A communication terminal

Abstract

The communication terminal provided in the application comprises a first antenna, the first antenna comprises a first main radiator and a parasitic radiator with a first gap between the first main radiator and the parasitic radiator. One end of the first main radiator away from the parasitic radiator is a ground end, and one end of the parasitic radiator away from the first main radiator is a ground end. A first tuning circuit is electrically connected between a first connection point of the first main radiator and the parasitic radiator, respectively. The distance S1 between the first connection point and the feed point of the first main radiator satisfies: S1≤1 / 2L1, wherein L1 is the length of the parasitic radiator. The first main radiator is used to form a main resonance corresponding to a first operating frequency band, and the parasitic radiator is used to form a parasitic resonance. The resonance point frequency f1 of the main resonance and the resonance point frequency f2 of the parasitic resonance satisfy: |f1-f2|≥30%*f1. The aperture and system efficiency of the first antenna are increased, and the communication performance of the communication terminal is improved.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a communication terminal. Background Technology

[0002] With the rapid development of communication technology and the widespread use of smartphones, people's demands for communication terminals are increasing. In particular, the requirements for the communication capabilities of communication terminals are also rising. Since the communication capabilities of a communication terminal are achieved through its antenna, improving the performance of the antenna in communication terminals is an important development direction in this field.

[0003] However, as communication terminals increasingly strive for thinner and lighter designs, their thickness becomes thinner, their bezels narrower, and their screen-to-body ratios larger. This makes the space for arranging antenna radiators increasingly limited, reducing the antenna clearance and consequently decreasing the antenna's system efficiency, thus affecting the communication capabilities of the terminal. Summary of the Invention

[0004] This application provides a communication terminal. The communication terminal includes a first antenna with a large aperture, resulting in high system efficiency and strong communication capabilities.

[0005] The communication terminal provided in this application includes a first antenna, which operates in a first operating frequency band, enabling the communication terminal to achieve communication within the first operating frequency band. The first antenna includes a first main radiator, a parasitic radiator, and a first tuning circuit, wherein the first main radiator and the parasitic radiator are arranged sequentially, and a first gap exists between them. The first main radiator includes a feed point for connection to a feed structure, enabling power feeding of the first main radiator. The end of the first main radiator facing away from the parasitic radiator is a ground terminal, and the end of the parasitic radiator facing away from the first main radiator is also a ground terminal. The first tuning circuit is electrically connected between a first connection point of the first main radiator and the parasitic radiator, wherein the distance S1 between the first connection point and the feed point satisfies: S1 ≤ 1 / 2L1, where L1 is the length of the parasitic radiator. The aforementioned first connection point and feed point are sufficiently close to facilitate tight coupling between the first main radiator and the parasitic radiator. Furthermore, it facilitates the use of the first tuning circuit to adjust the matching of the first antenna and regulate its main resonance. This scheme facilitates the diversion of current to the parasitic radiator. In this application, the first main radiator is used to form the main resonance corresponding to the first operating frequency band, and the parasitic radiator is used to form the parasitic resonance. Specifically, the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance satisfy: |f1-f2|≥30%*f1. The distance between the resonant frequency f2 of the parasitic resonance and the resonant frequency f1 of the main resonance is greater than or equal to 30%*f1. The distance between the resonant frequency f2 of the parasitic resonance generated by the parasitic radiator and the resonant frequency f1 of the main resonance generated by the first main radiator is relatively large, and the parasitic resonance generated by the parasitic radiator has little or no effect on the main resonance of the first main radiator. The strong and uniform coupling current generated by the parasitic radiator, along with the enhanced excitation of the floor current, increases the aperture of the first antenna and the system efficiency, thereby improving the communication performance of the communication terminal.

[0006] In one possible technical solution, the first antenna is a low-frequency antenna, with a first operating frequency band of 600MHz to 960MHz. The resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance satisfy |f1-f2|≥200MHz. Therefore, for a low-frequency antenna, the influence of parasitic resonance on the main resonance can be reduced, ensuring that parasitic resonance does not weaken the main resonance.

[0007] In another possible technical solution, the first antenna is a mid-to-high frequency antenna, with a first operating frequency band of 1.7 GHz to 2.7 GHz. The resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance satisfy |f1-f2|≥1 GHz. Therefore, for a mid-to-high frequency antenna, the influence of parasitic resonance on the main resonance can be reduced, ensuring that parasitic resonance does not weaken the main resonance.

[0008] The parasitic radiator mentioned above has a relatively short length. Specifically, the length L1 of the parasitic radiator satisfies: L1 ≤ 1 / 8λ, where λ is the wavelength in free space corresponding to the resonant frequency of the main resonant of the first main radiator. In this scheme, it is easier to generate a more uniform current in the parasitic radiator and it is less likely to generate resonance within the first operating frequency band.

[0009] The length of the first main radiator can also be relatively short. Specifically, the length L2 of the first main radiator satisfies: 1 / 8λ ≤ L2 ≤ 1 / 4λ, where λ is the wavelength in free space corresponding to the resonant frequency of the main resonant of the first main radiator. The length of the first main radiator does not need to be too long to achieve high-efficiency signal radiation. Therefore, a smaller total length of the first antenna can achieve a larger radiator aperture and system efficiency, thus improving the communication capability of the communication terminal.

[0010] In one possible technical solution, the first connection point and the feed point are the same point. Thus, the first tuning circuit and the feed structure are connected to the same location. This results in stronger coupling between the first main radiator and the parasitic radiator, and a more uniform current excited by the parasitic radiator.

[0011] In another possible technical solution, the first connection point and the feed point are different points, and the distance S1 between the first connection point and the feed point satisfies: S1≤1 / 16λ, where λ is the wavelength in free space corresponding to the resonant frequency of the main resonant of the first main radiator. The first connection point and the feed point are relatively close, which is beneficial to achieving tight coupling between the first main radiator and the parasitic radiator. In addition, the first tuning circuit is also used to adjust the matching of the first antenna and adjust the main resonance of the first antenna.

[0012] For the location of the first connection point in the first main radiator, the distance S2 between the first connection point and the first gap can satisfy: S2 ≤ 1 / 16λ, where λ is the wavelength in free space corresponding to the resonant frequency of the main resonance of the first main radiator. The first tuning circuit is connected to the end of the first main radiator near the parasitic radiator, which facilitates the adjustment of the main resonance of the first antenna and also facilitates the excitation of the current in the parasitic radiator, realizing tight coupling between the parasitic radiator and the first main radiator.

[0013] The aforementioned first tuning circuit is electrically connected to the parasitic radiator at the second connection point. The specific location of this second connection point is such that the distance S3 between the second connection point and the first gap satisfies: S3 ≤ 1 / 16λ, where λ is the wavelength in free space corresponding to the resonant frequency of the main resonant of the first main radiator. The first tuning circuit is connected to the end of the parasitic radiator closest to the first main radiator, achieving tight coupling between the parasitic radiator and the first main radiator. This facilitates exciting a current in the same direction throughout the entire parasitic radiator, and facilitates exciting a stronger current on the floor.

[0014] In one technical solution, the first tuning circuit may include a switch and multiple tuning devices. The switch is used to switch the conducting tuning devices, thereby switching the capacitance and / or inductance of the first tuning circuit. This adjusts the electrical length of the first main radiator, and consequently adjusts the resonant frequency of the main resonance of the first antenna. The resonant frequency of the main resonance of the first antenna can be adjusted within a wide range, expanding the bandwidth of the first antenna.

