Monopole antenna and intelligent terminal

Abstract

The utility model provides a monopole antenna and an intelligent terminal, the monopole antenna comprises an antenna radiator, a feed source and a signal processing circuit, the antenna radiator is not in contact with the side wall of a battery compartment of the intelligent terminal, and the projection length of the antenna radiator on the side wall of the battery compartment is greater than half of the total length of the antenna radiator; the antenna comprises an antenna radiator, a feed source and a signal processing circuit, the feed source is electrically connected with the antenna radiator through the signal processing circuit, and the signal processing circuit is configured to process a radio frequency signal transmitted by the feed source, so that the radio frequency signal is in a preset working frequency band. The monopole antenna provided by the utility model has high radiation efficiency in a small clearance environment in the intelligent terminal.

Description

Technical Field

[0001] This application relates to the field of communication technology, specifically to a monopole antenna and a smart terminal. Background Technology

[0002] With the rapid development of mobile communication, the communication technology of smart terminals has also been strengthened. Among them, the antenna is one of the core components for smart terminals to realize wireless communication, and its design and performance directly affect the communication capabilities and user experience of terminal devices.

[0003] In some solutions, a portion of the metal frame of the smart terminal is used as an antenna radiator for the communication frequency band. This antenna is physically connected to the battery compartment inside the smart terminal, and there is clearance between the side wall of the battery compartment and the antenna radiator.

[0004] As smart terminals become thinner and lighter, the battery compartment also becomes thinner and wider, resulting in a smaller clearance between it and the antenna radiator. Consequently, the antenna structure in related technologies has lower radiation efficiency under such conditions. Utility Model Content

[0005] To address the aforementioned technical problems, this application provides a monopole antenna and a smart terminal, wherein the monopole antenna has high radiation efficiency in a relatively small clearance environment within the smart terminal.

[0006] To address the aforementioned technical problems, this application provides a monopole antenna, comprising:

[0007] The antenna radiator does not contact the side wall of the battery compartment of the smart terminal, and the projected length of the antenna radiator on the side wall of the battery compartment is greater than half of the total length of the antenna radiator.

[0008] The feed source and signal processing circuit are provided. The feed source is electrically connected to the antenna radiator through the signal processing circuit. The signal processing circuit is configured to process the radio frequency signal transmitted by the feed source so that the radio frequency signal is within a preset operating frequency band.

[0009] Optionally, the antenna radiator operates in 1 / 2λ mode, where λ is the wavelength corresponding to the center frequency of the resonant frequency of the antenna radiator.

[0010] Optionally, the projected length of the antenna radiator on the side wall of the battery compartment is greater than three-quarters of the total length of the antenna radiator.

[0011] Optionally, the total length L of the antenna radiator satisfies the relationship between the wavelength λ0 corresponding to the preset operating frequency band: 3 / 8λ0 < L < 1 / 2λ0.

[0012] Optionally, the length of the antenna radiator is 70-90 mm.

[0013] Optionally, the signal processing circuit includes a tuning circuit, and the tuning circuit and the feed source are connected in series on the antenna radiator. The tuning circuit is used to tune the radio frequency signal transmitted by the feed source so that the radio frequency signal is within a preset operating frequency band.

[0014] Optionally, the tuning circuit includes a first tuning circuit, which includes a first capacitor connected between the antenna radiator and the feed source, the first capacitor being used to excite electromagnetic waves in the preset operating frequency band.

[0015] Optionally, the tuning circuit further includes a second tuning circuit, which includes a first control switch and at least one second capacitor. The second capacitor is electrically connected to the first capacitor, and one end of the first control switch is electrically connected to the second capacitor, while the other end is grounded.

[0016] Optionally, the tuning circuit further includes a third tuning circuit, which includes a third capacitor, a fourth capacitor, and a second control switch. The third capacitor is electrically connected between the first capacitor and the antenna radiator, the fourth capacitor is connected in parallel with the third capacitor, and the second control switch is electrically connected between the fourth capacitor and the antenna radiator.

