Antenna device and electronic equipment

Abstract

The invention relates to an antenna device and electronic equipment, the antenna device comprises a near field communication chip, the near field communication chip comprises a first transmitting end and a second transmitting end, the first transmitting end is used for providing a first differential feed signal, and the second transmitting end is used for providing a second differential feed signal; the phase conversion circuit is respectively connected with the first transmitting end and the second transmitting end and is used for converting the first differential feed signal and the second differential feed signal into single-end feed signals; the first end of the impedance matching circuit is connected with the phase conversion circuit, and the impedance matching circuit is used for transmitting the single-end feed signal and realizing impedance matching; the feed end of each near field communication antenna is connected with the second end of the impedance matching circuit, the grounding end of each near field communication antenna is connected to the common ground end, the at least two NFC antennas connected in parallel are arranged, the effective length and the induction area of the antennas are increased equivalently, the induced electromotive force can be increased, and the performance of the antenna is improved. And the near field communication performance is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of antennas, in particular to an antenna device and an electronic device. BACKGROUND

[0002] Near Field Communication (NFC) is a kind of short-range wireless communication, mainly used for fast and secure data exchange between devices (usually within 10 cm). Because NFC has the characteristics of short distance transmission, low power consumption and compatibility with RFID, most electronic devices now have NFC functions.

[0003] NFC technology can be widely used in public transportation (such as subway and bus card swiping), mobile payment, identity recognition and access control, Internet of Things device quick pairing, information exchange and other fields. Therefore, how to improve the performance of near field communication has become a problem to be solved. SUMMARY

[0004] The embodiment of the present application provides an antenna device, which can increase the oscillation current of each radiator, thereby increasing the induced electromotive force of the opposite end device performing near field communication with the antenna device, and improving the near field communication performance of the antenna device and the electronic device.

[0005] The present application provides an antenna device, comprising:

[0006] a near field communication chip, comprising a first transmitting end and a second transmitting end, the first transmitting end is used for providing a first differential feed signal, and the second transmitting end is used for providing a second differential feed signal;

[0007] a phase conversion circuit, connected with the first transmitting end and the second transmitting end respectively, used for converting the first differential feed signal and the second differential feed signal into a single-ended feed signal;

[0008] an impedance matching circuit, a first end of the impedance matching circuit is connected with the phase conversion circuit, used for transmitting the single-ended feed signal and realizing impedance matching;

[0009] at least two near field communication antennas, a feed end of each near field communication antenna is connected with a second end of the impedance matching circuit, and a ground end of each near field communication antenna is connected to a common ground end.

[0010] The present application also provides an electronic device comprising the aforementioned antenna device.

[0011] The antenna device and the electronic device, comprising a near field communication chip, a phase conversion circuit, an impedance matching circuit and at least two parallelly connected near field communication antennas, the near field communication chip can be fed by two transmitting ends respectively to provide a first differential feed signal and a second differential feed signal respectively, the phase conversion circuit can convert the first differential feed signal and the second differential feed signal into a single-end feed signal with an unchanged frequency, which can be conducive to suppressing common-mode interference signals. In addition, the single-end feed signal is transmitted to one feed end of each near field communication antenna through the impedance matching circuit to excite each near field communication antenna to radiate a near field communication signal. The antenna device provided by the embodiment of the application can realize the conversion of the double-end signal of the near field communication chip into a single-end signal transmission. Compared with the related art, both ends of the NFC antenna need to be connected to the near field communication chip through a feed connection structure such as a spring sheet to realize feeding. In the embodiment of the application, the NFC antenna is fed by a single end, and the other end of the NFC antenna is connected to a common ground. In this way, the number of feed connection structures can be reduced, the cost can be reduced, the occupied space can be saved, the feed transmission loss can be reduced, and the setting position of each NFC antenna can be more flexible. In addition, by arranging at least two parallelly connected NFC antennas, the effective length and the sensing area of the antenna are increased, the oscillation current of each NFC antenna is increased, the induced electromotive force of the opposite device for near field communication with the antenna device is increased, and the near field communication performance of the antenna device is improved. BRIEF DESCRIPTION OF DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0013] Figure 1 Structure schematic diagram of an embodiment of an electronic device;

[0014] Figure 2 Structure schematic diagram of an embodiment of an electronic device;

[0015] Figure 3 Structure schematic diagram of an embodiment of an antenna device;

[0016] Figure 4 Structure schematic diagram of an embodiment of an antenna device;

[0017] Figure 5 Structure schematic diagram of an embodiment of an antenna device;

[0018] Figure 6Fig. 5 is a structural schematic diagram of an antenna device according to an embodiment;

[0019] Figure 7 Fig. 6 is a structural schematic diagram of an antenna device according to an embodiment;

[0020] Figure 8 Fig. 7 is a structural schematic diagram of an antenna device according to an embodiment;

[0021] Figure 9 Fig. 8 is a structural schematic diagram of an antenna device according to an embodiment;

[0022] Figure 10 Fig. 9 is a structural schematic diagram of an antenna device according to an embodiment;

[0023] Figure 11 Fig. 10 is a structural schematic diagram of an antenna device according to an embodiment;

[0024] Figure 12 Fig. 11 is a structural schematic diagram of an antenna device according to an embodiment;

[0025] Figure 13 Fig. 12 is a structural schematic diagram of an antenna device according to an embodiment;

[0026] Figure 14 Fig. 13 is a structural schematic diagram of an electronic device according to another embodiment;

[0027] Figure 15 Fig. 14 is an internal structural block diagram of an antenna device according to an embodiment.