[0015] Specifically, the aforementioned first tuning circuit may include a capacitor with a capacitance value less than or equal to 3pF. The smaller capacitance value allows for a larger current flowing through the first tuning circuit, reducing losses caused by the first tuning circuit and improving the antenna's system efficiency.

[0016] Furthermore, the aforementioned first tuning circuit may include an inductor with an inductance value greater than or equal to 8nH. A larger inductance value results in a larger current flowing through the first tuning circuit, which can reduce losses caused by the first tuning circuit and improve the system efficiency of the antenna.

[0017] Regarding the specific formation of the first antenna, it can be a frame antenna. For example, the communication terminal includes a housing, and the first main radiator and the parasitic radiator each include a portion of the conductive structure of the frame of the housing. Alternatively, the first antenna can also be a support antenna.

[0018] The following lists several possible architectures for the first antenna. In one technical solution, the first main radiator is also grounded via an inductor between the first slot and the grounding terminal. Specifically, this first antenna can be a low-frequency antenna.

[0019] In one technical solution, the aforementioned first main radiator includes a first stub and a second stub, with a second gap between the first and second stubs, and the first and second stubs are electrically connected through a second tuning circuit; the second stub is located on the side of the first stub away from the parasitic radiator, with both ends of the first stub being open ends, the end of the second stub facing the first stub being an open end, and the end away from the first stub being a grounded end. Specifically, the first antenna can also be a low-frequency antenna.

[0020] In one technical solution, the end of the first main radiator facing the parasitic radiator is an open end, and the end away from the parasitic radiator is a grounded end. In this solution, the first antenna can specifically be a medium-to-high frequency antenna.

[0021] The first main radiator and the parasitic radiator can be arranged side by side, with no lower region between them. Alternatively, a portion of the structure of the first main radiator can extend to one side of the parasitic radiator in a first direction, perpendicular to the extension direction of the parasitic radiator. There is partial overlap between the structure of the first main radiator and the parasitic radiator. When the parasitic radiator is a conductive structure within the frame of the terminal device, it can be considered that a portion of the structure of the first main radiator extends into the interior of the terminal device. This helps to reduce the space occupied by the first antenna.

[0022] In one technical solution, the aforementioned terminal device may further include a second antenna, which operates in a second operating frequency band, different from the first operating frequency band. This enables the terminal device of this application to achieve communication across different operating frequency bands. Specifically, the second antenna includes a second main radiator, and the second main radiator and parasitic radiator share a branch. This helps reduce the space occupied by the antenna of the communication terminal and enriches the communication scenarios of the communication terminal. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a communication terminal in an embodiment of this application;

[0024] Figure 2 This is a schematic diagram of the structure of the first antenna in an embodiment of this application;

[0025] Figure 3 This is a schematic diagram of the structure of the first antenna in an embodiment of this application;

[0026] Figure 4 This is a schematic diagram of a tuning circuit in one embodiment of this application;

[0027] Figure 5 This is a schematic diagram of one structure of the first antenna in the comparative example;

[0028] Figure 6 This is a schematic diagram comparing the free-space return loss of the first antenna in the embodiments and comparative examples of this application.

[0029] Figure 7 This is a schematic diagram comparing the antenna efficiency of the first antenna in free space in the embodiments and comparative examples of this application;

[0030] Figure 8 This is a schematic diagram comparing the return loss of the first antenna in the embodiments and comparative examples of this application under manual conditions.

[0031] Figure 9 This is a schematic diagram comparing the antenna efficiency of the first antenna in the embodiments and comparative examples of this application under hand-mold conditions;

[0032] Figure 10A schematic diagram of the structure of the first antenna in an embodiment of this application;

[0033] Figure 11 This is a schematic diagram of one structure of the first antenna in the comparative example;

[0034] Figure 12 for Figure 11 The diagram shows the tuning circuit of the first antenna in the comparative example.

[0035] Figure 13 for Figure 11 A schematic diagram of the simulation data for the first traverse in the comparative example shown;

[0036] Figure 14 for Figure 10 The diagram shown is a schematic of the tuning circuit for the first antenna in this embodiment of the application.

[0037] Figure 15 for Figure 10 The above is a schematic diagram of the simulation data of the first antenna in the embodiment of this application;

[0038] Figure 16 This is a schematic diagram of the structure of the first antenna in an embodiment of this application;

[0039] Figure 17 This is a schematic diagram of one structure of the first antenna in the comparative example;

[0040] Figure 18 This is a schematic diagram comparing the free-space return loss of the first antenna in the embodiments and comparative examples of this application.

[0041] Figure 19 This is a schematic diagram comparing the efficiency of the first antenna in the free space system in the embodiments and comparative examples of this application;

[0042] Figure 20 This is a partial structural diagram of a communication terminal in an embodiment of this application;

[0043] Figure 21 This is a schematic diagram of the antenna structure of a communication terminal in an embodiment of this application;

[0044] Figure 22 This is a schematic diagram of one structure of the first antenna in an embodiment of this application.

[0045] Figure label:

[0046] 100 - Cover plate; 200 - Display screen / module;

[0047] 300 - Printed circuit board; 400 - Mid-frame;

[0048] 500 - Back cover; 600 - Bezel;

[0049] 700-Suspended retaining wall structure;

[0050] 1-First antenna; 11-First main radiator;

[0051] 111 - First connection point; 112 - Power supply point;

[0052] 114 - Ground terminal; 115 - Inductor;

[0053] 116 - First branch; 117 - Second branch;

[0054] 118 - Second gap; 119 - Second tuning circuit;

[0055] 1111 - Third branch; 1112 - Fourth branch;

[0056] 1113 - Third gap; 1114 - Third tuning circuit;

[0057] 1115 - Fourth tuning circuit; 1116 - Fifth tuning circuit;

[0058] 12-Parasitic radiator; 121-Second connection point;

[0059] 122 - Sixth tuning circuit; 123 - Seventh tuning circuit;

[0060] 13-First gap; 14-Feeding structure;

[0061] 15-First tuning circuit; 151-Switch;

[0062] 152 - Capacitor; A - Partial overlapping area;

[0063] 2-Secondary antenna; 21-Secondary primary radiator;

[0064] 22 - First capacitor; 23 - Second capacitor. Detailed Implementation

[0065] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0066] The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” and “this” are intended to also include expressions such as “one or more,” unless the context clearly indicates otherwise.

[0067] References to “an embodiment” or “a specific embodiment” as used in this specification mean that one or more embodiments of this application include a particular feature, structure, or characteristic described in connection with that embodiment. The terms “comprising,” “including,” “having,” and variations thereof mean “including, but not limited to,” unless otherwise specifically emphasized.

[0068] The following explains the terms that may appear in the embodiments of this application.

[0069] Radiator: In an antenna, this is the device used to receive / transmit electromagnetic wave radiation. In some cases, the term "antenna" is narrowly defined as a radiator, which converts guided wave energy from the transmitter into radio waves, or converts radio waves into guided wave energy, for radiating and receiving radio waves. The modulated high-frequency current energy (or guided wave energy) generated by the transmitter is transmitted to the transmitting radiator via a feed structure, where it is converted into electromagnetic wave energy of a specific polarization and radiated in the desired direction. The receiving radiator converts electromagnetic wave energy of a specific polarization from a specific direction in space back into modulated high-frequency current energy, which is then fed to the receiver input via a feed structure.

