Inductive coupling antenna for communication within battery packs

Abstract

A module antenna for use with a battery cell in a battery pack is provided. The module antenna enabling wireless communication between an electronic device coupled to the battery cell and a bus antenna. The module antenna comprises: a transmission line operatively coupled to the electronic device at one end and to at least one antenna at its other end, the at least one antenna enabling electro-magnetic coupling with the bus antenna, the at least one antenna having a plurality of sections arranged in series forming an unbalanced electrical path and being coupled to a termination resistor at its distal end. The module antenna further comprises at least one capacitive element located between the transmission line and the termination resistor, the capacitive element and the at least one antenna having a resonant frequency matched to an operating frequency of a desired transmission signal.

Description

[0001] INDUCTIVE COUPLING ANTENNA FOR COMMUNICATION WITHIN BATTERY PACKS

[0002] TECHNICAL FIELD

[0003]

[0001] The present disclosure relates to the field of batteries and battery cells. Embodiments of the disclosure relate to an assembly for use with a battery pack comprising a plurality of battery cells, the assembly suitable for enabling communication between an electronic device within the battery packs and a radio transceiver located remotely from the electronic device; a module antenna for use with battery cell in a battery pack; an assembly comprising the module antenna; a printed circuit board comprising the module antenna; a battery cell comprising the assembly enabling wireless communication between the electronic device within the battery pack and a remotely located radio transceiver; and a battery pack having a plurality of battery cells enabling wireless communication between the electronic devices within the battery pack and a remotely located radio transceiver.

[0004] BACKGROUND

[0005]

[0002] Battery systems, comprising a plurality of battery cells, are used in a wide variety of modern electric power applications. For example, they are used to power electric vehicles, they are used in industrial power applications, in transportation, and in commercial applications such as powering modern electronic devices. Given the relatively high-power demands of such applications, a battery system often comprises a plurality of battery cells coupled together to achieve the required power and / or voltage output. The battery cells may be coupled together to form a battery pack, and a battery system may comprise one or more battery packs.

[0006]

[0003] A battery system is often connected to a battery management system (BMS) configured to ensure that the battery system operates within its safe operating range. The safe operating range is defined as the temperature, voltage, and current conditions under which the battery system is expected to operate without self-damage. A BMS may include one or more Cell Monitoring Devices (CMDs) configured to monitor at least one battery cell and report back to the BMS. A CMD typically consists of an electronic device that may be configured to measure physical characteristics at the battery cell level, such as current, voltage, temperature, and other characteristics useful in determining the condition of a battery cell.

[0007]

[0004] BMS’s typically include communication means between each CMD and the management circuitry of the BMS. However, given the high-voltage environment in which BMS’s and the CMD’s are deployed, to ensure fault-free operation, it is necessary to ensure that such systems provide high voltage isolation and Electromagnetic Interference (EMI) immunity performance. High voltage isolation is required in respect of communication signals transmitted between individual battery cells or packs and the BMS, because each battery cell or pack may sit at a different voltage relative to the system ground. The voltage variation from the system ground can reach hundreds of volts in a typical battery system. Therefore, kilovolt isolation may be required. Additionally, electromagnetic interference can couple with the communication signals transmitted between the CMDs and the BMS, disrupting the communication signal or directly interfering with it. Since high-voltage battery systems are strong sources of EMI, the immunity performance of a communication system deployed within a battery pack is important.

[0008]

[0005] Known applications to mitigate for signal communication problems within a battery system include isolated wired communication protocols, such as CAN bus, or wireless communication protocols such as WiFi® or ZigBee®. Although both approaches address the isolation problem, wired communication protocols do not directly address the EMI problem and require more cumbersome assembly. The use of WiFi® or ZigBee®, which involves the use of far-field communication protocols, requires that each antenna in the battery system be separated by a plurality of wavelengths at which the radio frequency operates, in order to function optimally. These solutions may not fit the typical dimensions of many battery systems.

[0009]

[0006] It is an object of at least some embodiments of the present disclosure to address one or more of the shortcomings of the prior art and, in particular, to provide a more convenient means for enabling communication with a BMS within a battery system, which benefits from high voltage isolation and electromagnetic interference immunity. SUMMARY

[0010]

[0007] In accordance with an aspect of the disclosure, there is provided a module antenna for use with a battery cell in a battery pack, the module antenna enabling wireless communication between an electronic device coupled to the battery cell and a bus antenna. The module antenna may comprise: a transmission line operatively coupled to the electronic device at one end and to at least one antenna at its other end, the at least one antenna enabling electro-magnetic coupling with the bus antenna, the at least one antenna having a plurality of sections arranged in series forming an unbalanced electrical path and being coupled to a termination resistor at its distal end; and at least one capacitive element located between the transmission line and the termination resistor, the capacitive element and the at least one antenna having a resonant frequency matched to an operating frequency of a desired transmission signal.

[0011]

[0008] In accordance with another aspect there is provided an assembly comprising the aforementioned module antenna and a bus antenna.

[0012]

[0009] In accordance with an aspect of the disclosure, there is provided a printed circuit board comprising the aforementioned module antenna.

[0013]

[0010] Similarly, another aspect of the disclosure is directed to a battery cell comprising the aforementioned module antenna.

[0014]

[0011] In accordance with another aspect of the disclosure, there is provided an assembly for use with a battery pack comprising a plurality of battery cells, the assembly being suitable for enabling communication between an electronic device and a radio transceiver located remotely from the electronic device. The assembly may comprise: a module antenna comprising at least one antenna having a plurality of sections arranged in series forming an unbalanced electrical path and being coupled to a termination resistor at its distal end; a transmission line operatively coupled to the electronic device at one end and to the at least one antenna at its other end; and at least one capacitive element located between the transmission line and the termination resistor, the capacitive element and the at least one antenna having a resonant frequency matched to an operating frequency of a desired transmission signal. The assembly may further comprise: a bus antenna configured for operative communication with the radio transceiver, the bus antenna comprising at least two transmission lines, each transmission line being greater in length than any of the plurality of sections of the at least one antenna, and each one of the transmission lines being spaced apart from and positioned adjacent to a different one of at least one first section and at least one second section of the plurality of sections of the at least one antenna, to enable near-field coupling between the module antenna and the bus antenna when the desired transmission signal is input into either the module antenna or the bus antenna. In operation, the module antenna and the bus antenna may form a balun, and wherein when the desired transmission signal comprises an unbalanced electrical signal input in the module antenna, it may be output as a balanced electrical signal in the bus antenna. Or, when the desired transmission signal comprises a balanced electrical signal input in the bus antenna, it may be output as an unbalanced electrical signal in the module antenna.

[0015]

[0012] In accordance with another aspect of the disclosure, a battery pack having one or more battery modules, each module comprising one or more battery cells, the battery pack comprising the aforementioned assembly is provided.

[0016] BRIEF DESCRIPTION OF THE DRAWINGS

[0017]

[0013] Specific embodiments of the disclosure will be described in more detail below with reference to the accompanying drawings, in which :

[0018] FIG. 1 is a schematic illustration of a battery system, in accordance with an embodiment of the disclosure;

[0019] FIG. 2A is a schematic illustration of an exemplary balanced circuit using common mode rejection;

[0020] FIG. 2B is a schematic illustration of the balanced circuit of FIG. 2A comprising baluns;

[0021] FIG. 3A is a schematic illustration of an electronic circuit of an exemplary module antenna, wherein the module antenna includes a transmission line connected to a matched termination;

[0022] FIGS. 3B-3E are schematic illustrations of electronic circuits of exemplary module antennas as may be comprised in the battery system of FIG. 1, each module antenna comprising a transmission line connected to at least one antenna coupled to a termination resistor at its distal end, in accordance with embodiments of the disclosure; FIGS. 4A-4C are schematic illustrations of exemplary printed circuit boards (PCBs) comprising a module antenna and an electronic device, in accordance with embodiments of the disclosure;

[0023] FIGS. 4D and 4E are field distribution plots illustrating the magnetic field lines generated around the module antenna of FIG. 4B and FIG. 4C, respectively;

[0024] FIGS. 5A-5C are schematic illustrations of an exemplary bus / module antenna assembly, in accordance with embodiments of the disclosure;

[0025] FIG. 5D is a cross-sectional view of the assembly shown in FIG. 5A;

[0026] FIG. 6 is a graph illustrating the variation in coupling strength between the bus antenna and the module antenna of FIGS. 5A-5C as a function of the angle formed between them; and

[0027] FIG. 7 are graphs illustrating how the current circulating in an antenna (in dBA) and the magnetic field strength at a point above the antenna (in dBA / m) vary as a function of the transmission signal frequency, in accordance with embodiments of the present disclosure.

[0028] DETAILED DESCRIPTION

[0029]

[0014] Exemplary embodiments of the disclosure will now be described with reference to the accompanying drawings. The same reference numerals used in different drawings represent the same or similar elements unless otherwise stated. The below-described exemplary embodiments do not represent all envisaged implementations of the disclosure. Instead, they are merely non-limiting examples consistent with aspects of the disclosure as recited in the appended claims.

[0030]

[0015] Embodiments of the present disclosure provide an assembly comprising an electronic device and module antenna configured local to a battery cell, which enables wireless, near-field communication with a bus antenna. The bus antenna provides a signal path to a remotely located device, such as, but not limited to, a battery management system (BMS) located remotely from the battery module. Near-field communication with the bus antenna is achieved through electro-magnetic coupling between the module antenna and the bus antenna. The module antenna itself may comprise at least one antenna having a plurality of sections arranged in series, which enable electro-magnetic coupling with the bus antenna. Embodiments of the present disclosure therefore provide a convenient solution for achieving near-field communication within a battery system. Embodiments of the present disclosure are not limited to a specific battery system architecture and can be employed in a range of different battery system architectures. Further details follow below, along with an explanation of the underlying principles of operation.

