antenna assembly

Abstract

Embodiments of the present specification provide an antenna assembly. The antenna assembly is disposed on a wearable device and includes an antenna body and two or more feed ports. Two of the two or more feed ports are configured to respectively receive a first signal and a second signal. One of the first signal and the second signal is configured to increase a current intensity of the other of the first signal and the second signal generated on the antenna body.

Description

Technical Field

[0001] This specification generally relates to the field of antenna technology, and in particular to an antenna assembly for a wearable device. Background Technology

[0002] With the rapid development of wireless communication technology and the widespread adoption of wearable devices (such as Bluetooth headsets and smartwatches), the demand for miniaturized and portable antenna designs is increasing. As a key component for wireless signal transmission and reception, the antenna design of wearable devices directly impacts their communication performance, battery life, and user experience. However, due to the small size of wearable devices and the integration of various electronic modules to achieve multiple functions—for example, headsets integrate noise-canceling chips, audio processors, and batteries—the design space for antennas is greatly compressed, and antenna size is strictly limited.

[0003] Therefore, it is desirable to provide an antenna assembly that has a large effective radiating area, high antenna radiation efficiency, and stable antenna performance in the presence of small clearance and small size. Summary of the Invention

[0004] This specification provides an antenna assembly. The antenna assembly, disposed on a wearable device, includes an antenna body and two or more feed ports. Two of the two or more feed ports are configured to receive a first signal and a second signal, respectively. One of the first signal and the second signal is configured to increase the current intensity generated on the antenna body by the other of the first and second signals, thereby improving the radiation efficiency of the antenna body (i.e., the antenna), which facilitates the miniaturization and portability of the antenna assembly.

[0005] In some embodiments, the first signal and the second signal have the same frequency but different phases, thereby enabling the currents excited in the antenna body by the input signals of the first feed port and the second feed port to reinforce each other.

[0006] In some embodiments, the antenna assembly further includes a metal ground plane. The metal ground plane is spaced apart from the antenna body. By adjusting the distance between the metal ground plane and the antenna body, when a user wears the wearable device, it helps to enhance the vertical electric field component of the antenna radiation while reducing the electromagnetic radiation absorbed by the human body through the reflective effect of the metal ground plane. Simultaneously, it prevents changes in the electromagnetic field near the antenna due to human interference, thereby improving the antenna's radiation performance near the human body.

[0007] In some embodiments, the metal ground plane is configured to be closer to the human body than the antenna body when the wearable device is worn by the human body. By using the reflective effect of the metal ground plane to reduce absorption by the human body, the antenna of the wearable device can still have good antenna radiation performance in the wearing area while increasing the effective radiation area of ​​the antenna through two or more feed ports to improve efficiency.

[0008] In some embodiments, the metal floor and the antenna body are configured such that when the wearable device is worn by a human body, the metal floor and the antenna body are parallel to the sagittal plane of the human body, which helps the metal floor block the radiation of the antenna from being absorbed by the human body.

[0009] In some embodiments, the metal ground plane and the antenna body are respectively disposed on both sides of the first dielectric substrate.

[0010] In some embodiments, the thickness of the first dielectric substrate is 1 mm to 5 mm.

[0011] In some embodiments, the antenna body is provided with a grounding port, which is connected to a metal ground plane through a first matching circuit.

[0012] In some embodiments, the antenna assembly further includes a power divider and a phase shifter. The input of the power divider is electrically connected to the feed source, its first output is configured to output a first signal, and its second output is electrically connected to the input of the phase shifter. The output of the phase shifter is configured to output a second signal. By having the first output of the power divider output the first signal, the second output of the power divider electrically connected to the input of the phase shifter, and the output of the phase shifter output the second signal, the number of feed sources can be reduced, achieving dual-feed excitation of the antenna based on a single feed source. On the one hand, this helps reduce the number of components in the antenna assembly and reduce the space occupied; on the other hand, compared to single-feed excitation, dual-feed excitation can excite two modes and achieve mode superposition in a small-sized antenna, significantly enhancing the effective radiation area of ​​the antenna and thus improving radiation efficiency.

[0013] In some embodiments, the antenna assembly further includes a first dielectric substrate and a second dielectric substrate. A metal ground plane and the antenna body are respectively disposed on opposite sides of the first dielectric substrate. The second dielectric substrate is disposed on the side of the metal ground plane away from the first dielectric substrate. A power divider and a phase shifter are disposed on the second dielectric substrate.

[0014] In some embodiments, the antenna assembly further includes a third dielectric substrate. The antenna body, power divider, and phase shifter are disposed on the third dielectric substrate.

[0015] In some embodiments, the input of the power divider is electrically connected to a second matching circuit.

[0016] In some embodiments, the antenna body includes a rectangular metal patch. A first feed port of one of two or more feed ports is located at a first apex corner of the rectangular metal patch, and a second feed port of one of the two or more feed ports is located opposite one of the sides adjacent to the first apex corner. The first feed port is configured to receive a first signal, and the second feed port is configured to receive a second signal. This configuration allows the phase difference between the first and second signals to be adjusted based on the positional relationship of the two feed ports, such that the currents excited in the antenna by the input signals from the two feed ports reinforce each other, thereby improving the antenna's radiation efficiency.

[0017] In some embodiments, the distance between the second power supply port and the midpoint of the opposite side does not exceed 2 mm.

[0018] In some embodiments, the phase difference between the first signal and the second signal is 90° to 120°, which ensures that the superimposed current intensity in the antenna is greater, thereby obtaining better radiation efficiency.

[0019] In some embodiments, the antenna body includes a rectangular metal patch. A first feed port of one of two or more feed ports is located at a first apex corner of the rectangular metal patch, and a second feed port of one of two or more feed ports is located at a second apex corner opposite the first apex corner. The first feed port is configured to receive a first signal, and the second feed port is configured to receive a second signal. This configuration allows the phase difference between the first and second signals to be adjusted based on the positional relationship of the two feed ports, such that the currents excited in the antenna by the input signals from the two feed ports reinforce each other, thereby improving the antenna's radiation efficiency.