[0070] Ground / Plug: This can broadly refer to at least a portion of any grounding layer, ground plane, or grounding metal layer within an electronic device (such as a mobile phone), or at least a portion of any combination of the aforementioned grounding layers, ground planes, or grounding components. "Ground / Plug" can be used for grounding components within an electronic device. In one embodiment, "Ground / Plug" may include any one or more of the following: a grounding layer of a circuit board of an electronic device, a ground plane formed by the frame of the electronic device, a grounding metal layer formed by a thin metal film beneath the screen, a conductive grounding layer of a battery, and conductive or metallic components electrically connected to the aforementioned grounding layer / ground plane / metal layer. In one embodiment, the circuit board may be a printed circuit board (PCB), such as an 8-layer, 10-layer, or 12-14-layer board having 8, 10, 12, 13, or 14 layers of conductive material, or components separated and electrically insulated by dielectric or insulating layers such as glass fiber or polymers. In one embodiment, the circuit board includes a dielectric substrate, a grounding layer, and a trace layer, with the trace layer and grounding layer electrically connected via conductive vias. In one embodiment, components such as display 120, touchscreen, input buttons, transmitter, processor, memory, battery 140, charging circuit, and system-on-chip (SoC) architecture can be mounted on or connected to a circuit board; or electrically connected to trace layers and / or ground layers in the circuit board. For example, an RF source is disposed on a trace layer.

[0071] Any of the aforementioned grounding layers, ground planes, or grounding metal layers are made of conductive materials. In one embodiment, the conductive material may be any of the following: copper, aluminum, stainless steel, brass and their alloys, copper foil on an insulating substrate, aluminum foil on an insulating substrate, gold foil on an insulating substrate, silver-plated copper, silver-plated copper foil on an insulating substrate, silver foil on an insulating substrate and tin-plated copper, graphite-impregnated cloth, graphite-coated substrates, copper-plated substrates, brass-plated substrates, and aluminum-plated substrates. Those skilled in the art will understand that grounding layers / ground planes / grounding metal layers may also be made of other conductive materials.

[0072] The radio frequency (RF) chip is the combination of all components of an antenna used for receiving and transmitting radio frequency waves. In the case of a receiving antenna, the RF chip can be considered as the antenna section from the first amplifier to the front-end transmitter. In a transmitting antenna, the RF chip can be seen as the section after the last power amplifier. In some cases, the RF chip can also be understood as the feed unit. The RF chip has the function of converting radio waves into electrical signals and sending them to the receiver components. Generally, it is considered as part of the antenna system 3, used for converting radio waves into electrical signals and vice versa. Maximum power transfer possibilities and efficiency should be considered when designing an antenna. For this purpose, the antenna feed impedance must be matched with the load resistance. The antenna feed impedance is a combination of resistance, capacitance, and inductance. To ensure maximum power transfer conditions, the two impedances (load resistance and feed impedance) should be matched. Matching can be achieved by considering frequency requirements and antenna design parameters (e.g., gain, directivity).

[0073] Communication / Operating Frequency Band: Regardless of the type of antenna, it always operates within a certain frequency range (bandwidth). For example, an antenna supporting the B40 band operates within the frequency range of 2300MHz to 2400MHz, or in other words, its operating frequency band includes the B40 band. The frequency range that meets the specifications can be considered the antenna's operating frequency band. The width of the operating frequency band is called the operating bandwidth. The operating bandwidth of an omnidirectional antenna may reach 3-5% of the center frequency. The operating bandwidth of a directional antenna may reach 5-10% of the center frequency. Bandwidth can be considered as a frequency range on both sides of the center frequency (e.g., the resonant frequency of a dipole), where the antenna characteristics are within the acceptable range of the center frequency.

[0074] Antenna return loss: This can be understood as the ratio of the signal power reflected back to the antenna port after passing through the antenna circuit to the transmit power at the antenna port. The smaller the reflected signal, the larger the signal radiated into space through the antenna, and the higher the antenna's radiation efficiency. Conversely, the larger the reflected signal, the smaller the signal radiated into space through the antenna, and the lower the antenna's radiation efficiency.

[0075] Antenna return loss can be represented by the S11 parameter, which is one of the S-parameters. S11 represents the reflection coefficient, and this parameter characterizes the antenna's transmission efficiency.

[0076] In one embodiment, the S11 diagram can be understood as a schematic diagram representing the resonance generated by the antenna. In one embodiment, the resonance shown in the S11 diagram within the range of -6dB can be understood as the resonant frequency / frequency range / operating frequency band generated by the antenna. The S11 parameter is usually negative. The smaller the S11 parameter, the smaller the antenna return loss, the less energy reflected back by the antenna itself, which means more energy actually enters the antenna, and the higher the antenna radiation efficiency; the larger the S11 parameter, the greater the antenna return loss, and the lower the antenna radiation efficiency.

[0077] It should be noted that in engineering, an S11 value of -6dB is generally used as the standard. When the S11 value of an antenna is less than -6dB, the antenna can be considered to be working normally, or the antenna can be considered to have good transmission efficiency.

[0078] dB: This stands for decibel, a logarithmic concept with base 10. Decibels are used to evaluate the proportional relationship between two physical quantities; they themselves have no physical dimensions. For every 10-fold increase in the ratio between two quantities, their difference can be expressed as 10 decibels. For example: A = 100, B = 10, C = 5, D = 1, then A / D = 20 dB; B / D = 10 dB; C / D = 7 dB; B / C = 3 dB. In other words, a 10-decibel difference between two quantities is a 10-fold difference, a 20-decibel difference is a 100-fold difference, and so on. A 3-decibel difference is a 2-fold difference between the two quantities.

[0079] Coupling: This can be understood as indirect coupling, specifically, two conductors conducting electricity through a gap / non-contact method. In one embodiment, indirect coupling can also be called capacitive coupling, for example, signal transmission is achieved by forming an equivalent capacitance through coupling between the gaps between two conductive components. Whether a coupling connection can be achieved between two conductive components is directly related to the coupling distance between them. If the coupling distance between the two conductive components is greater than a preset value, a coupling connection cannot be achieved between them. The aforementioned preset value can be called the coupling distance.

[0080] Coupling area: The area of ​​the region where two conductive components can be coupled together; specifically, it refers to the area of ​​the region where the coupling distance between two conductive components is less than or equal to a preset value.

[0081] The term "end" in the context of the first / second / third / fourth / grounded / open end of a radiator should not be narrowly interpreted as an endpoint or end point physically disconnected from other radiators. It can also refer to a segment of the main radiator including the first endpoint, which is the endpoint of the main radiator at the gap. For example, the first end of the main radiator can be considered a segment of the main radiator within a range of one-eighth of a first wavelength from the first endpoint. The first wavelength can be the wavelength corresponding to the operating frequency band of the main radiator, the wavelength corresponding to the center frequency of the operating frequency band, or the wavelength corresponding to the resonant point. In one embodiment, "end / point" can include a connection / coupling region on the radiator coupled to other conductive structures. For example, a feed end / feed point can be a coupling region on the antenna radiator coupled to a feed structure (e.g., a region facing a part of the feed structure). Similarly, a grounded end / grounded point can be a connection / coupling region on the antenna radiator coupled to a grounding structure.

[0082] Open and Closed Terminals: In some embodiments, open and closed terminals are defined relative to whether or not they are grounded; the closed terminal is grounded, and the open terminal is not grounded. In one embodiment, the open terminal may also be referred to as a floating terminal, a free terminal, an open terminal, or an open-circuit terminal. In one embodiment, the closed terminal may also be referred to as a grounded terminal or a short-circuit terminal. It should be understood that in some embodiments, other conductors can be coupled through the open terminal to transfer coupled energy (which can be understood as transferring current).

