Flexible conformal radio frequency radiation device, head-mounted brain-computer interface terminal, and assembly method

Abstract

This invention provides a flexible conformal radio frequency (RF) radiation device, a head-mounted brain-computer interface (BCI) terminal, and an assembly method, relating to the field of BCI terminal technology. The flexible conformal RF radiation device includes: a flexible dielectric substrate; a radiator comprising multiple conductive patches attached to one side surface of the flexible dielectric substrate, with each adjacent pair of conductive patches connected by a microstrip line; a feed line connected to one end of the radiator for connection to a wireless communication module; and a near-human isolation structure disposed on the side surface of the flexible dielectric substrate opposite to the radiator. The flexible dielectric substrate can be bent into a closed-loop structure with its ends connected. This invention provides an RF radiation device more suitable for the commercial integration of head-mounted BCI terminals, maintaining relatively stable matching characteristics under different head circumferences and assembly conditions, and achieving a manufacturable, assemblable, and reliable conformal arrangement within a limited space, while simultaneously considering coverage of commonly used wireless frequency bands and near-human safety requirements.

Description

Technical Field

[0001] This invention relates to the field of brain-computer interface terminal technology, and in particular to a flexible conformal radio frequency radiation device, a head-mounted brain-computer interface terminal, and an assembly method. Background Technology

[0002] Existing non-invasive brain-computer interface (BCI) terminals mostly use helmets or head-mounted devices as carriers, such as smart helmets, smart hats, or head-mounted braces, to collect neural signals such as electroencephalograms (EEGs) and achieve information interaction by being close to the scalp.

[0003] In emergency rescue, earthquake collapse, and other mission scenarios, head-mounted brain-computer interface (BCI) terminals can serve as the sensing and interaction unit of rescue helmet terminals. They are used to collect electroencephalogram (EEG) or physiological information and wirelessly interconnect with command centers, gateways, or relay nodes to support rescue coordination, risk warning, and mission command interaction. To stably transmit the collected signals to external devices and obtain control and feedback, the terminal typically integrates a wireless communication link. The radiator structure, as a key component in the wireless communication system that enables the conversion between electrical signals and electromagnetic waves, directly affects the terminal's communication quality, anti-interference capabilities, and the reliability of interconnection with external devices.

[0004] In the aforementioned mission scenarios, the typical engineering characteristics of terminal communication include the wearer being in a mobile, obstructed, and multi-path environment, with multiple terminals operating concurrently and electromagnetic interference present on-site. The terminal must simultaneously support close-range pairing and control (such as rapid connection establishment with personal devices / gateways and status feedback) as well as stable feedback with relays or command centers (for collaborative instructions, risk warnings, and redundancy of critical services). Therefore, the radiator structure (RF radiating device) of the helmet terminal not only needs to achieve conformal installation and wearing comfort within a limited space, but also needs to maintain stable matching under near-human conditions and possess multi-band / dual-link support capabilities for mission-oriented applications.

[0005] Besides emergency rescue, head-mounted brain-computer interface terminals can also be applied to industrial inspection, underground safety production, fire fighting, search and rescue, and other scenarios. These scenarios share the common characteristic of requiring terminals to achieve rapid pairing, status feedback, and low-power continuous monitoring under short-range or near-range interconnection links. Simultaneously, they need a second extended or redundant feedback link to ensure the reliability of critical operations under conditions of obstruction, multipath propagation, and strong interference. Therefore, radio frequency radiating devices for helmet-mounted devices not only focus on the radiating structure itself but also require systematic design from dimensions such as assembly consistency, human coupling suppression, dual-link coordination, and maintenance reliability. The radiator system is primarily responsible for wireless communication functions, transmitting collected EEG signals to external processing units and receiving instructions from the cloud.

[0006] Existing radio frequency (RF) radiating devices typically employ traditional microstrip antenna radiating structures or simple wearable antenna structures. While these devices are simple in structure and easy to integrate, they suffer from the following problems: (1) Since traditional antenna radiators mostly use rigid materials or low-flexibility composite material substrates and conventional geometric patch structures, the traditional rigid microstrip patch antenna is directly installed inside the helmet of the brain-computer terminal device. The antenna cannot be bent to fit the curved surface of the helmet-like equipment to achieve a good conformal effect, resulting in obvious gaps between the antenna and the curved surface of the helmet. This "partial attachment" method not only affects the wearing comfort, but also causes communication performance fluctuations caused by inconsistent installation status, resulting in defects such as impedance mismatch, unstable performance and poor wearing comfort. (2) Conventional single patch or ordinary closed-loop structure often requires a trade-off between miniaturization, bandwidth and multi-band coverage, making it difficult to meet the space and performance requirements of head-mounted terminals. In helmet-mounted terminals, the helmet shell contains padding, straps, structural ribs, and wiring channels, leaving only locally distributed space for electronic modules and antennas. Furthermore, the helmet shell is a three-dimensional curved surface and needs to cover different head circumferences. Measurements of this terminal equipment show that its length and width are approximately 200mm, while the average adult head circumference is approximately 520mm-580mm. This significantly limits the antenna's size, installation location, and bending radius. Based on these constraints, existing technologies commonly use printed antennas on flexible substrates to conformally mount them to the edges or curved areas of the helmet shell.

[0007] Although existing technologies have proposed integrating printed antennas into head-mounted brain-computer interface terminals in a flexible and conformal manner, several objective drawbacks still exist in productization scenarios: First, the antenna will bend and deform when installed on the curved surface or edge area of ​​the helmet. Differences in bending radius, fitting position and fixing method will change the equivalent electrical length and input impedance of the antenna, making the resonant frequency and impedance matching highly sensitive to the assembly state, which can easily lead to frequency drift, deterioration of return loss and narrowing of bandwidth. When the same terminal is adapted to different head circumferences or different wearing tightness, this performance fluctuation is more obvious. Secondly, the shell material, internal padding, and human tissue of the head-mounted terminal will cause dielectric loading and near-field coupling to the antenna, further aggravating the problems of matching instability and radiation efficiency reduction, thereby affecting the stability and communication distance of Bluetooth, WiFi and other links. At the same time, as head-mounted terminals develop towards multi-service convergence, near-field interconnection protocols have gradually evolved from traditional Bluetooth and WLAN to low-power broadcast, Mesh or direct connection and other multi-form working modes, which put forward higher requirements for matching stability and multi-band, dual-link reliability under near-human conditions. Third, the limited internal space of helmets, coupled with numerous structural ribs and wiring channels, often forces antennas to be routed around narrow areas at the edges. This can lead to conflicts between feeder routing and module compartment locations, resulting in poor assembly consistency and inconvenient maintenance and replacement. For long strip antennas arranged along the head circumference, there are also reliability risks related to their length, stress on connectors and feed points, and fatigue from bending during long-term wear. Furthermore, head-mounted devices are near-human wearable devices, and current technologies often require trade-offs between size and radiation when achieving multi-band coverage, with insufficient consideration given to near-human radiation safety and structural measures to suppress coupling to the human body.

