System for intrinsic safety of wireless devices

Abstract

Disclosed is a system (200) for intrinsic safety in wireless devices. The system includes a wireless communication module (110) powered by direct-current (DC) power (116). Connected to this module is a radio-frequency (RF) output circuit (120), which includes a series of filters (122, 124, 126) and an antenna (128). The system further includes a limiting unit (210), associated with the RF output circuit. The limiting unit includes a resistor (310) for limiting the DC power, and a capacitor (320) for establishing a low impedance path for high-frequency signals to the ground, thereby ensuring overall safety and efficiency of operations of the wireless devices.

Description

SYSTEM FOR INTRINSIC SAFETY OF WIRELESS DEVICESTECHNICAL FIELD

[0001] The present invention generally relates to the field of wireless communication, and specifically to systems designed to ensure intrinsic safety in wireless devices deployed in hazardous or explosive environments.BACKGROUND

[0002] The use of wireless devices in various domains, including consumer electronics and commercial spaces, has fostered an ecosystem that promises reliable data transfer, convenience, flexibility, and scalability. The implementation of wireless communication has many benefits as compared to wired infrastructure, such as the absence of physical connectors and cables (meaning easier installations), dynamic network topologies, and reduced maintenance needs. With the advent of Industry 4.0, there is a growing trend towards integrating wireless communication into industries. However, many industrial environments, such as the petrochemical, oil, gas, and mining sectors, are fraught with the risk of explosions. The volatile nature of materials processed or stored in these areas demands stringent safety protocols. Hence, it becomes imperative that the wireless devices used in such surroundings are intrinsically safe, ensuring they do not act as ignition sources due to sparks or any other factors.

[0003] Traditionally, industries often refrained from using wireless devices in critical zones, relying instead on wired infrastructure. These wired devices, communicating over protocols like 4-20mA, HART, Profibus, Profinet, etc., are perceived as more reliable and safer. Their intrinsic safety is often achieved by design, ensuring that the energy levels remained below ignition thresholds. Some wireless devices that are used in industries with explosive areas are encapsulated in robust and explosion-proof enclosures, often termed “Ex-d” enclosures. These enclosures, while effective, are bulky, expensive, and often relegated the devicesto less hazardous zones, like Ex -Zone 2, keeping them away from more sensitive areas (Zone 1).

[0004] Such traditional approaches have many limitations. The reliance on wired devices, for instance, negated the primary advantage of wireless systems, which is flexibility. Every new sensor or device added to the network required additional cabling, increasing installation costs and complexity. The wireless devices, when used, despite their robust enclosures, had limitations. The bulky “Ex-d” enclosures added significant weight, making installations cumbersome. Furthermore, these enclosures often hampered signal quality, reducing the effective communication range of the devices. The relegation of these devices to less hazardous zones meant that industries could not leverage the full potential of wireless communication in areas where it may be most needed. This protective approach, while pragmatic, is more of a workaround than a solution, allowing for wireless communication but with significant trade-offs in terms of cost, flexibility, and deployment zones.

[0005] The present invention seeks to overcome these challenges by providing a system for intrinsic safety of wireless devices that addresses these limitations. The present system ensures reliable communication while adhering to stringent safety standards for explosive zones. The present system is robust enough to cater to the evolving safety standards, anticipating worst-case scenarios and mitigating risks proactively.SUMMARY

[0006] The object of the present invention is achieved by a system for intrinsic safety of wireless devices. The system comprises a wireless communication module powered by direct-current (DC) power. The system further comprises a radio-frequency (RF) output circuit connected to the wireless communication module. The RF output circuit includes a series of filters and an antenna. The system further comprises a limiting unit associated with the RF output circuit. Thelimiting unit comprises a resistor for limiting the DC power and a capacitor for establishing a low impedance path for high-frequency signals to the ground.

[0007] In one or more embodiments, the system further comprises a first ground plane associated with the wireless communication module and a second ground plane associated with the RF output circuit. Herein, the first ground plane and the second ground plane are implemented as a first Printed Circuit Board (PCB) layer and a second PCB layer, respectively, separated from each other.

[0008] In one or more embodiments, the limiting unit is connected between the first ground plane and the second ground plane.

[0009] In one or more embodiments, the capacitor of the limiting unit is constituted by the first PCB layer and the second PCB layer, and an isolation material interposed between the first PCB layer and the second PCB layer.