[0083] In some embodiments, the open end and the closed end are, for example, relative to other conductors, with the closed end electrically connected to other conductors and the open end not electrically connected to other conductors.

[0084] To put it simply, the "open end" of a radiator can be defined as one end of the radiator that is spaced apart from the floor or coupled to the floor through a capacitive device.

[0085] To put it simply, the "grounding terminal" of a radiator can be understood as: if one end of the radiator is directly connected to the floor or coupled to the floor through an inductive device, it can be regarded as the grounding terminal of the radiator.

[0086] In some embodiments, the understanding of "closed end" can also be from the perspective of current distribution. A closed end or ground end can be understood as a point of high current or low electric field on a radiator. In one embodiment, coupling electronic devices (e.g., inductive devices) through a closed end can maintain the current distribution characteristics of the point of high current / low electric field. In one embodiment, opening a slit at or near the closed end (e.g., filling the slit with insulating material) can maintain the current distribution characteristics of the point of high current / low electric field.

[0087] In some embodiments, the understanding of "open terminal" can also be from the perspective of current distribution. An open terminal or a floating terminal can be understood as a point with a small current or a point with a large electric field on the radiator. In one embodiment, coupling electronic devices (e.g., capacitive devices) through an open terminal can maintain the current distribution characteristics of the point with a small current or a large electric field.

[0088] It should be understood that when an electronic device (e.g., capacitor, inductor, etc.) is coupled at the radiator end of a gap (which, from the perspective of the radiator's structure, resembles a radiator at the opening of an open or suspended end), the radiator end can be a point with a large current / small electric field. In this case, it should be understood that the radiator end at the gap is actually a closed end or a grounded end, etc.

[0089] Electrical length: Electrical length can be expressed as the ratio of physical length (i.e., mechanical length or geometric length) multiplied by the time it takes for an electrical or electromagnetic signal to travel in a medium to the time required for that signal to travel a distance in free space equal to the physical length of the medium. Electrical length can be expressed by the following formula:

[0090]

[0091] Where L is the physical length, a is the transmission time of the electrical or electromagnetic signal in the medium, and b is the transmission time in free space.

[0092] Alternatively, electrical length can also refer to the ratio of physical length (i.e., mechanical length or geometric length) to the wavelength of the transmitted electromagnetic wave, and electrical length can satisfy the following formula:

[0093]

[0094] Where L is the physical length and λ is the wavelength of the electromagnetic wave.

[0095] In some embodiments of this application, the physical length of the radiator can be understood as within ±20% of the electrical length of the radiator, for example, within ±10% or within ±5%.

[0096] To facilitate understanding of the communication terminal provided in this application embodiment, its application scenario is first introduced below. The communication terminal in this application embodiment refers to a terminal with communication functions. Specifically, it can refer to a communication terminal employing one or more of the following communication technologies: Bluetooth (BT) communication technology, Global Positioning System (GPS) communication technology, Wireless Fidelity (WiFi) communication technology, Global System for Mobile Communications (GSM) communication technology, Wideband Code Division Multiple Access (WCDMA) communication technology, Long Term Evolution (LTE) communication technology, 5G communication technology, and other future communication technologies. The communication terminal in this application embodiment can include a fixed terminal or a mobile terminal. For example, a mobile terminal can be a mobile phone, tablet computer, laptop computer, smart bracelet, smartwatch, smart helmet, and smart glasses; a fixed terminal can be a router, smart TV, smart home device, smart speaker, and desktop computer. In addition, the aforementioned communication terminal may also be a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a communication terminal in a 5G network, or a communication terminal in a future evolved public land mobile network (PLMN), etc., and the embodiments of this application are not limited to this.

[0097] Figure 1 An exemplary embodiment of a communication terminal provided in this application is illustrated, with a mobile phone as the example. Figure 1 As shown, in one embodiment, the communication terminal includes a cover 100, a display / module 200, a printed circuit board (PCB) 300, a middle frame 400, and a rear cover 500. It should be understood that in some embodiments, the cover 100 may be a glass cover, or it may be replaced with a cover made of other materials, such as an ultra-thin glass cover, a PET (Polyethylene terephthalate) cover, etc. In one embodiment, the cover 100, the middle frame 400, and the rear cover 500 can all be considered as part of the housing.

[0098] The cover plate 100 can be set close to the display screen 200, and can be mainly used to protect the display screen 200 from dust.

[0099] In one embodiment, the display screen 200 may include a liquid crystal display (LCD), a light emitting diode (LED) display panel, or an organic light-emitting diode (OLED) display panel, etc., and this application does not limit it.

[0100] The 400mm mid-frame primarily serves to support the entire machine. Figure 1 The diagram shows PCB 300 positioned between the middle frame 400 and the back cover 500. It should be understood that in one embodiment, PCB 300 may also be positioned between the middle frame 400 and the display screen 200; this application does not impose any limitations on this. The printed circuit board PCB 300 may be made of flame-retardant material (FR-4) dielectric, or it may be made of Rogers dielectric, or a hybrid dielectric of Rogers and FR-4, etc. Here, FR-4 is a designation for a flame-retardant material grade, and Rogers dielectric is a high-frequency board. Electronic components, such as radio frequency chips, are mounted on PCB 300.

[0101] In one embodiment, a metal layer may be disposed on the printed circuit board 300. This metal layer can be used to ground electronic components carried on the PCB 300, or to ground other components such as bracket antennas, frame antennas, etc. This metal layer can be referred to as a ground plane, grounding plate, or grounding layer. In one embodiment, this metal layer can be formed by etching metal onto the surface of any dielectric substrate in the PCB 300. In one embodiment, the grounding metal layer can be disposed on the side of the PCB 300 near the middle frame 400. In one embodiment, the edge of the PCB 300 can be considered as the edge of its grounding layer. In one embodiment, the metal middle frame 400 can also be used for grounding the aforementioned components. The communication terminal may also have other ground planes / grounding plates, as previously described, which will not be repeated here.

[0102] The communication terminal may also include a battery (not shown in the figure). The battery may be disposed between the middle frame 400 and the back cover 500, or between the middle frame 400 and the display screen 200, and this application does not limit this. In some embodiments, the PCB 300 is divided into a motherboard and a daughterboard, and the battery may be disposed between the motherboard and the daughterboard. The motherboard may be disposed between the middle frame 400 and the upper edge of the battery, and the daughterboard may be disposed between the middle frame 400 and the lower edge of the battery.

[0103] The communication terminal may also include a frame 600, which may be formed of a conductive material such as metal. The frame 600 may be disposed between the display screen 200 and the back cover 500 and extend circumferentially around the periphery of the communication terminal. The frame 600 may have four sides surrounding the display screen 200 to help secure the display screen 200. In one implementation, the frame 600 made of metal can be directly used as the metal frame of the communication terminal, forming a metal frame appearance suitable for industrial design (ID). In another implementation, the outer surface of the frame 600 may also be made of a non-metallic material, such as a plastic frame, forming a non-metallic frame appearance suitable for non-metallic ID. The radiator in this embodiment may be a partially conductive structure of the frame of the housing 600.