[0031]

[0016] Batery System Overview.

[0032] FIG. 1 is a schematic illustration of a batery system 100 in accordance with embodiments of the present disclosure. Batery system 100 comprises, but is not limited to, a plurality of battery modules 103-1, 103-2, 103-3,..103 -N (where N is the total number of battery modules in batery system 100), BMS 101, a plurality of cell monitoring devices (CMD) 105-1, 105-2, 105-3,..105-N, and bus antenna 115. The plurality of batery modules 103-1, 103-2, 103-3,... , 103-N form a battery pack. In accordance with the illustrated embodiment, each battery module 103-1, 103-2, 13-3,... 103-N, is monitored by an associated CMD 105-1, 105-2, 105-3,... 105-N. While the illustrated embodiment of FIG. 1 illustrates a plurality of CMD’s 105-1, 105-2, 105-3,..105-N, in alternative embodiments there may be at least one CMD. Accordingly, it is not essential for present purposes that each batery module 103-1, 103-2, 13-3,... 103-N is associated with its own CMD, irrespective of what is illustrated in FIG. 1. In some embodiments, one or more CMDs may monitor one or more different batery modules. For example, a single CMD may monitor two or more different batery modules. Battery modules 103-1, 103-2, 13-3,... 103-N may be electrically coupled with each other to form a battery pack, and batery system 100 may include electrical terminals 119 for drawing electrical power from battery system 100. Batery modules 103-1, 103-2, 13-3,... 103-N may comprise a single batery cell or a plurality of battery cells arranged in series, in parallel, or a combination thereof. In the illustrated embodiment of FIG. 1, each CMD 105-1, 105-2, 105-3,... 105-N may be configured to communicate (e.g. transmit / receive data) with BMS 101, and more specifically with BMS management circuitry 113, by near field coupling (NFC) with bus antenna 115. BMS 101 may comprise radio transceiver 111, operatively connected to management circuitry 113. Bus antenna 115 may be operatively connected to radio transceiver 111, enabling data communication with management circuitry 113.

[0017] Each CMD 105-1, 105-2, 105-3,... 105-N may comprise electronic device 107 and module antenna 109. Electronic device 107 may comprise, or be operatively connected to, a plurality of sensors configured to measure and monitor one or more physical characteristics (e.g., voltage, current, charge, temperature, pressure, humidity) at the battery module level or the battery cell level. Module antenna 109 may relate to any physical system capable of establishing NFC communication with bus antenna 115. Accordingly, module antenna 109 and bus antenna 115 enable communication between each electronic device 107 of each CMD 105-1, 105-2, 105-3,... 105-N and radio transceiver 111, located remotely from the plurality of electronic devices 107.

[0033]

[0018] Within the context of the present disclosure, near-field coupling may be interpreted as involving a distance of separation between bus antenna 115 and each module antenna 109 of less than one wavelength of electromagnetic radiation, and more specifically, less than one wavelength of the radio wave transmission signal between bus antenna 115 and module antenna 109. For example, the distance of separation may be less than 120 mm when the wavelength is 120 mm. Stronger electromagnetic near-field coupling may occur when the separation is substantially less than one wavelength, for example, less than one-tenth of a wavelength. Battery system 100 may be configured so that each module antenna 109 is spaced from the transmission line by no more than one-half, one-third, one-quarter, one- fifth, one-sixth, one-seventh, one-eighth, one-ninth, or one-tenth of the wavelength of the electromagnetic radiation. In accordance with some embodiments, the wavelength of the transmission signal may relate to any Industrial Scientific Medical (ISM) short-range radio band. Exemplary, non-limiting wavelengths may comprise wavelengths corresponding to a frequency equal to 440MHz, 828MHz, 915MHz, 2.4-2.5GHz, or 5GHz.

[0034]

[0019] The use of near-field coupling may allow the plurality of module antennas 109 to be positioned close to bus antenna 115, and consequently module antennas 109 are less sensitive to external EMI interference than the far-field module antennas of the prior art, thereby overcoming some of the problems described above associated with the prior art. In accordance with some embodiments, the plurality of module antennas 109 may be arranged at substantially the same distance from bus antenna 115. The transmission of communication data between the plurality of electronic devices 107 and radio transceiver 111 may be subject to additional constraints arising as a result of the high-voltage environment of battery system 100. As mentioned previously, these additional constraints relate to: high voltage isolation and immunity to electromagnetic interference. These two constraints are described below.

[0035]

[0020] High-Voltage isolation

[0036] Battery system operating voltages (VB) are obtained by stacking different battery modules in series (as shown in FIG. 1). For most applications, these operating voltages are considered, although definitions may differ, as high voltages (e.g., VB>60 V). For example, automotive batteries typically have an operating voltage of about 400 V, buses may operate at 800V, and industrial energy storage systems may operate at 1500V. In the battery system 100 of FIG. 1, each battery module 103-1, 103-2, 103-3,... 103-N, may experience a different voltage / potential difference Vi+i-Vi (with i an integer between 1 and N) relative to the ground of battery system 100, with each Vi increasing progressively. It follows that the last battery module 103-N in battery system 100 is at a higher voltage than first battery module 103-1. It may be necessary to isolate these high voltages to prevent devices within the battery system from experiencing them, which may otherwise not be able to withstand the high voltages. In particular, high-voltage isolation is required between antenna module 109 and bus antenna 115. In FIG. 1 module antenna 109 and bus antenna 115 are separated by gaps 2, 4, 6, 8. It follows from the preceding discussion regarding the voltage each different battery module 103-1, 103-2, 103-3,... 103-N experiences, that the high-voltage isolation required across gaps 2,4, 6, and 8 may in principle be different for different battery modules 103-1, 103-2, 103- 3,... 103-N, subject to the voltage each battery module 103 is subject to. Thus, for example, the high-voltage isolation required across gap 2, between module antenna 109 of battery module 103-1 and bus antenna 115, may be less than the high-voltage isolation required across gap 8, between module antenna 109 of battery module 103-N and bus antenna 115, since battery module 103-N may be at a higher voltage relative to battery module 103-1. Thus, a battery system 100 in which different battery modules have a different high-voltage isolation is envisaged. However, for practical purposes, it is often easier to configure each battery module 103-1, 103-2, 103-3,... 103-N, associated module antenna 109 and gap 2, 4, 6, 8 to satisfy the maximum high-voltage isolation that may be experienced within battery system 100. In other words, each battery module, and more specifically the associated module antenna 109 and gap 2, 4, 6, 8, may be configured to ensure high-voltage isolation for the maximum voltage that battery module 103-N may experience.

[0037]

[0021] Consider an automotive battery consisting of ninety-six lithium polymer cells with a maximum voltage of 4.2 V. The maximum operating voltage VB of such an automotive battery is therefore 403.2 V. The automotive battery may be divided into 8 battery modules of 12 cells connected in series, each module having a voltage of 50.4 V. A CMD configured to handle 60 V is therefore capable of monitoring 12 cells, but as battery packs are connected in series, each subsequent CMD should be electrically isolated from all other CMDs and associated battery modules, and in particular should be isolated from experiencing the automotive battery operating voltage VB, to ensure that the maximum potential difference observed by a single CMD is less than 60 V. If two battery packs are not perfectly isolated, their respective CMD may not withstand the potential difference (of 100.8 V).

[0038]

[0022] High voltage isolation requires using the correct isolation components with the proper materials, but also adherence to the correct distances in the design of the battery system to ensure that high voltage insulation is maintained in all use cases, in all environments, and as the battery system ages. Two characteristic distances associated with the geometry of a battery system are decisive for ensuring high voltage isolation: clearance distance and creepage distance. The clearance distance (IEC 60664-1) corresponds to the shortest distance in air between two conductive parts, whereas the creepage distance (IEC 60664-1) corresponds to the shortest distance along the surface of a solid insulating material between two conductive parts. To ensure a specific level of voltage isolation between two conductive parts, a specific minimum clearage / creepage distance needs to be observed. These distances are generally specified in industry standards documentation, an example of which is IEC standard 60664-1. In practice, a voltage isolation level greater than the battery operating voltage VB may be selected, e.g., for a 400 V battery system, a voltage isolation level of 500 V, 1 kV or more may be appropriate.

[0039]

[0023] It should be noted that high voltages represent not only a risk of damage to battery system componentry but also present a risk of electric shock to an assembly operator or end user of the battery system. The components used for signal communication between CMDs, battery modules, and the BMS within a battery system are closely monitored as they present potential sources of current leakage, and the associated risks increase with increasing number of cells N.

[0040]

[0024] Electromagnetic-Interference Immunity and Common Mode rejection Electromagnetic interference (EMI) is the disturbance of electronic equipment or systems by electromagnetic radiation, electrostatic coupling, magnetic coupling, or electrical conduction. It can cause malfunction, data corruption, data loss, or even complete failure of the affected equipment. EMI may be caused by a variety of different sources, including power lines, radio waves, and even household appliances. Within the context of a battery system, the high voltages and currents present are strong sources of EMI, and electronic components such as CMDs or other circuitries are susceptible to EMI. Shielding, filtering, and grounding are common methods used to reduce the effects of EMI on electronic systems.

[0041]

[0025] In accordance with embodiments of the disclosure, the approach taken to reduce EMI resides in the use of balanced electrical paths and common mode rejection. For an electrical signal to propagate, there must be a return path. In an unbalanced system, a first conductor is provided to propagate a signal, and the return path is referred to as the ground connection. In a balanced system, a second conductor is provided to propagate the same signal as the first conductor, but with opposite polarity (e.g., same magnitude, but opposite phase). The second conductor is the return path for the first conductor, and vice versa.