[0010] In one or more embodiments, the resistor of the limiting unit is implemented as a surface-mounted resistance connected to the first PCB layer and the second PCB layer through one or more vias.

[0011] In one or more embodiments, the resistor of the limiting unit is split into multiple resistors distributed along the first PCB layer and the second PCB layer.

[0012] In one or more embodiments, a creepage distance between the first PCB layer and the second PCB layer is based on defined standard(s) for the intrinsic safety of the wireless devices.

[0013] In one or more embodiments, the wireless communication module comprises a system on chip (SoC) having a radio with a sender and a receiver, and connected to a decoupling capacitor.

[0014] In one or more embodiments, the RF output circuit comprises a first PI filter for impedance transformation, a rejection filter for preventing spurious emissions, and a second PI filter for further impedance matching to the antenna.

[0015] In one or more embodiments, the wireless communication module, with the RF output circuit having the limiting unit associated therewith, is adapted for use in explosive settings.

[0016] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and featuresdescribed earlier, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated herein and constitute a part of this disclosure, illustrate exemplary embodiments, and together with the description, serve to explain the disclosed principles. The same numbers are used throughout the figures to reference like features and components, wherein:

[0018] FIG. 1 is a schematic representation of a circuit for implementation of a wireless communication module with a radio-frequency (RF) output circuit;;

[0019] FIG. 2 is a schematic representation of a system for intrinsic safety of wireless devices implementing a limiting unit with the circuit of FIG 1, in accordance with one or more embodiments of the present invention;

[0020] FIG. 3 is a schematic representation of the limiting unit, in accordance with one embodiment of the present invention; and

[0021] FIG. 4 is a schematic representation of the limiting unit, in accordance with another embodiment of the present invention.DETAILED DESCRIPTION OF EMBODIMENTS

[0022] Various embodiments are described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for the purpose of explanation, numerous specific details are set forth in order to provide thorough understanding of one or more embodiments. It may be evident that such embodiments may be practiced without these specific details.

[0023] Examples of a system for intrinsic safety of wireless devices are disclosed herein. In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the invention. It is apparent, however, to one skilled in the art thatthe embodiments of the invention may be practiced without these specific details or with an equivalent arrangement. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the embodiments of the invention.

[0024] Referring now to FIG 1, illustrated is a schematic representation of a circuit (as represented by reference numeral 100) for implementation of a wireless communication module 110 with a radio-frequency (RF) output circuit 120, in accordance with an embodiment of the present invention. The circuit 100 is designed for managing RF signals optimally for both safety and performance. The circuit 100 provides components and modules to ensure optimal transmission, reception, and processing of signals. The circuit 100 is designed to handle a range of frequencies and signal strengths, making it versatile for various wireless communication needs. The components and modules within the circuit 100 are laid out to minimize interference, reduce signal loss, and enhance clarity. Further, the circuit 100 incorporates features that prevent overheating, and manage unexpected surges in power or signal strength.

[0025] In the circuit 100, the wireless communication module 110 fetches data that needs to be transmitted (for example, data from a sensor associated therewith), converts it into RF signals, and then sends it to the RF output circuit 120 for further processing. Similarly, when RF signals are received, the wireless communication module 110 processes these signals, extracts the data, and then sends it to the appropriate destination (like, commands to the sensor associated therewith). The wireless communication module 110 is designed to work with multiple wireless communication protocols, including Bluetooth, WLAN, GSM, or any other relevant standards, allowing the circuit 100 to be versatile and usable in various applications. Therefore, regardless of the specific communication needs, the wireless communication module 120 may be configured to handle them, ensuring that the circuit 100 remains relevant and functional across different scenarios.

[0026] In the present implementation, the wireless communication module 110 includes a system on chip (SoC) 112 having a radio (not shown) including asender and a receiver, with a RF output (RF_OUT pin) 118, and connected to a decoupling capacitor 114. Herein, the SoC integrates several components of the wireless communication module 110 into a single chip, which helps to shrink the footprint of the electronics and also enhances their efficiency and performance. The radio is the communication component, responsible for transmitting and receiving wireless signals. In the radio, the sender is responsible for converting data into RF signals and broadcasting them wirelessly. On the other end, the receiver captures incoming RF signals, converting them back into data for a system associated with the wireless communication module 110 to process. Electronic circuits, especially complex ones like the SoC 112, can sometimes experience minor fluctuations in their power supply. These fluctuations, if not managed, could lead to performance issues or even potential damage. The decoupling capacitor 114 acts as a buffer, stabilizing the power supply to the SoC 114 by storing and releasing energy as needed. When the SoC 114 requires a burst of energy, the decoupling capacitor 114 provides it, and conversely, when there is excess energy, the decoupling capacitor 114 absorbs it. This ensures that the SoC 112 receives a steady power flow, optimizing its performance and longevity.

