant ring with a side length of approximately 12 mm (preferably 12 mm) is designed and implemented using PCB technology (such as fabrication based on an FR4 substrate), with a unit period of λ / 4 (approximately 31 mm).

[0045] The unit structure can be optimized using FDTD (Finite-Difference Time-Domain) simulation to match the impedance characteristics of the target frequency band. A comparison of the absorption spectrum of the square resonator with different magnetic field distributions (including a comparison of absorption spectra for two different magnetic field distributions, wl1 and wl2) based on FDTD simulation is shown below. Figure 3 As shown.

[0046] Alternatively, metamaterial patch structures can be implemented using PCB technology, which can significantly reduce material costs.

[0047] In terms of performance, this design enables a wider frequency response range, meeting the needs of multi-band signal processing in IoT communication. It can further improve the radiation efficiency and signal transmission and reception capabilities of the antenna in different frequency bands, enhance the adaptability and stability of the device in complex electromagnetic environments, help improve communication quality, and ensure accurate and efficient data transmission.

[0048] In one embodiment, based on the above embodiments, the slot-coupled antenna is a nested hexagonal ring.

[0049] In this embodiment, the nested hexagonal ring can be composed of multiple nested hexagonal rings. This structure is more compact and has unique symmetry compared to traditional shapes. The nested form of multiple hexagonal rings increases the effective current path length of the antenna, and at the same time, the unique geometry of the hexagon allows for more complex current distribution within a limited space.

[0050] In terms of electromagnetic performance, the nested hexagonal ring slot-coupled antenna achieves excellent resonant characteristics in the Sub-1 GHz band. Multiple nested hexagonal rings generate multiple resonant modes, thereby expanding the antenna's bandwidth and enabling better coverage of different communication frequencies within this band. This is crucial for IoT applications requiring stable communication in the Sub-1 GHz band, effectively reducing signal distortion and interference and improving communication reliability.

[0051] Optional, refer to Figure 4 Nested hexagonal rings are composed of multiple hexagons of different sizes arranged in a nested manner, with multiple hexagons nested around the same center point to ensure the symmetry of the structure (the inner circle of the most central hexagon is the corresponding center aperture).

[0052] Different sized hexagonal rings correspond to different resonant frequencies. When nested together, the antenna can resonate on multiple frequency bands. This allows slot-coupled antennas to cover a wider frequency range, meeting the needs of multi-band signal processing in IoT communication and adapting to different communication standards and application scenarios.

[0053] Electromagnetic coupling exists between adjacent hexagonal rings. The nested structure increases the complexity and strength of this coupling, enabling more efficient energy transfer from the feed source to various parts of the antenna, thereby improving the antenna's radiation efficiency and gain.

[0054] In antenna design, the electromagnetic performance of an antenna can be precisely controlled by adjusting parameters such as the number, size, spacing, and nesting method of hexagons. For example, increasing the number of hexagons may further extend the frequency band; adjusting the spacing between adjacent hexagons can optimize the coupling effect, thereby achieving fine-tuning of antenna performance to meet specific design requirements.

[0055] Optionally, the nested hexagonal rings have an outermost hexagonal ring with a side length of approximately 30mm (preferably 30mm) and a thickness of approximately 4mm. Thus, the overall dimensions of the nested hexagonal rings can preferably be 60mm × (30mm × 4mm). ) mm × 4 mm.

[0056] Optionally, the nested hexagonal rings can be fabricated using a flexible LCP substrate, supporting far-field coupling.

[0057] Reference Figure 4 Due to the shared aperture design of the metamaterial patch and the slot-coupled antenna, when the nested hexagonal ring is combined with the fractal open resonant ring (a square resonant ring with two layers of openings facing different directions), this slot-coupled antenna can cooperate with the upper 2.4GHz band antenna. This not only enables efficient operation of both bands, but also reduces mutual interference through optimized structural design.

[0058] This utility model further proposes an Internet of Things (IoT) communication device, referring to... Figure 5 The IoT communication device includes a main control module and a radio frequency module; the radio frequency module includes a directional antenna and a feed network, and the directional antenna is electrically connected to the main control module via the feed network.