[0042]

[0026] In a balanced system, there are two modes of signal propagation. The first mode is differential, where the signal of interest is determined by the difference in signals propagating on the two conductors. The second mode is common mode, where the signal of interest is the signal that appears on both conductors. In a balanced system, EMI is usually coupled to the common mode, and noise filtering may be required to remove it. In contrast, when operating in differential mode, the signals are of opposite polarity, and the output is determined by calculating the difference of the two opposite polarity signals propagating on each conductor. Any EMI that couples to the two conductors may effectively be removed or filtered out when the signal difference is determined. The magnitude and polarity of the induced EMI in each conductor is essentially the same, since the two conductors are located close together relative to the distance of the source causing the EMI. Thus, when the difference of the two EMI noise affected signals propagating in the two conductors is determined, the induced EMI noise cancels. In this way, a desired signal may be transmitted without traces of EMI in the differential mode conductor. In practice, determining the difference of the two opposite polarity signals propagating on the two conductors may require a signal subtractor. In other words, a device that receives as its input the two differential signals, and outputs their difference, which is the signal of interest. A differential receiver is a non-limiting example of a signal subtractor that may be used to determine the difference. Similarly, a differential amplifier is another example of a signal subtractor, albeit the differential amplifier outputs an amplified difference signal. Conversely, generating a differential signal for input to two conductors may require a differential output block such as an input signal splitter and inverter, a differential output amplifier, or a phase splitter. The signal splitter separates an input signal Vdm into two equal magnitude signals Vdm / 2. The inverter inverts the polarity of one of the split signals (i.e., Vdm / 2). The end result is that two signals of opposite polarity are provided (i.e., equal magnitude but opposite phase), that may be input on separate conductors, thus forming a differential pair of signals. Functionally, the splitter-inverter performs the inverse of the subtractor - provided with a single input signal, it splits it into two signals and inverts the polarity of one of them. In contrast, the subtractor provided with a differential pair of signals determines the difference by subtracting the two differential signals to output the difference signal.

[0043]

[0027] FIG. 2A is a schematic illustration of an exemplary balanced circuit using common mode rejection. Signal source 201 provides an input signal Vs to be transmitted to receiver 209. The circuit comprises a first 203-1 and second 203-2 balanced conductor. Differential signals Vs / 2 and -Vs / 2 are generated using splitter-inverter 207-1, for a given input signal Vs. First differential signal Vs / 2 is output to first conductor 203-1 and second (inverted) differential signal -Vs / 2 is output to second conductor 203-2. If the circuit is not immune to EMI, both first 203-1 and second 203-2 conductors may experience an interference / noise signal Vnoise from a nearby noise source 205. Because both conductors 203- 1, 203-2 are balanced, the resulting signal propagating along first conductor 203-1 is equal to Vnoise + Vs / 2, and the resulting signal propagating on second conductor 203-2 is equal to Vnoise - Vs / 2. The two resulting signals are input to subtractor 207-2, where the difference signal is output from subtractor 207-2 and input to receiver 209. At receiver 209, a signal proportional to the difference between the two resulting signals from first 203-1 and second 203-2 conductors is measured, i.e., Vnoise + Vs / 2 - Vnoise -(-Vs / 2) = Vs. The common mode interference / noise signal Vnoise is thus removed from the difference signal. As mentioned previously, the function of subtractor 207-2 may be provided by different types of device, such as a differential amplifier, in which case the output signal received at receiver 209 is amplified, i.e., GVs, where G represents the gain of the differential amplifier. The measure of a differential amplifier's ability to eliminate common-mode voltage is known as the commonmode rejection ratio, or CMRR.

[0044]

[0028] The differential operations on the first 203-1 and second 203-2 conductor signals may be performed using baluns 208-1, 208-2, as illustrated in FIG. 2B. In other words, in accordance with some embodiments, the function of splitter- inverter 207-1 and subtractor 207-2 of FIG. 2A may be provided by baluns 208-1, 208-2. Baluns 208-1, 208-2 may be reciprocal three-port power splitters comprising one unbalanced port and two balanced ports, illustrated respectively in FIG. 2B as port 1, and ports 2 and 3. Signals at the balanced ports are equal in magnitude but opposite in phase. In the frequency domain, this corresponds to a phase shift of it radians, while in the time domain, one signal is the negative (inverted) version of the other. Baluns 208-1, 208-2 are designed to equally split the energy of a signal fed to the unbalanced port between the two balanced ports. Reciprocally baluns are able to combine at the unbalanced port a differential signal applied to the balanced ports. In the example shown in FIG. 2B, balun 208-1 splits source signal Vs applied to the unbalanced port 1, whereas balun 208-2 combines the differential signal applied to balanced ports 2 and 3. Receiver 209, which may relate to a radio transceiver, commonly possesses only one unbalanced input / output port. To use balanced communication with common mode rejection, a balun with a sufficient CMRR may be required. In accordance with at least some embodiments of the present disclosure, it is to be appreciated that while a balun may relate to a hardware device, the functionality provided by the balun may also be provided by alternative means. In particular, and as is described in the below description of exemplary embodiments, the functionality of balun 208-1, 208-2 may be provided by the configuration of module antenna 109 and bus antenna 115 of FIG. 1. More specifically, and applying the principles of FIG. 2B to the battery system of FIG. 1, when a signal is transferred from cell monitoring device 105-1, 105-2, 105-3,... 105-N, to BMS 101, electromagnetic coupling of module antenna 109 with bus antenna 115 provides the functionality of balun 208-1 of FIG 2B, and radio transceiver 111 provides the functionality of balun 208-2. To achieve this, radio transceiver 111 at BMS 101 may be provided with a balun, or other subtractor device, such as a differential amplifier. Further implementation details, in accordance with embodiments of the disclosure, follow. Alternatively, bus antenna 115, may be bidirectional, i.e. a transmission signal may be transmitted from any CMDs 105-1, 105-2, 105-3,... 105-N to BMS 101, or from BMS 101 to any of CMDs 105-1, 105-2, 105-3,... 105-N. In this latter situation, CMD 105-1, 105-2, 105-3,... 105-N corresponds to the receiver and radio transceiver 111 corresponds to the source, the electromagnetic coupling of module antenna 109 with bus antenna 115 provides the functionality of balun 208-2 of FIG. 2B, and radio transceiver 111 provides the functionality of balun 208-1. To achieve this, radio transceiver 111 at BMS 101 may be provided with a block that provides a differential output, such as a splitter inverter, a differential output amplifier, or a balun.

[0045]

[0029] NFC Communication Assembly

[0046] Returning to FIG. 1, and in accordance with embodiments of the present disclosure, an assembly comprising bus antenna 115 and module antenna 109, enabling near- field communication is provided. The assembly enables communication between CMDs 105-1, 105-2, 105-3,... 105-N and BMS 101, and specifically between at least one electronic device 107 of a respective CMD 105-1, 105-2, 105-3,... 105-N, and radio transceiver 111 of BMS 101. Such an assembly addresses both the high-voltage (HV) isolation and EMI problems simultaneously. Another advantage of using near-field coupling is that the value of the coupling strength may easily be adjusted to achieve weak coupling. The weak coupling may be set at a value not to overload bus antenna 115. Use of weak coupling is advantageous in that it enables a large number of CMDs 105-1, 105-2, 105-3,... 105-N (e.g., N >200) to be spaced along bus antenna 115, without overloading it or changing its characteristics. Module antenna 109 may be operatively coupled to electronic device 107, and bus antenna 115 may be configured for operative communication with radio transceiver 111. As mentioned previously, module antenna 109 and bus antenna 115 are arranged with respect to each other to enable near-field coupling between them when a transmission signal is input into either module antenna 109 or bus antenna 115. In other words, the herein disclosed assembly enables two-way communication between CMD 105 and BMS 101. Within the present context, a transmission signal may correspond to an electrical signal characterized by at least one of voltage, current, power, frequency, or wavelength. In use, the transmission signal may comprise data for transmission between electronic device 107 and BMS 101. Such data may, for example, comprise battery cell 103-1, 103-2, 103-3,... 103-N, diagnostic information, such as, but not limited to, state of charge, voltage, or any other information indicative of a characteristic of the battery cell. The transmission signal may, in some non-limiting embodiments, correspond to a radio wave having a frequency between 2.4 and 2.5 GHz, although, and as should be clear from the preceding description, this frequency range is by no means limiting, and any desired frequency may be selected, and more specifically any desired ISM band may be used.

[0047]

[0030] As shown in FIG. 1, bus antenna 115 may comprise at least two transmission lines 115-1, 115-2. A transmission line may refer more generically to any elongated conductor enabling the transmission of a signal; thus, examples of transmission lines may include a cable, a wire, a cable from a twisted pair or a microstrip. In some embodiments, bus antenna 115 may comprise more than two transmission lines. Thus, for present purposes, whilst the remaining embodiments are described with respect to a bus antenna having two transmission lines, it is to be appreciated that the bus antenna may comprise more than two transmission lines. In such embodiments, it is envisaged that the one or more additional transmission lines have a different, negligible, or no near-field coupling strength with module antenna 109 (e.g., a ground line). In accordance with some embodiments, bus antenna 115 may also include termination 117 (FIG. 1), which may be located at one end of bus antenna 115 opposite the end radio transceiver 111 (as shown in FIG. 1) is connected to. Bus antenna 115 may be configured such that substantially all of the energy in the transmission line that is not coupled to module antennas 109 is absorbed by termination 117. Termination 117 may include any electrical device configured to match a characteristic impedance of transmission lines 115-1, 105-2, such as a resistor. According to some embodiments, and as described in the preceding section, the two transmission lines 115-1, and 115-2 of bus antenna 115 may be configured as a balanced circuit, such that an electrical signal propagating in a first one of the two transmission lines (e.g. 115-1) is it radians out of phase with respect to an electrical signal propagating in a second one of the transmission lines (e.g. 115-2).

