A mobile terminal antenna and a mobile terminal

Abstract

The present invention provides a mobile terminal antenna and a mobile terminal. The mobile terminal antenna includes a first radiation unit, a second radiation unit, a coupling unit, and a chip unit disposed on a main board. One end of the first radiation unit is provided with a feeding point, and the feeding point is connected to the chip unit. The other end of the first radiation unit is connected to one end of the second radiation unit through the coupling unit without electrical connection, and the other end of the second radiation unit is grounded. By using the mobile terminal antenna and the mobile terminal provided by the embodiments of the present invention, a coupling unit with cross connection without internal electrical connection gap is adopted, which can avoid using a capacitor between the second radiation unit and the ground point, saving costs and overcoming the performance impact on the antenna caused by the introduction of the capacitor.

Description

Technical Field

[0001] The present invention relates to the technical field of mobile terminals, and in particular, to a mobile terminal antenna and a mobile terminal. Background Art

[0002] An antenna is the most front-end component for a mobile terminal to transmit and receive wireless signals. During transmission, the antenna effectively converts the high-frequency current in the circuit or the guided wave on the feeding transmission line into a space electromagnetic wave of a certain polarization and emits it in a specified direction; during reception, the reverse transformation is performed.

[0003] Currently, many antennas of mobile terminals, in addition to being used as radiators of the antenna, are also used as a capacitive sensor to sense the distance of a human body approaching the mobile terminal. When the distance between the human body and the mobile terminal is lower than a certain set value, the mobile terminal will reduce the transmission power, thereby reducing the SAR (Specific Absorption Rate) value, and further reducing the radiation of the antenna to the human body. Among them, the SAR value is a standard formulated internationally to measure whether electromagnetic wave radiation is safe. Specifically, it refers to the absorption ratio of the human body to electromagnetic radiation, that is, the smaller the SAR value, the less damage to the human body, and vice versa. Its unit is mW / g. Currently, there are two standards for the SAR value, namely CE (European standard) and FCC (American standard). Among them, the CE standard is 2 mW / g, and the FCC standard is 1.6 mW / g.

[0004] The magnitude of the SAR value has a great relationship with the radiation power of the antenna, the radiation direction of the antenna, and the distance between the human body and the antenna. When people use the mobile terminal of a wireless device, they will hold it in their hand or place it on a part of the body. When the human body is closer to the antenna of the device, the SAR value is higher, and vice versa. This requires the designer to ensure that the SAR value meets the standard requirements when the user is in full contact with the antenna. Generally, the greater the radiation power of the antenna, the higher the SAR value, and vice versa. In antenna design, to achieve certain standards for the radiation performance of the antenna, it is necessary to balance the relationship between the SAR value and the antenna performance, in order to achieve a state with a lower SAR value and better antenna performance.

[0005] If the antenna is used as a capacitive sensor for SAR, the grounded part of the antenna needs to pass through a capacitor first and then be grounded, which causes an impact of this capacitor on the antenna performance and also increases the cost. Summary of the Invention

[0006] To solve the above problems, an object of the embodiments of the present invention is to provide a mobile terminal antenna and a mobile terminal.

[0007] In a first aspect, an embodiment of the present invention provides a mobile terminal antenna, including: a first radiation unit, a second radiation unit, a coupling unit, and a chip unit disposed on a main board. One end of the first radiation unit is provided with a feeding point, the feeding point is connected to the chip unit, the other end of the first radiation unit is electrically connected to one end of the second radiation unit through the coupling unit, and the other end of the second radiation unit is grounded.

[0008] In a second aspect, an embodiment of the present invention further provides a mobile terminal, including the above-mentioned mobile terminal antenna.

[0009] The mobile terminal antenna and the mobile terminal provided by the embodiments of the present invention adopt a coupling unit with a cross-connected structure similar to a spiral structure without electrical connection inside, which can avoid using a capacitor between the second radiation unit and the grounding point, saving costs, and at the same time overcoming the performance impact on the antenna caused by the introduction of the capacitor.