[0028] Explanation of Reference Numerals:

[0029] 10 - electronic device; 11 - display screen assembly; 12 - bezel;

[0030] 110 - near field communication chip; 120 - phase conversion circuit; 121 - phase shift circuit; 1211 - first phase shift unit; 1212 - second phase shift unit; 122 - balun circuit;

[0031] 130 - impedance matching circuit; 131 - first matching unit; 132 - second matching unit; 133 - matching sub-circuit; 140 - near field communication antenna;

[0032] 150 - first filter circuit; 161 - second filter circuit; 162 - third filter circuit;

[0033] 171 - first reception circuit; 172 - second reception circuit;

[0034] 181 - third reception circuit; 182 - fourth reception circuit;

[0035] 31 - memory; 311 - operating system; 312 - communication module (or instruction set); 313 - global positioning system (GPS) module (or instruction set);

[0036] 32 - processing circuitry; 33 - peripheral device interface; 36 - input / output (I / O) subsystem; 361 - user press button;

[0037] 39 - communication bus or signal line. DETAILED DESCRIPTION

[0038] For the purpose of making the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and do not limit the present application.

[0039] It can be understood that the terms "first", "second" and the like used in the present application can be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the other element, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly and specifically limited. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there can be a middle element.

[0040] The electronic device related to the embodiments of the present application can be a handheld device, a vehicle-mounted device, a smart car, a wearable device, a computing device or other processing device connected to a wireless modem, and various forms of user equipment (UE) (for example, a mobile phone), a mobile station (MS), etc. For the convenience of description, the above-mentioned devices are collectively referred to as electronic devices.

[0041] As Figure 1As shown, in an embodiment, the electronic device is a mobile phone. The electronic device 10 includes a display assembly 11 and a housing (not shown). The display assembly 11 includes a display, which can be an OLED (Organic Light-Emitting Diode) screen or an LCD (Liquid Crystal Display) screen. The display assembly 11 can be used to display information and provide an interactive interface for a user. The display can have a rectangular shape or an arc-rectangular shape, which can also be referred to as a round-rectangular shape, i.e., the four corners of the rectangle are rounded.

[0042] The housing includes a frame 12 and a back cover. The frame 12 can be made of a metal material, such as an aluminum alloy or a magnesium alloy or stainless steel, or made of an insulating material, such as plastic. The frame 12 is arranged around the display assembly 11 to support and protect the display assembly 11. The frame 12 can further extend inward to form a middle plate, which can also be referred to as a middle frame. Alternatively, the middle plate and the frame 12 can be a separate structure. The back cover is arranged on a side of the display opposite the displayable area and connected to the frame 12. Further, the display assembly 11 and the back cover are respectively arranged on opposite sides of the middle plate.

[0043] The frame 12 has a substantially rectangular shape, which includes a first frame A and a second frame B arranged opposite each other, and a third frame C and a fourth frame D arranged opposite each other. The first frame A, the third frame C, the second frame B, and the fourth frame D are connected in sequence, and the length of the third frame C is greater than the length of the first frame A. It can be understood that the first frame A is the top frame of the electronic device, the second frame B is the bottom frame of the electronic device, and the third frame C and the fourth frame D are respectively the side frames of the electronic device. Specifically, the connection between the frames can be a right-angle connection or a rounded transition connection. Further, when the frame is a conductive frame, at least a portion of the conductive frame serves as an antenna radiator to receive / transmit radio frequency signals. The portion of the frame that serves as the radiator can have a gap with other portions of the middle plate to ensure that the antenna radiator has a good radiation environment. In an embodiment, the conductive frame can be provided with a gap or an aperture at the portion of the frame that serves as the radiator to facilitate the radiation of the antenna. The portion of the conductive frame that serves as the radiator can be formed by a break in the conductive frame.

[0044] The rear cover is located on the side facing away from the display area and connected to the mid-frame. Furthermore, the display assembly 11 and the rear cover are located on opposite sides of the mid-frame. The rear cover is connected to the frame 12 to define a receiving cavity, i.e., an installation space, for installing electronic components such as batteries, motherboards, and camera modules of the electronic device. The motherboard can be a PCB (Printed Circuit Board) or an FPC (Flexible Printed Circuit). The motherboard can integrate functional devices such as processors, storage units, power management modules, baseband chips, cameras, sensors, and receivers of the electronic device.

[0045] The electronic device may also include a ground plane. The ground plane can form a common ground of the electronic device 10, and can be a plane or structure with zero potential, or a common ground terminal of an antenna device. Exemplarily, the ground plane can be formed by conductors, printed circuits, or metal printed layers in the electronic device; or, the ground plane can be formed on the motherboard (e.g., PCB), small board, or other carrier board of the electronic device 10. In an exemplary embodiment, the frame 12 surrounds the ground plane, and it can be understood that the ground plane is disposed within the receiving space formed by the frame 12. The shape of the ground plane is generally rectangular. It should be noted that the above are several examples of ground planes and should not be construed as limiting the ground planes provided in the embodiments of this application.

[0046] The following description, in conjunction with the accompanying drawings, illustrates the specific structure of the antenna device included in the electronic device.

[0047] like Figure 2 As shown, the antenna device includes a Near Field Communication (NFC) chip 110, a phase conversion circuit 120, an impedance matching circuit 130, and at least two near field communication antennas 140 (or NFC antennas 140).

[0048] The near-field communication chip 110 includes a first transmitter TX1 and a second transmitter TX2. The first transmitter TX1 is used to provide a first differential feed signal, and the second transmitter TX2 is used to provide a second differential feed signal. The first differential feed signal and the second differential feed signal can be differential signals with equal frequency and amplitude but opposite phase, for example, differential signals with a phase difference of 180 degrees and the same amplitude.

[0049] For example, the phase of the first differential feed signal can be 180 degrees, and the phase of the second differential feed signal can be 0 degrees. Optionally, the phase of the first differential feed signal can be 90 degrees, and the phase of the second differential feed signal can be -90 degrees.

[0050] In an optional embodiment, the near-field communication chip 110 may also provide baseband processing capabilities for near-field communication signals.

[0051] Phase conversion circuit 120 is connected to the first transmitting terminal TX1 and the second transmitting terminal TX2, respectively, and is used to convert the first differential feed signal and the second differential feed signal into a single-ended feed signal. It should be understood that phase conversion circuit 120 can convert the phases of the received first differential feed signal and the second differential feed signal separately, for example, converting them into signals with the same phase and unchanged frequency, and then combining them to generate a single-ended feed signal, thereby meeting the single-ended feed requirements of each near-field communication antenna 140. The frequency of the single-ended feed signal is the same as the frequency of the first differential feed signal and the second differential feed signal.