[0104] The middle frame 400 may include a border 600. The middle frame 400, including the border 600, is a single unit that supports the electronic components in the device. The cover plate 100 and the rear cover 500 respectively cover the upper and lower edges of the border to form the outer shell or housing of the communication terminal. Alternatively, the border 600 may not be considered part of the middle frame 400. In one embodiment, the border 600 may be connected to the middle frame 400 and integrally formed. In another embodiment, the border 600 may include an inwardly extending protrusion to connect with the middle frame 400, for example, by means of spring clips, screws, welding, etc. In one embodiment, the cover plate 100, the rear cover 500, the border 600, and the middle frame 400 may be collectively referred to as the outer shell or housing of the communication terminal. It should be understood that "outer shell or housing" can be used to refer to part or all of any one of the cover plate 100, rear cover 500, frame 600 or middle frame 400, or to part or all of any combination of the cover plate 100, rear cover 500, frame 600 or middle frame 400.

[0105] The back cover 500 can be made of metal; it can also be made of non-conductive materials, such as glass or plastic; or it can be made of both conductive and non-conductive materials.

[0106] In one embodiment, the frame 600 can at least partially function as a radiator to receive / transmit radio frequency signals. This portion of the frame acting as the radiator may have gaps between itself and other parts of the middle frame 400, or between itself and the middle frame 400, thereby ensuring a good radiation environment for the radiator. In one embodiment, an aperture may be provided near this portion of the frame acting as the radiator. In one embodiment, the aperture may include an aperture located inside the communication terminal, for example, an aperture not visible from the exterior of the communication terminal. In one embodiment, the internal aperture may be formed by any one or more of the middle frame, battery, circuit board, back cover, display screen, and other internal conductive components; for example, the internal aperture may be formed by a structural component of the middle frame. In one embodiment, the aperture may also include a slot / slit / opening on the frame 600. In one embodiment, the slot / slit / opening on the frame 600 may be a slit formed on the frame, dividing the frame 600 into two parts without a direct connection at the slit. In one embodiment, the aperture may also include a slot / slit / opening on the back cover 500 or the display screen 200. In one embodiment, the back cover 500 includes a conductive material, and the apertures provided in the conductive material can communicate with the slots or breaks in the frame to form a continuous aperture on the surface of the communication terminal.

[0107] In one embodiment, the radiator of the communication terminal may also be disposed within the frame 600. The frame 600 comprises a non-conductive material, and the radiator of the antenna may be located within the communication terminal and disposed along the frame 600, or the radiator may be at least partially embedded within the non-conductive material of the frame. In one embodiment, the radiator is disposed close to the non-conductive material of the frame 600 to minimize the volume occupied by the radiator and to be closer to the outside of the communication terminal, thereby achieving better signal transmission performance. It should be noted that "disposed close to the frame 600" means that the radiator can be disposed tightly against the frame 600, or it can be disposed close to the frame 600, for example, there may be a small gap between the radiator and the frame 600.

[0108] In one embodiment, the radiator of the communication terminal may also be disposed within the housing, such as a bracket antenna, etc. Figure 1(Not shown in the image). A gap may exist between the radiator located within the housing and other conductive components inside the housing to ensure a good radiation environment for the radiator. In one embodiment, an aperture may be provided near the radiator. In one embodiment, the aperture may include an aperture located inside the communication terminal, for example, an aperture not visible from the exterior of the communication terminal. In one embodiment, the internal aperture may be formed by any one or more of the frame, mid-frame, battery, circuit board, back cover, display screen, and other internal conductive components; for example, the internal aperture may be formed by a structural component of the mid-frame. In one embodiment, the aperture may also include a slot / slit / opening on the frame 600. In one embodiment, the slot / slit / opening on the frame 600 may be a slit formed on the frame, at which the frame 600 is divided into two parts without a direct connection. In one embodiment, the aperture may also include a slot / slit / opening on the back cover 500 or the display screen 200. In one embodiment, the back cover 500 includes a conductive material, and the apertures formed in the conductive material can communicate with the slots or breaks in the frame to form continuous apertures on the surface of the communication terminal. In one embodiment, the apertures on the back cover 500 or the display screen can also be used to house other devices, such as cameras, and / or sensors, and / or microphones, and / or speakers, etc.

[0109] In one embodiment, the antenna can be based on a flexible printed circuit (FPC), a laser-direct structuring (LDS) antenna, or a microstrip disk antenna (MDA). In another embodiment, the antenna can be a transparent or semi-transparent structure embedded inside the screen of the communication terminal, making it a transparent antenna element embedded inside the screen of the communication terminal.

[0110] Figure 1 The diagram only schematically illustrates some of the components included in the communication terminal; the actual shape, size, and construction of these components are not subject to change. Figure 1 limited.

[0111] also, Figure 1 The above is just one possible form of the communication terminal. In other embodiments, the communication terminal may also be a foldable mobile terminal.

[0112] Figure 2 This is a schematic diagram of one structure of the first antenna in an embodiment of this application, such as... Figure 2As shown in the embodiment of this application, the communication terminal includes a first antenna 1 operating in a first operating frequency band, used to realize communication of the communication terminal in the first operating frequency band. The first antenna 1 includes a first main radiator 11 and a parasitic radiator 12 arranged in sequence, wherein: a first gap 13 is provided between the first main radiator 11 and the parasitic radiator 12, and one end of the first main radiator 11 facing the first gap 13 is coupled to the radio frequency chip through a feeding structure (not shown), so that the radio frequency chip transmits and / or receives radio frequency signals through the first main radiator. The end of the parasitic radiator 12 facing the first gap 13 is electrically connected to a first tuning circuit 15, which is disposed across the first gap 13. Specifically, one end of the first tuning circuit 15 is electrically connected to the first connection point 111 of the first main radiator 11, and the other end is electrically connected to the second connection point 121 of the parasitic radiator 12. The first tuning circuit 15 can be used to adjust the resonant frequency f1 of the main resonance of the first main radiator 11, so that the first antenna 1 operates in the target operating frequency band. The distance S1 between the first connection point 111 and the feed point 112 mentioned above satisfies: Where L1 is the length of the parasitic radiator 12. The first connection point 111 and the feed point 112 are sufficiently close to facilitate tight coupling between the first main radiator 11 and the parasitic radiator 12. Furthermore, it facilitates the use of the first tuning circuit 15 to adjust the matching of the first antenna 1 and regulate the main resonance of the first antenna 1. The parasitic radiator 12 has a ground terminal at the end opposite to the first main radiator 11, and the first main radiator 11 also has a ground terminal at the end opposite to the parasitic radiator 12. This facilitates the guidance of current to the parasitic radiator 12, improving the current uniformity and intensity on the parasitic radiator 12, and increasing the intensity of the ground current. In this application, the first main radiator 11 is used to form the main resonance corresponding to the first operating frequency band, and the parasitic radiator 12 is used to form the parasitic resonance. Specifically, the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance satisfy: |f1-f2|≥30%*f1. The aforementioned |f1-f2| can be understood as the absolute value of the difference between the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance, or in other words, the distance between the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance. Therefore, the distance between the resonant frequency f2 of the parasitic resonance and the resonant frequency f1 of the main resonance is greater than or equal to 30%*f1. The distance between the resonant frequency f2 of the parasitic resonance generated by the parasitic radiator 12 and the resonant frequency f1 of the main resonance generated by the first main radiator 11 is relatively large, and the parasitic resonance generated by the parasitic radiator 12 has little or no impact on the main resonance of the first main radiator 11. The strong and uniform coupling current generated by the parasitic radiator 12 enhances the excitation of the ground current, increases the aperture of the first antenna 1 and the system efficiency, and improves the communication performance of the communication terminal. For example, this communication terminal can still reliably achieve communication in weak signal scenarios or scenarios with strong interference.