[0010] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, makes a detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0012] Figure 1 Shows a circuit schematic diagram of a mobile terminal antenna in the prior art;

[0013] Figure 2 Shows a structural schematic diagram of a mobile terminal antenna in the prior art;

[0014] Figure 3 Shows a first circuit schematic diagram of the mobile terminal antenna provided by the embodiment of the present invention;

[0015] Figure 4 Shows a second circuit schematic diagram of the mobile terminal antenna provided by the embodiment of the present invention;

[0016] Figure 5 Shows a structural schematic diagram of the mobile terminal antenna provided by the embodiment of the present invention;

[0017] Figure 6 Shows a first structural schematic diagram of the coupling unit of the mobile terminal antenna provided by the embodiment of the present invention;

[0018] Figure 7Shows the second structural schematic diagram of the coupling unit of the mobile terminal antenna provided by the embodiment of the present invention;

[0019] Figure 8 Shows the third structural schematic diagram of the coupling unit of the mobile terminal antenna provided by the embodiment of the present invention;

[0020] Figure 9 Shows the fourth structural schematic diagram of the coupling unit of the mobile terminal antenna provided by the embodiment of the present invention;

[0021] Figure 10 Shows Figure 1 Example and Figure 3 S11 comparison simulation schematic diagram of the two examples;

[0022] Figure 11 Shows Figure 1 Example and Figure 3 Efficiency comparison simulation schematic diagram of the two examples;

[0023] Figure 12 Shows the structural schematic diagram of the mobile terminal provided by the embodiment of the present invention.

[0024] Reference numerals: 1 - feeding point, 2 - radiation unit, 3 - main board, 4 - first radiation unit, 5 - second radiation unit, 6 - coupling unit, 7 - SAR control chip, 8 - radio frequency chip, 9 - impedance adjustment unit, 10 - speaker, 11 - USB interface, 12 - motor, 13 - antenna body, 14 - left coupling end, 15 - right coupling end, 16 - coupling branch, 17 - matching unit. Detailed implementation manners

[0025] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0026] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0027] In the present invention, unless otherwise clearly defined and limited, terms such as "installation", "connection", "linkage", "fixation" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] Multiple-Input Multiple-Output (MIMO): Both the transmitting end and the receiving end of a signal include multiple radiation units. If the spacing between the radiation units is very far, the correlation between the radiation units will be very low. However, in mobile terminals such as mobile phones, due to the small space, the radiation units will not work relatively independently, but will generate strong electromagnetic coupling with each other.

[0029] Coupling: When there are more than two radiation units arranged in free space, a certain radiation unit is affected not only by the electromagnetic action generated by its own current, but also by the electromagnetic action generated by the currents of other radiation units. Especially when the radiation units are close to each other, complex interactions will occur between them, and this kind of interaction is called mutual coupling.

[0030] Isolation: The degree of independence of radiation units. The smaller the coupling degree between radiation units, the greater the isolation; conversely, the greater the coupling degree between radiation units, the smaller the isolation. For example, in practical applications, an isolation of 15 dB can meet the engineering requirements.

[0031] Pattern diversity: The power radiated by radiation units is generally unevenly distributed in all directions in space, that is, the antenna has directivity. The pattern is a function graph between the radiation characteristics of the antenna and the space coordinates, and it is a graphical description method of the directivity of the antenna. Therefore, pattern diversity can analyze the radiation characteristics of radiation units.

[0032] Polarization diversity: Two signals from the same signal source are carried by radio waves with different polarization directions of radiation units. For example, vertical polarization and horizontal polarization. These two signals are independent of each other, uncorrelated, and have different attenuation characteristics, having the effect of polarization diversity.

[0033] Microstrip line: A microstrip line is a microwave transmission line composed of a single conductor strip, which is suitable for making planar structure transmission lines of microwave integrated circuits. It has the advantages of small volume, light weight, wide operating frequency band, high reliability, and low manufacturing cost, with high conductor conductivity and good stability.

[0034] Throughput: The amount of signal that a communication system can transmit within a unit of time / bandwidth. Since the essence of a communication system is signal transmission, throughput is one of the most important system metrics for measuring a communication system.

[0035] Antenna Q value: The ratio of the energy storage to the energy dissipation of an antenna near the resonance point, which is used to characterize the sensitivity of the antenna resonance characteristics to frequency. The higher the Q value, the higher the sensitivity of the antenna resonance to frequency, and the narrower the corresponding reflection coefficient bandwidth.