[0027] The wireless communication module 110 is powered by direct-current (DC) power (as represented by reference numeral 116). The DC power 116 is characterized by a constant voltage or current flow, providing steady and uninterrupted energy to electronic devices. With the DC power 116, the wireless communication module 110 operates without fluctuations in its power source. Such fluctuations could potentially introduce noise or distortions in the transmitted or received signals. Thus, the wireless communication module 110 can maintain the integrity and clarity of wireless signals, ensuring accurate data transfer.

[0028] Further, in the circuit 100, the RF output circuit 120 is responsible for processing the RF signals, ensuring that these signal are of the right frequency and amplitude. The RF output circuit 110 includes various components, such as filters (including inductances, capacitors and / or any other components, which can store energy) and amplifiers, which work together to make sure that the RF signals areclear and strong. These components help in reducing any unwanted signals or noise from the RF signal. As illustrated, the RF output circuit 120 includes a series of filters, including a first PI filter 122, a rejection filter 124 and a second PI filter 126, each specifically designed and placed to optimize the quality and safety of the transmitted and received RF signals, and an antenna 128.

[0029] In particular, the RF output circuit 120 includes the first PI filter 122 for impedance transformation. In electronics and communications, impedance matching is required to ensure maximum power transfer from the source to the destination without unwanted reflections. The first PI filter 122 is configured to transform the impedance of, for instance, the RF signal from the wireless communication module 110 to match requirements of subsequent stages in the circuit 100 (usually 50 Ohm). Following the first PI filter 122, the RF output circuit 120 includes the rejection filter 124 to prevent spurious emissions. In wireless communication, it is not uncommon for devices to emit unwanted frequencies or signals, which can interfere with other devices or even violate regulatory standards. The rejection filter 124 is specifically designed to eliminate or significantly reduce these unwanted emissions, ensuring that only the desired frequency band is transmitted or received. This is also required for the radio certification according to FCC rules or RED / EN300328. Further, the RF output circuit 120 includes the second PI filter 126 which further refines the impedance matching process, specifically based on the connection to the antenna 128.

[0030] Antennas, in general, have specific impedance requirements and any mismatch can lead to reduced transmission power, signal distortions, or even potential damage to the system. The radio of the wireless communication module 110 provides output at the RF output 118 which usually has a different impedance than the antenna 128 (typically a higher one). The second PI filter 126 ensures that the RF signals, before they are transmitted through the antenna 128, are matched to impedance of the antenna 128. This ensures optimal transmission range and overall performance.

[0031] Typically, each of the first PI filter 122, the rejection filter 124 and the PI filter 126 is connected to a ground plane, which is a common approach for gettinga good RF performance. The grounding ensures minimal interference and distortion, thereby maintaining the strength of the RF signals transmitted and received. From a safety standpoint, particularly focusing on intrinsic safety, the current evaluation methodologies consider such systems under its standard functional mode. This means that the assessments are based on the premise of an undamaged system, with all components operating as intended. The maximal RF power emanating from corresponding SoC becomes the primary point of consideration. Importantly, this power is inherently capped by the design specifications of such SoC, such as its low power voltage, which may be, for instance, 1.8 V. As long as such SoC does not incorporate an internal DC-DC converter, such system stays within the parameters deemed safe.

[0032] However, with evolving safety norms, particularly for EN60079-11, the analysis of energy stored within every capacitor and coil in such system may be required to mitigate risks like sparking. For instance, referring to the circuit 100 of FIG 1, the energy associated with coils like Fl / Ll, F2 / L1, and F3 / L1 is not inherently limited. Theoretically, the current flowing through these coils could potentially be infinite, restrained only by the direct current resistance intrinsic to the coils. This resistance level, particularly for devices operating in a DC-power mode (like the circuit 100 using the DC power 116), often surpasses the safety thresholds for intrinsic devices.