[0031] As previously stated, in some embodiments, module antenna 109 and bus antenna 115 may form a balun in operation. In such embodiments, the transmission signal may comprise an unbalanced electrical signal input to module antenna 109, which is output as a balanced electrical signal in bus antenna 115. This occurs when a transmission signal is transmitted from module antenna 109 to bus antenna 115. When instead a transmission signal is sent from bus antenna 115 to module antenna 109, the transmission signal may comprise a balanced electrical signal input to bus antenna 115, which is output as an unbalanced electrical signal in module antenna 109. In these embodiments, advantageously, EMI immunity is reinforced via common mode rejection.

[0048]

[0032] Module Antenna Architecture and Electronic Circuit.

[0049] Now that the fundamental principles of operation of the present disclosure have been provided, more specific implementation details of module antenna 109 are provided. FIGS. 3A-3E are schematic electronic circuit illustrations of exemplary module antennas 109, in accordance with at least some of the disclosed embodiments. Module antenna 109 comprises at least one antenna 301 enabling electro-magnetic coupling with bus antenna 115, and represented in FIGS. 3A-E as an impedance. In the context of this disclosure, an impedance refers to any electronic component characterized by its capacity to resist the flow of alternating current, and combines both resistance (which dissipates energy) and reactance (which stores and releases energy through inductance or capacitance). An antenna configured to transform power from a transmitter or receiver into electromagnetic waves and vice versa, can be referred to as an impedance as its function involves an opposition to the flow of electrical current. Details relating to the structure of the at least one antenna 301 are provided below. Module antenna 109 further comprises a transmission line 303, operatively coupled to the electronic device 107 at one end and to the at least one antenna at its other end. As mentioned previously, a transmission line may refer more generically to any elongated conductor enabling the transmission of a signal; thus, examples of transmission lines may include a cable, a wire, a cable from a twisted pair, or a microstrip. Transmission line 303 enables bi-directional transmission of signals between electronic device 107 and the at least one antenna 301. The different configurations shown in FIGS. 3A-E are all passive and symmetrical, allowing operation in both directions.

[0033] FIG. 3A, illustrates a first electronic circuit configuration for module antenna 109. In this configuration, transmission line 303 is connected to matched termination 305, such as a 50 resistor. The at least one antenna 301 is connected in series with capacitive element 307 and the circuit formed by the at least one antenna 301 and the capacitive element 307 is connected in parallel with matched termination 305. The current in the at least one antenna 301 flows to ground through ground capacitive element 307, thereby forming a resonant or impedance-matching network, depending on the design. For example, ground capacitive element 307 may be sized such that the circuit formed by the at least one antenna 301 connected in series with ground capacitive element 307 resonates at a higher frequency than an operating frequency of a desired transmission signal. Within the present context, a capacitive element refers to any electronic component or structural feature configured to store electric charge in response to a voltage differential. A capacitive element may be implemented as a discrete component, such as a capacitor, or may arise unintentionally due to parasitic effects within a structure, such as track or stray capacitance. Such parasitic capacitance may nonetheless be deliberately influenced or controlled through structural design, for example, by adjusting the geometry, spacing, or dielectric properties of conductive traces, to achieve a desired capacitance value. This configuration facilitates a wide operating frequency range, provided the total impedance of the circuit formed by the at least one antenna 301 connected in series with ground capacitive element 307 is higher than the value (e.g., ten times the value) of matched termination 305 (e.g., 50 ) and does not change appreciably. If the effective termination impedance of transmission line 303 does change due to the impedance in the circuit formed by the at least one antenna 301 connected in series with ground capacitive element 307 being too low, then a mismatch may occur at termination 305, making the overall module antenna 109 sensitive to the length of transmission line 303. To avoid such a mismatch, the components of module antenna 109 should be selected such that the impedance of the electrical path associated with the at least one antenna 301 is high compared to the impedance of matched termination 305(e.g., 50 ). Avoiding mismatch limits the amplitude of the current flowing through the at least one antenna 301 to being less than that flowing in matched termination 305. This ensures that most of the transmission signal / current flows into matched termination 305, rather than into the at least one antenna 301 and its associated electrical path. Since the near-field coupling strength between module antenna 109 and bus antenna 115 is proportional to the current flowing in the at least one antenna 301, this configuration may result in a limited coupling strength. Therefore, module antenna 109 and bus antenna 115 may be placed closer together to maintain effective coupling and communication between the antennas. However, this shorter distance can impose constraints on system design, including high-voltage isolation requirements, as previously discussed.

[0050]

[0034] FIGS. 3B-3E illustrate alternative configurations of module antenna 109, in which the at least one antenna 301 is coupled to termination resistor 311 at its distal end. In the embodiments of FIGS. 3B-3E, module antenna 109 includes at least one capacitive element 309 located between transmission line 303 and termination resistor 311. The at least one capacitive element 309 and the at least one antenna 301 are configured to have a resonant frequency matched to an operating frequency of a desired transmission signal. For example, the capacitance value of the at least one capacitive element 309 may be chosen such that in combination with the at least one antenna 301, the antenna path resonates at the operating frequency of the desired transmission signal, which may be 868MHz, 915MHz, 2.45GHz, or 5GHz. This may require careful design to determine the capacitance value for the at least one capacitive element 309, which capacitance value should include consideration of stray parasitic capacitance . The physical dimensions of the at least one antenna 301 may also be accounted for, in other words the at least one antenna 301 is not be regarded as a lumped component system. For example, the at least one antenna 301 may be of a similar size to the wavelength at the desired operating frequency, accordingly distributed RF design techniques may be used for determining the capacitance value and / or design of the at least one antenna 301.

[0051]

[0035] At resonance, the impedance of the antenna path, i.e., the path followed by the current traversing the circuit formed by the at least one antenna 301 and at least one capacitive element 309 may drop to zero (disregarding real- world imperfections in the components), or near zero. Accordingly, electronic device 107 may be connected to transmission line 303, a near-zero ohm series impedance at resonance, and then a termination resistor 311 matched to transmission line 303. In this configuration, all the current flowing through transmission line 303 and into termination resistor 311 also flows through the at least one antenna 301. Since termination resistor 311 is connected at the end of the antenna path (e.g., distal end of the at least one antenna 301), there is only possible path for the current, in contrast with the circuit of FIG. 3 A in which matched termination 305 is connected at the end of transmission line 303, i.e., in parallel with the antenna path. This maximises the electromagnetic field strength formed around the at least one antenna 301. The coupling between the module antenna 109 and the bus antenna 115 may still be set to provide weak coupling, such that bus antenna 115 does not experience a loading effect in the vicinity of module 109. However, this increased magnetic field strength may allow for either a reduction in the at least one antenna’s 301 size, or an increase in the distance of separation between bus antenna 115 and module antenna 109, while still maintaining the same coupling strength achievable with the configuration shown in FIG. 3 A. As mentioned previously, and in accordance with some embodiments, the at least one antenna 301, the termination resistor 311, the at least one capacitive element 309 and the transmission line 303 may form a closed circuit, as shown for example, in FIGS. 3B-3E.

[0052]

[0036] In accordance with some embodiments, the at least one capacitive element 309 may be located between the at least one antenna 301 and the termination resistor 311 , as shown in FIG. 3B. In other words, electronic device 107, transmission line 303, the at least one antenna 301, the at least one capacitive element 309, and termination resistor 311 may be connected in series and form a closed circuit. In alternative embodiments, the at least one capacitive element 309 may be located upstream of the at least one antenna 301 and termination resistor 311 (i.e., between transmission line 303 and the at least one antenna 301), forming a closed circuit. For example, electronic device 107, transmission line 303, the at least one capacitive element 309, the at least one antenna 301, and termination resistor 311 may be all connected in series and form a closed circuit.

[0053]

[0037] In some embodiments, module antenna 109 may comprise two capacitive elements 309-1, 309-2, and the at least one antenna 301 may be located between the two capacitive elements 309-1, 309-2. The two capacitive elements 309-1, 309-2 may be connected in series with the at least one antenna 301. For example, as shown in FIG. 3C, the at least one antenna 301 is located between, and connected in series with, the two capacitive elements 309-1, 309-2. The two capacitive elements 309-1, 309-2 are placed symmetrically on either side of the at least one antenna 301, which improves balance and common mode rejection. Although the two capacitive elements 309-1, 309-2 may have different capacitance values, their combined series capacitance determines the tuning of the module antenna circuit. The two capacitive elements 309-1, 309-2 may be chosen to have equal or nearly equal capacitance values to preserve symmetry. In some embodiments, the two capacitive elements 309-1, 309-2 may be connected at one of their ends to either side of the at least one antenna 301, and each capacitive element 309-1, 309-2 may be connected at its other end to ground, forming a shunt configuration, as shown in FIG. 3D. This arrangement can also be used to tune the resonant frequency of the circuit and provides the advantage of reducing the required capacitance values compared to the series configuration shown in FIG. 3C, which may be beneficial at high operating frequencies. However, because the capacitance values are smaller, the circuit shown of module antenna 109 shown in FIG. 3D may become more susceptible to the effects of parasitic capacitance, which can undesirably shift the resonant frequency and impact performance.