[0020] In some embodiments, the phase difference between the first signal and the second signal is 90° to 180°, which ensures that the superimposed current intensity in the antenna is greater, thereby obtaining better radiation efficiency.

[0021] In some embodiments, the diagonal length of the rectangular metal patch is no greater than λ / 4, where λ is the operating wavelength of the antenna assembly. This configuration allows the antenna assembly to be used in wearable devices (such as headphones), i.e., to achieve miniaturized antennas.

[0022] In some embodiments, the distance between the first feed port and the second feed port is no greater than λ / 4, where λ is the operating wavelength of the antenna assembly. This configuration allows the antenna assembly to be used in wearable devices (such as headphones), i.e., to achieve a miniaturized antenna.

[0023] In some embodiments, the length of the long side of the rectangular metal patch is 10mm to 12.5mm.

[0024] In some embodiments, the wearable device includes headphones. When the headphones are worn by a human body, the projections of the two power supply ports onto the sagittal plane of the human body are located within the projection range of the ear canal opening onto the sagittal plane, which can further reduce the absorption of electromagnetic radiation by the human body.

[0025] In some embodiments, the antenna body includes a strip patch forming a semi-enclosed structure. A first feed port and a second feed port, two or more of the feed ports, are respectively disposed at both ends of the strip patch.

[0026] In some embodiments, the wearable device includes headphones. The strip patch is configured such that when the headphones are worn by a person, the opening of its semi-closed structure faces the person's auricle. In this case, the antenna body is far from the person's auricle, which helps reduce the impact of the human body on electromagnetic radiation and improves the antenna's radiation efficiency. Furthermore, the large electric field region corresponding to the ends of the antenna body's branches is closer to the head, which increases the absorption loss of electromagnetic radiation by the head. Therefore, by respectively providing a first feed port and a second feed port at the ends of the antenna body's branches, it helps to reduce electromagnetic radiation loss.

[0027] In some embodiments, the semi-enclosed structure is L-shaped.

[0028] In some embodiments, the phase difference between the first signal and the second signal is 150° to 180° in order to ensure that when the antenna body includes a strip patch forming a semi-enclosed structure, the superimposed current intensity in the antenna is greater, so as to obtain better radiation efficiency.

[0029] In some embodiments, the distance between any two points on the antenna body is no greater than λ / 4, where λ is the operating wavelength of the antenna assembly. This configuration allows the antenna assembly to be used in wearable devices (such as headphones), i.e., to achieve miniaturized antennas. Attached Figure Description

[0030] This specification will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting; in these embodiments, the same reference numerals denote the same structures, wherein:

[0031] Figure 1 This is a schematic diagram of an exemplary antenna assembly shown according to some embodiments of this specification;

[0032] Figure 2A This is a schematic diagram of the current distribution of a single-fed antenna at 2.45 GHz, as shown in some embodiments of this specification.

[0033] Figure 2B This is a schematic diagram of the current distribution of a dual-fed antenna (i.e., an antenna or antenna assembly containing two feed points) at 2.45 GHz, as shown in some embodiments of this specification.

[0034] Figure 3A This is a schematic diagram of an exemplary antenna assembly shown according to some embodiments of this specification;

[0035] Figure 3B This describes the wiring configuration of the feed, power divider, and phase shifter on the circuit board according to some embodiments of this specification;

[0036] Figure 4 This is a schematic diagram of an exemplary antenna assembly shown according to other embodiments of this specification;

[0037] Figure 5 This is a comparison diagram of the reflection coefficients of a dual-fed antenna and a single-fed antenna according to some embodiments shown in this specification;

[0038] Figure 6A This is a schematic diagram comparing the radiation efficiency of a dual-fed antenna and a single-fed antenna according to some embodiments of this specification;

[0039] Figure 6B This is a schematic diagram comparing the system radiation efficiency of a dual-fed antenna and a single-fed antenna according to some embodiments of this specification;

[0040] Figure 7A This is a schematic diagram showing the headphone antenna at different positions on the human ear when the headphone antenna is a dual-fed antenna according to some embodiments of this specification;

[0041] Figure 7B This is a graph showing the scattering parameters of the headphone antenna at different positions of the human ear when the headphone antenna is a dual-fed antenna, according to some embodiments shown in this specification.

[0042] Figure 7C This is a graph showing the radiation efficiency of the headphone antenna at different positions of the human ear when the headphone antenna is a dual-fed antenna according to some embodiments of this specification.

[0043] Figure 8A This is a schematic diagram of an exemplary antenna assembly shown according to some embodiments of this specification;

[0044] Figure 8B This is a schematic diagram of an exemplary antenna assembly shown according to other embodiments of this specification;

[0045] Figure 9 These are schematic diagrams of exemplary antenna assemblies shown according to some embodiments of this specification; and

[0046] Figure 10 This is a schematic diagram of an exemplary antenna assembly shown according to some embodiments of this specification. Detailed Implementation

[0047] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are merely some examples or embodiments of this application. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0048] It should be understood that the terms “system,” “device,” “unit,” and / or “module” used herein are one way to distinguish different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0049] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0050] In the description of this specification, it should be understood that the terms "first," "second," "third," "fourth," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," "third," or "fourth" may explicitly or implicitly include at least one of that feature. In the description of this specification, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0051] In this specification, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, the term "connection" can refer to a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this specification according to the specific circumstances.

[0052] Due to the small size of wearable devices, traditional full-size antennas are unsuitable, necessitating the development of miniaturized antennas. Currently, in situations with limited clearance (the unobstructed space around the antenna required to ensure its normal operation and optimal performance) and small size, single-fed antennas (i.e., antennas or antenna assemblies containing only a single feed point) suffer from problems such as a small effective radiating area, insufficient utilization of the antenna's metal structure, and inadequate antenna efficiency. Therefore, this specification provides an antenna assembly that can increase the effective radiating area and improve the antenna's radiation efficiency while maintaining stable antenna performance in situations with limited clearance and small size.

[0053] The antenna components involved in the embodiments of this specification will be described in detail below with reference to the accompanying drawings. It should be noted that the following embodiments are only used to explain this specification and do not constitute a limitation thereof.