[0113] Furthermore, in this scheme, the first antenna 1 can increase the antenna aperture and system efficiency with the same physical size, or it can reduce the physical size with the same antenna aperture and system efficiency. Therefore, in some application scenarios, this scheme is also conducive to reducing the physical size of the first antenna, thereby making it easier to place the first antenna in a smaller communication terminal.

[0114] In this application, the feed point 112 of the first main radiator 11 can be directly electrically connected to the feed structure 14, or coupled electrically connected. That is, the feed method of the first main radiator 11 can be DC feed or coupled feed, and this application does not limit this.

[0115] For example, in some specific embodiments, the distance |f1-f2| between the resonant frequency f2 of the parasitic resonance and the resonant frequency f1 of the main resonance is 32%*f1, 35%*f1, 38%*f1, 40%*f1, 41%*f1, 43%*f1, 45%*f1, 48%*f1, 50%*f1, 52%*f1, 53%*f1, 55%*f1, 58%*f1, 60%*f1, 62%*f1, 65%*f1, 70%*f1, 72%*f1, 75%*f1, 78%*f1, 80%*f1, 85%*f1, 90%*f1, 92%*f1, 95%*f1, or 100%*f1, etc. Therefore,

[0116] In some embodiments, it can also be considered that the parasitic radiator 12 does not resonate, or in other words, does not resonate effectively with the antenna. For example, if the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance satisfy |f1-f2|≥2*f1, it can be considered that the parasitic radiator 12 does not resonate. It is understandable that if no resonance of the parasitic radiator 12 is observed within a region 2*f1 away from the resonant frequency f1 of the main resonance, it can be considered that the parasitic radiator 12 does not resonate.

[0117] In some specific embodiments, the first antenna 1 can operate in the low-band (LB) of cellular communication, for example, any band within the range of 600MHz to 960MHz. This ensures that the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance satisfy: |f1-f2|≥200MHz. That is, the absolute value of the difference between the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance is greater than or equal to 200MHz, or in other words, the distance between the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance is greater than or equal to 200MHz. This reduces the impact of parasitic resonance on the main resonance, preventing it from weakening the main resonance. In some embodiments, a larger |f1-f2| is better, as it helps reduce the impact of parasitic resonance on the main resonance, thereby improving the system efficiency of the first antenna 1.

[0118] For example, in some embodiments, the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance can satisfy: |f1-f2|≥400MHz, or the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance can satisfy: |f1-f2|≥500MHz. Specifically, the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance can satisfy the following: |f1-f2| is 250MHz, 280MHz, 300MHz, 320MHz, 335MHz, 350MHz, 368MHz, 380MHz, 410MHz, 420MHz, 450MHz, 480MHz, 520MHz, 530MHz, 550MHz, 570MHz, 600MHz, 650MHz, 670MHz, 700MHz, 750MHz, 760MHz, 780MHz, 800MHz, 810MHz, 850MHz, 860MHz, 900MHz, 950MHz, 960MHz, etc., which will not be listed here.

[0119] In some embodiments, the first antenna 1 can operate in the mid-high band (MHB) of cellular communication. For example, the first operating frequency band can be any frequency band within the range of 1.7 GHz to 2.7 GHz. This ensures that the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance satisfy the condition: |f1-f2| ≥ 1 GHz. That is, the absolute value of the difference between the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance is greater than or equal to 1 GHz, or in other words, the distance between the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance is greater than or equal to 1 GHz. This reduces the impact of parasitic resonance on the main resonance, preventing it from weakening the main resonance. In some embodiments, a larger |f1-f2| is better, as it helps reduce the impact of parasitic resonance on the main resonance, thereby improving the system efficiency of the first antenna 1.

[0120] For example, in some embodiments, the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance can satisfy: |f1-f2|≥1.5GHz, or |f1-f2|≥1.8GHz, or |f1-f2|≥2GHz. Specifically, the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance can satisfy: |f1-f2| is 1.2GHz, 1.5GHz, 1.6GHz, 1.9GHz, 2.1GHz, 2.4GHz, 2.5GHz, 2.6GHz, 2.8GHz, 3GHz, 3.2GHz, 3.5GHz, 4GHz, 4.2GHz, 4.5GHz, etc., which will not be listed here.

[0121] Please continue to refer to this. Figure 2 In one specific embodiment, the length L1 of the parasitic radiator 12 satisfies: Wherein, λ is the wavelength in free space corresponding to the resonant frequency of the main resonant of the first main radiator 11. In this scheme, the length L1 of the parasitic radiator 12 is relatively short, which facilitates the generation of a more uniform current in the parasitic radiator 12 and makes it less likely to generate resonance within the first operating frequency band. In addition, this scheme is also conducive to further reducing the size of the first antenna 1 and reducing the physical space required for the layout of the first antenna 1 in the communication terminal, so as to adapt to the miniaturization development of the communication terminal.

[0122] In a further embodiment, the length L1 of the parasitic radiator 12 satisfies: This further shortens the size of the first antenna 1 and makes it easier to make the distance between the parasitic resonance generated by the parasitic radiator 12 and the main resonance of the first main radiator 11 greater, thereby reducing the negative impact of the parasitic resonance generated by the parasitic radiator 12 on the current of the first main radiator 11 and thus improving the system efficiency of the first antenna 1.

[0123] Please continue to refer to this. Figure 2 For the first main radiator 11, the length L2 of the first main radiator 11 in this embodiment of the application satisfies: Wherein, λ is the wavelength in free space corresponding to the resonant frequency of the primary resonant of the first primary radiator 11. For example, in some embodiments, the length L2 of the first primary radiator 11 satisfies: In this scheme, the length of the first main radiator 11 does not need to be too long to achieve high-efficiency signal radiation. Therefore, the total length of the first antenna 1 is small, which is beneficial to reduce the physical space occupied by the first antenna 1 while ensuring the system efficiency and radiation aperture of the first antenna 1, so as to adapt to the miniaturization development of communication terminals.

[0124] In this application, such as Figure 2 As shown, in a specific embodiment, the first tuning circuit 15 and the first main radiator 11 are electrically connected at the first connection point 111. The first connection point 111 and the feed point 112 are different points, but they are close enough to facilitate the excitation of the floor current by the current excited by the parasitic radiator 12, thereby also achieving a tight coupling connection between the first main radiator 11 and the parasitic radiator 12.

[0125] In one specific embodiment, the distance S1 between the first connection point 111 and the feed point 112 can satisfy: Wherein, λ is the wavelength in free space corresponding to the resonant frequency of the main resonance of the first main radiator 11. In this scheme, the first connection point 111 and the feed point 112 are closer, which is beneficial to achieving tight coupling between the first main radiator 11 and the parasitic radiator 12. In addition, the first tuning circuit 15 is also used to adjust the matching of the first antenna 1 and adjust the main resonance of the first antenna 1.

[0126] Figure 3 This is a schematic diagram of one structure of the first antenna 1 in an embodiment of this application, as shown below. Figure 3 As shown, in some embodiments, the first connection point 111 and the feed point 112 can be the same point, and the first tuning circuit 15 and the feed structure 14 can be connected to the same location. Alternatively, a tight coupling connection can be achieved between the first main radiator 11 and the parasitic radiator 12. In this embodiment, the first tuning circuit 15 and the feed structure 14 are connected to the same location, resulting in stronger coupling between the first main radiator 11 and the parasitic radiator 12, and a more uniform current excited by the parasitic radiator 12.