[0008] Therefore, there is an urgent need for a radio frequency radiation device that is more suitable for the commercial integration of head-mounted brain-computer interface terminal products. This device should maintain relatively stable matching characteristics under different head sizes and assembly conditions, and achieve a manufacturable, assemblable, and reliable conformal arrangement within a limited space, while also taking into account coverage of commonly used wireless frequency bands and near-human safety requirements. Summary of the Invention

[0009] The purpose of this invention is to provide a flexible conformal radio frequency radiation device, a head-mounted brain-computer interface terminal, and an assembly method to alleviate the aforementioned technical problems existing in the prior art.

[0010] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions: In a first aspect, embodiments of the present invention provide a flexible conformal radio frequency radiation device, wherein the flexible conformal radio frequency radiation device is applied to a head-mounted brain-computer interface terminal, comprising: Flexible dielectric substrate, unfolded into a long strip-shaped sheet structure; The radiator includes a plurality of conductive patches attached to one side surface of the flexible dielectric substrate. Along the length of the flexible dielectric substrate, the plurality of conductive patches are arranged at intervals, and each pair of adjacent conductive patches is connected by a microstrip line so that all the conductive patches are connected in series to form a continuous current path. A feeder line, connected to one end of the radiator, is used to connect to the wireless communication module; A near-human body isolation structure is provided on the surface of the flexible dielectric substrate away from the radiator. The flexible dielectric substrate can be bent into a closed-loop structure with the ends connected. The radiator is located on the outer ring surface of the closed-loop structure, and the near-human body isolation structure is located on the inner ring surface of the closed-loop structure.

[0011] In an optional embodiment, the conductive patch includes a substrate and a local disturbance structure disposed on the substrate. The local disturbance structure includes at least one of a notch, a groove, and an extension branch, extending along the length direction of the flexible dielectric substrate in its unfolded state: the spacing between each pair of adjacent substrates is the same.

[0012] In an optional embodiment, the flexible dielectric substrate is made of a polyimide material with a relative permittivity εr=4.3 and a dielectric loss tangent tanδ=0.03.

[0013] In an optional embodiment, the feed line is a 50Ω microstrip line; and / or, along the length extension direction of the flexible dielectric substrate in its unfolded state: the overall length of the radiator is 520mm, the width is 44mm, and the thickness is 2.6mm.

[0014] Secondly, embodiments of the present invention provide a head-mounted brain-computer interface terminal, including a helmet and a flexible conformal radio frequency radiation device as described in any of the foregoing embodiments, wherein the inner sidewall of the helmet shell is provided with a circumferential mounting surface for mounting the flexible conformal radio frequency radiation device, and the flexible dielectric substrate is bent into the closed-loop structure and conformally attached to the circumferential mounting surface along the helmet.

[0015] In an optional embodiment, a positioning and fixing assembly for fixing the flexible dielectric substrate is provided on the inner sidewall of the helmet shell.

[0016] In an optional embodiment, the positioning and fixing component includes a positioning pressure strip and at least two limiting buckles; The positioning strip is fixed to the inner side wall of the helmet shell and extends along the circumference of the helmet. A slot is provided between the positioning strip and the circumferential mounting surface. At least part of the flexible dielectric substrate is inserted into the slot. The positioning strip presses the flexible dielectric substrate toward the circumferential mounting surface. The limiting buckle is fixed to the inner wall of the helmet shell and is used to clamp the end of the flexible dielectric substrate to constrain the closed-loop circumference of the closed-loop structure formed by the flexible dielectric substrate.

[0017] Thirdly, embodiments of the present invention provide an assembly method for mounting a flexible conformal radio frequency radiation device onto a helmet of a head-mounted brain-computer interface terminal, used to manufacture the head-mounted brain-computer interface terminal as described in any of the foregoing embodiments. When the flexible dielectric substrate is bent into a closed-loop structure conforming to the circumferential mounting surface, the shape of the flexible dielectric substrate is a conformal closed-loop shape. The assembly method includes the following steps: To determine the closed-loop circumferential length C and equivalent bending radius Req when the flexible dielectric substrate is in a conformal closed-loop configuration: Define a circumferential reference line along the circumferential mounting surface, measure the path length Lpath along the circumferential reference line as the closed-loop circumferential length C, determine the preset target range of the closed-loop circumferential length C as [Cmin; Cmax], and further determine the preset target range of the equivalent bending radius Req as [Rmin; Rmax], where Req = Lpath / (2π); Attach the flexible dielectric substrate to the circumferential mounting surface in a conformal closed-loop form along a preset mounting path, and limit the circumferential length C of the closed-loop form of the conformal closed-loop within [Cmin; Cmax], and limit the equivalent bending radius Req within [Rmin; Rmax].

[0018] In an optional embodiment, the assembly method further includes an acceptance step: Within the set target operating frequency band, the return loss of the flexible conformal radio frequency radiation device is S11. After the flexible dielectric substrate is mounted on the circumferential mounting surface in the conformal closed-loop form, within the target operating frequency band, measure the return loss S11 of the flexible conformal radio frequency radiation device. When S11 ≤ 10 dB, it is determined that the assembly is qualified. When S11 > 10 dB, it is determined that the assembly is unqualified. If unqualified, disassemble and reinstall the flexible dielectric substrate.

[0019] In an optional embodiment, the step of attaching the flexible dielectric substrate to the circumferential mounting surface in a conformal manner along a preset mounting path includes: First, bend the flexible dielectric substrate with the aid of a cylinder so that the flexible dielectric substrate assumes the conformal closed-loop form, and limit the circumferential length C of the closed-loop form of the conformal closed-loop within [Cmin; Cmax], and limit the equivalent bending radius Req within [Rmin; Rmax]; Then attach the flexible dielectric substrate to the circumferential mounting surface.