[0036] Currently, during the design process of mobile terminals, in addition to considering the transmitting and receiving performance (TRP and TIS) of mobile terminal antennas, the magnitude of the radiation power of mobile terminals to the human body also needs to be considered. Excessive radiation power may cause harm to the human body. Therefore, there is also an important test metric for mobile terminal antennas, which is SAR, and this metric is used to measure the radiation magnitude of mobile terminals to the human body.

[0037] Previously, the way to solve the SAR of mobile terminals was to debug the antenna traces. However, now, because the SAR metric of the human body needs to be tested, the method of debugging antenna traces can no longer meet the requirements. The most direct way is to reduce the conduction power of the mobile phone, which directly reduces the transmitting performance of the antenna and the SAR value will also decrease. However, this method will also make the transmitting performance of the mobile terminal fail to meet the standards.

[0038] Currently, the conventional solution is to add a SAR control chip and regard the antenna itself as a sensor. When the mobile terminal is closer to the human body than the safe distance, the conduction power of the mobile terminal decreases, and the mobile terminal antenna will not cause harm to the human body; when the mobile terminal is not closer to the human body than the safe distance, the mobile terminal transmits power normally. In the above process, the mobile terminal antenna needs to act as both a transmitting antenna and a sensor for detecting the distance at the same time. Therefore, for the mobile terminal antenna, two branches need to be connected simultaneously, one is the branch of the antenna, and the other is the branch of the capacitive sensor, and there will inevitably be a conflict between the two.

[0039] The signal propagated by the mobile terminal antenna belongs to a high-frequency signal, and the signal of the sensor belongs to a low-frequency signal. Inductors and capacitors can be used to separate the high-frequency and low-frequency signals respectively, so that the two do not interfere with each other.

[0040] As Figure 1 、 Figure 2 shown, one end of the feeding point 1 is connected to one end of the radiation element 2. The radiation element 2 is arranged on the main board 3. The other end of the radiation element 2 is grounded through the capacitor C2. The other end of the feeding point 1 is respectively connected to the SAR control chip 7 and the radio frequency chip 8. Among them, the other end of the feeding point 1 is connected to the SAR control chip 7 through the inductor L1, and is connected to the radio frequency chip 8 through the series circuit of the capacitor C1 and the antenna matching unit 9.

[0041] Among them, the antenna matching unit 9 uses a series-parallel combination of inductors and capacitors to adjust the antenna impedance, reduce the reflection of signals at the antenna input end, and enable more signals to enter the antenna.

[0042] In Figure 1 the prior art, L1 is a relatively large inductor, L1 > 100 nH. For a high-frequency antenna, this inductor is equivalent to an open state, having little impact on the antenna performance. Its function is to isolate the influence of the SAR control chip 7 on the antenna. For the low-frequency SAR control chip 7, this inductor is equivalent to a conducting path.

[0043] In Figure 1 the prior art, C1 is a relatively large capacitor, C1 > 20 pF. This capacitor is equivalent to a conducting path for the branch of the antenna RF chip 8, with little impact. For the branch of the SAR control chip 7, this capacitor is equivalent to an open state, isolating the influence of the RF signal on the SAR control chip 7.

[0044] In Figure 1 the prior art, C2 is a relatively large capacitor, C2 > 20 pF. Here, the antenna should be grounded, but grounding the antenna is equivalent to grounding the SAR control chip 7, so that the SAR control chip 7 will not play its corresponding role. Therefore, the capacitor C2 is used, but the capacitor C2 will have an impact on the antenna performance:

[0045] (1) As a passive device, C2 itself has insertion loss and will consume a certain amount of energy;

[0046] (2) Inserting the capacitor C2 at the end of the antenna will affect the antenna impedance and is not conducive to antenna debugging.

[0047] In Figure 1 the technical solution of the mobile terminal antenna in the prior art, the radiation unit 2 of the antenna is a continuous piece of metal without being disconnected.

[0048] As Figure 3 shown, in the embodiment of the present invention, it includes a first radiation unit 4, a second radiation unit 5, a coupling unit 6, and a chip unit disposed on the main board 3. One end of the first radiation unit 4 is provided with a feeding point, and the feeding point 1 is connected to the chip unit. The other end of the first radiation unit 4 is electrically connected to one end of the second radiation unit 5 through the coupling unit 6, and the other end of the second radiation unit 5 is grounded.