[0127] Please continue to refer to this. Figure 2 The first tuning circuit 15 and the first main radiator 11 are electrically connected at the first connection point 111, and the distance S2 between the first connection point 111 and the first gap 13 satisfies: Wherein, λ is the wavelength in free space corresponding to the resonant frequency of the main resonance of the first main radiator 11. The aforementioned distance S2 can also be understood as the distance between the first connection point 111 and the end face adjacent to the first main radiator 11 and the first gap 13. In this scheme, the first tuning circuit 15 is connected to the end of the first main radiator 11 near the parasitic radiator 12, thereby facilitating the adjustment of the main resonance of the first antenna 1 and also facilitating the excitation of the current in the parasitic radiator 12, achieving tight coupling between the parasitic radiator 12 and the first main radiator 11.

[0128] Please continue to refer to this. Figure 2 and Figure 3 In some embodiments, the first tuning circuit 15 and the parasitic radiator 12 are electrically connected to the second connection point 121, and the distance S3 between the second connection point 121 and the first gap 13 satisfies: Wherein, λ is the wavelength in free space corresponding to the resonant frequency of the main resonant point of the first main radiator 11. The aforementioned distance S3 can also be understood as the distance between the second connection point 121 and the end face adjacent to the parasitic radiator 12 and the first gap 13. In this embodiment, the first tuning circuit 15 is connected to the end of the parasitic radiator 12 near the first main radiator 11, realizing tight coupling between the parasitic radiator 12 and the first main radiator 11, which facilitates exciting the entire parasitic radiator 12 to have current in the same direction, and facilitates exciting a strong current on the ground. Moreover, the size of the parasitic radiator 12 can be fully utilized to improve the miniaturization of the first antenna 1, so as to adapt to the miniaturization development of communication terminals.

[0129] Figure 4 This is a schematic diagram of a tuning circuit in one embodiment of this application, combined with... Figure 3 and Figure 4 In this embodiment, the first tuning circuit 15 can be a tunable circuit. The tunable circuit has different capacitance and / or inductance values ​​under different operating states. The tunable circuit includes a switch and multiple tuning devices. By adjusting the switch, the conducting tuning devices can be switched, thereby switching the capacitance and / or inductance values ​​of the tunable circuit, thereby adjusting the electrical length of the first main radiator 11, thereby adjusting the resonant frequency of the main resonance of the first antenna 1, and thus adjusting the first operating frequency band of the first antenna 1. The tunable circuit can adjust the resonant frequency of the main resonance of the first antenna 1 within a wide range, thus expanding the bandwidth of the first antenna 1.

[0130] Regarding the specific composition of the aforementioned tunable circuit, it can also include a variable capacitor. By adjusting the capacitance value of the variable capacitor, the resonant frequency of the main resonance of the first antenna 1 can be adjusted. Furthermore, the aforementioned tuning device can be a capacitor and / or an inductor. In one embodiment, the tunable circuit can also include a switch and multiple inductors. Here, inductors refer to inductive devices, and different inductors have different inductance values. In this embodiment, the inductance value of the inductor connected to the tunable circuit can be selected by the switch. In a specific embodiment, the aforementioned switch can be a single-pole multi-throw switch. In one embodiment, such as... Figure 4 As shown, the tunable circuit described above may further include a switch 151 and multiple capacitors 152, where capacitors 152 refer to capacitors with different capacitance values. In a specific embodiment, the switch may be a single-pole multi-throw switch. In this embodiment, the capacitance value of the capacitor 152 connected to the tunable circuit can be selected via switch 151, thereby tuning the first antenna 1.

[0131] In this embodiment, when the first tuning circuit 15 includes a capacitor, the capacitance value of the capacitor connected to the circuit is relatively small, specifically less than or equal to 3pF. For example, in some embodiments, the capacitance value of the capacitor included in the first tuning circuit 15 includes 0.3pF, 0.5pF, 0.8pF, 1pF, 1.2pF, 1.3pF, 1.5pF, 1.8pF, 2pF, 2.1pF, 2.2pF, 2.3pF, 2.5pF, 2.6pF, 2.7pF, or 2.8pF, etc. This results in a larger current flowing through the first tuning circuit 15, which can reduce the losses caused by the first tuning circuit 15 and improve the system efficiency of the antenna.

[0132] Similarly, when the first tuning circuit 15 includes an inductor, the inductance value of the inductor connected to the circuit is relatively large, specifically, the inductance value can be greater than or equal to 8nH. For example, in some embodiments, the inductance value of the inductor included in the first tuning circuit 15 includes 9nH, 9.5nH, 9.8nH, 10nH, 10.2nH, 10.5nH, 11nH, 11.8nH, 12nH, 12.5nH, 13nH, 13.5nH, 13.8nH, 14nH, 14.5nH, or 15nH, etc. This results in a larger current flowing through the first tuning circuit 15, which can reduce the losses caused by the first tuning circuit 15 and improve the system efficiency of the antenna.

[0133] like Figure 3As shown, in a specific embodiment, the first main radiator 11 of the first antenna 1 includes a branch 113. Specifically, the end of the first main radiator 11 facing the parasitic radiator 12 is an open end, and the end of the first main radiator 11 away from the parasitic radiator 12 is a grounded end 114. The first main radiator 11 is also grounded between the open end and the grounded end 114 through an inductor 115. The inductor 115 here can be an inductor or an equivalent inductor, and this application does not limit this. In this embodiment, the middle part of the first main radiator 11 is grounded through the inductor 115, which is beneficial for the uniform distribution of current in the first main radiator 11, so that the main resonance of the first main radiator 11 corresponds to the first operating frequency band. The first connection point 111 and the feed point 112 are both located near the open end of the first main radiator 11. Figure 3 The first antenna 1 shown can be a low-frequency LB antenna for cellular communication. Therefore, the first operating frequency band of the first antenna 1 in this embodiment can be any frequency band within the range of 600MHz to 960MHz.

[0134] Figure 5 This is a schematic diagram of one structure of the first antenna 1 in the comparative example, as shown below. Figure 5 As shown in the comparative example, the first antenna 1 does not include the parasitic radiator 12; the remaining structure is the same as... Figure 3 The first main radiator 11 shown is similar. Specifically, the first antenna 1 in the comparative example also includes a first main radiator 11, one end of which is an open end and the other end is a ground end 114. The first main radiator 11 is also grounded through an inductor 115 between the open end and the ground end 114, and the feed point 112 is located near the open end of the first main radiator 11. This application Figure 3 The first antenna 1 shown is relatively small in size; specifically, in this application... Figure 3 The size of the first antenna 1 shown is smaller than Figure 5 The dimensions of the first antenna 1 shown in the comparative example. In a specific embodiment, Figure 5 In the comparative example shown, the length D of the first main radiator 11 is 90 mm, wherein the length D1 of the first main radiator 11 between the open end and the connection point of the inductor 115 is 42 mm, and the length D2 of the first main radiator 11 between the connection point of the inductor 115 and the ground end 114 is 48 mm. However, in this application... Figure 3 In the illustrated embodiment, the length d of the first main radiator 11 is 80 mm, wherein the length d1 of the first main radiator 11 between the open end and the connection point of the inductor 115 is 30 mm, the length d2 of the first main radiator 11 between the connection point of the inductor 115 and the ground end 114 is 35 mm, and the length d3 of the parasitic radiator 12 is 15 mm. It can be seen that the length of the first antenna 1 in this embodiment is reduced, which helps to reduce the space required to install the first antenna 1, thereby improving the communication capability of the miniaturized communication terminal.