[0020] Specifically, in the embodiments of the present invention, "and / or" means that among the first feature before "and / or" and the second feature after "and / or", the following specific setting modes are included: (1) only set the first feature and not set the second feature; (2) only set the second feature and not set the first feature; (3) set the first feature and the second feature simultaneously.

[0021] The embodiments of the present invention can at least achieve the following beneficial effects: In typical emergency rescue operation tasks, the head-mounted brain-computer interface terminal needs to simultaneously meet the requirements of short-distance pairing and data backhaul with portable terminal devices, extended backhaul with relay or command terminals, and safe and stable operation under the condition of being worn close to the human body; This embodiment employs a topological co-design of the flexible dielectric substrate, radiator, feed line, and near-human isolation structure. By utilizing the deformable structural properties of the flexible dielectric substrate, the entire radio frequency radiating device conforms to the circumferential mounting surface of the helmet's inner sidewall. This makes the assembly state of the radio frequency radiating device onto the helmet shell controllable. Compared to the prior art, which simply attaches ordinary printed antennas to the edge or curved surface of the helmet shell, the flexible conformal radio frequency radiating device provided in this embodiment exhibits higher assembly consistency when mounted on a helmet. It can still achieve repeatable electrical performance even with assembly differences for helmets designed for different head circumferences, thus improving the matching stability of the radio frequency radiating device under near-human environmental conditions. Meanwhile, by forming a gap or electromagnetic isolation through a near-human body isolation structure, the near-field coupling between the radiator and human tissue can be reduced, the matching stability and radiation efficiency under near-human body conditions can be improved, and the electromagnetic exposure risk under wearable conditions can be reduced, providing a structural basis for the safety assessment of wearables under near-human body conditions.

[0022] For a more detailed and comprehensive description of the effects achievable in this embodiment, please refer to the detailed implementation section of this application specification. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the overall structure of the flexible conformal radio frequency radiation device provided in the embodiment of the present invention in the state of the flexible dielectric substrate unfolded in a planar manner. Figure 2 This is a schematic diagram of the overall structure of the flexible conformal radio frequency radiation device provided in an embodiment of the present invention, in which the flexible dielectric substrate is in a closed ring state. Figure 3 A schematic diagram of the overall structure of the head-mounted brain-computer interface terminal provided in an embodiment of the present invention. Figure 1 ; Figure 4 A schematic diagram of the overall structure of the head-mounted brain-computer interface terminal provided in an embodiment of the present invention. Figure 2 ; Figure 5 The return loss curve of the flexible conformal radio frequency radiation device provided in the embodiment of the present invention in the planar unfolded state of the flexible dielectric substrate (before conforming with the helmet) is shown. Figure 6The return loss curve of the flexible conformal radio frequency radiation device provided in the embodiment of the present invention after conforming with a helmet; Figure 7 The schematic diagram shows the surface current distribution of the radiator at resonant frequencies of 6.67 GHz, 9.04 GHz, and 10.86 GHz in the case of a flexible conformal radio frequency radiating device provided in an embodiment of the present invention, with the flexible dielectric substrate in a planar unfolded state. Figure 8 The schematic diagram shows the surface current distribution of the radiator at resonant frequencies of 2.5 GHz and 4.6 GHz in a flexible conformal radio frequency radiating device provided in the embodiments of the present invention, with the flexible dielectric substrate in a closed ring state. Figure 9 The flexible conformal radio frequency radiation device provided in this embodiment of the invention has a two-dimensional radiation pattern in the two orthogonal tangential planes E / H at a resonant frequency of 2.5 GHz when the flexible dielectric substrate is in a closed ring state. Figure 10 The flexible conformal radio frequency radiation device provided in this embodiment of the invention has a two-dimensional radiation pattern in the two orthogonal tangential planes E / H at a resonant frequency of 4.6 GHz when the flexible dielectric substrate is in a closed ring state. Figure 11 A comparison diagram of the three-dimensional gain direction of the flexible conformal radio frequency radiation device provided in the embodiment of the present invention before and after conforming with the helmet; Figure 12 This is a schematic diagram of a filling method for a flexible conformal radio frequency radiation device provided in an embodiment of the present invention when applied to a flexible circuit board.

[0025] Icons: 100 - Flexible conformal radio frequency radiation device; 1 - Flexible dielectric substrate; 2 - Radiator; 3 - Feed line; 4 - Near-human body isolation structure; 200- Helmet. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0028] It should be noted that similar labels and letters in the accompanying drawings indicate similar items. Therefore, once an item is defined in one accompanying drawing, it does not need to be further defined and explained in subsequent accompanying drawings.

[0029] In the description of this invention, it should be noted that: Unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] The terms “upper,” “lower,” “vertical,” “horizontal,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use. They are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the invention.

[0031] The terms “first,” “second,” “third,” etc., are used only for distinguishing descriptions and do not indicate totality or relative position in time and / or space, nor should they be construed as indicating or implying relative importance.

[0032] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the features of the following embodiments and optional embodiments can be combined with each other.

[0033] First aspect This embodiment provides a flexible conformal radio frequency radiation device, referring to... Figure 1 and Figure 2 The flexible conformal radio frequency radiation device 100 is applied to a head-mounted brain-computer interface terminal, including a flexible dielectric substrate 1, a radiator 2, a feed line 3, and a near-human body isolation structure 4.

[0034] Specifically: such as Figure 1As shown, the flexible dielectric substrate 1 unfolds into a long strip-shaped sheet structure; the radiator 2 includes multiple conductive patches attached to one side surface of the flexible dielectric substrate 1, along the length direction of the flexible dielectric substrate 1: the multiple conductive patches are arranged at intervals, and each adjacent pair of conductive patches is connected by a microstrip line to connect all the conductive patches in series to form a continuous current path; the feed line 3 is connected to one end of the radiator 2 for connection with a wireless communication module; the near-human body isolation structure 4 is disposed on the side surface of the flexible dielectric substrate 1 opposite to the radiator 2. Figure 2 As shown, the flexible dielectric substrate 1 can be bent into a closed loop structure with the ends connected. The radiator 2 is located on the outer ring surface of the closed loop structure, and the near-human body isolation structure 4 is located on the inner ring surface of the closed loop structure.

[0035] The flexible conformal radio frequency radiation device 100 provided in this embodiment can be applied in a head-mounted brain-computer interface terminal. Specifically, the head-mounted brain-computer interface terminal includes a helmet 200. The inner sidewall of the helmet 200 shell is provided with a circumferential mounting surface. The assembly method is as follows: the flexible dielectric substrate 1 is bent into a closed-loop structure and conformally attached to the circumferential mounting surface of the helmet 200.