[0017] The monopole antenna provided in this application has at least the following beneficial effects:

[0018] When this antenna is applied to a smart terminal, the antenna radiator does not contact the side wall of the battery compartment and has no grounding point. Furthermore, the 1 / 2λ mode generated by the antenna under excitation (λ is the wavelength corresponding to the resonant frequency of the antenna radiator) is independent of the motherboard current mode. This makes the antenna performance less affected by the motherboard current distribution and highly adaptable to small clearance environments. Compared with related technologies where the antenna is grounded to the side wall of the battery compartment to generate the 1 / 4λ mode, the antenna of this application has higher radiation efficiency under the same volume clearance.

[0019] This application also provides a smart terminal, which includes a monopole antenna provided by any of the above-described solutions.

[0020] Optionally, it also includes a motherboard and a metal frame, with the feed of the monopole antenna disposed on the motherboard; the metal frame surrounds the outer periphery of the motherboard, and a portion of the metal frame is the antenna radiator. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0022] Figure 1 A schematic diagram of the hardware structure of a smart terminal to implement the various embodiments of this application;

[0023] Figure 2 A communication network system architecture diagram provided for an embodiment of this application;

[0024] Figure 3 This is a schematic diagram of the layout structure of a monopole antenna on a smart terminal according to an embodiment of this application;

[0025] Figure 4 It is shown Figure 3 Enlarged structural diagram of area A in the middle;

[0026] Figure 5 It is shown Figure 3 Current distribution diagram of the unipolar 1 / 2λ mode of the radiator of the medium-capacitor-excited antenna;

[0027] Figure 6 This is a Smith chart of the port impedance of the antenna radiator of the monopole antenna provided in this application embodiment without capacitor excitation;

[0028] Figure 7 This is a comparison chart of the radiation efficiency of the monopole antenna provided in the embodiments of this application and a conventional 1 / 4λ ground-mounted antenna;

[0029] Figure 8 This is a schematic diagram of the layout of a monopole antenna including a second tuning circuit provided in an embodiment of this application;

[0030] Figure 9 yes Figure 8 Waveform diagram of port reflection coefficient when the first control switch is switched to different states;

[0031] Figure 10 This is a schematic diagram of the layout of a monopole antenna including a third tuning circuit provided in an embodiment of this application;

[0032] Figure 11 yes Figure 10 Waveform of port reflection coefficient under intermediate serial tuning;

[0033] Figure 12 yes Figure 3The embodiment provides a current distribution diagram of the antenna radiator under multiple modes;

[0034] Figure 13 This is a waveform diagram of the port reflection coefficient of a multimode monopole antenna.

[0035] The realization of the objectives, functional features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. The accompanying drawings have illustrated specific embodiments of this application, which will be described in more detail below. These drawings and textual descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concepts of this application to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0036] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0037] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, components, features, and elements with the same names in different embodiments of this application may have the same meaning or different meanings, the specific meaning of which must be determined by its interpretation in that specific embodiment or further in conjunction with the context of that specific embodiment.

[0038] It should be understood that although the terms first, second, third, etc., may be used herein to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this document, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if," as used herein, may be interpreted as "when," "when," or "in response to determination." Furthermore, as used herein, the singular forms "a," "an," and "the" are intended to also include the plural forms unless the context indicates otherwise. It should be further understood that the terms "comprising," "including," indicate the presence of the stated feature, step, operation, element, component, item, kind, and / or group, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, kinds, and / or groups. The terms "or," "and / or," "including at least one of the following," etc., as used in this application, may be interpreted as inclusive, or mean any one or any combination thereof. For example, "including at least one of the following: A, B, C" means "any one of the following: A; B; C; A and B; A and C; B and C; A and B and C." Similarly, "A, B, or C" or "A, B, and / or C" means "any one of the following: A; B; C; A and B; A and C; B and C; A and B and C." Exceptions to this definition only occur when the combination of elements, functions, steps, or operations is inherently mutually exclusive in some way.

[0039] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0040] In the following description, the use of suffixes such as "module," "part," or "unit" to denote elements is solely for the purpose of illustrative purposes and has no specific meaning in itself. Therefore, "module," "part," or "unit" may be used interchangeably.