[0054] Figure 1 This is a schematic diagram of an exemplary antenna assembly according to some embodiments of this specification. The antenna assembly 100 is disposed on a wearable device for enabling communication between the wearable device and external devices (e.g., mobile phones, computers, etc.). Exemplary wearable devices may include smart bracelets, smartwatches, smart glasses, VR / AR headsets, Bluetooth headsets, smart jewelry, etc. For ease of description, this specification will use a Bluetooth headset (hereinafter referred to as a headset) as an example of a wearable device, which does not limit the scope of this application. Figure 1 As shown, the antenna assembly 100 includes an antenna body 110 (also referred to as an antenna) and two or more feed ports.

[0055] The antenna body 110 is the radiating element of the antenna assembly 100. Effective radiation and reception of electromagnetic waves can be achieved by designing the structure of the antenna body 110. For example, by adjusting the shape (e.g., rectangular, L-shaped) and size of the antenna body 110, the operating frequency, polarization, and radiation direction of the antenna body 110 can be controlled.

[0056] In some embodiments, the antenna body 110 is a metal patch. In some embodiments, the metal patch may be made of one or more materials selected from copper, aluminum, gold, silver, etc. In some embodiments, the thickness of the metal patch is 0.01 mm to 0.02 mm. For example, the thickness of the metal patch may be 0.01 mm, 0.012 mm, 0.014 mm, 0.016 mm, 0.018 mm, 0.02 mm, etc. In some embodiments, the shape of the metal patch may be rectangular, L-shaped, U-shaped, circular, annular, triangular, etc. For more descriptions of the shape of the metal patch, please refer to, for example... Figure 8A , Figure 8B , Figure 9 And its description.

[0057] In some embodiments, such as Figure 1 As shown, when the antenna body 110 is a rectangular metal patch, the length of the long side of the rectangular metal patch is 10mm to 12.5mm. For example, the length of the long side of the rectangular metal patch can be 10mm, 10.5mm, 11mm, 11.5mm, 12mm, 12.5mm, etc. Preferably, the antenna body 110 can be a square metal patch, and the side length of the square metal patch can be 11.5mm.

[0058] In this specification, the feed port, also referred to as the feed point, is the point where the antenna body 110 connects to the transmission line (such as a coaxial cable or microstrip line), used to transmit electromagnetic energy from the transmitter to the antenna body 110, or from the antenna body 110 to the receiver. A coaxial cable is a cable consisting of an inner conductor, an insulation layer, an outer conductor (i.e., a shielding layer), and an outer sheath. It is widely used for transmitting high-frequency electrical signals, and its structural design effectively reduces electromagnetic interference and signal loss. Specifically, the inner conductor (e.g., made of copper or copper alloys) is used to transmit electrical signals; the insulation layer (e.g., made of polyethylene or foam) is used to isolate the inner and outer conductors; the outer conductor (e.g., made of copper braid or aluminum foil) is used to shield against external interference and serve as a signal loop; and the outer sheath (e.g., made of PVC or other materials) is used to protect the internal structure from physical and environmental influences. A microstrip line is a planar transmission line used to transmit microwave signals. It consists of a dielectric substrate, a conductor strip, and a ground plane. Due to its compact structure and ease of integration, it can be applied to microwave circuits and antenna designs. Specifically, the dielectric substrate (e.g., made of materials such as ceramic or polytetrafluoroethylene) provides mechanical support and electrical isolation; the conductor strip (e.g., made of materials such as copper) is located above the dielectric substrate and transmits the microwave signal; the ground plane (e.g., made of materials such as copper) is located below the dielectric substrate and provides signal return and shielding.

[0059] Two of the two or more feed ports are configured to receive a first signal and a second signal, respectively. For example, the two or more feed ports may include a first feed port 112 and a second feed port 114. The first feed port 112 is used to receive the first signal, and the second feed port 114 is used to receive the second signal. The first signal and the second signal are configured to increase the current intensity on the antenna body 110, thereby improving the radiation efficiency of the antenna body 110 (i.e., the antenna), which is beneficial for achieving miniaturized and portable antenna components. The current intensity on the antenna body 110 refers to the magnitude of the current generated on the antenna body 110 due to the input signal (e.g., the first signal, the second signal, etc.). In some embodiments, the current intensity on the antenna body 110 can be calculated and analyzed by electromagnetic simulation software (e.g., CST, HFSS, etc.). In some embodiments, in actual testing, the current intensity on the antenna body 110 can also be estimated by measuring the radiated power of the antenna body 110.

[0060] It's important to understand that configuring the first and second signals to increase the current intensity on the antenna body 110 can be understood as follows: when both the first and second signals are simultaneously connected to the antenna body 110, the current intensity on the antenna body 110 is stronger than when only one of the first and second signals is connected. In other words, one of the first and second signals is configured to increase the current intensity generated by the other of the first and second signals on the antenna body 110. Specifically, this can be achieved by designing the connection position, amplitude, phase, and frequency of the first and second signals, allowing the currents generated by the two signals in the antenna body 110 to be superimposed and enhanced. The radiation efficiency of an antenna is a parameter that measures how efficiently an antenna converts input power into radiated power. It represents the energy conversion efficiency of the antenna when radiating electromagnetic waves, i.e.: Where, η r P represents the radiation efficiency of the antenna. rad P represents the input power of the antenna. in This indicates the radiated power of the antenna. The greater the current intensity in the antenna, the greater the antenna's radiation efficiency, which is more conducive to the miniaturization of antenna components.

[0061] Figure 2A This is a schematic diagram of the current distribution of a single-fed antenna at 2.45 GHz, as shown in some embodiments of this specification. Figure 2B This is a schematic diagram of the current distribution of a dual-fed antenna (i.e., an antenna or antenna assembly containing two feed points) at 2.45 GHz, as shown in some embodiments of this specification.

[0062] like Figure 2A As shown, the current distribution on a small-sized single-fed metal patch antenna is different from that on a normal half-wavelength metal patch antenna. Its current distribution is mainly concentrated near the location of the feed port 210, while there is no current distribution or a small current distribution in the area far away from the feed port 210. The effective radiation area is small and the antenna radiation efficiency is low.