[0036] This embodiment can achieve at least the following beneficial effects: In typical emergency rescue operations, head-mounted brain-computer interface terminals must simultaneously meet the requirements of close-range pairing and data transmission with wearable terminal devices, extended transmission with relay or command terminals, and safe and stable operation under near-human wearing conditions. In this embodiment, the flexible dielectric substrate 1, radiator 2, feed line 3, and near-human body isolation structure 4 are topologically co-designed. By utilizing the deformable structural properties of the flexible dielectric substrate 1, the entire radio frequency radiation device is conformally aligned with the circumferential mounting surface of the inner sidewall of the helmet 200. As a result, the assembly state of the radio frequency radiation device on the helmet 200 shell becomes controllable. Compared with the prior art, which simply attaches ordinary printed antennas to the edge or curved surface of the helmet 200 shell, the flexible conformal radio frequency radiation device 100 provided in this embodiment has higher assembly consistency when mounted on the helmet 200. It can still achieve repeatable electrical performance under the assembly differences of helmets 200 designed for different head circumferences, and improve the matching stability of the radio frequency radiation device under near-human body environment conditions. Meanwhile, by forming a gap or electromagnetic isolation through the near-human body isolation structure 4, the near-field coupling between the radiator 2 and human tissue is reduced, the matching stability and radiation efficiency under near-human body conditions are improved, and the electromagnetic exposure risk under wearable conditions is reduced, providing a structural basis for the safety assessment of wearables under near-human body conditions.

[0037] It should be noted that in this embodiment, the near-human body isolation structure 4 is disposed on the side of the flexible dielectric substrate 1 facing away from the radiator 2, and the flexible dielectric substrate 1 maintains a distance from the radiator 2. The near-human body isolation structure 4 can be a conductive isolation layer formed by metal foil, conductive cloth, or printed grounding layer, etc., and is electrically connected to the terminal reference ground by conductive adhesive or pressing, or used as a floating ground isolation layer when connection is inconvenient. Optionally, the conductive isolation layer can be in the form of a continuous surface structure to reduce human body coupling while taking into account flexibility and reducing assembly difficulty. Optionally, the above-mentioned near-human body isolation structure 4 can be integrated with the inner lining, buffer pad, strap structure, or inner wall interlayer of the helmet 200, thereby achieving a stable isolation effect without significantly increasing the installation complexity.

[0038] In an optional embodiment of this example, for the radiator 2 disposed on the flexible dielectric substrate 1, each conductive patch includes a substrate and a local perturbation structure disposed on the substrate. The local perturbation structure includes at least one of a notch, a groove, and an extension branch. Along the length extension direction in the unfolded state of the flexible dielectric substrate 1, the spacing between each pair of adjacent substrates is the same. That is, each conductive patch uses the substrate as the basic unit to superimpose the local perturbation structure, the spacing between adjacent substrates is the same, and each pair of adjacent substrates is connected in series via microstrip lines to form a linear array. The basic topological shape of the substrate can be selected, but is not limited to, a rectangle, a circle, or other shapes. Preferably, such as... Figure 1 and Figure 2 As shown, the basic topology of the substrate is rectangular. Local perturbation structures such as notches, slots, and extended branches are set on the rectangular substrate. Preferably, the basic topology (outer contour after removing the local perturbation structures) of every two adjacent substrates has the same shape and size. The local perturbation structures are used to guide the current distribution on the substrate surface, enhance the radiation efficiency in a specific direction, and also serve as part of the matching network to improve input impedance matching and reduce reflection loss.

[0039] In an optional embodiment of this example, the flexible dielectric substrate 1 is made of polyimide material with a relative permittivity εr=4.3 and a dielectric loss tangent tanδ=0.03; the feed line 3 is a 50Ω microstrip line; along the length extension direction of the flexible dielectric substrate 1 in its unfolded state: the overall length of the radiator 2 is 520mm, the width is 44mm, and the thickness is 2.6mm.

[0040] The following describes in more detail the beneficial effects that the flexible conformal radio frequency radiation device 100 provided in this embodiment can achieve, with reference to experimental examples: Experimental example: The flexible conformal radio frequency radiating device 100 uses a flexible dielectric substrate 1 made of polyimide material with a relative permittivity εr=4.3 and a dielectric loss tangent tanδ=0.03; the feed line 3 uses a 50Ω microstrip line; along the length extension direction of the flexible dielectric substrate 1 in its unfolded state: the overall length of the radiator 2 is 520mm, the width is 44mm, and the thickness is 2.6mm; the basic topology of the substrate of all conductive patches of the radiator 2 is rectangular, and along the length extension direction of the flexible dielectric substrate 1 in its unfolded state: the spacing between each two adjacent substrates is the same, and the dimensions of the basic topology (outer contour after removing local disturbance structures) of each two adjacent substrates are the same.

[0041] Before the flexible conformal radio frequency radiation device 100 conforms to the helmet 200, the planar unfolded shape of the flexible dielectric substrate 1 is as follows: Figure 1 The structure shown is a long, strip-shaped sheet; as Figures 2 to 4 As shown, the flexible dielectric substrate 1 is bent into a closed-loop structure and conformally attached to the circumferential mounting surface of the inner wall of the helmet 200 along the circumference. After conforming with the helmet 200, the flexible conformal radio frequency radiation device 100 forms a conformal closed-loop shape with the flexible dielectric substrate 1, forming a circumferential closed current loop. This allows the flexible conformal radio frequency radiation device 100 to simultaneously possess circumferential circulating current, closed-loop mode, and conductive patch local mode. The circumferential circulating current and closed-loop mode cause the current to propagate continuously along the circumference and form an approximate ring standing wave. The conductive patch local mode causes the current to mainly form local resonance near a single or a few conductive patches and their local perturbation structures. The dominant current paths of the two types of modes are different, thus forming two stable resonance points near 2.5GHz and 4.6GHz respectively, which can be tuned by loading the equivalent capacitance and inductance of the local perturbation structure.

[0042] The closed loop transforms the boundary at the radiator 2 from an open-circuit end to a continuous periodic boundary, and the equivalent electrical length changes from a strip length to a circumferential equivalent perimeter. When the circumferential equivalent perimeter satisfies the approximate ring resonance condition, a circulating mode dominated by circumferential current will appear, which is naturally beneficial for circumferential angular domain coverage.