[0052] In an exemplary embodiment, the frequencies of the first differential feed signal, the second differential feed signal, and the single-ended feed signal are the frequencies corresponding to the near-field communication signals, such as the center frequency of the NFC communication band.

[0053] The first terminal of the impedance matching circuit 130 is connected to the phase conversion circuit 120 for transmitting single-ended feed signals. The second terminal of the impedance matching circuit 130 is connected to the feed terminal of each near-field communication antenna 140. The ground terminal of each near-field communication antenna 140 is connected to a common ground terminal.

[0054] It should be understood that the near-field communication antenna 140 included in the antenna device can be equivalent to an inductor. The antenna device includes at least two near-field communication antennas 140, and the connection between each near-field communication antenna 140 can be equivalent to a parallel connection. That is, the antenna device includes at least two near-field communication antennas 140 connected in parallel with each other.

[0055] Impedance matching circuit 130 transmits the single-ended feed signal output from phase conversion circuit 120 to each near-field communication antenna 140. Impedance matching circuit 130 is also used to achieve impedance matching between each near-field communication antenna 140 and near-field communication chip 110, and to adjust the resonant frequency. For example, impedance matching circuit 130 may include a capacitor, which can form a resonant circuit (or oscillation circuit) with the equivalent inductance of near-field communication antenna 140. By adjusting the capacitance value of the capacitor in impedance matching circuit 130, its resonant frequency can be adjusted, thereby obtaining maximum power transmission.

[0056] It should be understood that the equivalent reactance / inductance value of each near-field communication antenna 140 connected in parallel is the total inductance of the equivalent inductances of each near-field communication antenna 140 connected in parallel. For example, if the antenna device includes m (where m is a positive integer greater than or equal to 2) near-field communication antennas 140, the equivalent reactance / inductance value of each near-field communication antenna 140 connected in parallel is the total inductance of the m equivalent inductances of the m near-field communication antennas 140 connected in parallel.

[0057] The oscillating current of at least two near-field communication antennas 140 connected in parallel is inversely proportional to their equivalent inductive reactance / inductance value. For example, the larger the equivalent inductive reactance / inductance value, the smaller the oscillating current; the smaller the equivalent inductive reactance / inductance value, the larger the oscillating current.

[0058] In this embodiment, since the impedance matching circuit 130 is connected in parallel with at least two near-field communication antennas 140, the total equivalent inductance / inductance value of the at least two near-field communication antennas connected in parallel with the same impedance matching circuit 130 is lower than that of a single near-field communication antenna. Therefore, the antenna device provided in this embodiment can increase its oscillation current, thereby increasing the induced electromotive force (EMF) of the peer device communicating with the antenna device in the near field. For example, if the induced EMF of a single near-field communication antenna 140 is 11V, and the induced EMF of two near-field communication antennas 140 connected in parallel is 15.2V, the induced EMF of two near-field communication antennas 140 can be 1.38 times that of a single near-field communication antenna 140.

[0059] The antenna device provided in this application includes a near-field communication chip, a phase conversion circuit, an impedance matching circuit, and at least two near-field communication antennas connected in parallel. The near-field communication chip can be fed through two transmitting ends to provide a first differential feed signal and a second differential feed signal, respectively. The phase conversion circuit can convert the first differential feed signal and the second differential feed signal into a single-ended feed signal with an unchanged frequency, which is beneficial for suppressing common-mode interference signals. In addition, the single-ended feed signal is transmitted to one feed end of each near-field communication antenna after passing through the impedance matching circuit to excite each near-field communication antenna to radiate near-field communication signals. The antenna device provided in this application can realize the conversion of the dual-ended signal of the near-field communication chip into a single-ended signal transmission. Compared with related technologies, where both ends of the NFC antenna need to be connected to the near-field communication chip through feed connection structures such as spring contacts to achieve feed, the NFC antenna in this application embodiment is single-ended fed, and the other end of the NFC antenna is connected to the common ground. In this way, the number of feed connection structures can be reduced, costs can be reduced, space can be saved, and feed transmission losses can be reduced. It also allows for more flexible placement of each NFC antenna. Furthermore, by setting at least two NFC antennas connected in parallel, the effective length and sensing area of ​​the antenna are increased, and the oscillation current of each radiator can also be increased, thereby increasing the induced electromotive force of the peer device that communicates with the antenna device in the near field, and improving the near field communication performance of the antenna device.

[0060] like Figure 3 As shown, in an exemplary embodiment, the impedance matching circuit 130 includes a first matching unit 131 and a second matching unit 132. The first terminal of the first matching unit 131 is the first terminal of the impedance matching circuit 130, and the first terminal of the second matching unit 132 is the second terminal of the impedance matching circuit 130.

[0061] The first end of the first matching unit 131 is connected to the phase conversion circuit 120. The second end of the first matching unit 131 is connected to the first end of the second matching unit 132 and the feed end of each near-field communication antenna 140, respectively. The second end of the second matching unit 132 is connected to the common ground.

[0062] The first matching unit 131 is used to achieve impedance matching between each NFC antenna 140 and the NFC chip 110. The first matching unit 131 may include a capacitive element. For example, the capacitance value of the first matching unit 131 can be set according to the requirements of achieving impedance matching between the multiple NFC antennas 140 and the NFC chip 110.

[0063] The first matching unit 131 and the second matching unit 132 can form a resonant circuit (or oscillation circuit) with the equivalent inductance of the correspondingly connected near-field communication antenna 140. By adjusting the capacitance values ​​of the first matching unit 131 and the second matching unit 132 in the impedance matching circuit 130, its resonant frequency can be adjusted, thereby obtaining maximum power transmission. The resonant frequency can be the frequency of the near-field communication signal, for example, 13.56MHz, or the difference between its resonant frequency and the frequency of the near-field communication signal is within a preset range, which can support near-field wireless communication. Among them, the capacitance value of the second matching unit 132 plays a major role in adjusting its resonant frequency, while the capacitance value of the first matching unit 131 plays an auxiliary role in adjusting its resonant frequency.