[0054]

[0038] In accordance with some embodiments, and as illustrated in FIG. 3E, the at least one antenna may include a first sub-antenna 301-1 and a second sub-antenna 301-2 connected in series via the at least one capacitive element 309. The at least one antenna may have a plurality of sections arranged in series forming a loop. In such embodiments, the at least one antenna may include a first set of sections that form first sub-antenna 301-1 and a second set of sections that form second sub-antenna 301-2, connected in series via the at least one capacitive element 309. To maintain symmetry in the circuit of module antenna 109, the first 301-1 and second 301-2 sub-antennae may have substantially the same impedance. For example, the first and second sets of sections may include an identical number of sections, optionally with matching physical characteristics (e.g., length, width, etc.).

[0055]

[0039] Further details of the electronic circuitry of module antenna 109 are now provided, in particular regarding the architecture and physical configuration of module antenna 109. Consistent with the disclosed embodiments, the at least one antenna 301 may comprise a plurality of sections arranged in series, forming an unbalanced electrical path. In some embodiments, the plurality of sections may correspond to at least some of the segments of a transmission line. In other words, the at least one antenna 301 may be formed from multiple elongated conductors that enable signal transmission, such as distinct sections of cables, wires, twisted pairs, or microstrip lines. These sections may have differing characteristics, such as differing physical dimensions, conductive materials, or other physical parameters, depending on the specific design requirements of the antenna. In some embodiments, where the at least one antenna 301 is directly connected to transmission line 303 (e.g., as illustrated in FIGS. 3B and 3D), both transmission line 303 and the at least one antenna 301 may be formed by a single conductive trace, with one portion corresponding to transmission line 303 and another portion to the at least one antenna 301. In some embodiments, the plurality of sections of the at least one antenna 301 may form a loop. It should be appreciated that the number of sections forming the at least one antenna 301 is immaterial, and is not limited to a specific value. In some embodiments the antenna may include two, three, six, eight, ten, or any other suitable number of sections, depending on the desired electrical and / or geometric configuration.

[0056]

[0040] In accordance with some embodiments, module antenna 109 may be comprised on a printed circuit board (PCB). The PCB may comprise electronic device 107 and module antenna 109. The module antenna 109 may be constructed on either a thick or thin rigid substrate, such as FR4, Rogers (e.g., R04003), or ceramic-filled PTFE, or on a thick or thin flexible substrate, such as a polyimide-based flex PCB. When implemented on a thin substrate, the electromagnetic field lines generated by the at least one antenna 301 tend to be confined by the presence of a ground plane, which in turn limits the effective range over which module antenna 109 may couple to bus antenna 115. To avoid this limitation and to preserve the desired electromagnetic radiation pattern, the at least one antenna 301 may be positioned in a region of the PCB without a ground plane.

[0057]

[0041] FIGS. 4A-4C illustrate various exemplary printed circuit boards (PCBs) 400a, 400b, 400c, that include module antenna 109 and may also include electronic device 107, in accordance disclosed embodiments. FIGS. 4A-4C illustrate the back side of the PCBs; as a result, components such as the electronic device 107 (where included on the PCB) and transmission line 303, which are located on the front side, are not visible. Other components, such as the at least one capacitive element 309 and termination resistor 311, are illustrated. In all figures, the at least one antenna 301 is visible and positioned in a region of the PCB that lacks a ground plane 410. The ground plane 410 is represented by a black surface in the figures.

[0058]

[0042] FIG. 4A illustrates a configuration in which module antenna 109 includes two capacitive elements, 309-1, 309-2, connected in series with the at least one antenna 301, which is positioned between them. This configuration corresponds to the configuration shown in FIG. 3C. FIGS. 4B and 4C illustrate configurations in which the plurality of sections forming the at least one antenna 301 are divided into two sets: a first set of sections forming first sub-antenna 301-1, and a second set forming second sub-antenna 301-2. The first subantenna 301-1 and the second sub-antenna 301-2 are connected in series via at least one capacitive element 309. This arrangement corresponds to the schematic configuration shown in FIG. 3E.

[0059]

[0043] The at least one antenna 301 may be rotationally symmetrical about an axis perpendicular to a plane of the at least one antenna 301 (e.g., a PCB plane). Within the context of this disclosure, rotational symmetry means that the at least one antenna structure 301 remains unchanged when rotated by a given angle around this axis. For example, the at least one antenna may possess a C2 symmetry, meaning it is symmetric under a 180-degree rotation; a C4 symmetry, meaning it is symmetric under 90-degree rotations; a C6 symmetry, meaning it is symmetric under 60-degree rotations; or any other possible symmetry under specific angle rotations. All configurations illustrated in FIGS. 4A-4C possess at least a C2 symmetry.

[0060]

[0044] It should be appreciated that the term “rotationally symmetric” applies specifically to the sections of the at least one antenna 301 that participate in electromagnetic coupling with bus antenna 115. This symmetry may be seen not only in the geometric layout of the conductive elements but also in the resulting electromagnetic field distribution, which may exhibit similar rotational symmetry patterns. In other words, the electromagnetic field lines generated by the at least one antenna may themselves exhibit a rotationally symmetric pattern. For example, FIGS. 4D and 4E are field distribution plots 400d and 400e, which illustrate the magnetic field patterns generated around the module antenna of PCB 400b (illustrated in FIG. 4B) and PCB 400c (illustrated in FIG. 4C), respectively. The electromagnetic field patterns associated with both configurations, exhibit clear rotational symmetry. As further explained below, rotational symmetry may contribute to help ensure consistent coupling behaviour between the at least one antenna 301 and bus antenna 115, regardless of their relative orientations.

[0061]

[0045] In accordance with some embodiments, the at least one antenna 301 may be elliptical or circular in shape. The plurality of sections that form the at least one antenna 301 may be arranged to define a structure with a generally elliptical or circular geometry. The sections forming the at least one antenna 301 need not necessarily all be straight. In some embodiments, at least one of the sections may be curvilinear or meandering, contributing to the curved shape of the antenna. In some embodiments, the at least one antenna 301 may be polygon-shaped. Polygon-shaped loop configurations of antenna still enable effective electromagnetic coupling and provide rotationally symmetric electromagnetic field patterns. For example, the at least one antenna 301 may comprise any one of a hexagon shape or an octagon shape, as shown in FIGS. 4A-4C. In some embodiments, each of the plurality of sections may correspond to one of the sides of the polygon. More specifically, each of the plurality of sections contributing to the electromagnetic coupling with bus antenna 115 may correspond to one of the sides of the polygon.

[0062]

[0046] It is to be appreciated that, in embodiments where the plurality of sections forming the at least one antenna 301 are divided into first and second set sections 301-1, 301 - 2, each forming a sub-antenna, the two sub-antennas may collectively define an antenna structure exhibiting rotational symmetry about an axis perpendicular to the plane of the antenna, and / or an antenna having a circular, elliptical, or polygonal shape, as shown for example in FIGS. 4B and 4C.

[0063]

[0047] In some embodiments, each of the plurality of sections may be of substantially equal electrical length. The electrical length is a measure of the phase shift experienced by a carrier wave (i.e., to an electromagnetic waveform that may be modulated or manipulated to carry information) as it travels through a conductor, it corresponds to the physical length measured in terms of the operating wavelength X of the carrier wave modulo 2TT. Accordingly, two different sections of a transmission line may have an equal electrical length but two different physical lengths (e.g. when the physical lengths differ by an integer multiple of the operating wavelength). In some embodiments, each of the plurality of sections may be of substantially equal physical length. Note that when two sections are of equal physical length then it follows for the same operating wavelength, that they also have the same electrical length, but two sections of equal electrical length do not necessarily have the same physical length. In the antenna configurations illustrated in FIGS. 4A and 4B, each of the plurality of sections of the at least one antenna 301 shares substantially the same electrical and physical length.

[0048] In some embodiments, at least two of the plurality of sections may be of longer electrical length than the other sections of the plurality of sections. Additionally, in some embodiments, at least two of the plurality of sections may be of longer physical length than the other sections. For example, in the configuration shown in FIG. 4C, two of the plurality of sections of the at least one antenna 301 arranged parallel to the width of PCB 400c are of longer electrical length and physical length than the other sections.

[0064]

[0049] A total electrical path length of the plurality of sections of the at least one antenna 301 may be half, or any odd multiple of half, of an operating wavelength of the desired transmission signal. In other words, the phase difference between the transmission signal at one end of the at least one antenna 301, and the desired transmission signal at the other end of the at least one antenna is it.

[0065]

[0050] Assembly Architecture

[0066] Details of the bus / module antenna assembly architecture are now provided. This assembly may incorporate any of the module antennas 109 described in the preceding sections with a bus antennas. As mentioned previously, module antenna 109 includes at least one antenna 301 comprising a plurality of sections arranged in series, forming an unbalanced electrical path coupled to a termination resistor 311 at its distal end. Transmission line 303 is operatively coupled to electronic device 107 at one end, and to the at least one antenna 301 at its other end. At least one capacitive element 309 may be positioned between transmission line 303 and termination resistor 311. The at least one capacitive element 309 and the at least one antenna 309 are configured to have a resonance frequency matching the operating frequency of the desired transmission signal.

[0067]

[0051] As previously mentioned, bus antenna 115 is configured for operative communication with radio transceiver 111, and comprises at least two transmission lines 115- 1, 115-2. Each one of transmission lines 115-1, 115-2 is greater in length than any one of the plurality of sections of the at least one antenna 301 of module antenna 109. Furthermore, each one of transmission lines 115-1, 115-2 may be spaced apart from and positioned adjacent to a different one of at least one first section and at least one second section of the at least one antenna 301, to enable near-field coupling when the desired transmission signal is input in either bus antenna 115 or module antenna 109. Within the present context, sections adjacent to a transmission line may refer to the sections closest to the transmission line.