[0043] The series-connected conductive patches are coupled via microstrip lines, effectively forming multiple local resonant units. At higher frequencies, current is more likely to concentrate in impedance abrupt changes or loading regions such as the conductive patches near feed line 3 and local perturbation structures, forming local modes dominated by local units. The local perturbation structure can be equivalent to an additional capacitor or inductor loading and impedance transformation network, which can not only change the direction of local current flow, but also pull out a second resonant point at higher frequencies and improve input matching.

[0044] To verify whether the above design meets the requirements of the mission scenario, this experimental example evaluates the design from the aspects of matching stability, frequency drift sensitivity caused by assembly consistency, circumferential coverage capability, and radiation pattern stability. Correspondingly, the return loss (S11) curves, key frequency current distribution, and two-dimensional radiation / three-dimensional gain pattern results of the flexible conformal RF device before and after conformal configuration are presented to demonstrate that the flexible conformal RF radiating device 100 provided in this experimental example has usable port matching and radiation output capabilities in the target frequency band when in conformal closed-loop state, and can support dual-link mission-oriented communication.

[0045] Specifically, in this experimental example, the assembly state of the flexible conformal radio frequency radiation device 100 conformally mounted on the circumferential mounting surface of the helmet 200 is taken as the main working state of the flexible conformal radio frequency radiation device 100: like Figure 5 and Figure 6 As shown, the return loss (S11) curve of the flexible conformal radio frequency radiation device 100 changes significantly before and after conformal bending, indicating that conformal bending has a strong influence on the equivalent electrical length and impedance matching.

[0046] Before conformal conformal operation, the planar unfolded state of the flexible conformal RF radiator 100 is a test state for electrical performance consistency detection, and its return loss curve is as follows: Figure 5 As shown. Before conformal design, radiator 2 mainly operates in three frequency bands: 5.87GHz–6.92GHz, 8.81GHz–9.17GHz, and 10.62GHz–11.50GHz, with center frequencies of 6.67GHz, 9.04GHz, and 10.86GHz, and -10dB bandwidths of 15.7%, 3.6%, and 8.1%, respectively. Specifically, the reflection loss at the center resonant frequency of 6.67GHz is -21.35dB, at the center resonant frequency of 9.04GHz it is -12.75dB, and at the center resonant frequency of 10.86GHz it is -35.99dB.

[0047] like Figure 6 As shown, after conformal fitting of radiator 2, radiator 2 mainly operates in two frequency bands: 2.38 GHz–2.57 GHz and 4.55 GHz–4.66 GHz, with two center frequencies of 2.5 GHz and 4.6 GHz, respectively. The -10 dB bandwidths are 7.6% and 2.3%, respectively. Specifically, the reflection loss at the center resonant frequency of 2.5 GHz is -13.27 dB, and the reflection loss at the center resonant frequency of 4.6 GHz is -10.67 dB.

[0048] The 2.4GHz band is preferentially used for establishing short-range links and data backhaul between head-mounted brain-computer interface terminals and mobile phones, tablets, and portable gateways, supporting, but not limited to, Bluetooth, BLE near-range pairing, and low-power data transmission. Direct and relay connections (including 802.11b / g / n / ax / be, i.e., the 2.4GHz mode of Wi-Fi 4 / 6 / 7) of 2.4GHz Wi-Fi are used for high-throughput data backhaul or firmware upgrades. Other 2.4GHz ISM near-range access methods (such as 802.15.4 category short-range interconnection) are also supported. These short-range links can meet the interactive needs of real-time uploading of EEG or physiological data, command issuance, and status feedback.

[0049] Meanwhile, the second operating frequency near 4.6 GHz is preferably used for extended or redundant links between terminals and relay nodes, vehicle-mounted or fixed command terminals, to achieve higher throughput or stronger anti-interference backhaul channels. In complex electromagnetic environments or scenarios with multiple concurrent devices, link availability and mission reliability can be improved through dual-link redundancy and traffic splitting (2.4 GHz for paired and low-speed control, 4.6 GHz for high-speed backhaul or critical service redundancy). In addition, operating points near this frequency band can also serve as optional extended frequencies for dedicated wireless backhaul and mission communication.

[0050] For tasks such as emergency rescue and command coordination, the wireless communication of head-mounted brain-computer interface terminals can be abstracted into two types of links: near-field access links (2.4GHz ISM) are used for pairing, control, and routine data backhaul between the terminal and mobile phones, tablets, or portable gateways. They support BLE low-power broadcast and GATT data, Bluetooth pairing links, and 2.4GHz Wi-Fi access and direct connection to meet the needs of real-time uploading of EEG or physiological data, command issuance, and status feedback. Extended or redundant links (4.6GHz) are used for backhaul channels between the terminal and relay nodes, vehicle-mounted or fixed command terminals. They can serve as anti-interference backup links in complex electromagnetic environments or undertake high-throughput services (such as multi-channel data backhaul and critical service redundancy) when multiple devices are running concurrently. This achieves dual-link redundancy and traffic splitting (2.4GHz carries pairing and low-speed control, and 4.6GHz carries high-speed backhaul or critical service redundancy) to improve mission reliability.

[0051] Therefore, the flexible conformal radio frequency radiation device 100 provided in this embodiment can simultaneously support short-range interconnection or near-range access frequency bands represented by 2.4GHz ISM and task communication and extended backhaul frequency bands represented by 4.6GHz, thereby improving the link availability and reliability of the helmet terminal in different task scenarios from the system level.

[0052] like Figure 7The image shows the surface current distribution of the radiator 2 at resonant frequencies of 6.67 GHz, 9.04 GHz, and 10.86 GHz in a planar unfolded state of the flexible conformal radio frequency radiating device 100. This is used to illustrate the resonance mechanism and key current paths in the planar tuning state. Figure 7 It can be seen that at 6.67 GHz, the current is mainly concentrated in the lower middle part and end of the local perturbation structure (extended branches) of radiator 2, indicating that this frequency is dominated by a longer equivalent current path. At 9.04 GHz, the current distribution between the conductive patches of each cascaded radiator 2 and the feed line 3 is more uniform, reflecting the resonance involving multiple elements. At 10.86 GHz, the current gathers at the end of radiator 2 and in the vicinity of feed line 3, exhibiting short-path resonance. Overall, the increase in frequency corresponds to the shortening of the equivalent wavelength, and the effective current path participating in the resonance gradually changes from a long path to a short path, providing a comparative benchmark for subsequent mode conversion (circumferential circulating mode and local mode) after conformal closed-loop.