[0041] Smart terminals can be implemented in various forms. For example, the smart terminals described in this application may include smart terminals such as mobile phones, tablets, laptops, handheld computers, personal digital assistants (PDAs), portable media players (PMPs), navigation devices, wearable devices, smart bracelets, pedometers, etc., as well as fixed terminals such as digital TVs and desktop computers.

[0042] The following description will use a mobile terminal as an example. Those skilled in the art will understand that, apart from elements specifically designed for mobile purposes, the construction according to the embodiments of this application can also be applied to fixed-type terminals.

[0043] Please see Figure 1 This is a schematic diagram of the hardware structure of a mobile terminal implementing various embodiments of this application. The smart terminal 100 may include: an RF (Radio Frequency) unit 101, a WiFi module 102, an audio output unit 103, an A / V (Audio / Video) input unit 104, a sensor 105, a display unit 106, a user input unit 107, an interface unit 108, a memory 109, a processor 110, and a power supply 111, etc. Those skilled in the art will understand that... Figure 1 The mobile terminal structure shown does not constitute a limitation on the mobile terminal. The mobile terminal may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0044] The following is combined Figure 1 A detailed introduction to each component of the mobile terminal:

[0045] The radio frequency unit 101 can be used for receiving and transmitting signals during information transmission or calls. Specifically, it receives downlink information from the base station and processes it with the processor 110; additionally, it transmits uplink data to the base station. Typically, the radio frequency unit 101 includes, but is not limited to, an antenna, at least one amplifier, a transceiver, a coupler, a low-noise amplifier, and a duplexer. Furthermore, the radio frequency unit 101 can also communicate wirelessly with networks and other devices. The aforementioned wireless communications may use any communication standard or protocol, including but not limited to GSM (Global System of Mobile communication), GPRS (General Packet Radio Service), CDMA2000 (Code Division Multiple Access 2000), WCDMA (Wideband Code Division Multiple Access), TD-SCDMA (Time Division-Synchronous Code Division Multiple Access), FDD-LTE (Frequency Division Duplexing-Long Term Evolution), TDD-LTE (Time Division Duplexing-Long Term Evolution), and 5G, etc.

[0046] WiFi is a short-range wireless transmission technology. Mobile terminals, through the WiFi module 102, can help users send and receive emails, browse web pages, and access streaming media, providing users with wireless broadband internet access. Although Figure 1 WiFi module 102 is shown, but it is understood that it is not a necessary component of a mobile terminal and can be omitted as needed without changing the nature of the application.

[0047] The audio output unit 103 can convert audio data received by the radio frequency unit 101 or the WiFi module 102 or stored in the memory 109 into audio signals and output them as sound when the smart terminal 100 is in call signal receiving mode, call mode, recording mode, voice recognition mode, broadcast receiving mode, etc. Furthermore, the audio output unit 103 can also provide audio output related to specific functions performed by the smart terminal 100 (e.g., call signal receiving sound, message receiving sound, etc.). The audio output unit 103 may include a speaker, a buzzer, etc.

[0048] The A / V input unit 104 is used to receive audio or video signals. The A / V input unit 104 may include a graphics processing unit (GPU) 1041 and a microphone 1042. The GPU 1041 processes image data of still images or videos acquired by an image capture device (such as a camera) in video capture mode or image capture mode. The processed image frames can be displayed on the display unit 106. The image frames processed by the GPU 1041 can be stored in the memory 109 (or other storage medium) or transmitted via the radio frequency unit 101 or the WiFi module 102. The microphone 1042 can receive sound (audio data) in operating modes such as telephone call mode, recording mode, and voice recognition mode, and can process such sound into audio data. The processed audio (voice) data can be converted into a format that can be transmitted to a mobile communication base station via the radio frequency unit 101 in telephone call mode. The microphone 1042 can implement various types of noise cancellation (or suppression) algorithms to eliminate (or suppress) noise or interference generated during the reception and transmission of audio signals.