[0033] Some potential solutions may be contemplated by a person skilled in the art to reduce the excessive energy stored in the coils. In an example, one could consider placing a resistor in series with the RF output 118 of the wireless communication module 110. While this may reduce potential energy surges, it concurrently reduces RF performance, making it an undesirable solution. In another example, a fuse may be placed in line of the DC power 116 preceding the decoupling capacitor 114. But this may not curtail the possibility of the energy within the decoupling capacitor 114 discharging into the coils. Conversely, positioning a fuse post the decoupling capacitor 114 compromises its intended functionality, making this approach also inefficient. In yet another example, a capacitor may be introduced in series with RF output, which can effectivelyprevent the DC power 116 from reaching the coils without hampering RF power. But compliance with safety norms mandates such capacitors to be intrinsically safe, safeguarding against shorts. For this purpose, specialized failsafe capacitors (at least 3) would be required which is a costly and bulky approach, and may often result in subpar behaviour at high frequencies, thereby impacting RF power. These conventional approaches does not rectify the core issue of the potential risk of high energy being stored in the coils of the RF output circuit 120.

[0034] Referring to FIG 2, illustrated is a schematic representation of a system 200 for intrinsic safety of wireless devices. As illustrated, the system 200 works with the circuit 100 of FIG 1. The system 200 is specifically designed to enhance and complement the functionalities of the circuit 100, ensuring a comprehensive approach to wireless communication safety. The components and modules of the system 200 seamlessly integrate with those of the circuit 100, creating an overall circuit optimized for both wireless performance and safety.

[0035] As illustrated, the system 200 of the present disclosure includes a limiting unit 210 associated with the RF output circuit 120 of the circuit 100. The limiting unit 210 works in conjunction with the RF output circuit 120, ensuring the system 200 operates with increased safety, particularly in environments with potentially explosive conditions. Given the potential risks associated with power surges or excessive energy storage, the integration of the limiting unit 210 acts as a safeguard, ensuring that the RF signals are processed, transmitted, and received within safe energy parameters. The primary role of the limiting unit 210 is to manage and regulate the power flow within the RF output circuit 120. The limiting unit 210 is configured to limit the power in the coils by cutting the ground plane of the RF output circuit 120 (‘GND’ of the filters 122, 124, 126). In this case, the RF output energy can only be fed “to the air” over the antenna 128 or pass through the limiting unit 210.

[0036] In an embodiment, as illustrated in FIG 3, the limiting unit 210 includes a resistor 310 (also represented as ‘RL’) for limiting the DC power 116 and a capacitor 320 (also represented as ‘CL’) for establishing a low impedance path for high-frequency signals to the ground. In particular, the resistor 310 is designed toregulate the DC power 116 flowing through the RF output circuit 120. By introducing specific resistance, the resistor 310 reduces excessive currents, ensuring that the DC power remains within safe and predetermined limits. This resistance-based limitation safeguards components of the system 200 from potential damages due to overcurrent. Further, the capacitor 320, in the limiting unit 210, helps in managing high-frequency signals. By its very design, a capacitor offers a low impedance path to high-frequency signals, directing them safely to the ground. This function is helpful in preventing potential feedback or interference that may arise from stray high-frequency signals within the system 200. Herein, the capacitor 320 maintains the strength of the RF signals by ensuring these signals are effectively grounded.

[0037] In the present configuration, the limiting unit 210, with the resistor 310 and the capacitor 320, provides safety against potential hazards. Herein, the resistor 310 within the limiting unit 210 ensures that the system 200 operates within defined power limits. The resistor 310 is configured for limiting the DC power 116, ensuring that the system 200 does not draw excessive power that could lead to overheating or other hazards. By effectively managing consumption of the DC power 116, the system 200 not only ensures operational efficiency but also significantly reduces the risks associated with energy-related anomalies, such as overheating or sparking. This strategic power management translates to longer device lifespans, reduced maintenance needs, and, most critically, enhanced safety in explosive environments. On the other hand, the capacitor 320 plays a role in establishing a low impedance path for high-frequency signals, ensuring they are effectively grounded. Herein, the capacitor 320 has a good behaviour at high frequencies (no inductivity) and provides safety to fulfil the intrinsic safety norm. Thus, the capacitor 320 ensures that any high-frequency noise, whether from internal components, external interferences, or harmonics, is effectively grounded, preventing potential disturbances or hazards. This dual mechanism provided by the limiting unit 210, using the resistor 310 and the capacitor 320, ensures that both DC and high-frequency risks are managed simultaneously.