[0053] like Figure 8 The diagram shows the surface current distribution of the radiator 2 at resonant frequencies of 2.5 GHz and 4.6 GHz in the conformal closed-loop state of the flexible conformal RF radiating device 100. Conformity significantly alters the geometry and electromagnetic environment of the flexible conformal RF radiating device 100, thus affecting the current distribution, amplitude, and phase. At 2.5 GHz, the current exhibits a more continuous circumferential propagation trend along the cascaded conductive patches and their connecting lines. The closed-loop structure allows the current to form a longer equivalent path circumferentially, reflecting the circumferential circulating current mode. At 4.6 GHz, the current is mainly concentrated in the region adjacent to the conductive patches and the local perturbation structure of the feed line 3, reflecting the local mode of the conductive patches. This verifies that the dual-frequency resonance of the flexible conformal RF radiating device 100 after closed-loop conformity is dominated by two types of current paths.

[0054] In summary, the flexible conformal radio frequency radiation device 100 has different main current concentration areas on the surface before and after conformal design. Its local disturbance structure can change the equivalent current path and form a resonant mode at the corresponding frequency point, thereby achieving impedance matching and radiation within the target frequency band.

[0055] In terms of radiation performance, the flexible conformal radio frequency radiator 100 is more suitable for the circumferential installation scenario of the helmet 200 after conformal mounting. To characterize its circumferential coverage and radiation pattern stability, such as Figure 9 and Figure 10 As shown, two-dimensional radiation patterns of the flexible conformal radio frequency radiation device 100 in the E / H orthogonal tangent planes at 2.5 GHz and 4.6 GHz are given respectively. The red line represents the dB (GainPhi) component and the green line represents the dB (GainTheta) component. The two correspond to orthogonal polarization components and can be used to observe the stability of the main polarization direction as the conformal assembly changes.

[0056] Depend on Figure 9 As can be seen from (a) and (b), usable radiation output is available in both orthogonal tangential planes at 2.5 GHz. The main radiation component distribution in the H-plane is relatively continuous with small gain fluctuations, which is beneficial for the circumferential angular coverage of the helmet-mounted terminal. Meanwhile... Figure 10 (c) and (d) further provide the radiation pattern cross-section results at 4.6 GHz, which can be used as a verification of the radiation performance of the flexible conformal RF radiation device 100 in the conformal closed-loop state at the selectable extended frequency point. Together with the return loss results, they prove that the flexible conformal RF radiation device 100 has usable port matching and radiation output capabilities in the target frequency band when it is in the conformal closed-loop state.

[0057] The above radiation pattern results and return loss results together demonstrate that the conformal assembly structure has both usable port matching and radiation output capabilities within the target frequency band.

[0058] like Figure 11 As shown, a comparison of the three-dimensional gain patterns of the flexible conformal radio frequency radiation device 100 in two states: before conformation (planar unfolded form) and after conformation (conformal closed-loop form). Figure 11 It can be seen that the flexible conformal radio frequency radiation device 100 helps to obtain better circumferential coverage and three-dimensional radiation morphology stability after conformal design. Compared with the planar unfolded state, the radiation energy is more uniformly distributed in the circumferential angular domain after conformal design, the sidelobe and sublobe levels are suppressed, the directionality reaches the best at the feed point, and a clearer effective radiation area is formed on the side away from the human body, thus making it more suitable for the circumferential installation scenario of the helmet 200.

[0059] In summary, the flexible conformal radio frequency radiation device 100 provided in this embodiment forms a planar radiation structure and a feeding structure on a flexible dielectric substrate 1, and is then installed on a designated position (the circumferential mounting surface on the inner sidewall) of the helmet 200 shell by bending, bonding, or fixing. This conforms the flexible conformal radio frequency radiation device 100 to the brain-computer interface helmet carrier, meeting preset matching criteria within the target operating frequency band. Preferably, it covers the 2.4GHz ISM band and is compatible with common Bluetooth and WLAN frequency band requirements. Within the 2.35GHz to 2.56GHz range, it can cover ISM and is compatible with Bluetooth / BLE and the IEEE 802.11 series WLAN operating modes in 2.4GHz (including 802.11b / g / n / ax / be, i.e., the 2.4GHz mode of Wi-Fi 4 / 6 / 7), thereby ensuring wireless interconnection between the helmet terminal and external devices.

[0060] Compared with existing technologies where rigid printed antennas or simple strip printed antennas are directly attached to the edge, curved surface, or uncontrolled assembly of the helmet 200, this embodiment achieves structural synergy by biomimetic conformal integration of the flexible conformal radio frequency radiation device 100 with the inner wall of the helmet 200. This enables multi-frequency communication without significantly occupying internal space, resulting in the following technical effects: (1) The conformal closed-loop state of the flexible conformal radio frequency radiation device 100 is controllable, and the matching stability with the helmet terminal is improved; (2) The radiator 2 is formed by a series of conductive patches connected by microstrip lines to create a continuous current path. Local perturbation structures are introduced in the patch area to change the current path and equivalent electrical length. In the conformal closed-loop state, the current distribution shows different main concentration areas and flow paths at 2.5 GHz and 4.6 GHz. At 2.5 GHz, the current is mainly concentrated in the middle of the local perturbation structure (extended branches) and at the feed line 3, and the path is relatively long. At 4.6 GHz, the current is more concentrated at the end of the radiator 2 and at the feed line 3. This difference indicates that at least two different equivalent current paths and resonant modes are formed after the conformal closed loop, realizing dual-frequency or multi-frequency coverage at 2.5 GHz and 4.6 GHz. (3) In the closed-loop conformal installation configuration, the flexible conformal radio frequency radiation device 100 can simultaneously meet the engineering requirements of port matching (return loss S11) and available radiation pattern in the target frequency band. The conformal ring configuration improves the radiation omnidirectionality compared to the planar configuration. (4) A near-human isolation structure 4 is proposed to be integrated on the side surface of the flexible dielectric substrate 1 away from the radiator 2 to face the near-human wearing conditions, so as to reduce human coupling and improve the matching stability under near-human conditions, and provide a structural basis for the safety assessment of wearables under near-human conditions.

[0061] Furthermore, the flexible conformal radio frequency radiation device 100 provided in this embodiment can also be structurally laid out and filled using CAD methods, suitable for applications such as... Figure 12 The printing and processing of the flexible circuit board shown, combined with the aforementioned preset installation area and wiring structure, facilitates mass assembly in helmet terminals.