[0063] like Figure 2B As shown, for a small-sized dual-fed antenna, when the feed ports are set at two locations that are far apart on the antenna body 110 (such as... Figure 4 As shown, by adjusting the phase shifter and the grounding port, the antenna can be fed simultaneously with a phase difference, thereby achieving the superposition of two incomplete excitation modes at the location of the feed port 220 and the location of the feed port 230. This is manifested as the superposition of the current distribution of the corresponding modes, resulting in a larger current intensity after superposition, which significantly improves the effective radiation area of ​​the antenna and thus improves the radiation efficiency.

[0064] In some embodiments, the first signal and the second signal may originate from the same or different feed sources. A feed source is a device that generates an antenna excitation signal. For example, a feed source may be an radio frequency circuit that modulates data to be transmitted onto a target signal (e.g., a Bluetooth signal). Exemplarily, the data to be transmitted may include audio data, text data, image data, sensor data, etc. In some embodiments, a first signal may be output from a first feed source, and a second signal may be output from a second feed source. In some embodiments, the signals output from the feed sources may be directly split to obtain the first signal and the second signal, or the split signals may be adjusted to obtain the first signal and the second signal.

[0065] Figure 3A This is a schematic diagram of an exemplary antenna assembly shown according to some embodiments of this specification. Figure 3B This describes the wiring configuration of the feeder, power divider, and phase shifter on the circuit board according to some embodiments shown in this specification. For example... Figure 3A and Figure 3B As shown, the signal output from the feed 310 can be split. At this time, the antenna assembly 100 also includes a power divider 320 and a phase shifter 330. The power divider 320 and the phase shifter 330 can be excitation circuit components of the antenna body 110. Specifically, as... Figure 3A As shown, the input terminal P of the power divider 320 in1 It is electrically connected to the feed 310. The power divider 320 is used to split the signal from the feed 310 into two signals, such as two signals with equal power. One of the signals (i.e., the first signal) is output through the first output terminal P of the power divider 320. out1 The signal is fed into the first power supply port 112, and another signal is fed into the second output terminal P of the power divider 320. out2Input (i.e., through input terminal P) in2 The signal is fed into phase shifter 330. Phase shifter 330 is used to adjust the phase of its input signal. The phase-adjusted signal (i.e., the second signal) passes through the output terminal P of phase shifter 330. out3 Input to the second power supply port 114.

[0066] In some embodiments, the power divider 320 may include one or more of the following: a microstrip power divider, a waveguide power divider, a MEMS power divider, a cavity power divider, a transformer-type power divider, and an electromagnetic coupler. In some embodiments, the phase shifter 330 may be implemented using a microstrip line, a digital phase shifter, a MEMS-based phase shifter, a dielectric phase shifter, a switching phase shifter, a lumped element matching circuit, or a distributed element matching circuit. For example, the first output terminal P of the power divider 320... out1 The second output terminal P is connected to the first power supply port 112 via the first wire. out2 The first and second wires are connected to the second power supply port 114 by a second wire, so that the lengths of the first and second wires are different. The transmission of one input signal is delayed relative to the other, which makes the phases of the two input signals different, thus achieving the function of a phase shifter.

[0067] According to some embodiments of this specification, by connecting the first power supply port 112 to the first output terminal P of the power divider 320... out1 Connected, the second feed port 114 is connected to the output terminal P of the phase shifter 330. out3 Connecting the feed sources reduces the number of feed sources, enabling dual-feed excitation of the antenna based on a single feed source. On one hand, this helps reduce the number of components in the antenna assembly 100 and decreases the space occupied. On the other hand, compared to single-feed excitation, dual-feed excitation allows for the excitation of two modes and mode superposition in a small-sized antenna, significantly enhancing the effective radiating area and thus improving radiation efficiency. The effective radiating area of ​​an antenna is a parameter measuring its ability to receive electromagnetic waves; it represents the effective area over which the antenna captures energy from incident electromagnetic waves.

[0068] In some embodiments, to enable the currents excited in the antenna body 110 by the input signals of the first feed port 112 and the second feed port 114 to reinforce each other, the first signal and the second signal can have the same frequency but different phases. Preferably, the first signal and the second signal also have the same amplitude.

[0069] It is important to understand that the phase difference between the input signals (i.e., the first signal and the second signal) at the two feed ports is related to the positions of the two feed ports. Adjusting the phase difference between the first and second signals based on their positional relationship allows the currents excited by the input signals at both feed ports in the antenna to reinforce each other, thereby improving the antenna's radiation efficiency. Specifically, when the distance between the first feed port 112 and the second feed port 114 is relatively small, the phase difference between the first and second signals can be small, and they can even be in phase. For example, when the antenna body 110 is a rectangular metal patch, the first feed port 112 and the second feed port 114 are located on the same side of the rectangular metal patch; in this case, the phase difference between the first and second signals can be small.

[0070] When the distance between the first feed port 112 and the second feed port 114 is large, the phase difference between the first signal and the second signal can be large. For example, when the antenna body 110 is a rectangular metal patch, the first feed port 112 and the second feed port 114 can be arranged opposite or nearly opposite each other on the rectangular metal patch. For example, the first feed port 112 and the second feed port 114 can be located near two opposite sides of the rectangular metal patch, respectively. Specifically, as... Figure 1 As shown, the first feed port 112 is located at the first apex A1 of the rectangular metal patch, and the second feed port 114 is located at the opposite side of one of the sides adjacent to the first apex A1. Preferably, the distance between the second feed port 114 and the midpoint B of the aforementioned opposite side does not exceed 2 mm. More preferably, the second feed port 114 is located at the midpoint of the aforementioned opposite side. In this case, in order to ensure a larger superimposed current intensity in the antenna and obtain better radiation efficiency, the phase difference between the first signal and the second signal is 90° to 120°, for example, it can be 100°, 110°, 120°, etc.