[0059] The specific structure of the directional antenna refers to the directional antenna for IoT communication described in the above embodiments. Since this IoT communication device adopts all the technical solutions of all the above embodiments, it has at least all the technical effects brought about by the technical solutions of the above embodiments, and will not be described in detail here.

[0060] The main control module is the core control unit of the entire IoT communication device. Its main function is to manage and control the radio frequency module, enabling it to switch between different working modes to adapt to different communication needs and save power.

[0061] The radio frequency module is responsible for signal transmission and reception. It mainly consists of a directional antenna and a power supply network. The directional antenna is electrically connected to the main control module via the power supply network.

[0062] The function of the power supply network is to transmit the electrical signal output by the main control module to the directional antenna, and at the same time transmit the signal received by the directional antenna back to the main control module. It acts as a bridge connecting the main control module and the directional antenna, ensuring stable signal transmission.

[0063] This IoT communication device based on directional antennas achieves multi-band communication and low-power operation through a unique antenna design and a flexible mode switching mechanism, making it suitable for various IoT application scenarios.

[0064] When conducting conducted tests on the directional antenna of this IoT communication device, the measured gain was 8.2 dBi and the radiation efficiency was ≥75% in the 2.4 GHz band; the omnidirectional gain was 5.5 dBi and the directional gain could reach 8.5 dBi in the Sub-1 GHz band.

[0065] When conducting road tests on the directional antenna of this IoT communication device, in urban environments, the coverage distance of this directional antenna in the Sub-1GHz band is more than 2km compared to the 1.2km coverage of traditional solutions; in directional transmission, the transmission distance of the directional antenna in the 2.4GHz band is more than 300m (compared to only 100m for omnidirectional antennas).

[0066] Based on this, IoT communication devices can also combine GPS / BeiDou positioning to dynamically adjust the beam direction, so that the positioning error is within 5m.

[0067] In one embodiment, based on the above embodiments, the power supply network integrates a duplex filter adapted to the 2.4 GHz band and the Sub-1 GHz band.

[0068] In this embodiment, a duplex filter is integrated into the power supply network to suppress interference between the 2.4 GHz and Sub-1 GHz frequency bands.

[0069] The 2.4GHz band is commonly used in IoT communication for short-range, high-speed communication scenarios, such as Wi-Fi and Bluetooth. A full-duplex filter specifically processes signals in the 2.4GHz band, ensuring that these signals can pass smoothly through the power supply network while blocking interference signals from other bands, thus guaranteeing the purity and strength of the 2.4GHz signal. This improves the stability and reliability of 2.4GHz band communication, enabling IoT communication devices to perform short-range data transmission more efficiently.

[0070] The Sub-1GHz band features long propagation distance, strong penetration, and low signal loss, making it suitable for long-distance, low-data-rate IoT communications, such as LoRa and SigFox technologies. Duplex filters also optimize Sub-1GHz signals, ensuring stable transmission within the feeder network. By suppressing interference from other frequency bands, the quality of Sub-1GHz signals is improved, guaranteeing accuracy and stability for long-distance communication.

[0071] A duplex filter can effectively isolate the 2.4GHz band and the Sub-1GHz band. By using the filtering characteristics of the duplex filter, the signals of the two bands are isolated, avoiding interference between the bands. This allows communication between the two bands to be carried out simultaneously and independently, improving the efficiency and reliability of communication.

[0072] By filtering out unwanted frequency band signals and interference signals, duplex filters can significantly improve the quality of signals in the 2.4 GHz and Sub-1 GHz bands. At the transmitting end, duplex filters ensure accurate frequency and stable power of the transmitted signal; at the receiving end, they reduce noise and interference, making the received signal clearer and more accurate. This helps reduce the bit error rate, improves the accuracy of data transmission, and thus enhances the performance of the entire IoT communication device.

[0073] A duplex filter works closely with a directional antenna to complete the tasks of signal transmission and reception. The directional antenna is responsible for transmitting and receiving signals in the 2.4 GHz band and Sub-1 GHz band in a specific direction, while the duplex filter processes and optimizes these signals. Through their coordinated operation, the advantages of the directional antenna can be fully utilized, improving signal transmission efficiency and coverage.