[0062] Second aspect This embodiment provides a head-mounted brain-computer interface terminal, referring to... Figure 3 and Figure 4 The head-mounted brain-computer interface terminal includes a helmet 200 and a flexible conformal radio frequency radiation device 100 provided in any of the optional embodiments of the first aspect. The inner sidewall of the helmet 200 shell is provided with a circumferential mounting surface for mounting the flexible conformal radio frequency radiation device 100. The flexible dielectric substrate 1 is bent into a closed-loop structure and conformally attached to the circumferential mounting surface along the helmet 200.

[0063] The specific structure and achievable effects of the flexible conformal radio frequency radiation device 100 involved in the head-mounted brain-computer interface terminal provided in this embodiment can be obtained by referring to the optional or preferred embodiments of the first aspect.

[0064] Furthermore, in an optional embodiment of this example, a positioning and fixing component for fixing the flexible dielectric substrate 1 is provided on the inner sidewall of the helmet 200 shell.

[0065] In an optional embodiment of this example, the positioning and fixing component includes a positioning pressure strip and at least two limiting buckles. The positioning pressure strip is fixed to the inner wall of the helmet 200 shell and extends circumferentially along the helmet 200. A slot is provided between the positioning pressure strip and the circumferential mounting surface. At least a portion of the flexible dielectric substrate 1 is inserted into the slot. The positioning pressure strip presses the flexible dielectric substrate 1 toward the circumferential mounting surface, providing a continuous circumferential clamping force toward the inner wall of the helmet 200 shell to the radiator 2, suppressing the warping, relative slippage, and sudden changes in local curvature of the radiator 2 under wearing and vibration conditions. The limiting buckles are fixed to the inner wall of the helmet 200 shell and are used to clamp the end of the flexible dielectric substrate 1 to constrain the closed-loop circumference of the closed-loop structure formed by the flexible dielectric substrate 1, thereby limiting the contact position between the radiator 2 and the inner wall of the shell and the overall equivalent bending radius of the flexible conformal radio frequency device.

[0066] Reference Figure 5 and Figure 6 The S11 curves of the flexible conformal RF radiating device 100 before and after conformal bending show significant differences, indicating that bending is sensitive to the resonant point and bandwidth. In the planar state, three frequency bands are mainly observed: 5.87–6.92 GHz, 8.81–9.17 GHz, and 10.62–11.50 GHz. In the conformal closed-loop state, two frequency bands are mainly formed: 2.38–2.57 GHz and 4.55–4.66 GHz, corresponding to center frequencies of 2.5 GHz and 4.6 GHz. This difference demonstrates that conformal bending of the flexible conformal RF radiating device 100 is sensitive to the resonant point and bandwidth of the device. Therefore, if the assembly bending radius and fitting position of the flexible conformal RF radiating device 100 are uncontrollable, frequency drift and matching fluctuations are easily caused. This optional embodiment, by setting a positioning and fixing component, ensures that the bending radius and fitting position of the flexible conformal radio frequency radiation device 100 fall within a preset range, thereby transforming conformal sensitivity into a controllable assembly variable. When the flexible conformal radiation component forms a closed-loop conformal shape after assembly, its fitting position, closed-loop circumference, and equivalent bending radius on the inner side of the helmet 200 are structurally defined, thereby achieving repeatable assembly and batch consistency, and improving the performance stability of the end product.

[0067] Third aspect This embodiment provides an assembly method for assembling a flexible conformal radio frequency radiation device to the helmet of a head-mounted brain-computer interface terminal, which is used to manufacture the head-mounted brain-computer interface terminal provided by any one of the optional embodiments in the aforementioned second aspect. When the flexible dielectric substrate 1 is bent into a closed-loop structure conformal to the circumferential mounting surface, the shape of the flexible dielectric substrate 1 is a conformal closed-loop shape. The assembly method includes the following steps: First, determine the closed-loop circumferential length C and the equivalent bending radius Req when the flexible dielectric substrate 1 is in the conformal closed-loop shape: Define a circumferential reference line along the circumferential mounting surface, measure the path length Lpath along the circumferential reference line for one week as the closed-loop circumferential length C, determine the preset target range of the closed-loop circumferential length C as [Cmin; Cmax], and further determine the preset target range of the equivalent bending radius Req as [Rmin; Rmax], where Req = Lpath / (2π); It should be noted that: the circumferential reference line may be a standard ring or an approximate ring (the cross-section is not strictly circular, for example, it is an ellipse or has an irregular curvature). When the circumferential reference line C is a standard ring, C = Lpath, Req = Lpath / (2π) = C / (2π); When the circumferential reference line C is an approximate ring, measure the path length Lpath along the circumferential reference line as the closed-loop circumferential length C, and define the equivalent bending radius with Req = Lpath / (2π) to uniformly quantify and control the assembly state. For example: when the closed-loop perimeter interval [Cmin; Cmax] corresponding to the circumferential mounting area is set to 520 mm to 580 mm, and the allowable deviation ΔC of ±3 mm is further given as the process tolerance control in combination with the manufacturing and assembly capabilities, the equivalent bending radius can be obtained as approximately 82.8 mm to 92.4 mm, and the actual range can be adjusted according to the size of the helmet 200 and the structural dimensions of the mounting area; Then, conformally attach and install the flexible dielectric substrate 1 along the preset installation path to the circumferential mounting surface in the conformal closed-loop shape, limit the closed-loop circumferential length C of the conformal closed-loop shape within [Cmin; Cmax], and limit the equivalent bending radius Req within [Rmin; Rmax].

[0068] In an optional embodiment of this embodiment, this assembly method for assembling a flexible conformal radio frequency radiation device to the helmet of a head-mounted brain-computer interface terminal further includes an acceptance step. Specifically: Set the return loss of the flexible conformal radio frequency radiation device 100 within the target operating frequency band as S11. After installing the flexible dielectric substrate 1 on the circumferential mounting surface of the flexible dielectric substrate 1 to make the flexible dielectric substrate 1 in the conformal closed-loop shape, measure the return loss S11 of the flexible conformal radio frequency radiation device 100 within the target operating frequency band. When S11 ≤ 10 dB, it is determined that the assembly is qualified. When S11 > 10 dB, it is determined that the assembly is unqualified. If unqualified, disassemble and reinstall the flexible dielectric substrate 1.