[0071] For example, the first power supply port 112 and the second power supply port 114 are located near the two vertices on the diagonal of the rectangular metal patch, respectively. Figure 4 This is a schematic diagram of an exemplary antenna assembly shown according to other embodiments of this specification. Specifically, as... Figure 4 As shown, the first feed port 112 is located at the first apex A1 of the rectangular metal patch, and the second feed port 114 is located at the second apex A2 opposite to the first apex A1. In this case, in order to ensure a larger superimposed current intensity in the antenna and obtain better radiation efficiency, the phase difference between the first signal and the second signal can be between 90° and 180°, for example, it can be 100°, 120°, 140°, 150°, 160°, 170°, etc.

[0072] According to some embodiments of this specification, by providing two or more feed ports on the antenna body 110, and by adjusting the phase difference of the input signals of the two feed ports, the currents excited by the input signals of the two feed ports in the antenna can be mutually reinforced (see...). Figure 2A and Figure 2B This increases the current intensity in the antenna, thereby improving its radiation efficiency. Furthermore, achieving dual-fed excitation of the antenna based on a single feed source helps reduce the number of components in the antenna assembly and minimizes the space required.

[0073] In some embodiments, due to the limited clearance of the antenna on wearable devices (such as headphones), when the distance between any two points on the antenna body 110 is no greater than one-quarter of the operating wavelength of the antenna assembly 100, the antenna assembly 100 can be considered a small antenna, or mainly operates in quarter-wavelength mode. The operating wavelength of the antenna assembly 100 refers to the distance the target wave (corresponding to the target frequency) propagates within one vibration cycle. The operating wavelength λ is equal to the product of the wave speed μ and the period T, and also equal to the quotient of the wave speed μ divided by the target frequency f, i.e., λ = μT = μ / f. For example, when the target frequency band of the antenna assembly 100 is the Bluetooth signal (a type of electromagnetic wave) band, the operating wavelength of the antenna assembly 100 is: Where c is the speed of light and f is the frequency of the Bluetooth signal. One-quarter of the operating wavelength of the antenna assembly 100 is λ / 4.

[0074] In this configuration, with two feed ports, the antenna body 110 can operate in a superposition of two quarter-wavelength modes. Therefore, to enable the antenna assembly 100 to be used in wearable devices (such as headphones), i.e., to achieve a miniaturized antenna, the distance between any two points on the antenna body 110 must not exceed one-quarter of the operating wavelength of the antenna assembly 110. For example, the distance between the first feed port 112 and the second feed port 114 must not exceed one-quarter of the operating wavelength of the antenna assembly 100. As another example, when the antenna body 110 is a rectangular metal patch, the diagonal length of the rectangular metal patch must not exceed one-quarter of the operating wavelength of the antenna assembly 100.

[0075] In some embodiments, the antenna assembly 100 further includes a metal ground plane 120. In some embodiments, the metal ground plane 120 may be made of one or more materials selected from copper, aluminum, gold, silver, etc. In some embodiments, the thickness of the metal ground plane 120 is 0.01 mm to 0.02 mm. For example, the thickness of the metal ground plane 120 may be 0.01 mm, 0.012 mm, 0.014 mm, 0.016 mm, 0.018 mm, 0.02 mm, etc.

[0076] The metal ground plane 120 is spaced apart from the antenna body 110, meaning the metal ground plane 120 and the antenna body 110 do not contact each other. It should be understood that by adjusting the distance between the metal ground plane 120 and the antenna body 110, when a user wears the wearable device, it helps to enhance the vertical electric field component of the antenna radiation while reducing the electromagnetic radiation absorbed by the human body through the reflective effect of the metal ground plane 120. Simultaneously, it prevents changes in the electromagnetic field near the antenna due to human interference, thus improving the antenna's radiation performance near the human body. In some embodiments, the distance between the metal ground plane 120 and the antenna body 110 is 1mm to 5mm. In some embodiments, the distance between the metal ground plane 120 and the antenna body 110 is 1.5mm to 4.5mm. In some embodiments, the distance between the metal ground plane 120 and the antenna body 110 is 2mm to 4mm. In some embodiments, the distance between the metal ground plane 120 and the antenna body 110 is 2.5mm to 3.5mm. In some embodiments, the distance between the metal ground plane 120 and the antenna body 110 is 3mm.

[0077] In some embodiments, the metal ground plane 120 is configured to be closer to the human body than the antenna body 110 when the wearable device is worn. For example, when the wearable device is a Bluetooth headset, in order to ensure the radiation performance of the Bluetooth headset antenna near the head, the metal ground plane 120 is closer to the human body than the antenna body 110. By reducing absorption by the human body through the reflection effect of the metal ground plane 120, it is ensured that the Bluetooth headset antenna still has good antenna radiation performance in the area near the head, even while increasing the effective radiation area of ​​the antenna through two or more feed ports to improve efficiency.

[0078] In some embodiments, in order to facilitate the metal floor 120 blocking the radiation of the antenna from being absorbed by the human body, the metal floor 120 and the antenna body 110 are configured such that when the wearable device is worn by the human body, the metal floor 120 and the antenna body 110 are parallel or substantially parallel to the sagittal plane of the human body.

[0079] In some embodiments, in order to further reduce the absorption of electromagnetic radiation by the human body, when the Bluetooth headset is worn by the human body, the projections of the first power supply port 112 and the second power supply port 114 on the sagittal plane of the human body are located within the projection range of the human ear canal opening on the sagittal plane of the human body.

[0080] In some embodiments, the antenna body 110 is provided with a ground port 140. The ground port 140 is connected to the metal ground plane 120 through a first matching circuit.

[0081] The first matching circuit includes components such as inductors and capacitors. For example... Figure 3AThe first matching circuit shown includes a parallel capacitor 340, one end of which is connected to the ground port 140, and the other end is connected to the metal ground plane 120. The main function of the first matching circuit is to achieve impedance matching with RF circuits such as the power divider 320 and the phase shifter 330, reduce power loss, and improve the coverage of the antenna's effective operating frequency band in the target frequency band (e.g., the Bluetooth band).