[0049] The smart terminal 100 also includes at least one sensor 105, such as a light sensor, a motion sensor, and other sensors. Optionally, the light sensor includes an ambient light sensor and a proximity sensor. Optionally, the ambient light sensor can adjust the brightness of the display panel 1061 according to the ambient light level, and the proximity sensor can turn off the display panel 1061 and / or backlight when the smart terminal 100 is moved to the ear. As a type of motion sensor, the accelerometer sensor can detect the magnitude of acceleration in various directions (generally three axes), and can detect the magnitude and direction of gravity when stationary. It can be used for applications that recognize the phone's posture (such as landscape / portrait switching, related games, magnetometer posture calibration), vibration recognition related functions (such as pedometer, tapping), etc. Other sensors that can also be configured in the phone, such as fingerprint sensors, pressure sensors, iris sensors, molecular sensors, gyroscopes, barometers, hygrometers, thermometers, and infrared sensors, will not be described in detail here.

[0050] The display unit 106 is used to display information input by the user or information provided to the user. The display unit 106 may include a display panel 1061, which may be configured in the form of a liquid crystal display (LCD), an organic light-emitting diode (OLED), or the like.

[0051] User input unit 107 can be used to receive input numerical or character information, and generate key signal inputs related to user settings and function control of the mobile terminal. Optionally, user input unit 107 may include touch panel 1071 and other input devices 1072. Touch panel 1071, also known as a touch screen, can collect touch operations performed by the user on or near it (such as operations performed by the user using a finger, stylus, or any suitable object or accessory on or near touch panel 1071), and drive corresponding connection devices according to a pre-set program. Touch panel 1071 may include a touch detection device and a touch controller. Optionally, the touch detection device detects the user's touch position and the signal generated by the touch operation, and transmits the signal to the touch controller; the touch controller receives touch information from the touch detection device, converts it into touch point coordinates, sends it to processor 110, and can receive and execute commands sent by processor 110. In addition, touch panel 1071 can be implemented using various types such as resistive, capacitive, infrared, and surface acoustic wave. In addition to the touch panel 1071, the user input unit 107 may also include other input devices 1072. Optionally, other input devices 1072 may include, but are not limited to, one or more of the following: physical keyboard, function keys (such as volume control buttons, power buttons, etc.), trackball, mouse, joystick, etc., without being specifically limited here.

[0052] Optionally, the touch panel 1071 may cover the display panel 1061. When the touch panel 1071 detects a touch operation on or near it, it transmits the information to the processor 110 to determine the type of touch event. Subsequently, the processor 110 provides corresponding visual output on the display panel 1061 based on the type of touch event. Although in Figure 1 In this embodiment, the touch panel 1071 and the display panel 1061 are two independent components to realize the input and output functions of the mobile terminal. However, in some embodiments, the touch panel 1071 and the display panel 1061 can be integrated to realize the input and output functions of the mobile terminal. The specific implementation is not limited here.

[0053] Interface unit 108 serves as an interface through which at least one external device can connect to smart terminal 100. For example, the external device may include a wired or wireless headset port, an external power supply (or battery charger) port, a wired or wireless data port, a memory card port, a port for connecting a device with an identification module, an audio input / output (I / O) port, a video I / O port, a headphone port, and so on. Interface unit 108 may be used to receive input (e.g., data, power, etc.) from the external device and transmit the received input to one or more elements within smart terminal 100, or it may be used to transmit data between smart terminal 100 and the external device.

[0054] The memory 109 can be used to store software programs and various data. The memory 109 may primarily include a program storage area and a data storage area. Optionally, the program storage area may store the operating system, applications required for at least one function (such as sound playback, image playback, etc.), etc.; the data storage area may store data created based on the use of the mobile phone (such as audio data, phonebook, etc.). Furthermore, the memory 109 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0055] The processor 110 is the control center of the mobile terminal. It connects various parts of the mobile terminal via various interfaces and lines. By running or executing software programs and / or modules stored in the memory 109, and by calling data stored in the memory 109, it performs various functions and processes data of the mobile terminal, thereby providing overall monitoring of the mobile terminal. The processor 110 may include one or more processing units; preferably, the processor 110 may integrate an application processor and a modem processor. Optionally, the application processor mainly handles the operating system, user interface, and applications, while the modem processor mainly handles wireless communication. It is understood that the modem processor may not be integrated into the processor 110.