[0049] In an embodiment of the present invention, the introduction of the coupling unit 6 enables the second radiation unit 5 to be directly grounded without using a capacitor at the grounding point of the antenna. Through the coupling process of the coupling unit 6 at the end of the antenna, energy is transmitted to the grounding point through the second radiation unit 5. However, the first radiation unit 4 and the second radiation unit 5 are not directly physically connected, which is equivalent to being disconnected for the sensor signal of the chip unit and not connected to the grounding point. Preferably, the mobile terminal antenna of the embodiment of the present invention further includes a matching unit 17. The chip unit includes a SAR control chip 7 and a radio frequency chip 8. The feeding point 1 is electrically connected to the chip unit through the matching unit 17. That is to say, the first radiation unit 4 and the second radiation unit 5 are not directly physically connected and are disconnected for the sensor signal of the SAR control chip 7 in the chip unit.

[0050] Specifically, as a sensor, when the antenna approaches the human body, a capacitive effect will be generated, and this capacitive effect will be transmitted to the SAR control chip 7. The SAR control chip 7 judges the distance between the antenna and the human body according to the magnitude of the induced capacitance transmitted.

[0051] In Figure 3 the embodiment of the present invention, it is possible to avoid using a capacitor between the second radiation unit 5 and the grounding point, saving costs and reducing the performance impact on the antenna caused by the introduction of the capacitor. For specific impacts, refer to the above content.

[0052] As Figure 3 shown, the embodiment of the present invention introduces the coupling unit 6 to divide the mobile terminal antenna into two unconnected parts, namely the first radiation unit 4 and the second radiation unit 5. The first radiation unit 4 and the second radiation unit 5 are arranged on the main board 3. One end of the first radiation unit 4 is connected to one end of the second radiation unit 5 through the coupling unit 6. The other end of the second radiation unit 5 is grounded. The other end of the first radiation unit 4 is connected with a feeding point 1, and the feeding point 1 is connected with the chip unit.

[0053] In the embodiment of the present invention, the matching unit 17 includes an inductor L1, a capacitor C1, and an impedance adjustment unit 9. The feeding point 1 is connected to both the SAR control chip 7 and the radio frequency chip 8 at the same time. Among them, the feeding point 1 is connected to the SAR control chip 7 through the inductor L1, and the feeding point 1 is connected to the radio frequency chip 8 through the capacitor C1 and the impedance adjustment unit 9. Preferably, the feeding point 1 is connected to the radio frequency chip 8 through a series branch composed of the capacitor C1 and the impedance adjustment unit 9. Of course, other connection methods can also be set between the capacitor C1 and the impedance adjustment unit 9, as long as the feeding point 1 and the radio frequency chip 8 can be connected, and no further limitation is made here.

[0054] Among them, the main board 3 is a conventional PCB (Printed Circuit Board, printed circuit board).

[0055] Among them, the impedance adjustment unit 9 uses a series-parallel combination of inductors and capacitors. Its function is to adjust the antenna impedance, reduce the reflection of signals at the antenna input end, and enable more signals to enter the antenna.

[0056] In Figure 4 and Figure 5 in the embodiments of the present invention, the branch of the capacitive sensor is composed of the inductor L1 and the SAR control chip 7, and the branch of the antenna is composed of the capacitor C1, the impedance adjustment unit 9, and the RF chip 8. The two branches are connected to the feeding point 1.

[0057] As Figures 6 - 9 shown, the coupling unit 6 includes a coupling left end 14 and a coupling right end 15. The coupling left end 14 is connected to one end of the second radiation unit 5, and the coupling right end 15 is connected to the other end of the first radiation unit 4. The coupling left end 14 and the coupling right end 15 are connected in a cross manner through a slit without electrical connection.

[0058] Specifically, a slit is provided between the above-mentioned coupling left end 14 and the coupling right end 15, and there is no direct physical connection. The width of the slit can be set according to actual needs, and the width of the slit can be the width of the slit at any position between the coupling left end 14 and the coupling right end 15.

[0059] Among them, the width of the slit of the above-mentioned slit is between 0.2 mm and 1.2 mm. The larger the width, the lower the coupling degree, and the smaller the width, the stronger the coupling. In actual debugging, the width of the slit is appropriately adjusted according to the need of coupling strength.