[0082] In some embodiments, the grounding port 140 can be located at any position on the antenna body 110. In some embodiments, in practical applications, in order to take into account the capacitance value of mainstream capacitors on the market, the grounding port 140 is located at the edge G of the antenna body 110, and the capacitance value of the parallel capacitor 340 is between 1pF and 2pF.

[0083] In some embodiments, the power divider 320 input terminal P in1 The system includes a second matching circuit to adjust impedance matching together with the ground port 140, reducing metal transmission line loss, improving antenna efficiency, and achieving coverage of the target frequency band (such as the Bluetooth band). In some embodiments, the first matching circuit and the second matching circuit may be the same or different. For example, both the first matching circuit and the second matching circuit may be a single capacitor. Another example is that the first matching circuit is a single capacitor, while the second matching circuit includes components such as capacitors and inductors.

[0084] In some embodiments, a first dielectric substrate 130 is provided between the antenna body 110, the metal ground plane 120, and / or other components of the antenna assembly 100 (e.g., power divider 320, phase shifter 330, etc.) to support the antenna body 110, the metal ground plane 120, and / or other components of the antenna assembly 100 (e.g., power divider 320, phase shifter 330, etc.). That is, the metal ground plane 120 and the antenna body 110 are respectively disposed on opposite sides of the first dielectric substrate 130. In this case, the thickness of the first dielectric substrate 130 is equal to the distance between the metal ground plane 120 and the antenna body 110; for example, the thickness of the first dielectric substrate 130 is 1 mm to 5 mm. Preferably, the thickness of the first dielectric substrate 130 is 3 mm.

[0085] In some embodiments, the antenna body 110 and the metal ground plane 120 can be fixed to the first dielectric substrate 130 by means of adhesive bonding, screw connection or other methods.

[0086] In some embodiments, the first dielectric substrate 130 may include one or more of the following: epoxy fiberglass cloth (FR-4) dielectric substrate, polyimide substrate, ceramic substrate, phenolic paper substrate, flexible substrate, polytetrafluoroethylene vinyl sheet, etc. An exemplary FR-4 dielectric substrate may be an FR-4 dielectric substrate with a dielectric constant of 4.2 to 4.8. For example, the first dielectric substrate 130 may be an FR-4 dielectric substrate with a dielectric constant of 4.3.

[0087] The size of the first dielectric substrate 130 is mainly limited by the size of the wearable device. For example, when the wearable device is a Bluetooth headset, the thickness of the first dielectric substrate 130 can be 2mm-5mm, the length can be 20mm-30mm, and the width can be 10mm-20mm. Preferably, the thickness of the first dielectric substrate 130 can be 2.5mm-4mm, the length can be 22mm-28mm, and the width can be 12mm-18mm. Preferably, the thickness of the first dielectric substrate 130 can be 3mm, the length can be 25mm, and the width can be 15mm.

[0088] It should be noted that when the antenna body 110 has a large thickness, good radiation efficiency, and is not easily deformed or bent, the first dielectric substrate 130 used for support can be omitted. In some embodiments, the first dielectric substrate 130 can be replaced with other forms of insulating support, such as a plastic bracket.

[0089] In some embodiments, the antenna assembly 100 may simultaneously include a first dielectric substrate 130 and a second dielectric substrate 135. A metal ground plane 120 and the antenna body 110 are respectively disposed on opposite sides of the first dielectric substrate 130. The second dielectric substrate 135 is disposed on the side of the metal ground plane 120 away from the first dielectric substrate 130. In this case, the second dielectric substrate 135 can be used to support circuit components such as a power divider 320 and a phase shifter 330.

[0090] In some embodiments, the second dielectric substrate 135 may include one or more of the following: a polytetrafluoroethylene (PTFE) high-frequency antenna board (F4B dielectric substrate), a PTFE dielectric substrate, a Rogers dielectric substrate, etc. An exemplary F4B dielectric substrate may be an F4B dielectric substrate with a dielectric constant of 2.2 to 5. For example, the second dielectric substrate 135 may be an F4B dielectric substrate with a dielectric constant of 3. In some embodiments, the thickness of the second dielectric substrate 135 may be 0.3 mm to 1 mm, the length may be 20 mm to 30 mm, and the width may be 10 mm to 20 mm. Preferably, the thickness of the second dielectric substrate 135 may be 0.5 mm to 0.8 mm, the length may be 22 mm to 28 mm, and the width may be 12 mm to 18 mm. Preferably, the thickness of the second dielectric substrate 135 may be 0.6 mm, the length may be 25 mm, and the width may be 15 mm.

[0091] In some embodiments, the antenna assembly 100 may further include a third dielectric substrate (not shown). The antenna body 110, the power divider 320, and the phase shifter 330 are disposed on the third dielectric substrate.

[0092] Figure 5 This is a comparison diagram of the reflection coefficients of a doubly-fed antenna and a single-fed antenna according to some embodiments shown in this specification. The reflection coefficient is the ratio of the amplitude of the reflected wave at the antenna input to the amplitude of the incident wave. For example... Figure 5 As shown, the -6dB impedance bandwidth of a single-fed antenna is 2410MHz-2480MHz. Some embodiments of the dual-fed antenna shown in this specification have a -6dB impedance bandwidth of 2390MHz-2480MHz, fully covering the Bluetooth band. The Bluetooth band refers to the 2.4GHz ISM (Industry Science Medicine) band, specifically the frequency range of 2.402GHz to 2.480GHz. The 6dB impedance bandwidth refers to the frequency range within which the antenna or circuit achieves a reflection loss of -6dB. Specifically, when the reflection coefficient is equal to or less than -6dB, the corresponding frequency range is the -6dB impedance bandwidth. Within this frequency range, the reflected power is less than 10%, which is generally considered the effective operating frequency band of the antenna. The smaller the reflection coefficient value, the less reflection and the better the antenna matching.

[0093] Figure 6A This is a schematic diagram comparing the radiation efficiency of a doubly-fed antenna and a single-fed antenna according to some embodiments shown in this specification. Figure 6A As shown, the radiation efficiency of the doubly-fed antenna at 2.45 GHz is -7.5 dB, which is 1.6 dB higher than the simulated radiation efficiency of the single-fed antenna, indicating a significant improvement in the antenna's radiation efficiency.