[0038] In an embodiment, as illustrated in FIG 4, the system 200 is implemented to have a first ground plane 410 associated with the wireless communication module 110, and a second ground plane 420 associated with the RF output circuit 120 (including the antenna 128). Herein, the system 200 is designed to incorporate distinct grounding mechanisms to optimize both performance and safety. The first ground plane 410 ensures that any electrical noise or interference related to the operations of the wireless communication module 110 is effectively grounded, thereby maintaining the strength of signals managed by the wireless communication module 110. The second ground plane 420 provides a grounding path for the RF signals processed by the RF output circuit 120, to ensure that the RF signals, both incoming and outgoing, remain free from unwanted interference or distortions. This dedicated grounding also aids in protecting the RF output circuit 120 from potential electrical anomalies or surges, enhancing its longevity and operational reliability.

[0040] Herein, as depicted in FIG 4, the first ground plane 410 and the second ground plane 420 are implemented as a first Printed Circuit Board (PCB) layer (referred by reference numeral 412) and a second PCB layer (referred by reference numeral 422), respectively, separated from each other. That is, the ground planes 410, 420 are implemented on separate PCB layers 412, 422, ensuring they are distinctly separated from each other. It may be contemplated by a person skilled in the art that the ground planes 410, 420 may be disposed on either inside or outside of the corresponding PCB layers 412, 422 (i.e., inner or outer faces of the corresponding boards), without any limitations. By embodying the ground planes 410, 420 within the PCB layers 412, 422, the system 200 allows that the grounding paths for the wireless communication module 110 and the RF output circuit 120 remain isolated from each other. This configuration also provides a reliable and consistent grounding path, given the uniformity and precision associated with PCB manufacturing processes. Further, with this configuration, the system 200 ensures a compact and efficient layout, making the most of the available space.

[0041] In this configuration, the separation is provided as the limiting unit 210 is connected (embodied) between the first ground plane 410 and the second ground plane 420, ensuring effective grounding and safety. Herein, the capacitor 320 of the limiting unit 210 is constituted by the first PCB layer 412 and the second PCB layer 422, with an isolation material 430 interposed between the first PCB layer 412 and the second PCB layer 422. In a non-limiting example, the isolation material 430 is a PCB substrate material as well known in the art. A creepage distance ‘d’ (also referred to as “insulation distance”) between the first PCB layer 412 and the second PCB layer 422 is set based on defined standard(s) for the intrinsic safety of the wireless devices. For instance, the creepage distance ‘d’ may be set to meet the requirements of the standard for intrinsic safety, for example IEC60079-11 (for ATEX Europe) and IECEX. In an example, the creepage distance ‘d’ is set to be at least 0.5 mm for voltages less than 10 V. This configuration ensures optimal performance, while the creepage distance ‘d’ between the PCB layers is maintained based on defined standards, ensuring that any potential risks are mitigated, keeping the device within safe operational parameters.

[0042] Further, in the present embodiments, the resistor 310 of the limiting unit 210 is implemented as a surface-mounted resistance connected to the first PCB layer 412 and the second PCB layer 422 through one or more vias 432. That is, instead of a traditional through-hole resistor or any other conventional resistor form-factor, the resistor 310 is realized as a surface-mounted device (SMD) resistance. Herein, the SMD (also referred to as Surface-mounted technology (SMT)) is utilized for its compactness, efficiency, and precision. By employing the surface-mounted resistance for the resistor 310, the system 200 ensures a smaller footprint, leading to a more compact design, while also benefiting from the high reliability and performance associated with the SMD components. Moreover, the integration of the resistor 310 within the system 200 is achieved in a manner that allows it to interact with both the first PCB layer 412 and the second PCB layer 422. This is accomplished through the strategic use of the one or more vias 432. Vias are conductive pathways that facilitate electricalconnections between different layers of a PCB. In the present configuration, the vias 432 enable the resistor 310 to establish a connection with both the PCB layers 412, 422, thereby ensuring that it can effectively manage and regulate the DC power flow across these layers.

[0043] In an embodiment, the resistor 310 of the limiting unit 210 is split into multiple resistors distributed along the first PCB layer 412 and the second PCB layer 422. By utilizing multiple resistors along the first PCB layer 412 and the second PCB layer 422, instead of one monolithic resistor, the design achieves a more uniform distribution of resistance. This can lead to better heat dissipation, reduced localized heating, and an overall more efficient and reliable operation. Such a distribution may also aid in minimizing potential electromagnetic interference (EMI) or cross-talk between components, and also adds to redundancy, given the disrupted nature of the resistor 310.