[0074] In one embodiment, based on the above embodiment, the directional antenna is electrically connected to the feed network through a Sub-1GHz front end, and the Sub-1GHz front end integrates an SX1262 chip.

[0075] In this embodiment, the Sub-1GHz front-end acts as a bridge between the directional antenna and the feed network, undertaking the important task of preprocessing and adapting the Sub-1GHz band signals. It performs preliminary amplification and filtering on the weak Sub-1GHz signals received by the directional antenna to better adapt them to the transmission requirements of the feed network. Simultaneously, it also processes the signals to be transmitted from the feed network to ensure that the signals are transmitted through the directional antenna in the best possible condition.

[0076] The directional antenna connects to the feed network via a Sub-1GHz front-end and, with the support of the SX1262 chip, can efficiently process signals in the Sub-1GHz band. Simultaneously, it supports LoRaWAN Class A / B / C modes, allowing the IoT communication device to flexibly select the appropriate communication mode according to different application scenarios and needs, achieving long-distance, low-power, and reliable IoT communication, further expanding the device's application range and practicality.

[0077] In one embodiment, based on the above embodiments, the radio frequency module further includes an NB-IoT module.

[0078] In this embodiment, the radio frequency module is further provided with an NB-IoT module, which enables the main control module to control Quectel BC95 through the SPI (Serial Peripheral Interface) interface, so that the radio frequency module is in PSM (Power Saving Mode) / eDRX (Extended Discontinuous Reception) power saving mode in the monitoring mode.

[0079] The Quectel BC95 is a high-performance NB-IoT module that integrates core components required for NB-IoT communication, such as the RF front-end, baseband processor, and memory. The main control module communicates with the Quectel BC95 via the SPI interface to control its operating status and parameters.

[0080] In monitor mode, when the RF module enters PSM mode, the Quectel BC95 will cease operation of most functions, retaining only a timer for waking the device. In this mode, the device's power consumption is extremely low, almost negligible. When the timer reaches its preset time, the device will wake up and check for any signals that need processing. If no signal is found, the device will re-enter PSM mode.

[0081] eDRX mode is an energy-saving mechanism optimized for NB-IoT networks. In listener mode, devices periodically wake up to check if downlink data is being sent to them. Compared to traditional DRX mode, eDRX mode has a longer wake-up cycle, thus reducing device power consumption. In eDRX mode, devices can flexibly adjust the wake-up cycle according to network conditions and application requirements to balance power consumption and communication timeliness.

[0082] The main control module is responsible for controlling the Quectel BC95 to enter PSM / eDRX power-saving mode. In monitoring mode, the main control module sends corresponding commands to the Quectel BC95 via the SPI interface according to preset rules and algorithms, causing it to enter PSM or eDRX mode. Simultaneously, the main control module monitors the device's status and timer activity to ensure the device is woken up at the appropriate time to handle any incoming signals. When a signal requiring processing is detected, the main control module controls the Quectel BC95 to exit power-saving mode and enter normal operating mode, running at full power to complete signal processing and communication tasks.

[0083] By incorporating an NB-IoT module into the RF module and using the Quectel BC95, combined with PSM / eDRX power-saving mode, this IoT communication device significantly reduces power consumption while maintaining communication capabilities. This enables the device to operate stably for extended periods on battery power, reducing maintenance costs and the frequency of battery replacements.

[0084] In one embodiment, based on the above embodiments, the radio frequency module adopts an integrated module design, which integrates a noise amplifier and a power amplifier.

[0085] In this embodiment, the IoT communication device adopts an integrated radio frequency module design, which also integrates a low noise amplifier (LNA) and a power amplifier (PA).

[0086] When the noise amplifier operates in the 2.4GHz band, the noise figure (NF) does not exceed 1.5dB. This means that the noise introduced during signal amplification is very small, which can ensure the purity of the signal to the greatest extent. At the same time, the gain of the noise amplifier is greater than or equal to 20dB, which can effectively amplify weak input signals and provide a signal with sufficient strength for subsequent signal processing.