[0064] The second matching unit 132 may include a tuning capacitor. The capacitance value of the tuning capacitor is related to the equivalent inductance / inductance value of the multiple NFC antennas 140 connected in parallel. According to Thomson's law, the capacitance value of the tuning capacitor is negatively correlated with the equivalent inductance / inductance value. That is, the larger the equivalent inductance / inductance value of each NFC antenna 140, the smaller the capacitance value of the tuning capacitor.

[0065] like Figure 4 He Ru Figure 5 As shown, in an exemplary embodiment, the first matching unit 131 includes at least one first capacitor C1, such as an impedance capacitor, and the second matching unit 132 includes at least one second capacitor C2, such as a tuning capacitor. The first terminal of the first capacitor C1 is connected to the phase conversion circuit 120, the second terminal of the first capacitor C1 is connected to the first terminal of the second capacitor C2 and the feed point of each NFC antenna 140, and the second terminal of the second capacitor C2 is connected to a common ground terminal.

[0066] The number of first capacitors C1 and second capacitors C2 can be set according to the specific type of phase conversion circuit 120. For example, phase conversion circuit 120 may include one of phase shift circuit 121 and balun circuit 122. For example, when phase conversion circuit 120 is phase shift circuit 121, its first matching unit 131 includes one or more first capacitors C1, and the second matching circuit may include one or more second capacitors C2. When phase conversion circuit 120 is balun circuit 122, its first matching unit 131 includes multiple first capacitors C1, and the second matching circuit may include multiple second capacitors C2.

[0067] When there are at least two first capacitors C1, each first capacitor C1 is connected in parallel; when there are at least two second capacitors C2, each second capacitor C2 is connected in parallel.

[0068] In practical applications, the number and capacitance values ​​of the first capacitors C1 included in the first matching unit 131, and the number and capacitance values ​​of the second capacitors C2 included in the second matching unit 132, can be set according to the type of the phase conversion circuit 120, the number of NFC antennas 140 connected in parallel, and the equivalent inductive reactance / inductance value, etc. The capacitance values ​​of each first capacitor C1 can be the same or different, and the capacitance values ​​of each second capacitor C2 can be the same or different.

[0069] The specific circuit structure of the phase conversion circuit 120, as well as the specific circuit structure of the phase conversion circuit 120 and the impedance matching circuit 130, will be described below with reference to the accompanying drawings.

[0070] like Figure 6 As shown, in an exemplary embodiment, the phase conversion circuit 120 may include a phase shifting circuit 121. The phase shifting circuit 121 is connected to the first transmitting terminal TX1, the second transmitting terminal TX2, and the impedance matching circuit 130, respectively, and is used to adjust the phases of the first differential feed signal and the second differential feed signal to be the same, and to synthesize them into a single-ended feed signal. It should be understood that the phase shifting circuit 121 can convert the first differential feed signal into a first signal and the second differential feed signal into a second signal, wherein the first signal and the second signal have the same phase. Furthermore, the phase shifting circuit 121 can synthesize and superimpose the generated first signal and the second signal to generate a single-ended feed signal with a constant frequency, and output it to the impedance matching circuit 130.

[0071] For example, the phase shifting circuit 121 may include a first phase shifting unit 1211 and a second phase shifting unit 1212. A first end of the first phase shifting unit 1211 is connected to a first transmitting end TX1, a first end of the second phase shifting unit 1212 is connected to a second transmitting end TX2, and a second end of the first phase shifting unit 1211 is connected to a second end of the second phase shifting unit 1212. This connection point is connected to a first end of the impedance matching circuit 130.

[0072] For example, the first phase-shifting unit 1211 can phase-shift the first differential feed signal, converting it into a first signal; the second phase-shifting unit 1212 can phase-shift the second differential feed signal, converting it into a second signal, such that the first and second signals have the same phase. The first and second signals are combined at the junction point to generate a single-ended feed signal. Since the first and second signals have the same phase and frequency, the amplitude of the combined single-ended feed signal is the sum of the amplitudes of the first and second differential feed signals. In this way, the performance of the near-field communication chip 110 can be fully utilized, effectively improving the transmission power.

[0073] In an exemplary embodiment, one of the first phase shifting unit 1211 and the second phase shifting unit 1212 may be a phase-leading unit, and the other of the first phase shifting unit 1211 and the second phase shifting unit 1212 may be a phase-lag unit. The first phase shifting unit 1211 performs a phase-leading phase shift of the first differential feed signal by a first phase shift angle, and the second phase shifting unit 1212 performs a phase-lag phase shift of the second differential feed signal by a second phase shift angle.

[0074] The sum of the first phase shift angle and the second phase shift angle is 180°. For example, the first phase shift angle is 90 degrees and the second phase shift angle is 90 degrees; or, the first phase shift angle is 45 degrees and the second phase shift angle is 135 degrees; or, the first phase shift angle is 0 degrees and the second phase shift angle is 180 degrees, etc.

[0075] In an exemplary embodiment, the phase shifting circuit 121 formed by the first phase shifting unit 1211 and the second phase shifting unit 1212 may be an LC phase shifting circuit 121, an RC phase shifting circuit 121, or an RL phase shifting circuit 121, etc.

[0076] Please continue to refer to this. Figure 6 In this embodiment of the application, for ease of explanation, the phase shifting circuit 121 is described as an LC phase shifting circuit 121. One of the first phase shifting unit 1211 and the second phase shifting unit 1212 includes a third capacitor C3, and the other of the first phase shifting unit 1211 and the second phase shifting unit 1212 includes a first inductor L1.