[0094] Figure 6B This is a schematic diagram comparing the system radiation efficiency of a doubly-fed antenna and a single-fed antenna according to some embodiments shown in this specification. Figure 6B As shown, the average efficiency of the dual-fed antenna within the 100MHz bandwidth of the Bluetooth band is -9dB, which is an improvement of 1.4dB compared with the efficiency simulation results of the single-fed antenna, indicating a significant improvement in antenna efficiency.

[0095] Figure 7A These are schematic diagrams showing the headphone antenna at different positions on the human ear when using a dual-fed antenna, as illustrated in some embodiments of this specification. Figure 7A As shown, Figure 7A (a) and (b) show the antenna body 110 positioned close to and away from the ear canal opening when the antenna assembly 100 is located near the ear canal opening, respectively. Figure 7A (c) and (d) show the antenna body 110 positioned close to and far from the ear canal opening when the antenna assembly 100 is located behind the auricle.

[0096] Figure 7B This is a graph showing the scattering parameters of the headphone antenna at different positions on the human ear when the headphone antenna is a dual-fed antenna, as illustrated in some embodiments of this specification. Figure 7BAs shown, curve 710 represents the antenna scattering parameter curve when the antenna assembly 100 is located near the ear canal opening and the antenna body 110 is positioned close to the ear canal opening. Curve 720 represents the antenna scattering parameter curve when the antenna assembly 100 is located near the ear canal opening and the antenna body 110 is positioned far from the ear canal opening. Curve 730 represents the antenna scattering parameter curve when the antenna assembly 100 is located behind the auricle and the antenna body 110 is positioned close to the ear canal opening. Curve 740 represents the antenna scattering parameter curve when the antenna assembly 100 is located behind the auricle and the antenna body 110 is positioned far from the ear canal opening.

[0097] from Figure 7A and Figure 7B It can be seen that the range of the -6dB impedance frequency band varies depending on the position of the headphone antenna near the ear. The range of the -6dB impedance frequency band when the antenna is near the ear canal opening (corresponding to curves 710 and 720) is wider than the range of the -6dB impedance frequency band when the antenna is behind the auricle (corresponding to curves 730 and 730), which can cover more of the Bluetooth frequency band (approximately between 2.4GHz and 2.5GHz).

[0098] Therefore, in some embodiments, when the wearable device is an earphone, the antenna assembly 100 can be configured to be close to the ear canal opening when the earphone is worn by a human body. Preferably, the antenna assembly 100 is close to the ear canal opening, and the antenna body 110 is far from the ear canal opening (e.g., as shown in the image). Figure 7A (The location shown in Figure (b)).

[0099] Figure 7C This is a graph showing the radiation efficiency of the headphone antenna at different positions on the human ear when using a dual-fed antenna, as illustrated in some embodiments of this specification. Figure 7C As shown, curves 712 and 714 represent the system radiation efficiency and the antenna radiation efficiency at 2.45 GHz when the antenna assembly 100 is located near the ear canal opening and the antenna body 110 is positioned close to the ear canal opening, respectively. Curves 722 and 724 represent the system radiation efficiency and the antenna radiation efficiency at 2.45 GHz when the antenna assembly 100 is located near the ear canal opening and the antenna body 110 is positioned far from the ear canal opening, respectively. Curves 732 and 734 represent the system radiation efficiency and the antenna radiation efficiency at 2.45 GHz when the antenna assembly 100 is located behind the auricle and the antenna body 110 is positioned close to the ear canal opening, respectively. Curves 742 and 744 represent the system radiation efficiency and the antenna radiation efficiency at 2.45 GHz when the antenna assembly 100 is located behind the auricle and the antenna body 110 is positioned far from the ear canal opening, respectively. System radiation efficiency refers to the overall radiation efficiency of the wearable device (e.g., headphones) including the antenna assembly 100.

[0100] Specifically, Table 1 shows the average efficiency of the headphone antenna at different positions on the human ear and its radiation efficiency at 2.45 GHz. The average efficiency refers to the average system radiation efficiency within the 2.4 GHz-2.5 GHz range. The average efficiency reflects the antenna's average performance across the entire operating frequency band (standard Bluetooth band 2.4-2.484 GHz), and it is a better representation of the antenna's overall performance than the radiation efficiency at a single frequency point. Table 1 shows the radiation efficiency of the headphone antenna at different positions of the human ear when using a doubly fed antenna. Radiative efficiency (dB) at 2.45 GHz Average efficiency (dB) Ear canal opening - near -8.67 -9.53 Ear canal opening - away -6.84 -7.75 Behind the ear - near -8.2 -9.2 Behind the ear - away -6.84 -7.94

[0101] from Figure 7C As can be seen from Table 1, the closer the antenna assembly 100 (or antenna body 110) is to the head area, the greater the absorption of electromagnetic radiation by the head. Therefore, regardless of the type of earphone, positioning the antenna body 110 away from areas such as the auricle will result in better radiation efficiency.

[0102] Based on this, in some embodiments, the earphone shell can be hung in front of the ear via ear hooks, headbands, elastic bands, etc. In this case, the antenna assembly 100 can be located on the outer side of the earphone shell away from the human body, which is beneficial for communication with external devices through the antenna assembly 100. Furthermore, the metal ground plate 120 is closer to the human body than the antenna body 110, so as to reduce human absorption by means of the reflection effect of the metal ground plate 120. This ensures that while the effective radiation area of ​​the antenna is increased through two or more feed ports to improve efficiency, the earphone antenna still has better antenna radiation performance in the area near the head.

[0103] Figure 8A This is a schematic diagram of an exemplary antenna assembly shown according to some embodiments of this specification. Figure 8B This is a schematic diagram of an exemplary antenna assembly shown according to other embodiments of this specification. In some embodiments, such as Figure 8A and Figure 8B As shown, the antenna body 110 may include a strip patch forming a semi-enclosed structure. A first feed port 112 and a second feed port 114 are respectively disposed at both ends of the strip patch.