[0056] The smart terminal 100 may also include a power supply 111 (such as a battery) that supplies power to various components. Preferably, the power supply 111 can be logically connected to the processor 110 through a power management system, thereby enabling functions such as managing charging, discharging, and power consumption through the power management system.

[0057] although Figure 1 As not shown, the smart terminal 100 may also include a Bluetooth module, etc., which will not be described in detail here.

[0058] To facilitate understanding of the embodiments of this application, the communication network system on which the mobile terminal of this application is based is described below.

[0059] Please see Figure 2 , Figure 2 This application provides a communication network system architecture diagram. The communication network system is an LTE system based on the universal mobile communication technology. The LTE system includes a UE (User Equipment) 201, an E-UTRAN (Evolved UMTS Terrestrial Radio Access Network) 202, an EPC (Evolved Packet Core) 203, and the operator's IP services 204, which are connected in sequence.

[0060] Optionally, UE201 can be the aforementioned terminal 100, which will not be described in detail here.

[0061] E-UTRAN202 includes eNodeB2021 and other eNodeB2022, etc. Optionally, eNodeB2021 can connect to other eNodeB2022 via backhaul (e.g., X2 interface), and eNodeB2021 connects to EPC203, providing access from UE201 to EPC203.

[0062] EPC203 may include MME (Mobility Management Entity) 2031, HSS (Home Subscriber Server) 2032, other MMEs 2033, SGW (Serving Gateway) 2034, PGW (Packet Data Network Gateway) 2035, and PCRF (Policy and Charging Rules Function) 2036, etc. Optionally, MME2031 is the control node that handles signaling between UE201 and EPC203, providing bearer and connection management. HSS2032 is used to provide registers to manage functions such as the Home Location Register (not shown in the figure) and stores user-specific information such as service characteristics and data rates. All user data can be sent through SGW2034. PGW2035 can provide UE 201 IP address allocation and other functions. PCRF2036 is the policy and charging control decision point for service data flow and IP bearer resources. It selects and provides available policy and charging control decisions for the policy and charging enforcement function unit (not shown in the figure).

[0063] IP services 204 may include the Internet, intranet, IMS (IP Multimedia Subsystem), or other IP services.

[0064] Although the above description uses the LTE system as an example, those skilled in the art should understand that this application is not only applicable to the LTE system, but also to other wireless communication systems, such as GSM, CDMA2000, WCDMA, TD-SCDMA, and future new network systems (such as 5G), etc., without limitation.

[0065] Based on the above-described mobile terminal hardware structure and communication network system, various embodiments of this application are proposed.

[0066] As described in the background section, the antenna is one of the core components for wireless communication in smart terminals, and its design and performance directly affect the communication capabilities and user experience of the terminal device. In related technologies, a portion of the smart terminal's metal frame serves as the antenna radiator for the communication frequency band, physically connected to the battery compartment inside the smart terminal, with a clearance between the battery compartment's sidewall and the antenna radiator. However, as smart terminals become thinner and lighter, the battery compartment also becomes thinner and wider, resulting in a smaller clearance between it and the antenna radiator. Consequently, the antenna structure in these technologies exhibits lower radiation efficiency under these small clearance conditions.

[0067] Combination Figures 1 to 13 This application provides a monopole antenna applied to a smart terminal 100. The smart terminal 100 has a battery compartment 20. The monopole antenna includes: an antenna radiator 30, which does not contact the side wall of the battery compartment 20; a feed 40; and a signal processing circuit 50, with the feed 40 electrically connected to the antenna radiator 30 through the signal processing circuit 50.

[0068] Optionally, the signal processing circuit 50 is configured to process the radio frequency signal transmitted by the feed 40, so that the radio frequency signal is within a preset operating frequency band. Optionally, the feed 40 is connected to the radio frequency transceiver system.