[0077] The first inductor L1 and the third capacitor C3 adjust the phase in opposite directions. By using the smaller inductance value of the first inductor L1 and the smaller capacitance value of the third capacitor C3, the phases of the first differential feed signal and the second differential feed signal can be adjusted in opposite directions to achieve the same phase. For example, the third capacitor C3 can lead the first differential feed signal by 90 degrees, and the first inductor L1 can lag the second differential feed signal by 90 degrees. Since the original phase difference was 180 degrees, after adjustment, the phase difference is increased by 180 degrees, meaning the phase difference is now 360 degrees, or 0 degrees, thus achieving the same phase. In this way, a co-phase signal can be obtained through phase shifting, and then a single-ended feed signal can be obtained by superimposing the co-phase signals. This simplifies the topology of the phase shifting circuit 121 in the antenna device, converts a dual-ended signal to a single-ended signal, and further reduces costs.

[0078] like Figure 7As shown, in an exemplary embodiment, when the phase conversion circuit 120 includes a phase shifting circuit 121, the impedance matching circuit 130 may include a first terminal and at least two second terminals. The impedance matching circuit 130 includes at least two matching sub-circuits 133. Exemplarily, the number of matching sub-circuits 133 is the same as the number of NFC antennas 140. Each NFC antenna 140 is configured with one matching sub-circuit 133.

[0079] In this circuit, the first ends of each matching sub-circuit 133 are connected to each other, and their connection nodes can serve as the first end of the impedance matching circuit 130, which is connected to the phase conversion circuit 120. The second end of each matching sub-circuit 133 serves as the second end of the impedance matching circuit 130, and is respectively connected to the feed end of a near-field communication antenna 140.

[0080] For example, each matching sub-circuit 133 may include a first serial capacitor C1' and a first parallel capacitor C2'. The first terminal of the first serial capacitor C1' can serve as the first terminal of the matching sub-circuit 133 and is connected to the phase conversion circuit 120. The second terminal of the first serial capacitor C1' is connected to the first terminal of the first parallel capacitor C2' and the feed point corresponding to an NFC antenna 140, respectively. The second terminal of the first parallel capacitor C2' is connected to the common ground terminal.

[0081] In an optional embodiment, the number of first serial capacitors C1' can be at least two, and each first serial capacitor C1' is connected in parallel; the number of first parallel capacitors C2' can also be at least two, and each first parallel capacitor C2' is connected in parallel.

[0082] In this embodiment, the impedance matching circuit includes at least two matching sub-circuits, each of which can be connected to the feed point of an NFC antenna. Thus, one matching sub-circuit can be configured for each NFC antenna. The capacitance values ​​of the first and second capacitors in each matching sub-circuit can be configured according to the equivalent inductance of the NFC antenna 140 to which it is connected, allowing the impedance and frequency of each NFC antenna to be matched, thereby improving the near-field communication performance of each NFC antenna.

[0083] like Figure 8 As shown, in an exemplary embodiment, when the phase conversion circuit 120 includes a phase shifting circuit 121, the impedance matching circuit 130 may include a first terminal and at least two second terminals. The impedance matching circuit 130 includes a first matching unit 131 and at least two second matching units 132. The number of second matching units 132 may be the same as the number of NFC antennas 140. Each NFC antenna 140 is correspondingly configured with a second matching unit 132.

[0084] The first end of the first matching unit 131 is connected to the phase conversion circuit 120 as the first end of the impedance matching circuit 130. The first end of each second matching unit 132 is connected to the second end of the first matching unit 131 and the feed end of a near-field communication antenna 140, respectively, and the second end of each second matching unit 132 is connected to the common ground.

[0085] The first matching unit 131 may include at least one second serial capacitor C1'', and the second matching unit 132 may include at least one second parallel capacitor C2''. Their connection method can be referred to the foregoing description, and will not be repeated here.

[0086] In practical applications, the capacitance value of the second serial capacitor C1'' included in the first matching unit 131 is set according to the requirement of impedance matching between multiple NFC antennas 140 and the NFC chip 110, and the capacitance value of the second parallel capacitor C2'' included in the second matching unit 132 can be set according to the equivalent inductance of the NFC antenna 140 connected to it. The capacitance values ​​of each second serial capacitor C1'' can be the same or different, and the capacitance values ​​of each second parallel capacitor C2'' can also be the same or different.

[0087] In the impedance matching circuit of this application, a second matching unit is configured for each NFC antenna to achieve frequency tuning of the near-field communication signal. The same tuning capacitor value can be set for each NFC antenna to achieve frequency tuning of the near-field communication signal. In addition, each NFC antenna can reuse the same first matching unit for impedance matching to reduce costs.

[0088] Please continue to refer to this. Figure 5 In one exemplary embodiment, the phase conversion circuit 120 includes a balun circuit 122. The balun circuit 122 includes an input coil and an output coil. The two ends of the input coil are respectively connected to the first transmitting terminal TX1 and the second transmitting terminal TX2. One end of the output coil is connected to the first terminal of the impedance matching circuit 130, and the other end of the output coil is connected to a common ground terminal. The balun circuit 122 is used to convert the first differential feed signal and the second differential feed signal into a single-ended feed signal. The frequency of the single-ended feed signal is the same as the frequencies of the first differential feed signal and the second differential feed signal, and the amplitude of the single-ended feed signal is also the same as the amplitudes of the first differential feed signal and the second differential feed signal.

[0089] For example, the balun circuit 122 has a turns ratio of 1:1 for its input and output coils, and the balun circuit 12252 can be roughly analogous to a transformer with a turns ratio of 1:1.

[0090] In this embodiment, the balun circuit exhibits excellent common-mode noise suppression, effectively suppressing common-mode interference signals. Furthermore, the balun circuit can convert the first differential feed signal and the second differential feed signal into a single-ended feed signal with the same frequency and amplitude, meeting the single-ended feed requirements of each NFC antenna. In addition, the balun circuit provides even better suppression of common-mode interference signals.

[0091] Please continue to refer to this. Figure 5 In an exemplary embodiment, the phase conversion circuit 120 includes a balun circuit 122, and the first matching unit 131 in the impedance matching circuit 130 of the antenna device may include a plurality of first capacitors C1 connected in parallel, and the second matching unit 132 may include a plurality of second capacitors C2 connected in parallel.