[0044] The present embodiments, especially one disclosed in FIG 4, ensures intrinsic safety by integrating and utilizing the resistor 310 to block the DC power and the capacitor 320 to ensure optimal RF performance, while adhering to the safety requirements for DC operations of the circuit 100 for wireless devices. Grounding is a critical aspect of any electronic system, more so for devices operating in explosive settings. The proposed grounding mechanism, characterized by the unique placement of the limiting unit 210 and by the dual ground plane configuration, with separation between the first ground plane 410 and the second ground plane 420, ensures that the system 200 remains stable and safe. The proposed invention ensures the intrinsic safety of wireless devices, especially in explosive settings, bridging the gap between convenience of the wireless technology and the stringent safety requirements of such industrial settings. The introduction of the limiting unit 210, comprising both the resistor 310 and the capacitor 210, ensures that the wireless device (embodied by the circuit 100) remains within safe operational parameters, irrespective of internal or external disturbances. Thus, the present system 200 not only mitigates risks but also ensures optimal RF performance, providing a balance that may not be possible to achieve by traditional systems, ensuring that the system 200 can bedeployed in diverse sectors, from petrochemical industries to mining operations, and even in sectors where intrinsic safety may not be the primary concern but where reliable and efficient wireless communication is desired.

[0045] While the present invention has been described in detail with reference to certain embodiments, it should be appreciated that the present invention is not limited to those embodiments. In view of the present invention, many modifications and variations may be present themselves, to those skilled in the art without departing from the scope of the various embodiments of the present invention, as described herein. The scope of the present invention is, therefore, indicated by the following claims rather than by the foregoing description. All changes, modifications, and variations coming within the meaning and range of equivalency of the claims are to be considered within their scope.

Claims

Claims1. A system (200) for intrinsic safety of wireless devices, the system (200) comprising: a wireless communication module (110) powered by direct-current (DC) power (116); a radio-frequency (RF) output circuit (120) connected to the wireless communication module (110), the RF output circuit (120) including a series of filters (122, 124, 126) and an antenna (128); and a limiting unit (210) associated with the RF output circuit (120), the limiting unit (210) comprising a resistor (310) for limiting the DC power (116) and a capacitor (320) for establishing a low impedance path for high-frequency signals to the ground.

2. The system (200) as claimed in claim 1 further comprising a first ground plane (410) associated with the wireless communication module (110) and a second ground plane (420) associated with the RF output circuit (120), wherein the first ground plane (410) and the second ground plane (420) are implemented as a first Printed Circuit Board (PCB) layer (412) and a second PCB layer (422), respectively, separated from each other.

3. The system (200) as claimed in claim 2, wherein the limiting unit (210) is connected between the first ground plane (410) and the second ground plane (420).

4. The system (200) as claimed in claim 3, wherein the capacitor (320) of the limiting unit (210) is constituted by the first PCB layer (412) and the second PCB layer (422), and an isolation material (430) interposed between the first PCB layer (412) and the second PCB layer (422).

5. The system (200) as claimed in claim 3 or 4, wherein the resistor (310) of the limiting unit (210) is implemented as a surface-mounted resistance connected to the first PCB layer (412) and the second PCB layer (422) through one or more vias (432).

6. The system (200) as claimed in any of the claims 3 to 5, wherein the resistor (310) of the limiting unit (210) is split into multiple resistor (310)s distributed along the first PCB layer (412) and the second PCB layer (422).

7. The system (200) as claimed in claim 4, wherein a creepage distance (‘d’) between the first PCB layer (412) and the second PCB layer (422) is based on defined standard(s) for the intrinsic safety of the wireless devices.

8. The system (200) according to any of the preceding claims, wherein the wireless communication module (110) comprises a system (200) on chip (SoC) (112) having a radio with a sender and a receiver, and connected to a decoupling capacitor (320) (114).

9. The system (200) according to any of the preceding claims, wherein the RF output circuit (120) comprises a first PI filter (122) for impedance transformation, a rejection filter (124) for preventing spurious emissions, and a second PI filter (126) for further impedance matching to the antenna (128).

10. The system (200) according to any of the preceding claims, wherein the wireless communication module (110), with the RF output circuit (120) having the limiting unit (210) associated therewith, is adapted for use in explosive settings.

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