[0069] Optionally, the antenna radiator 30 is a suspended support with no grounding position. Optionally, the projected length of the antenna radiator on the side wall of the battery compartment is greater than half the total length of the antenna radiator, and the antenna radiator operates in 1 / 2λ mode, where λ is the wavelength corresponding to the center frequency of the resonant frequency of the antenna radiator.

[0070] Optionally, the antenna radiator in 1 / 2λ mode can generate resonance in the 1.575 GHz frequency band, where the wavelength in the half-wavelength mode refers to the wavelength of the signal radiated by the antenna in the 1.575 GHz frequency band. Optionally, the wavelength of the radiated signal in air can be calculated as follows: Wavelength = Speed ​​of light / Frequency, where the frequency is the frequency of the radiated signal. The wavelength of the radiated signal in the medium can be calculated as follows: ε is the relative permittivity of the medium, and the frequency is the frequency of the radiated signal.

[0071] Optionally, an excitation capacitor is electrically connected between the feed 40 and the antenna radiator 30. In this way, the antenna radiator 30 can be excited by the excitation capacitor to achieve f0 frequency radiation. f0 is the same as the preset operating frequency band, which can be 600-960MHz.

[0072] When the antenna provided in this embodiment is applied to the smart terminal 100, the λ / 2 mode generated by the excited antenna radiator 30 is independent of the motherboard current mode. The antenna performance is less affected by the motherboard current distribution and has high adaptability to small clearance environments. Optionally, Figure 4 The alloy clearance 22 shown between the first sidewall 21 of the battery compartment 20 and the antenna radiator 30 can optionally include an extended design where the projected length of the antenna radiator on the sidewall of the battery compartment is greater than half the total length of the antenna radiator. This design allows the length of the radiator to be closer to the actual current length of the motherboard of the smart terminal, and closer to the balanced mode radiation, thereby improving the antenna radiation efficiency.

[0073] In some embodiments, the projected length of the antenna radiator 30 on the side wall of the battery compartment 20 is greater than three-quarters of the total length of the antenna radiator 30. Optionally, the projected length of the antenna radiator 30 on the side wall of the battery compartment 20 is four-fifths of the total length of the antenna radiator 30 itself. With this configuration, compared to the conventional scheme where one end of the antenna radiator 30 is grounded and connected to the side wall of the battery compartment 20 to excite the λ / 4 mode to achieve radiation in a preset operating frequency band, the physical length of the antenna radiator 30 is increased. This makes the length of the antenna radiator 30 closer to the length from the feed 40 on the motherboard to the lower edge of the frame of the smart terminal 100. Therefore, for the smart terminal 100 as a whole, it is closer to balanced mode radiation, thereby improving the overall radiation efficiency.

[0074] In some embodiments, the total length L of the antenna radiator 30 satisfies the relationship 3 / 8λ0 < L < 1 / 2λ0, where λ0 is the equivalent dielectric wavelength, which is related to the dielectric constant of the antenna radiator 30 material. The preset operating frequency band is 600-960MHz, and the product of the preset operating frequency band and the wavelength λ0 is equal to the speed of light c. Optionally, the preset operating frequency band is 600MHz, or 960MHz, or 780MHz.

[0075] In some embodiments, the length of the antenna radiator 30 is 70-90 mm. Optionally, the length of the antenna radiator 30 is 70 mm, 80 mm, or 90 mm.

[0076] In some embodiments, the signal processing circuit 50 includes a tuning circuit 511. The tuning circuit 511 and the feed 40 are connected in series on the antenna radiator 30. The tuning circuit 511 is used to tune the radio frequency signal transmitted by the feed 40 connected to it, so that the radio frequency signal is within a preset operating frequency band.

[0077] In some embodiments, the tuning circuit includes a first tuning circuit 511, which includes a first capacitor 5111 connected between the antenna radiator 30 and the feed 40. The first capacitor 5111 is used to excite the antenna radiator 30 to radiate electromagnetic waves corresponding to a preset operating frequency band.