[0060] Specifically, the coupling unit is composed of two separate radiation units that are not electrically connected to each other and cross each other. The coupling left end 14 is one radiation unit, and the coupling right end 15 is the other radiation unit. The cross structure is as Figures 6 - 9 shown. Due to the existence of the slit between the coupling left end 14 and the coupling right end 15, when the antenna transmits high-frequency signals, the two radiation units cross each other, and the high-frequency signals can be transmitted from the first radiation unit 4 to the second radiation unit 5 through the coupling method. The cross part of the coupling unit 6 should be as much as possible, so as to increase the mutual coupling amount. However, when the antenna is used as a capacitive sensor, the signal used by the capacitive sensor is a low-frequency signal, and there is no coupling between the first radiation unit 4 and the second radiation unit 5 in the low-frequency state, and they can be regarded as disconnected. Therefore, the function of the coupling unit 6 is to block low-frequency and connect high-frequency.

[0061] The mobile terminal antenna in the embodiments of the present invention neither introduces an additional capacitor (such as C2) to affect the antenna performance and reduce the cost, nor realizes the function of multiplexing the antenna as a capacitive sensor.

[0062] As Figure 7As shown, the coupling unit further includes a coupling stub 16 for increasing the radiation area of the antenna. Preferably, the coupling stub 16 is configured in a U-shaped stub structure. The shape of the coupling stub 16 can also be set to other structures according to the actual situation of the antenna, which is not limited herein.

[0063] As Figure 6 shown, the structure of the first coupling unit of the mobile terminal antenna according to the embodiment of the present invention is disclosed. The first radiation unit 4 and the second radiation unit 5 are connected to each other through the coupling right end 15 and the coupling left end 14 of the coupling unit 6.

[0064] Among them, both the coupling left end 14 and the coupling right end 15 of the coupling unit 6 are in a serrated structure. The first radiation unit 4 and the second radiation unit 5 are connected through the serrated structure. The energy of the first radiation unit 4 can be transmitted to the second radiation unit 5 through the coupling unit 6. The existence of the slit will cause some energy loss.

[0065] Specifically, one end of the first radiation unit 4 is connected to the coupling right end 15, and one end of the second radiation unit 5 is connected to the coupling left end 14. The coupling right end 15 connected to one end of the first radiation unit 4 is in a serrated structure, and the coupling left end 14 connected to one end of the second radiation unit 5 is also in a serrated structure. The above-mentioned coupling right end 15 and the coupling left end 14 are cross-connected to form the coupling unit 6. The other ends of the first radiation unit 4 and the second radiation unit 5 are respectively connected to the feeding point 1 and the grounding point, thus forming a loop antenna.

[0066] Preferably, in the embodiment of the present invention Figure 6 , the serrated structure generally adopts an equidistant setting, that is, the pitch distance between every two adjacent serrations of the serrated structure is equal. The adjacent pitch of the serrations is generally between 0.3 mm and 1 mm, and can be adjusted according to the actual situation. The shape of the serrations of the serrated structure is generally regularly set, for example, it can be set into a rectangle, a triangle, a square, etc.

[0067] When the antenna transmits high-frequency signals, the first radiation unit 4 and the second radiation unit 5 cross each other, and the high-frequency signals can be transmitted from the first radiation unit 4 to the second radiation unit 5 by coupling. The more the cross-sectional parts of the serrated structure of the coupling unit 6, the more the overall coupling amount of the antenna. When the antenna transmits low-frequency signals, the coupling unit 6 is equivalent to a capacitor, that is, when the antenna is used as a capacitive sensor, the signal used by the capacitive sensor is a low-frequency signal. The first radiation unit 4 and the second radiation unit 5 have no coupling in the low-frequency state and can be regarded as disconnected. Therefore, the function of the coupling unit 6 is to block low-frequency signals and connect high-frequency signals.

[0068] As Figure 7As shown, the structure of the second coupling unit of the mobile terminal antenna according to an embodiment of the present invention is disclosed. The first radiation unit 4 and the second radiation unit 5 are connected to each other through the coupling right end 15 and the coupling left end 14 of the coupling unit 6.

[0069] Among them, the coupling left end 14 and the coupling right end 15 have a concave-convex structure that matches each other. If the coupling left end 14 has a "concave" structure, the coupling right end 15 has a "convex" structure; if the coupling left end 14 has a "convex" structure, the coupling right end 15 has a "concave" structure.