[0068]

[0052] FIGS. 5A-5C are schematic illustrations of exemplary bus and module antenna assemblies, consistent with disclosed embodiments. A portion of module antenna 109 implemented in PCB 400b , specifically the at least one antenna 301-1, 301-2, is represented in these figures, and is identical to the one represented in FIG. 4B. However, it is to be appreciated that any one of the different antenna module architectures disclosed herein may be implemented within the assembly. In some embodiments, the assembly may comprise a PCB, and the PCB may comprise module antenna 109. The bus antenna may comprise a cable located external to the PCB, and optionally the cable may be any one of: a twin core cable, a multi-core cable, a ribbon cable. This is shown in FIGS. 5A-5C, which illustrate different plan views of PCB 400b and external bus antenna 115, located above the back side of PCB 400b.

[0069]

[0053] In accordance with some of the disclosed embodiments, the at least one antenna 301 may include a first set of sections and a second set of sections connected in series through the at least one capacitive element 309. As described in relation to previous embodiments, in FIGS. 5A-5C, the plurality of sections forming the at least one antenna 301 are divided into two sets: a first set of sections forming first sub-antenna 301-1, and a second set forming second sub-antenna 301-2. The first and second set of sections may include a same number of sections, as illustrated in FIGS. 5A-5C. In such embodiments where antenna 301 comprises two distinct sub-antennas 301-1, 301-2, each transmission line 115-1, 115-2, may be positioned adjacent to at least one section of the first sub-antenna 301-1, and at least one section of the second sub-antenna 301-2, or adjacent to sections of both sub-antennas. For example, in FIG. 5A, transmission line 115-1 is positioned adjacent to at least one section of first sub-antenna 301-1, while transmission line 115-2 is positioned adjacent to at least one section of second sub-antenna 301-2. In contrast, in FIGS. 5B and 5C, both transmission lines 115-1 and 115-2 are positioned adjacent to sections from both first sub-antenna 301-1 and second sub-antenna 301-2.

[0070]

[0054] As disclosed previously, in some embodiments, the at least one antenna 301 may be polygon-shaped. The polygon may be at least one of a hexagon or an octagon, as shown in FIGS. 5A-5C. As disclosed previously, the at least one antenna 301 may comprise an even number of sides, and the at least one first section (positioned adjacent to first transmission line 115-1) and the at least one second section (positioned adjacent to second transmission line 115-2) may correspond to opposite sides of the polygon. For instance, in FIG. 5 A, transmission lines 115-1, 115-2 are each positioned adjacent to opposing sides of the polygon, specifically, the sides that are parallel to the width of PCB 400b, formed by the plurality of sections comprised in the at least one antenna 301.

[0071]

[0055] In FIGS. 5A-5C each of the plurality of sections of the antenna are of substantially equal electrical and / or physical length, as disclosed previously. As with previously disclosed embodiment, at least two of the plurality of sections may be of longer electrical length and / or physical length than the other sections of the plurality of sections. For example, the at least one first section (positioned adjacent to the first transmission line 115-1) and the at least one second section (positioned adjacent to the second transmission line 115-2) may be of longer electrical path length than the other sections of the plurality of sections.

[0072]

[0056] In some of the disclosed embodiments, the at least one antenna 301 may be rotationally symmetrical about a common axis perpendicular to a plane of the at least one antenna 301-1, 301 -2 and a plane of the bus antenna 115. As previously discussed, such rotational symmetry enables a more consistent electromagnetic coupling to be achieved between module antenna 109 and bus antenna 115, regardless of their relative orientations with respect to each other. In general, the greater the symmetry of the at least one antenna 301, the less sensitive the coupling strength is to angular misalignment between module antenna 109 and bus antenna 115. This may facilitate the alignment and mechanical integration of bus antenna 115 with module antenna 109, particularly in embodiments where bus antenna 115 is external to the PCB comprising module antenna 109. Improved rotational tolerance reduces the need for precise orientation of the bus antenna relative to module antenna during assembly, thereby simplifying system integration and improving manufacturing flexibility.

[0073]

[0057] FIG. 6 is a graph 600 illustrating how the coupling strength between the bus antenna 115 and module antenna 109 varies as a function of the angle between them, based on the module antenna configurations shown in FIGS. 5A-5C. The angle is measured relative to a direction parallel to the width of the PCB, increasing in the counterclockwise direction. The relative orientation of the bus antenna 115 with respect to module antenna 109 corresponds to an angle of 0° in FIG. 5A, 45° in FIG. 5B, and 90° in FIG. 5C. In the graph of FIG. 6, S2.1 and S3.1 illustrate the coupling strength to each of the two conductors of bus antenna 115. The graph shows that the coupling strength remains nearly identical across these angles, indicative of a well-balanced system. The coupling strength is relatively stable around -30 dB and exhibits minimal variation as the bus antenna 115 is rotated through 180°, demonstrating strong rotational tolerance. Comparable performance may also be achieved using an antenna with a circular shape. In contrast, the elongated shaped antenna configuration shown in FIG. 4C, while functionally effective, does not possess the same level of rotational symmetry as the configuration shown in FIG. 4B (which is identical to the antenna configurations shown in FIGS. 5A-5C). As a result, the coupling strength for the elongated antenna configuration illustrated in FIG. 4C peaks when bus antenna 115 is aligned with a lengthwise axis of the at least one antenna 301, and decreases as bus antenna 115 rotates relative to the lengthwise axis. This shows that the elongate shaped antenna configuration has a narrower angular margin for optimal performance.

[0074]

[0058] In embodiments where module antenna 109 and bus antenna 115 form a balun in operation, the balanced ports (ports 2 and 3 illustrated in FIG. 2B) are formed by the two bus antenna transmission lines 115-1, 115-2. It follows that the two bus antenna transmission lines 115-1, 115-2 form a balanced circuit. The unbalanced port (port 1 in FIG. 2B) is formed by transmission line 303 of module antenna 109, and is located at one of its ends. The level of balance between the two bus antenna transmission lines 115-1, 115-2 is related to the ability of the assembly comprising module antenna 109 in combination with bus antenna 115, to transmit an electrical signal in each transmission line 115-1, 115-2, with a substantially identical scalar magnitude (recall that the transmission signals in the bus antenna transmission lines 115-1, 115-2 have a relative phase shift of it radians). In other words, the level of balance depends on the ability of the assembly to provide substantially the same coupling strength between each transmission line of the bus antenna and the adjacent sections of the at least one antenna 301. By two substantially identical magnitudes, it is intended, within the present context, that the magnitudes may refer to two values whose relative difference is less than a predetermined percentage. For example, two values of induced current may be substantially identical if they differ by less than 1% or 2%. The closer the magnitude of the electrical signal in each transmission line, the higher the level of balance and the better the CMRR of the balun formed by bus antenna 115 and module antenna 109. According to some embodiments, the balance level between the two balanced ports may be configured to yield a CMRR greater than or equal to 0, 10 dB, 20 dB or more. The unbalanced port (port 1) may be operatively connected to electronic device 107.

[0075]

[0059] The near- field coupling strength between two transmission lines is the strength of the electromagnetic coupling that occurs between them due to their proximity and, more specifically, depends on the overlap between their respective electromagnetic modes. The degree of mode overlap depends on multiple factors such as the distance between the two transmission lines, the geometrical characteristics of the transmission lines (cross-section, radius, height, width etc.) and the physical properties (dielectric permittivity, conductivity etc.) of the material of the transmission lines and of the surrounding environment. It is difficult to find an exact analytical expression of the coupling as a function of these parameters, so to accurately determine the near-field coupling strength between two transmission lines, detailed electromagnetic analysis and modelling techniques, such as electromagnetic simulations or circuit simulations, are often employed. Without loss of generality, the magnitude of the electromagnetic field generated by a source decreases with the distance from the source, meaning that when the distance of separation between two antennas is small, the electromagnetic fields are more likely to interact and couple.

[0076]

[0060] Accordingly, the near field coupling strength between bus antenna 115 and module antenna 109 depends on a distance of separation between the transmission lines 115-1 and 115-2 and their adjacent sections of the at least one antenna 301. FIG. 5D is a cross- sectional view of the assembly shown in FIG. 5 A, taken in the vertical plane along line 500. As illustrated, bus antenna transmission line 115-1 is separated by a distance di from the at least one first section of first sub antenna 301-1, while bus antenna transmission line 115-2 is separated by a distance d2 from at least one second section of second sub antenna 301-2.

[0077]

[0061] Near-field coupling strength is greater as the distances of separation di and d2 decrease. Therefore, the distances of separation di and d2 may be selected to tune the desired value of the near-field coupling strength. In accordance with some embodiments, each one of bus antenna transmission lines 115-1, 115-2 may be located equidistant relative to a different section of the at least one antenna 301. For example, as illustrated in FIG. 5D, the distance of separation di between first sub antenna 301-1 and bus antenna transmission line 115-1, is substantially the same as the distance of separation d2between second sub antenna 301-2 and bus antenna transmission line 115-2. Notwithstanding the above, alternative embodiments are also envisaged in which each separation distance between bus antenna transmission lines 115- 1, 115-2, and their adjacent antenna sections is different. In accordance with some embodiments, distance of separation d d2between each one of the bus antenna transmission lines 115-1, 115-2 and its adjacent section of the at least one antenna may be selected to achieve a coupling strength greater than or equal to -50dB, and less than or equal to -lOdB. Alternatively, distance of separation d d2may be selected to achieve a coupling strength greater than or equal to -40dB, and less than or equal to -20dB; or a coupling strength greater than or equal to -35dB and less than or equal to -25dB; or a coupling strength of -30dB (as shown in FIG. 6).