[0069] In an optional embodiment of this example, the step of conformally attaching the flexible dielectric substrate 1 to the circumferential mounting surface along a preset mounting path specifically includes: firstly, bending the flexible dielectric substrate 1 with a cylinder to form a conformal closed-loop shape, limiting the circumferential length C of the conformal closed-loop shape to within [Cmin; Cmax], and limiting the equivalent bending radius Req to within [Rmin; Rmax]; and then attaching the flexible dielectric substrate 1 to the circumferential mounting surface.

[0070] Finally, it should be noted that the above embodiments and optional implementations in this specification are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing optional implementations, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention. Furthermore, it is emphasized again that, in the absence of conflict, the features of the embodiments and optional implementations in the embodiments in this specification can be combined with each other.

Claims

1. A flexible conformal radio frequency radiation device, applied to a head-mounted brain-computer interface terminal, characterized in that, include: The flexible dielectric substrate (1) unfolds into a long strip-shaped sheet structure; The radiator (2) includes a plurality of conductive patches attached to one side surface of the flexible dielectric substrate (1). Along the length direction of the flexible dielectric substrate (1), the plurality of conductive patches are arranged at intervals, and each pair of adjacent conductive patches are connected by a microstrip line so that all the conductive patches are connected in series to form a continuous current path. A feeder line (3) is connected to one end of the radiator (2) for connection to a wireless communication module; A near-human isolation structure (4) is provided on the side surface of the flexible dielectric substrate (1) away from the radiator (2); The flexible dielectric substrate (1) can be bent into a closed-loop structure with the ends connected. The radiator (2) is located on the outer ring surface of the closed-loop structure, and the near-human isolation structure (4) is located on the inner ring surface of the closed-loop structure.

2. The flexible conformal radio frequency radiation device according to claim 1, characterized in that, The conductive patch includes a substrate and a local disturbance structure disposed on the substrate. The local disturbance structure includes at least one of a notch, a groove, and an extension branch. The length extension direction along the unfolded state of the flexible dielectric substrate (1) is such that the spacing between each two adjacent substrates is the same.

3. The flexible conformal radio frequency radiation device according to claim 1, characterized in that, The flexible dielectric substrate (1) is made of polyimide material with a relative permittivity εr=4.3 and dielectric loss tangent tanδ=0.

03.

4. The flexible conformal radio frequency radiation device according to claim 1, characterized in that, The feed line (3) is a 50Ω microstrip line; and / or, along the length extension direction of the flexible dielectric substrate (1) in its unfolded state: the overall length of the radiator (2) is 520mm, the width is 44mm, and the thickness is 2.6mm.

5. A head-mounted brain-computer interface terminal, characterized in that, The device includes a helmet (200) and a flexible conformal radio frequency radiation device (100) as described in any one of claims 1-4, wherein the inner sidewall of the shell of the helmet (200) is provided with a circumferential mounting surface for mounting the flexible conformal radio frequency radiation device (100), and the flexible dielectric substrate (1) is bent into the closed-loop structure and conformally attached to the circumferential mounting surface along the helmet (200).

6. The head-mounted brain-computer interface terminal according to claim 5, characterized in that, The helmet (200) has a positioning and fixing assembly on the inner side wall of the shell for fixing the flexible dielectric substrate (1).

7. The head-mounted brain-computer interface terminal according to claim 6, characterized in that, The positioning and fixing component includes a positioning pressure strip and at least two limiting buckles; The positioning strip is fixed to the inner side wall of the helmet (200) and extends along the circumference of the helmet (200). A slot is provided between the positioning strip and the circumferential mounting surface. At least part of the flexible dielectric substrate (1) is inserted into the slot. The positioning strip presses the flexible dielectric substrate (1) toward the circumferential mounting surface. The limiting buckle is fixed to the inner side wall of the helmet (200) shell and is used to clamp the end of the flexible dielectric substrate (1) to constrain the closed-loop circumference of the closed-loop structure formed by the flexible dielectric substrate (1).

8. A method for assembling a flexible conformal radio frequency radiation device onto a helmet of a head-mounted brain-computer interface terminal, used to manufacture the head-mounted brain-computer interface terminal according to any one of claims 5-7, characterized in that, When the flexible dielectric substrate (1) is bent into a closed-loop structure conforming to the circumferential mounting surface, the shape of the flexible dielectric substrate (1) is a conformal closed-loop shape, and the assembly method includes the following steps: Determine the closed-loop circumferential length C and equivalent bending radius R when the flexible dielectric substrate (1) is in a conformal closed-loop configuration. eq Define a circumferential reference line along the circumferential mounting surface, measure the path length Lpath along the circumferential reference line as the closed-loop circumferential length C, and determine the preset target range of the closed-loop circumferential length C as [C]. min C max Furthermore, the preset target range of the equivalent bending radius Req is determined to be [Rmin; Rmax], where Req = Lpath / (2π); The flexible dielectric substrate (1) is conformally attached to the circumferential mounting surface along a preset mounting path to form a conformal closed-loop shape, and the circumferential length C of the conformal closed-loop shape is limited to [C]. min C max Within [Rmin; Rmax], the equivalent bending radius Req is limited to [Rmin; Rmax].

9. The assembly method for mounting a flexible conformal radio frequency radiation device onto a helmet of a head-mounted brain-computer interface terminal according to claim 8, characterized in that, The assembly method also includes an acceptance step: Within the set target operating frequency band, the return loss of the flexible conformal radio frequency radiation device (100) is S11. After the flexible dielectric substrate (1) is installed on the circumferential mounting surface to form the conformal closed-loop shape, within the target operating frequency band, measure the return loss S11 of the flexible conformal radio frequency radiation device (100). When S11 ≤ 10 dB, it is determined that the assembly is qualified. When S11 > 10 dB, it is determined that the assembly is unqualified. If it is unqualified, remove and reinstall the flexible dielectric substrate (1).

10. The assembly method for mounting a flexible conformal radio frequency radiation device onto a helmet of a head-mounted brain-computer interface terminal according to claim 8, characterized in that, The step of conformally attaching the flexible dielectric substrate (1) to the circumferential mounting surface along a preset mounting path includes: First, the flexible dielectric substrate (1) is bent using a cylinder to make it conform to the conformal closed-loop shape, and the circumferential length C of the conformal closed-loop shape is limited to [C]. min C max Within [Rmin; Rmax], the equivalent bending radius Req is limited to [Rmin; Rmax]. The flexible dielectric substrate (1) is then attached and mounted on the circumferential mounting surface.

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