[0092] In practical applications, the number and capacitance of the first capacitors C1 in the first matching unit 131, and the number and capacitance of the second capacitors C2 in the second matching unit 132, can be set according to the number of NFC antennas 140 connected in parallel and the equivalent inductive reactance / inductance value, thereby achieving impedance matching and frequency tuning of the near-field communication signal. The capacitance values ​​of each first capacitor C1 can be the same or different, and the capacitance values ​​of each second capacitor C2 can also be the same or different.

[0093] In one exemplary embodiment, the antenna device further includes a filtering circuit that can filter out interference signals other than near-field communication signals. In this application embodiment, the phase conversion circuit 120 is different, and its corresponding filtering circuit is also different.

[0094] like Figure 9 As shown, the following description uses the phase conversion circuit 120 as an example of the phase shifting circuit 121 to illustrate the filtering circuit of the antenna device.

[0095] The antenna device includes a first filter circuit 150, wherein a first terminal of the first filter circuit 150 is connected to a phase conversion circuit 120, a second terminal of the first filter circuit 150 is connected to an impedance matching circuit 130, and a third terminal of the first filter circuit 150 is connected to a common ground terminal, for filtering out interference signals other than near-field communication signals.

[0096] It is understood that the first filter circuit 150 is connected in series between the phase conversion circuit 120 and the impedance matching circuit 130. Exemplarily, the first filter circuit 150 includes a capacitor and an inductor connected in series or parallel, or at least two capacitors connected in series or parallel. For ease of explanation, the example given is the first filter circuit 150 including a fourth capacitor C4 and a second inductor L2. The first terminal of the second inductor L2 is connected to the phase shift circuit 121, the second terminal of the second inductor L2 is connected to the first terminal of the fourth capacitor C4 and the impedance matching circuit 130, and the second terminal of the fourth capacitor C4 is connected to a common ground.

[0097] In an optional embodiment, the first filter circuit 150 may also include a capacitor and a resistor connected in series.

[0098] In practical applications, the specific circuit form of the first filter circuit 150 is not specifically limited, and is limited to the example described above. It can filter out interference signals other than near-field communication signals.

[0099] In this embodiment, by setting a first filter circuit between the phase shifting circuit and the matching circuit, each NFC antenna can reuse the first filter circuit, which can filter out interference signals and effectively improve the communication performance of near-field communication signals.

[0100] like Figure 10 As shown, in an exemplary embodiment, when the impedance matching circuit 130 includes at least two matching sub-circuits 133, the first filter circuit 150 includes at least two filter units 151, each filter circuit having a different passband frequency range. Exemplarily, different frequency ranges can be understood as the passband frequencies of each filter circuit not being completely identical; they can be completely different, or they can partially overlap.

[0101] The number of filter units 151 can be the same as the number of matching sub-circuits 133. The first end of each filter unit 151 is connected to the phase conversion circuit 120, the second end of each filter unit 151 is connected to a matching sub-circuit 133 respectively, and the third end of each filter unit 151 is connected to the common ground.

[0102] It is understood that each NFC antenna 140 can be individually configured with a matching sub-circuit 133 and a filtering unit 151 connected to the matching sub-circuit 133. For example, each filtering unit 151 may include a fourth capacitor C4 and a second inductor L2. The first terminal of the second inductor L2 is connected to the phase-shifting circuit 121, the second terminal of the second inductor L2 is connected to the first terminal of the fourth capacitor C4 and the matching sub-circuit 133, and the second terminal of the fourth capacitor C4 is connected to a common ground terminal.

[0103] The capacitance value of the fourth capacitor C4 and the inductance value of the second inductor L2 in the filter unit 151 can be set according to the capacitance values ​​of the first capacitor C1 and the second capacitor C2 in the matching sub-circuit 133 connected to it, and the equivalent inductance of the corresponding NFC antenna 140.

[0104] In this embodiment, each NFC antenna can be individually configured with a matching sub-circuit and a filtering unit connected to the matching sub-circuit, which can make the near-field communication signals supported by at least two NFC antennas have different frequencies. In this way, the bandwidth of the near-field communication signal can be increased, thereby improving the near-field communication performance of the antenna device.

[0105] like Figure 11 As shown, the following description uses the phase conversion circuit 120 as an example of the balun circuit 122 to illustrate the filtering circuit of the antenna device.

[0106] In one exemplary embodiment, the antenna device includes a second filter circuit 161 and a third filter circuit 162. Both the second filter circuit 161 and the third filter circuit 162 can filter out interference signals other than near-field communication signals.

[0107] The first terminal of the second filter circuit 161 is connected to the first transmitter TX1, the second terminal of the second filter circuit 161 is connected to one end of the input coil, and the third terminal of the second filter circuit 161 is connected to a common ground. For example, the second filter circuit 161 includes a third inductor L3 and a fifth capacitor C5. The first terminal of the second inductor L3 is connected to the first transmitter TX1, the second terminal of the second inductor L2 is connected to the first terminal of the fifth capacitor C5 and the first end of the input coil of the balun circuit 122, and the second terminal of the fifth capacitor C5 is connected to a common ground.

[0108] The first terminal of the third filter circuit 162 is connected to the second transmitter TX2, the second terminal of the third filter circuit 162 is connected to the other end of the input coil, and the third terminal of the third filter circuit 162 is connected to a common ground. For example, the third filter circuit 162 includes a fourth inductor L4 and a sixth capacitor C6, wherein the first terminal of the third inductor L4 is connected to the second transmitter TX2, the second terminal of the third inductor L3 is connected to the first terminal of the sixth capacitor C6 and the second terminal of the input coil of the balun circuit 122, and the second terminal of the sixth capacitor C6 is connected to a common ground.

[0109] The capacitors and inductors in the second filter circuit 161 and the third filter circuit 162 can form a series resonant circuit. When the resonant frequency of this resonant circuit is the same as or close to the frequency of the near-field communication signal, it can shield interference signals other than the near-field communication signal. In this embodiment, the values ​​of the capacitors and inductors in the second filter circuit 161 and the third filter circuit 162 can be adjusted according to the formula of the series resonant circuit to minimize link loss.

[0110] In practical applications, the specific circuit configurations of the second filter circuit 161 and the third filter circuit 162 are not specifically limited, and are limited to the examples described above. They can filter out interference signals other than near-field communication signals.