[0078] In some embodiments, the capacitance value of the first capacitor 5111 is 0.5pF-3.6pF. Optionally, the capacitance value of the first capacitor 5111 is 0.5pF, 3.6pF, or 2pF. This larger capacitance value, compared to an antenna architecture grounded to the sidewall of the battery compartment 20, can offset the inductance generated by the dipole mode, allowing the modal impedance of the antenna radiator 30 to match the RF impedance of the feed 40, thus optimizing the antenna's radiation efficiency.

[0079] Combination Figure 5 The embodiment of this application shown uses the first capacitor 5111 to excite the current distribution of the antenna λ / 2 mode. It is easy to see that the maximum current point Imax of the antenna radiator 30 is located in the middle along its own length direction. The current symmetry on both sides of the middle part is good. In the existing antenna scheme that is grounded to the side wall of the battery compartment 20, the maximum current is concentrated at the end of the antenna radiator 30, and the symmetry is not good. Compared with this, the embodiment of this application significantly improves the current distribution symmetry of the antenna radiator 30.

[0080] Optionally, combined Figure 6 This is the port impedance diagram of a monopole antenna without the first capacitor 5111 excitation. Optionally, f0 is the center frequency resonant point. This diagram represents the role of the excitation capacitor, which pulls the original impedance of the antenna in the second quadrant biased inductive 1 / 2λ mode to the 50 ohm position, achieving matching with the 50 ohm RF system and completing the effective excitation of the 1 / 2λ mode.

[0081] Optionally, refer to Figure 7 Compared to the conventional 1 / 4λ antenna radiator 30 grounded to the side wall of the battery compartment 20, it is easy to see that the radiation performance of the embodiment of this application is significantly improved compared to the comparative example. Specifically, the antenna efficiency is improved by more than 1dB.

[0082] In some embodiments, the tuning circuit 511 further includes a second tuning circuit 512, which includes a first control switch 5121 and at least one second capacitor. The second capacitor is electrically connected to the first capacitor 5111, one end of the first control switch 5121 is electrically connected to the second capacitor, and the other end of the first control switch 5121 is grounded.

[0083] Optionally, refer to Figure 8 The second tuning circuit 512 includes a first control switch 5121, three second capacitors, and an inductor. Optionally, the three second capacitors and the inductor are connected in parallel. The three second capacitors are M1, M2, and M3, and their capacitance values ​​can be the same or different, and all are less than or equal to 10pF. This configuration can achieve parallel tuning of the antenna radiator 30.

[0084] Optionally, refer to Figure 9 In this embodiment, the waveform diagrams showing the changes in the port reflection coefficient of the monopole antenna under different states of the first control switch 5121 clearly show that the parallel capacitor of the first control switch 5121 effectively lengthens the antenna radiator 30, shifting the antenna resonant frequency to the left. The parallel inductor of the switch effectively shortens the antenna radiator 30, shifting the antenna resonant frequency to the right. The fully off state is an intermediate state, and its resonant frequency is directly related to the actual length of the antenna radiator 30. By reasonably setting the length of the antenna radiator 30 to match the first control switch 5121, broadband low-frequency waveform and radiation performance coverage can be achieved.

[0085] In some embodiments, the tuning circuit 511 further includes a third tuning circuit 513, which includes a third capacitor, a fourth capacitor, and a second control switch. The third capacitor is electrically connected between the first capacitor 5111 and the antenna radiator 30, the fourth capacitor is connected in parallel with the third capacitor, and the second control switch is electrically connected between the fourth capacitor and the antenna radiator 30.

[0086] Optionally, combined Figure 10 The third capacitor is capacitor C1, the fourth capacitor is M5, and it also includes capacitors M6 and M7 and inductor M8. In this way, when the second control switch is switched to the M5 path, it is equivalent to M5 and C1 being connected in parallel and then in series with the excitation capacitor C0, which can change the size of the excitation capacitor. Switching to the M6, M7 and M8 paths can achieve parallel tuning. Under this scheme, the frequency switching range of the antenna is expanded by combining series and parallel tuning.