[0078]

[0062] The distances of separation d d2may also be selected as a function of a clearance / creepage distance. As a specific clearance / creepage distance is required to ensure a certain level of voltage isolation, a minimum distance of separation d d2may be required. The differentiation between clearance and creepage distance depends on the nature of the material that separates each of bus antenna transmission lines 115-1, 115-2 and its adjacent antenna section. In accordance with some embodiments, each one of the bus antenna transmission lines and its adjacent section may be separated by a dielectric insulating material. Non-limiting examples of dielectric insulating material may include any one or more of: air, a plastic material, a glass-filled plastic material, an epoxy composite material, polyethylene terephthalate “PET”, acrylonitrile butadiene styrene “ABS”, polytetrafluoroethylene “PTFE”, polyvinyl chloride “PVC”, polybutylene terephthalate “PBT”, polyethylene “PE”, polyamide “PA”, FR4, ceramic-filled polytetrafluoroethylene “PTFE”, ceramic laminates, or mylar. In the embodiments of FIGS. 5A-5D each bus antenna transmission line 115-1, 115-2, and its adjacent antenna section are separated by air. In some embodiments, the dielectric insulating material may be selected to have a dielectric breakdown voltage greater than the operating voltage of the battery system. Dielectric breakdown voltage is to be understood as the voltage at which a dielectric material undergoes a significant increase in its electrical conductivity, resulting in the breakdown of its insulating properties. For example, if the operating voltage VB of a battery system is equal to 400 V, and the distance of separation between each one of the bus antenna transmission lines 115-1, 115- 2 and its adjacent antenna section is 4 mm, a material with a dielectric breakdown voltage with a minimum breakdown voltage of 100 V / mm may be used to address the high voltage isolation issue. In practice, it is common to select a material with a dielectric breakdown voltage orders of magnitude greater than the required dielectric breakdown voltage. In the above example, it would be common to select a dielectric material having a dielectric breakdown voltage of several kV / mm, for added safety. Examples of such materials are listed above, e.g., Mylar has a dielectric breakdown voltage equal to 7 kV / mm.

[0079]

[0063] As mentioned above, the near-field coupling strength between two antennas depends on the geometric parameters of the transmission lines. The plurality of sections forming the at least one antenna may have a transverse profile defined by one or more characteristic dimensions. It should be noted that the transverse profile of a section may have any shape (square, rectangular, circular, etc.). In accordance with some embodiments, all of the plurality of sections forming the at least one antenna may share a same transverse profile as shown in FIG. 5D. Similarly, each bus antenna transmission line 115-1, 115-2 has a transverse profile. In accordance with some embodiments, bus antenna transmission lines 115-1, 115-2 may share the same transverse profile.

[0080]

[0064] Each of the aforementioned parameters (transverse profiles, distances of separations d d2) may have a direct impact on the value of the near-field coupling strength between each of bus antenna transmission lines 115-1, 115-2 and its adjacent section. It should be appreciated that by carefully varying these parameters, it may be possible to obtain a constant near-field coupling strength. Furthermore, two transmission line / section couples may present the same near-field coupling strength, even if they are separated by different distances or have different characteristic parameters. For example, if a transmission line / section pair is separated by a first spacing distance and a second transmission line / section pair is separated by a second spacing distance greater than the first, a same near-field coupling strength may be achieved for the second pair by adjusting the one or more characteristic dimensions of the transmission line or section transverse profile.

[0081]

[0065] Electromagnetic Coupling Nature and Resonance Frequency Tuning.

[0082] Due to the specific configuration of the electronic circuit of the module antenna 109, such as those illustrated in FIGS. 3B to 3E, enhancing the coupling strength is achieved by maximizing the electrical current circulating through the at least one antenna 301. This reflects the fact that the coupling mechanism is sensitive to variations in current, rather than voltage. As a result, the at least one antenna 301 behaves predominantly as an inductive element, presenting a relatively low impedance across the frequency range of interest, such as 868 MHz, 915 MHz, 2.45 GHz, or 5 GHz. Under these conditions, the electromagnetic coupling between module antenna 109 and bus antenna 115 is primarily inductive in nature, meaning that the magnetic component of the electromagnetic field is the dominant contributor to the coupling interaction.

[0083]

[0066] This inductive coupling behaviour stands in contrast to other well-known antenna architectures, such as the Marchand balun antenna, which rely on capacitive coupling mechanisms. In such designs, the antenna exhibits high impedance and behaves more like a capacitive element, where the electric field plays the primary role in coupling. By contrast, the inductive approach adopted in the disclosed embodiments promotes strong magnetic field interactions, enabling efficient energy transfer over short distances typical of near-field applications.

[0084]

[0067] An advantage of the disclosed antenna architecture, compared to conventional inductive coupling designs such as wound coils, lies in the physical layout of the at least one antenna 301. In the disclosed embodiments, any pair of parallel conductive sections is spaced farther apart than in typical coil structures. This increased spacing reduces parasitic capacitance between adjacent conductors, thereby decreasing sensitivity to variations in the effective permittivity of the surrounding environment, such as changes in the PCB substrate or nearby air gaps. As a result, the parasitic capacitances remain more stable, which allows for more accurate and predictable tuning of the antenna’s resonant frequency, especially when used in conjunction with the at least one capacitive element 309.

[0085]

[0068] FIG. 7 illustrates this behaviour, showing graphs 710 and 720 that represent the current in the at least one antenna 301 (in dBA) and the magnetic field strength at a point above the at least one antenna 301 (in dBA / m), respectively. A distinct resonance peak 750 is observed in both graphs (highlighted by an arrow), confirming the presence of a well-defined resonant frequency.

[0086]

[0069] Moreover, the at least one antenna designs described here employ a single-turn configuration, unlike traditional multi-turn coil antennas. Despite this simplicity, the circuit design promotes high current flow through the antenna, resulting in a strong magnetic field. This enhanced field strength allows the single-turn antenna to achieve inductive coupling performance comparable to that of multi-turn coils, while offering advantages in design simplicity, mechanical robustness, and reduced sensitivity to environmental and material variations. Notwithstanding the foregoing, it is to be appreciated that multi-turn antenna configurations may be implemented in any of the embodiments described, and would provide equivalent functionality. Similarly, in certain configurations, an integer number of single-turn antennas, each paired with at least one corresponding capacitive element, may be employed to achieve the same functional outcome, provided that symmetry is preserved across the electronic circuit. A multi -turn and / or multiple-antenna configuration may be selected to meet specific design requirements and may deliver comparable performance to single-turn implementations. However, such configurations may be somewhat less favourable from a manufacturing perspective due to increased complexity and a higher component count.

[0087]

[0070] The description of the example embodiments provided herein have been presented for purposes of illustration. The description is not intended to be exhaustive or to limit example embodiments to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of various alternatives or equivalents to the provided embodiments. The examples discussed herein were chosen and described in order to explain the principles and the nature of various example embodiments, and their practical application to enable one skilled in the art to utilize the example embodiments in various manners and with various modifications as are suited to the particular use contemplated. The features of the embodiments described herein may be combined in all possible combinations of methods, apparatus, modules, systems, and computer program products. It should be appreciated that the example embodiments presented herein may be practiced in any combination with each other.

[0088]

[0071] It should be noted that the word "comprising" does not necessarily exclude the presence of other elements or steps than those listed and the words "a" or "an" preceding an element do not exclude the presence of a plurality of such elements. It should further be noted that any reference signs do not limit the scope of the claims, that the example embodiments may be implemented at least in part by means of both hardware and software, and that several "means", "units" or "devices" may be represented by the same or functionally equivalent item of hardware.

[0089]

[0072] In the drawings and specifications, there have been disclosed example embodiments. However, many variations and modifications can be made to these embodiments. Accordingly, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the embodiments being defined by the following claims.

[0090]

[0073] Features in accordance with embodiments of the disclosure are also outlined in the following clauses:

[0091] 1. An antenna module for use with a battery cell in a battery pack, the antenna module enabling wireless communication between an electronic device coupled to the battery cell and a bus antenna, the antenna module comprising: a transmission line operatively coupled to the electronic device at one end and to at least one antenna at its other end, the at least one antenna enabling electro-magnetic coupling with the bus antenna, the at least one antenna being coupled to a termination resistor at its distal end; and at least one capacitor located between the electronic device and the termination resistor, the capacitor and at least one antenna having a resonant frequency matched to the operating frequency of a desired transmission signal.

[0092] 2. The antenna module of clause 1 , wherein the at least one capacitor is located between the at least one antenna and the termination resistor.

[0093] 3. The antenna module of clause 2, wherein the antenna module comprises two capacitors, and the at least one antenna is located between the two capacitors.

[0094] 4. The antenna module of clause 1 or 2, wherein the transmission line comprises a first and a second antenna, and the at least one capacitor is located between the first and the second antennas.

[0095] 5. The antenna module of any preceding clause, wherein the at least one antenna is elliptical in shape. 6. The antenna module of any preceding clause, wherein the at least one antenna is circular in shape.

[0096] 7. The antenna module of any one of clauses 1-4, wherein the at least one antenna is polygon-shaped.

[0097] 8. The antenna module of clause 7, wherein the at least one antenna comprises any one of: a hexagon shape, an octagon shape.

[0098] 9. An assembly comprising the antenna module of any preceding clause, and a bus antenna.

[0099] 10. A printed circuit board comprising the antenna module of any one of clauses 1 to 8.