[0111] like Figure 12 and Figure 13 As shown, in one exemplary embodiment, the near-field communication chip 110 includes a first receiver TX1 and a second receiver TX2, and the antenna device may further include two receiving circuits. In this embodiment, the phase conversion circuit 120 is different, and the two corresponding receiving circuits are not entirely the same.

[0112] Please continue to refer to this. Figure 12 The following description uses the phase conversion circuit 120 as an example of the phase shifting circuit 121 to illustrate the two receiving circuits of the antenna device.

[0113] Based on the foregoing embodiments, the antenna device further includes a first receiving circuit 171 and a second receiving circuit 172.

[0114] The first receiving circuit 171 is connected to the first receiving terminal TX1 and the impedance matching circuit 130, respectively, and is used to filter out interference signals other than near-field communication signals received by the near-field communication antenna 140. For example, the first receiving circuit 171 may include a series filter branch, which includes a resistor Rx and a first filter capacitor Crx1 connected in series. The first end of the series filter branch is connected to the first receiving terminal TX1, and the second end of the series filter branch is connected to the impedance matching circuit 130 and the feed terminals of each NFC antenna 140. The series filter branch can filter the signals received by each NFC antenna 140 and output near-field communication signals to the near-field communication chip 110 to achieve the reception of near-field communication signals.

[0115] The second receiving circuit 172 is connected to the second receiving terminal TX2 and a common ground terminal, respectively, and is used to filter out interference signals other than near-field communication signals. For example, the second receiving circuit 172 may include a second filter capacitor Crx2, wherein the first terminal of the second filter capacitor Crx2 is connected to the second receiving terminal TX2, and the second terminal of the second filter capacitor Crx2 is connected to the common ground terminal.

[0116] In this embodiment, the second receiving end of the near-field communication chip is connected to the common ground end through the second filter capacitor, which can effectively conduct interference signals generated by other components due to coupling interference to the ground, and avoid conducting interference signals to the near-field communication chip through the second receiving end, thereby effectively improving the antenna device's reception performance of near-field wireless signals.

[0117] Please continue to refer to this. Figure 13 The following description uses the phase conversion circuit 120 as an example of the balun circuit 122 to illustrate the two receiving circuits of the antenna device.

[0118] Based on the foregoing embodiments, the antenna device further includes a third receiving circuit 181 and a fourth receiving circuit 182.

[0119] The third receiving circuit 181 is connected to the first receiving terminal TX1 and one end of the input coil, respectively, and is used to filter out interference signals other than near-field communication signals received by the near-field communication antenna 140.

[0120] The fourth receiving circuit 182 is connected to the second receiving terminal TX2 and the other end of the input coil, respectively, and is used to filter out interference signals other than near-field communication signals received by the near-field communication antenna 140.

[0121] The third receiving circuit 181 and the fourth receiving circuit 182 each include a series filter branch. The first end of the series filter branch of the third receiving circuit 181 is connected to the first receiving terminal TX1, and the second end of its series filter branch is connected to the first end of the input coil of the balun circuit 122. The first end of the series filter branch of the fourth receiving circuit 182 is connected to the second receiving terminal TX2, and the second end of its series filter branch is connected to the second end of the input coil of the balun circuit 122. For example, the series filter branch may include a resistor Rx2 and a filter capacitor Crx3 connected in series.

[0122] In practical applications, the specific circuit configurations of the third receiving circuit 181 and the fourth receiving circuit 182 are not specifically limited, and are limited to the examples described above. They can filter out interference signals other than near-field communication signals.

[0123] In this embodiment, each receiving end of the near-field communication chip 110 is connected to a receiving circuit, which can filter out interference signals other than near-field communication signals received by the near-field communication antenna 140, thereby effectively improving the antenna device's reception performance for near-field wireless signals.

[0124] In one exemplary embodiment, the NFC antenna 140 in the antenna device can be one of the following: a flexible printed circuit (FPC) antenna, a laser direct forming (LDS) antenna, a print direct forming (PDS) antenna, a metal radiator, an in-mold decoration antenna (MDA), or a conductive coil. In this embodiment, the type of NFC antenna 140 is not further limited.

[0125] like Figure 14 As shown, for ease of explanation, the NFC antenna 140 is described as a metal radiator. The metal radiator can be a portion of the conductive frame of the electronic device, for example, the top frame of the conductive frame. For example, the multiple NFC antennas 140 of the antenna device are all portions of the top frame of the conductive frame. For ease of explanation, the antenna device is described as including two NFC antennas 140. The top frame of the conductive frame can be formed into two independent radiating branches by means of a slit, for example, a first radiating branch and a second radiating branch. The first radiating branch and the second radiating branch are two NFC antennas 140.

[0126] In this embodiment, the first and second radiating segments can support not only the radiation of near-field communication signals, but also the radiation of cellular signals, WiFi signals, or Bluetooth signals. Thus, the NFC antenna 140 can reuse its radiating segment that supports cellular signals without the need for additional radiating segments. This is beneficial for the thinner and lighter design of electronic devices and can also improve the communication performance of near-field communication.

[0127] like Figure 15 As shown, further explanation will be given using a mobile phone as an example of the aforementioned antenna device. Specifically, as follows... Figure 15 As shown, the mobile phone may include a memory 31 (which optionally includes one or more computer-readable storage media), processing circuitry 32, a peripheral device interface 33, an antenna arrangement as described in the above embodiments, and an input / output (I / O) subsystem 36. These components optionally communicate via one or more communication buses or signal lines 39. Those skilled in the art will understand that... Figure 15 The mobile phone shown does not constitute a limitation on the mobile phone and may include more or fewer components than shown, or combine certain components, or have different component arrangements. Figure 15 The various components shown are implemented in hardware, software, or a combination of both, including one or more signal processing and / or application-specific integrated circuits.