[0087] When the power amplifier operates in the Sub-1GHz band, its output power can reach +20dBm, which is sufficient to meet the signal transmission requirements in this band. Moreover, the power amplifier efficiency is not less than 35%, which means that it can work with high efficiency in the process of converting electrical energy into radio frequency signal power, reducing energy waste and helping to reduce the power consumption of the entire system.

[0088] In one embodiment, based on the above embodiment, the main control module is equipped with an nRF9160 chip as the main control chip.

[0089] In this embodiment, the main control chip in the main control module can be the low-power nRF9160 chip, which integrates a Cortex-M33 processor and an LTE-M / NB-IoT modem. The Cortex-M33 processor offers high performance and low power consumption, meeting the system's data processing and control requirements; while the LTE-M / NB-IoT modem enables IoT communication devices to easily access the IoT network and achieve remote communication functions, providing excellent support for IoT applications.

[0090] Furthermore, a hardware watchdog can be integrated into the main control module to prevent software deadlock. During system operation, software may malfunction for various reasons, causing the program to enter an infinite loop or become unresponsive. The hardware watchdog can monitor the system's operating status in real time and take timely measures to reset when it detects a software malfunction, ensuring the system's stability and reliability.

[0091] The main control chip supports the μC / OS-III real-time operating system, which boasts highly efficient task scheduling capabilities. Compared to traditional operating systems, it can improve task scheduling efficiency by 30%. This means the system can respond to various task requests more quickly and accurately, allocate system resources more efficiently, and improve overall system performance and real-time performance.

[0092] In this way, by adopting the electromagnetic metasurface technology, it is possible to achieve miniaturization and high-gain directional radiation in IoT communication devices; at the same time, it integrates a low-power MCU to achieve μA-level standby current; and it supports SPI interface control, making it compatible with mainstream IoT communication chips.

[0093] The above description is only a part or preferred embodiment of this utility model. Neither the text nor the drawings should limit the scope of protection of this utility model. All equivalent structural transformations made using the content of this utility model specification and drawings under the overall concept of this utility model, or direct / indirect applications in other related technical fields, are included within the scope of protection of this utility model.

Claims

1. A directional antenna for Internet of Things (IoT) communication, characterized in that, The directional antenna includes an artificial magnetic conductor reflector on the upper layer and a gradient metamaterial layer on the lower layer. The artificial magnetic conductor reflector includes metamaterial units arranged in a 5×5 array. In each metamaterial unit, the upper layer is a metamaterial patch covering the 2.4 GHz frequency band, and the lower layer is a slot-coupled antenna covering the Sub-1 GHz frequency band. The central axis of the central aperture of the upper fractal open resonant ring coincides with the central axis of the central aperture of the lower nested hexagonal ring.

2. The directional antenna for IoT communication as described in claim 1, characterized in that, The metamaterial patch is a fractal open-ended resonant ring.

3. The directional antenna for IoT communication as described in claim 1, characterized in that, The slot-coupled antenna is a nested hexagonal ring.

4. An Internet of Things (IoT) communication device, characterized in that, It includes a main control module and an RF module; the RF module includes a directional antenna and a feed network, and the directional antenna is electrically connected to the main control module via the feed network; The directional antenna is a directional antenna for Internet of Things communication as described in any one of claims 1-3.

5. The Internet of Things communication device as described in claim 4, characterized in that, The power supply network integrates a duplex filter adapted to the 2.4GHz band and the Sub-1GHz band.

6. The Internet of Things communication device as described in claim 4, characterized in that, The directional antenna is electrically connected to the feed network via a Sub-1GHz front-end, and the Sub-1GHz front-end integrates an SX1262 chip.

7. The Internet of Things communication device as described in claim 4, characterized in that, The radio frequency module also includes an NB-IoT module.

8. The Internet of Things communication device as described in claim 4, characterized in that, The radio frequency module adopts an integrated module design, which integrates a noise amplifier and a power amplifier.

9. The Internet of Things communication device as described in claim 4, characterized in that, The main control module is equipped with an nRF9160 chip as its main control chip.

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