[0070] The first radiation unit 4 and the second radiation unit 5 are connected through the concave-convex structure, and the energy of the first radiation unit 4 can be transmitted to the second radiation unit 5 through the coupling unit 6. The existence of the slit will cause some energy loss.

[0071] As Figure 8 shown, the structure of the third coupling unit of the mobile terminal antenna according to an embodiment of the present invention is disclosed. The first radiation unit 4 and the second radiation unit 5 are connected to each other through the coupling right end 15 and the coupling left end 14 of the coupling unit 6.

[0072] Among them, the coupling left end 14 and the coupling right end 15 have a U-shaped structure with opposite openings. The first radiation unit 4 and the second radiation unit 5 are connected through the U-shaped structure with opposite openings. The energy of the first radiation unit 4 can be transmitted to the second radiation unit 5 through the coupling unit 6. The existence of the slit will cause some energy loss.

[0073] As Figure 9 shown, the structure of the fourth coupling unit of the mobile terminal antenna according to an embodiment of the present invention is disclosed. The first radiation unit 4 and the second radiation unit 5 are connected to each other through the coupling right end 15 and the coupling left end 14 of the coupling unit 6.

[0074] Among them, the coupling left end 14 and the coupling right end 15 have a spiral structure. The first radiation unit 4 and the second radiation unit 5 are connected through the spiral structure. The energy of the first radiation unit 4 can be transmitted to the second radiation unit 5 through the coupling unit 6. The existence of the slit will cause some energy loss.

[0075] Specifically, one end of the first radiation unit 4 is connected to the coupling right end 15, one end of the second radiation unit 5 is connected to the coupling left end 14. The coupling right end 15 connected to one end of the first radiation unit 4 has a spiral structure, and the coupling left end 14 connected to one end of the second radiation unit 5 also has a spiral structure. The above-mentioned coupling right end 15 and the coupling left end 14 are cross-connected to form the coupling unit 6. The other ends of the first radiation unit 4 and the second radiation unit 5 are respectively connected to the feeding point 1 and the grounding point, thus forming a loop antenna.

[0076] When the antenna transmits high-frequency signals, the first radiation unit 4 and the second radiation unit 5 cross each other. The high-frequency signals can be transmitted from the first radiation unit 4 to the second radiation unit 5 by means of coupling. The more the cross-sectional parts of the spiral structure of the coupling unit 6 are, the more the overall coupling amount of the antenna is. When the antenna transmits low-frequency signals, the coupling unit 6 is equivalent to a capacitor. That is, when the antenna is used as a capacitive sensor, the signals used by this capacitive sensor are low-frequency signals. There is no coupling between the first radiation unit 4 and the second radiation unit 5 in the low-frequency state and they can be regarded as disconnected. Therefore, the function of the coupling unit 6 is to block low-frequency signals and connect high-frequency signals.

[0077] It should be noted that the shapes, sizes, lengths, materials, etc. of the radiation unit 2, the first radiation unit 4, and the second radiation unit 5 in the embodiments of the present invention can be set according to actual needs, and the embodiments of the present invention do not limit this here.

[0078] From Figure 10 and Figure 11 the simulation results of, Figure 3 the antenna with a coupling unit adopted in the embodiment and Figure 1 the antenna without a coupling unit adopted in the embodiment, the antenna performance differences between the two are small, but the antenna with a coupling unit realizes the non-grounding of the radiation unit of the antenna body, effectively overcoming the influence of the introduced capacitor on the antenna performance.

[0079] The influence of the introduced capacitor on the antenna performance includes but is not limited to:

[0080] (1) As a passive device, the introduced capacitor itself has insertion loss and will consume a certain amount of energy;

[0081] (2) Inserting an introduced capacitor at the end of the antenna will affect the impedance of the antenna, which is not conducive to the debugging of the antenna.

[0082] Preferably, the first radiation unit 4, the second radiation unit 5, and the coupling unit 6 form a loop antenna (Loop Antenna) or an IFA antenna.

[0083] As Figure 12 shown, the mobile terminal of the embodiment of the present invention includes components such as a speaker 10, a USB (Universal Serial Bus) interface 11, a motor 12, and an antenna body 13.

[0084] In Figure 12 the embodiment of the present invention, setting the mobile terminal antenna body 13 in the clearance area of the PCB main board 3 can reduce the influence of devices such as the USB interface 11, the motor 12, or the microphone on the performance of this antenna. The so-called clearance area of the PCB means that no other devices are arranged in this area.