[0128] Memory 31 optionally includes high-speed random access memory, and also optionally includes non-volatile memory, such as one or more disk storage devices, flash memory devices, or other non-volatile solid-state memory devices. Exemplary examples include software components stored in memory 31 such as an operating system 311, a communication module (or instruction set) 312, a global positioning system (GPS) module (or instruction set) 313, etc.

[0129] The processing circuit 32 and other control circuits can be used to control the operation of the mobile phone. The processing circuit 32 can be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio codec chips 110, application-specific integrated circuits, etc. The processing circuit 32 can be configured to implement control algorithms for controlling the use of the antenna device in the mobile phone. The processing circuit 32 can also issue control commands for controlling various switches in the antenna device.

[0130] I / O subsystem 36 couples input / output peripherals on the mobile phone, such as the keypad and other input control devices, to peripheral interface 33. I / O subsystem 36 optionally includes a touchscreen, buttons, a tone generator, an accelerometer (motion sensor), an ambient light sensor and other sensors, light-emitting diodes and other status indicators, data ports, etc. For example, a user can control the operation of the mobile phone by supplying commands via I / O subsystem 36, and can use the output resources of I / O subsystem 36 to receive status information and other outputs from the mobile phone. For example, a user can press button 361 to turn the mobile phone on or off.

[0131] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this patent application. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An antenna device, characterized in that, include: A near-field communication chip includes a first transmitter and a second transmitter, wherein the first transmitter is used to provide a first differential feed signal and the second transmitter is used to provide a second differential feed signal; A phase conversion circuit, connected to the first transmitting end and the second transmitting end respectively, is used to convert the first differential feed signal and the second differential feed signal into a single-ended feed signal; An impedance matching circuit, wherein the first terminal of the impedance matching circuit is connected to the phase conversion circuit, is used to transmit the single-ended feed signal and to achieve impedance matching; At least two near-field communication antennas, the feed terminal of each near-field communication antenna is connected to the second terminal of the impedance matching circuit, and the ground terminal of each near-field communication antenna is connected to a common ground terminal.

2. The antenna device according to claim 1, characterized in that, The impedance matching circuit includes: A first matching unit, the first end of which is connected to the phase conversion circuit; The second matching unit; the first end of the second matching unit is connected to the second end of the first matching unit and the feed end of each of the near-field communication antennas, and the second end of the second matching unit is connected to the common ground.

3. The antenna device according to claim 2, characterized in that, The first matching unit includes at least one first capacitor, and the second matching unit includes at least one second capacitor; wherein, When there are at least two first capacitors, each first capacitor is connected in parallel. When there are at least two second capacitors, each second capacitor is connected in parallel.

4. The antenna device according to claim 1, characterized in that, The phase conversion circuit includes: The phase-shifting circuit is connected to the first transmitter, the second transmitter, and the impedance matching circuit, respectively. The phase-adjusting circuit is used to adjust the phases of the first differential feed signal and the second differential feed signal to be the same, and to synthesize them into the single-ended feed signal.

5. The antenna device according to claim 4, characterized in that, The impedance matching circuit includes at least two matching sub-circuits; wherein... The first terminal of each of the matching sub-circuits is connected to the phase conversion circuit. The second terminal of each of the matching sub-circuits is connected to the feed terminal of one of the near-field communication antennas.

6. The antenna device according to claim 4, characterized in that, The impedance matching circuit includes: A first matching unit, the first end of which is connected to the phase conversion circuit; At least two second matching units, the first end of each second matching unit is connected to the second end of the first matching unit and the feed end of the near-field communication antenna, respectively, and the second end of each second matching unit is connected to the common ground.

7. The antenna device according to claim 4, characterized in that, The antenna device further includes: A first filtering circuit, wherein a first terminal of the first filtering circuit is connected to the phase conversion circuit, a second terminal of the first filtering circuit is connected to the impedance matching circuit, and a third terminal of the first filtering circuit is connected to the common ground terminal, is used to filter out interference signals other than near-field communication signals.

8. The antenna device according to claim 7, characterized in that, When the impedance matching circuit includes at least two matching sub-circuits, the first filter circuit includes at least two filter units, each of which has a different passband frequency range; wherein, The first end of each filter unit is connected to the phase conversion circuit, the second end of each filter unit is connected to a matching sub-circuit, and the third end of each filter unit is connected to the common ground.

9. The antenna device according to claim 4, characterized in that, The near-field communication chip includes a first receiver and a second receiver, wherein the antenna device further includes: The first receiving circuit is connected to the first receiving end and the impedance matching circuit respectively, and is used to filter out interference signals other than near-field communication signals received by the near-field communication antenna. The second receiving circuit is connected to the second receiving terminal and the common ground terminal respectively, and is used to filter out interference signals other than the near-field communication signal.

10. The antenna device according to any one of claims 1-3, characterized in that, The phase conversion circuit includes: A balun circuit includes an input coil and an output coil. The two ends of the input coil are respectively connected to the first transmitting end and the second transmitting end. One end of the output coil is connected to the first end of the impedance matching circuit, and the other end of the output coil is connected to the common ground. The balun circuit is used to convert the first differential feed signal and the second differential feed signal into a single-ended feed signal.

11. The antenna device according to claim 10, characterized in that, The antenna device further includes: The second filter circuit has a first terminal connected to the first transmitter, a second terminal connected to one end of the input coil, and a third terminal connected to the common ground terminal. The third filter circuit has a first terminal connected to the second transmitter, a second terminal connected to the other end of the input coil, and a third terminal connected to the common ground terminal.

12. The antenna device according to claim 11, characterized in that, The near-field communication chip includes a first receiver and a second receiver, wherein the antenna device further includes: The third receiving circuit is connected to the first receiving end and one end of the input coil, respectively, and is used to filter out interference signals other than near-field communication signals received by the near-field communication antenna. The fourth receiving circuit is connected to the second receiving end and the other end of the input coil, respectively, and is used to filter out interference signals other than the near-field communication signal received by the near-field communication antenna.

13. An electronic device, characterized in that, include: The antenna device as described in any one of claims 1-12.

14. The electronic device according to claim 13, characterized in that, The electronic device includes a conductive frame, and each of the near-field communication antennas is a portion of the conductive frame.

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