[0104] In some embodiments, when the wearable device is an earphone, the strip patch is configured such that when the earphone is worn by a human, the opening of its semi-closed structure faces the human ear. In this case, the antenna body 110 is far from the human ear, which helps reduce the influence of the human body on electromagnetic radiation and improves the antenna's radiation efficiency. Furthermore, the large electric field region corresponding to the branch ends of the antenna body 110 is closer to the human head, which increases the absorption loss of electromagnetic radiation by the human head. Therefore, by respectively providing a first feed port 112 and a second feed port 114 at the branch ends of the antenna body 110, it helps to reduce electromagnetic radiation loss.

[0105] In some embodiments, the semi-enclosed structure can be L-shaped (e.g., Figure 8A As shown), U-shaped (as shown) Figure 8B (as shown in the figure). In this case, in order to ensure that the superimposed current intensity in the antenna is greater and to obtain better radiation efficiency, the phase difference between the first signal and the second signal is 150° to 180°, for example, it can be 150°, 160°, 170°, 180°, etc.

[0106] In some embodiments, when the antenna body 110 is L-shaped, in order to achieve the best radiation efficiency of the antenna, the length of the long side of the L-shape can be less than or equal to one-quarter of the operating wavelength of the antenna assembly 100 (i.e., λ / 4).

[0107] Figure 9 This is a schematic diagram of an exemplary antenna assembly shown according to some embodiments of this specification. In some embodiments, such as Figure 9 As shown, the antenna body 110 in the antenna assembly 100 may include a first antenna body 1102 and a second antenna body 1104. A first feed port 112 and a second feed port 114 may be respectively provided on the first antenna body 1102 and the second antenna body 1104. For example, the first feed port 112 may be located at the end of the first antenna body 1102, and the second feed port 114 may be located at the end of the second antenna body 1104. The ground port 140 may be located at any position on the first antenna body 1102 and / or the second antenna body 1104.

[0108] Figure 10 This is a schematic diagram of an exemplary antenna assembly shown according to some embodiments of this specification. In some embodiments, such as Figure 10 As shown, the antenna body 110 is a rectangular metal patch. The first feed port 112 and the second feed port 114 are located at two adjacent apex corners of the rectangular metal patch. In some embodiments, in order to make the antenna assembly 100 more compact, efficient, easy to integrate, and have better omnidirectional radiation performance, the antenna body 110, the power divider 320, and the phase shifter 330 are disposed on the first dielectric substrate 130.

[0109] The basic concepts have been described above. Obviously, for those skilled in the art, the detailed disclosure above is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application, and therefore remain within the spirit and scope of the exemplary embodiments of this application.

Claims

1. An antenna assembly, characterized in that, It is installed on wearable devices and includes the antenna body and two or more feed ports; Two of the two or more feed ports are configured to receive the first signal and the second signal, respectively. One of the first signal and the second signal is configured to increase the current intensity generated on the antenna body by the other of the first signal and the second signal.

2. The antenna assembly according to claim 1, characterized in that, The first signal and the second signal have the same frequency but different phases.

3. The antenna assembly according to claim 1, characterized in that, It also includes a metal floor, which is spaced apart from the antenna body and is configured to be closer to the human body than the antenna body when the wearable device is worn by the human body.

4. The antenna assembly according to claim 1, characterized in that, It also includes a metal floor, which is spaced apart from the antenna body and is configured such that when the wearable device is worn by a human body, the metal floor and the antenna body are parallel to the sagittal plane of the human body.

5. The antenna assembly according to claim 1, characterized in that, It also includes power dividers and phase shifters; The input terminal of the power divider is electrically connected to the feed source, the first output terminal of the power divider is configured to output the first signal, and the second output terminal of the power divider is electrically connected to the input terminal of the phase shifter. The output of the phase shifter is configured to output the second signal.

6. The antenna assembly according to claim 5, characterized in that, It also includes a metal floor, a first dielectric substrate, and a second dielectric substrate; The metal ground plane and the antenna body are respectively disposed on both sides of the first dielectric substrate; The second dielectric substrate is disposed on the side of the metal ground away from the first dielectric substrate, and the power divider and the phase shifter are disposed on the second dielectric substrate.

7. The antenna assembly according to claim 1, characterized in that, The antenna body includes a rectangular metal patch; The first of the two or more power supply ports is located at the first apex corner of the rectangular metal patch; The second power supply port of the two or more power supply ports is located on the opposite side of one of the sides adjacent to the first vertex. The first power supply port is configured to receive the first signal, and the second power supply port is configured to receive the second signal.

8. The antenna assembly according to claim 7, characterized in that, The distance between the second power supply port and the midpoint of the opposite side does not exceed 2mm, and the phase difference between the first signal and the second signal is 90° to 120°.

9. The antenna assembly according to claim 1, characterized in that, The antenna body includes a rectangular metal patch; The first of the two or more power supply ports is located at the first apex corner of the rectangular metal patch; The second feed port of the two or more feed ports is located at the second vertices opposite to the first vertices; The first power supply port is configured to receive the first signal, and the second power supply port is configured to receive the second signal.

10. The antenna assembly according to claim 9, characterized in that, The phase difference between the first signal and the second signal is 90° to 180°.

11. The antenna assembly according to claim 7 or 9, characterized in that, The distance between the first feed port and the second feed port is no greater than λ / 4, where λ is the operating wavelength of the antenna assembly.

12. The antenna assembly according to claim 1, characterized in that, The wearable device includes headphones; When the earphone is worn by a human body, the projections of the two power supply ports onto the sagittal plane of the human body are located within the projection range of the human ear canal opening onto the sagittal plane of the human body.

13. The antenna assembly according to claim 1, characterized in that, The antenna body includes a strip patch forming a semi-enclosed structure; The first and second power supply ports of the two or more power supply ports are respectively located at both ends of the strip patch.

14. The antenna assembly according to claim 13, characterized in that, The wearable device includes headphones; The strip patch is configured such that when the earphone is worn by a person, the opening of its semi-closed structure faces the auricle of the person.

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