[0085] The application scenarios of the mobile terminal antenna according to the embodiments of the present invention include various mobile terminals, including communication antennas in 2G / 3G / 4G / 5G frequency bands of mobile phones, laptop devices, etc., or GPS / BT / WiFi antennas, etc. Further, the operating frequency band of the mobile terminal antenna according to the embodiments of the present invention is 1710 MHz - 2690 MHz, covering frequency bands such as GSM 1800 / 1900, WCDMA Band1 / 2 / 3 / 4, LTE Band 1 / 2 / 3 / 4 / 7 / 38 / 39 / 40 / 41, etc. The main board 3 is specifically a flexible printed circuit board FPC (Flexible Printed Circuit) mounted on the antenna bracket, or is made by processes such as LDS (Laser Direct Structuring).

[0086] Some mobile terminals, such as mobile phones, may use a metal frame as the mobile phone antenna. The feeding point of the mobile phone antenna is connected to the radio frequency end of the mobile phone main board through a coaxial cable, and the signal of the antenna as a sensor is connected to the SAR control chip of the main board through the cable of the mobile phone.

[0087] As described above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any technical personnel familiar with the technical field of the present invention can easily think of technical solutions of changes or substitutions within the technical scope disclosed by the present invention, and all should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims described above.

Claims

1. A mobile terminal antenna, characterized in that, Comprising: A first radiation unit, a second radiation unit, a coupling unit, and a chip unit disposed on a main board. One end of the first radiation unit is provided with a feeding point, the feeding point is connected to the chip unit, the other end of the first radiation unit is connected to one end of the second radiation unit through the coupling unit without electrical connection, and the other end of the second radiation unit is grounded; The antenna further includes a matching unit. The chip unit includes a SAR control chip and a radio frequency chip; the feeding point is electrically connected to the chip unit through the matching unit; The matching unit includes an inductor, a capacitor, and an impedance adjustment unit; the feeding point is connected to the SAR chip through the inductor, and the feeding point is connected to the radio frequency chip through the capacitor and the impedance adjustment unit; the inductor and the SAR control chip form a capacitive sensor branch, and the capacitor, the impedance adjustment unit, and the radio frequency chip form an antenna branch; the antenna branch is used to transmit high-frequency signals, and the capacitive sensor branch is used to transmit low-frequency signals; When transmitting high-frequency signals, the first radiation unit transmits high-frequency signals to the second radiation unit in a coupling manner through the coupling unit; When transmitting low-frequency signals, there is no coupling between the first radiation unit and the second radiation unit, and the coupling unit is equivalent to an open state.

2. The antenna according to claim 1, wherein The coupling unit includes a coupling left end and a coupling right end. The coupling left end is connected to one end of the second radiation unit, the coupling right end is connected to the other end of the first radiation unit, and the coupling left end and the coupling right end are connected in a cross manner with a non-electrical connection gap.

3. The antenna according to claim 2, characterized in that, The coupling unit further includes coupling branches for increasing the radiation area of the antenna.

4. The antenna according to claim 2, wherein The coupling left end and the coupling right end are in a mutually adapted concave-convex structure, and the first radiation unit and the second radiation unit are connected through the concave-convex structure.

5. The antenna according to claim 2, characterized in that, The coupling left end and the coupling right end are in a serrated structure, and the first radiation unit and the second radiation unit are connected through the serrated structure.

6. The antenna according to claim 5, wherein the serrated structure is arranged at equal intervals, and the adjacent tooth pitch of the serrated structure is between 0.3 mm and 1 mm.

7. The antenna according to claim 2, wherein The coupling left end and the coupling right end are in a U-shaped structure with opposite openings, and the first radiation unit and the second radiation unit are connected through the U-shaped structure with opposite openings.

8. The antenna according to claim 2, characterized in that The coupling left end and the coupling right end are in a spiral structure, and the first radiation unit and the second radiation unit are connected through the spiral structure.

9. The antenna according to claim 1 or 2, characterized in that, The first radiation unit, the second radiation unit, and the coupling unit form a loop antenna or an IFA antenna.

10. The antenna according to claim 2, wherein The gap width of the gap is between 0.2 mm and 1.2 mm.

11. A mobile terminal, characterized in that, Including the mobile terminal antenna according to any one of claims 1-10.

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