[0087] In other embodiments, combined with Figure 12 and Figure 13 When the preset operating frequency band is mid-to-high frequency (1.3GHz-4GHz), efficient modes will also be excited. Generally, the higher-order modes excited simultaneously are 3 / 4λ mode and 5 / 4λ mode. This application also provides a smart terminal, including a motherboard, a metal frame, and a monopole antenna as described in any of the above embodiments; the feed is disposed on the motherboard; the metal frame surrounds the outer periphery of the motherboard, and a portion of the metal frame is the antenna radiator.

[0088] The embodiments of the smart terminal provided in this application may include all the technical features of any of the above-described monopole antenna embodiments. The extended and explanatory content of the specification is basically the same as the embodiments of the above methods, and will not be repeated here.

[0089] It is understood that the above scenarios are merely examples and do not constitute a limitation on the application scenarios of the technical solutions provided in the embodiments of this application. The technical solutions of this application can also be applied to other scenarios. For example, as those skilled in the art will know, with the evolution of system architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0090] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0091] The steps in the method of this application embodiment can be adjusted, combined, or deleted according to actual needs.

[0092] The units in the device of this application embodiment can be merged, divided, and deleted according to actual needs.

[0093] In this application, the same or similar terms, concepts, technical solutions and / or application scenario descriptions are generally described in detail only when they appear for the first time. When they appear again, they are generally not repeated for the sake of brevity. When understanding the technical solutions and other contents of this application, the same or similar terms, concepts, technical solutions and / or application scenario descriptions that are not described in detail later can be referred to their previous relevant detailed descriptions.

[0094] In this application, the descriptions of the various embodiments have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0095] The technical features of the present application can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of the present application.

[0096] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A monopole antenna, characterized in that, include: The antenna radiator does not contact the side wall of the battery compartment of the smart terminal, and the projected length of the antenna radiator on the side wall of the battery compartment is greater than half of the total length of the antenna radiator. The feed source and signal processing circuit are provided. The feed source is electrically connected to the antenna radiator through the signal processing circuit. The signal processing circuit is configured to process the radio frequency signal transmitted by the feed source so that the radio frequency signal is within a preset operating frequency band.

2. The monopole antenna according to claim 1, characterized in that, The projected length of the antenna radiator on the side wall of the battery compartment is greater than three-quarters of the total length of the antenna radiator.

3. The monopole antenna according to claim 1 or 2, characterized in that, The total length L of the antenna radiator satisfies the following relationship with the wavelength λ0 corresponding to the preset operating frequency band: 3 / 8λ0 < L < 1 / 2λ0.

4. The monopole antenna according to claim 3, characterized in that, The length of the antenna radiator is 70-90mm.

5. The monopole antenna according to claim 1 or 2, characterized in that, The signal processing circuit includes a tuning circuit. The tuning circuit and the feed source are connected in series on the antenna radiator. The tuning circuit is used to tune the radio frequency signal transmitted by the feed source so that the radio frequency signal is within a preset operating frequency band.

6. The monopole antenna according to claim 5, characterized in that, The tuning circuit includes a first tuning circuit, which includes a first capacitor connected between the antenna radiator and the feed source. The first capacitor is used to excite electromagnetic waves in the preset operating frequency band.

7. The monopole antenna according to claim 6, characterized in that, The tuning circuit further includes a second tuning circuit, which includes a first control switch and at least one second capacitor. The second capacitor is electrically connected to the first capacitor, and one end of the first control switch is electrically connected to the second capacitor, while the other end is grounded.

8. The monopole antenna according to claim 6, characterized in that, The tuning circuit further includes a third tuning circuit, which includes a third capacitor, a fourth capacitor, and a second control switch. The third capacitor is electrically connected between the first capacitor and the antenna radiator. The fourth capacitor is connected in parallel with the third capacitor. The second control switch is electrically connected between the fourth capacitor and the antenna radiator.

9. A smart terminal, characterized in that, Includes a monopole antenna as described in any one of claims 1 to 8.

10. The smart terminal according to claim 9, characterized in that, It also includes a motherboard and a metal frame, with the feed of the monopole antenna disposed on the motherboard; the metal frame surrounds the outer periphery of the motherboard, and a portion of the metal frame is the antenna radiator.

Images