[0100] 11. An assembly for use with a battery pack comprising a plurality of battery cells, the assembly suitable for enabling communication between an electronic device and a radio transceiver located remotely from the electronic device, the assembly comprising: a module antenna operatively connected to the electronic device, the module antenna comprising a transmission line having a plurality of sections arranged in series forming an unbalanced electrical path; a bus antenna configured for operative communication with the radio transceiver, the bus antenna comprising at least two transmission lines, each transmission line being greater in length than any of the plurality of sections of the module antenna, and each one of the transmission lines being spaced apart from and positioned adjacent to a different one of a first section and a second section of the plurality of sections of the module antenna’s transmission line, to enable near-field coupling between the module antenna and the bus antenna when a transmission signal is input into either the module antenna or the bus antenna.

[0101] 12. The assembly of clause 11, wherein in operation the module antenna and the bus antenna form a balun, and wherein when the transmission signal comprises an unbalanced electrical signal input in the module antenna, it is output as a balanced electrical signal in the bus antenna; or, when the transmission signal comprises a balanced electrical signal input in the bus antenna, it is output as an unbalanced electrical signal in the module antenna. The assembly of clause 11 or 12, wherein the transmission line of the module antenna is polygon-shaped, each of the plurality of sections corresponding to one of the sides of the polygon. The assembly of clause 13, wherein the polygon comprises an even number of sides, and the first and second sections correspond to opposite sides of the polygon. The assembly of clause 12 or 13, wherein the polygon is at least one of a hexagon or an octagon. The assembly of clause 11 or 12, wherein the plurality of sections of the transmission line of the module antenna includes a first set of sections and a second set of sections connected in series through a capacitor. The assembly of clause 16, wherein the first and second set of sections include an identical number of sections. The assembly of any one of clauses 11 to 17, wherein each one of the bus antenna transmission lines is located equidistant relative to a different section of the module antenna. The assembly of clause 18, wherein the at least two transmission lines of the bus antenna are configured as a balanced circuit, such that an electrical signal propagating in a first one of the two transmission lines is it radians out of phase with respect to an electrical signal propagating in a second one of the transmission lines. The assembly of any one of clauses 11 to 19, wherein the transmission line of the module antenna is connected at one end to a termination resistor. The assembly of any one of clauses 11 to 20, wherein the transmission line of the module antenna forms a closed circuit. The assembly of any one of clauses 11 to 21, wherein the transmission line of the module antenna, is rotationally symmetrical about a common axis perpendicular to a plane of the transmission line of the module antenna and a plane of the bus antenna.

Claims

Claims1. A module antenna for use with a battery cell in a battery pack, the module antenna enabling wireless communication between an electronic device coupled to the battery cell and a bus antenna, the module antenna comprising: a transmission line operatively coupled to the electronic device at one end and to at least one antenna at its other end, the at least one antenna enabling electro-magnetic coupling with the bus antenna, the at least one antenna having a plurality of sections arranged in series forming an unbalanced electrical path and being coupled to a termination resistor at its distal end; and at least one capacitive element located between the transmission line and the termination resistor, the capacitive element and the at least one antenna having a resonant frequency matched to an operating frequency of a desired transmission signal.

2. The module antenna of claim 1, wherein the at least one capacitive element is located between the at least one antenna and the termination resistor, or between the transmission line and the at least one antenna.

3. The module antenna of claim 1 wherein the module antenna comprises two capacitive elements, and the at least one antenna is located between the two capacitive elements.

4. The module antenna of claim 3, wherein the two capacitive elements are connected in series with the at least one antenna.

5. The module antenna of claim 3, wherein the two capacitive elements are connected at one of their ends to either side of the at least one antenna, and each capacitive element is connected at its other end to ground, forming a shunt configuration.

6. The module antenna of claim 1, wherein the plurality of sections of the at least one antenna include a first set of sections and a second set of sections connected in series via the at least one capacitive element.

7. The module antenna of claim 6, wherein the first and second sets of sections comprise a same number of sections.

8. The module antenna of any preceding claim, wherein the at least one antenna is rotationally symmetrical about an axis perpendicular to a plane of the at least one antenna.

9. The module antenna of any preceding claim, wherein the at least one antenna is elliptical in shape.

10. The module antenna of any one of claims 1 to 8, wherein the at least one antenna is circular in shape.

11. The module antenna of any one of claims 1 to 8, wherein the at least one antenna is polygon-shaped.

12. The module antenna of claim 11, wherein each of the plurality of sections corresponds to a side of the polygon-shaped antenna.

13. The module antenna of claim 11 or 12, wherein the at least one antenna comprises any one of: a hexagon shape, an octagon shape.

14. The module antenna of any one of claims 11 to 13, wherein each of the plurality of sections is of substantially equal electrical length.

15. The module antenna of any one of claims 11 to 13, wherein at least two of the plurality of sections are of longer electrical length than the other sections of the plurality of sections.

16. The module antenna of any preceding claim, wherein the at least one antenna, the termination resistor, the at least one capacitive element, and the transmission line form a closed circuit.

17. The module antenna of any preceding claim, wherein a total electrical path length of the plurality of sections of the at least one antenna is half an operating wavelength of the desired transmission signal.

18. An assembly comprising the module antenna of any one of claims 1 to 17, and a bus antenna.

19. A printed circuit board comprising the module antenna of any one of claims 1 to 17.

20. A battery cell comprising the module antenna of any one of claims 1 to 17.

21. An assembly for use with a battery module comprising one or more battery cells, the assembly suitable for enabling communication between an electronic device and a radio transceiver located remotely from the electronic device, the assembly comprising: a module antenna comprising: at least one antenna having a plurality of sections arranged in series forming an unbalanced electrical path and being coupled to a termination resistor at its distal end; a transmission line operatively coupled to the electronic device at one end and to the at least one antenna at its other end; and at least one capacitive element located between the transmission line and the termination resistor, the capacitive element and the at least one antenna having a resonant frequency matched to an operating frequency of a desired transmission signal; and a bus antenna configured for operative communication with the radio transceiver, the bus antenna comprising at least two transmission lines, each transmission line being greater in length than any of the plurality of sections of the at least one antenna, and each one of the transmission lines being spaced apart from and positioned adjacent to a different one of at least one first section and at least one second section of the plurality of sections of the at least one antenna, to enable near-field coupling between the module antenna and the bus antenna when the desired transmission signal is input into either the module antenna or the bus antenna.

22. The assembly of claim 21 , wherein in operation the module antenna and the bus antenna form a balun, and wherein when the desired transmission signal comprises anunbalanced electrical signal input in the module antenna, it is output as a balanced electrical signal in the bus antenna; or, when the desired transmission signal comprises a balanced electrical signal input in the bus antenna, it is output as an unbalanced electrical signal in the module antenna.

23. The assembly of claim 21 or 22, wherein the at least one antenna is polygon-shaped.

24. The assembly of claim 23, wherein the at least one antenna comprises an even number of sides, and the at least one first section and the at least one second section correspond to opposite sides of the polygon-shaped antenna.

25. The assembly of claim 23 or 24, wherein the polygon-shape is at least one of a hexagon or an octagon.

26. The assembly of any one of claims 23 to 25, wherein the at least one first section and the at least one second section are of longer electrical path length than other sections of the plurality of sections.

27. The assembly of any one of claims 21 to 25, wherein the plurality of sections of the at least one antenna includes a first set of sections and a second set of sections connected in series through the at least one capacitive element.

28. The assembly of claim 27, wherein the first and second sets of sections include an identical number of sections.

29. The assembly of any one of claims 21 to 28, wherein each one of the bus antenna transmission lines is located equidistant relative to a different section of the at least one antenna.

30. The assembly of any one of claims 21 to 29, wherein the at least two transmission lines of the bus antenna are configured as a balanced circuit, such that an electrical signal propagating in a first one of the two transmission lines is it radians out of phase with respect to an electrical signal propagating in a second one of the transmission lines.

31. The assembly of any one of claims 21 to 30, wherein the at least one antenna is rotationally symmetrical about an axis perpendicular to a plane of the at least one antenna and a plane of the bus antenna.

32. The assembly of any one of claims 21 to 31, wherein each transmission line of the bus antenna is connected at one end to a termination resistor.

33. The assembly of any one of claims 21 to 32, wherein a distance of separation between each one of the bus antenna transmission lines and its adjacent section of the at least one antenna is selected to achieve a coupling strength greater than or equal to -50dB, and less than or equal to -lOdB.

34. The assembly of claim 32, wherein a distance of separation between each one of the bus antenna transmission lines and its adjacent section of the at least one antenna is selected to achieve a coupling strength greater than or equal to -40dB, and less than or equal to -20dB.

35. The assembly of claim 33 or 34, wherein the distance of separation between each one of the bus antenna transmission lines and its adjacent section of the at least one antenna is selected to achieve a coupling strength of -30dB.

36. The assembly of any one of claims 21 to 35, wherein each one of the bus antenna transmission lines and its adjacent section of the at least one antenna is separated by a dielectric insulating material.

37. The assembly of claim 36, wherein the dielectric material has a dielectric breakdown voltage greater than a working voltage of the battery pack.

38. The assembly of claim 36 or 37, wherein the dielectric insulating material comprises any one of: air, a plastic material, a glass-filled plastic material, an epoxy composite material.

39. The assembly of any one of claims 21 to 38, comprising a printed circuit board “PCB” comprising the electronic device, and wherein the PCB comprises the module antenna.

40. The assembly of claim 39, wherein the bus antenna comprises a cable located external to the PCB.

41. The assembly of claim 40, wherein the cable is any one of: a twin core cable, a multicore cable, a ribbon cable.

42. A batery pack having one or more batery modules, each module comprising one or more batery cells, the batery pack comprising the assembly of any one of claims 21 to 41, wherein each battery module is associated with an electronic device and the assembly enables communication between each electronic device and a radio transceiver located remotely from the batery pack via the bus antenna and the module antenna of the battery module.

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