[0135] Figure 6 This is a schematic diagram comparing the free-space return loss of the first antenna 1 in the embodiments and comparative examples of this application. Figure 7 This is a schematic diagram comparing the return loss of the first antenna 1 in the embodiments and comparative examples of this application under hand-made conditions. Figure 6 and Figure 7 In the middle, the solid line shows the contents of this application. Figure 3 The return loss S11 curve of the first antenna in the illustrated embodiment is shown by the dashed line, which represents the characteristics of this application. Figure 5 The return loss curve S11 of the first antenna in the comparative example is shown. Figure 6 and Figure 7 As shown, the main resonance frequency generated by the first antenna 1 in this embodiment is the same as the parasitic resonance frequency generated by the first antenna 1 in the comparative example, allowing the first antenna 1 to still operate in the first operating frequency band. Furthermore, the return loss S11 curve of the first antenna 1 under hand-held conditions is very similar to the return loss S11 curve in free space. Figure 8 This is a schematic diagram comparing the antenna efficiency of the first antenna 1 in free space in the embodiments and comparative examples of this application. Figure 9 This is a schematic diagram comparing the system efficiency of the first antenna 1 in the embodiments and comparative examples of this application under hand mold conditions. Figure 8 and Figure 9 In the text, the dotted line indicates the scope of this application. Figure 3 The system efficiency curve of the first antenna in the illustrated embodiment, with the double-dotted line representing the present application, is shown. Figure 3 The radiation efficiency curve of the first antenna in the illustrated embodiment; the solid line represents the radiation efficiency curve of this application. Figure 5 The system efficiency curve of the first antenna in the comparative example shown is represented by the dashed line of this application. Figure 5 The radiative efficiency curve of the first ray shown in the comparative example. Figure 8 and Figure 9 As shown, this application Figure 3 The first antenna 1 in the illustrated embodiment can achieve high system efficiency over a wide frequency band. The antenna efficiency mentioned in this embodiment can include system efficiency and radiation efficiency, and the trends of system efficiency and radiation efficiency are basically the same. Furthermore, the system efficiency of the first antenna 1 under hand-held conditions is similar to its system efficiency in free space, both achieving a significant improvement in system efficiency. Specifically, as... Figure 8 As shown, the system efficiency improvement of the first antenna 1 in free space is approximately 1.2 dB, as... Figure 9 As shown, the system efficiency of the first antenna 1 is improved by approximately 1.5 dB under hand-operated conditions. Furthermore, as... Figure 8 and Figure 9As shown, because the system efficiency of the first antenna 1 is improved across a wider frequency band, the bandwidth of the first antenna 1 is also increased. For example, Figure 3 In the specific embodiment shown, the sideband performance bandwidth of the first antenna 1 is improved by 30%.

[0136] Figure 10 A schematic diagram of the structure of the first antenna 1 in this application embodiment is shown below. Figure 10 As shown, in one embodiment, the first main radiator 11 of the first antenna 1 includes a first stub 116 and a second stub 117, with a second gap 118 between the first stub 116 and the second stub 117, and the first stub 116 and the second stub 117 are electrically connected by a second tuning circuit 119. This second tuning circuit 119 can tune the first main radiator 11 to reduce its size and expand the bandwidth of the first antenna. The second stub 117 is located on the side of the first stub 116 away from the parasitic radiator 12. Both ends of the first stub 116 are open terminals, and the end of the second stub 117 facing the first stub 116 is an open terminal, while the end away from the first stub 116 is a ground terminal. The first connection point 111 and the feed point 112 are both located on the first stub 116. Figure 10 The first antenna 1 shown in this application can also be a low-frequency LB antenna for cellular communication. In this embodiment, the first operating frequency band of the first antenna 1 can be any frequency band within the range of 600MHz to 960MHz.

[0137] Figure 11 This is a schematic diagram of one structure of the first antenna 1 in the comparative example, as shown below. Figure 11 As shown in the comparative example, the first antenna 1 does not include the parasitic radiator 12; the remaining structure is the same as... Figure 10 The first main radiator 11 shown is similar. In specific embodiments, this application... Figure 10 In the embodiment shown, the length of the parasitic radiator 12 is 15 mm, which is relatively short.

[0138] Figure 12 for Figure 11 The diagram shows the tuning circuit of the first antenna 1 in the comparative example. Figure 13 for Figure 11 The simulation data diagram of the first antenna 1 in the comparative example is shown below. Figure 13 The solid line in the middle represents Figure 11 The return loss S11 curve of the first antenna in the comparative example shown is represented by the long dashed line. Figure 11 The radiation efficiency curve of the first ray shown in the comparative example is represented by the short dashed line. Figure 11 The system efficiency curve of the first antenna in the comparative example is shown. Figure 14 for Figure 10The schematic diagram of the tuning circuit of the first antenna 1 in this embodiment of the application is shown below. Figure 12 Compared to the addition of the first tuning circuit 15, Figure 15 for Figure 10 The diagram shown is a simulation data diagram of the first antenna 1 in this embodiment of the application. Figure 15 The solid line in the middle represents Figure 10 The return loss S11 curve of the first antenna in this embodiment of the application is shown, with the long dashed line indicating the return loss. Figure 10 The radiation efficiency curve of the first antenna shown in this embodiment of the application is illustrated by the short dashed line. Figure 10 The system efficiency curve of the first antenna in this embodiment is shown. It can be seen that in this embodiment, by adding the parasitic radiator 12, the first operating frequency band of the first antenna can be maintained, and the system efficiency of the first antenna 1 is improved.

[0139] Figure 16 This is a schematic diagram of one structure of the first antenna 1 in an embodiment of this application, as shown below. Figure 16 As shown, in one embodiment, the first main radiator 11 of the first antenna 1 includes a branch. The end of the first main radiator 11 facing the parasitic radiator 12 is an open end, and the end away from the parasitic radiator 12 is a grounded end. Figure 16 The first antenna 1 shown can be a mid-to-high frequency (MHB) antenna for cellular communication. Therefore, the first operating frequency band of the first antenna 1 in this embodiment can be any frequency band within the range of 1.7 GHz to 2.7 GHz.

[0140] Figure 17 This is a schematic diagram of one structure of the first antenna 1 in the comparative example, as shown below. Figure 17 As shown in the comparative example, the first antenna 1 does not include the parasitic radiator 12. Figure 17 The first antenna 1 in the comparative example shown includes a third stub 1111 and a fourth stub 1112, wherein a third gap 1113 is provided between the third stub 1111 and the fourth stub 1112, and the third stub 1111 and the fourth stub 1112 are connected by a third tuning circuit 1114, and the third stub 1111 is connected to a fourth tuning circuit 1115, and the fourth stub 1112 is connected to a fifth tuning circuit 1116. Figure 17 In the comparative example shown, the first antenna generates two current modes, resulting in two resonances within the first operating frequency band. These two resonances are relatively close to each other. In certain frequency bands, the current generated by the third stub 1111 and the current generated by the fourth stub 1112 are in opposite directions, causing current cancellation and resulting in lower efficiency for the first antenna 1.

[0141] Figure 18 This is a schematic diagram comparing the free-space return loss of the first antenna 1 in the embodiments and comparative examples of this application. Figure 18 The solid line in the middle represents this application. Figure 17 The return loss S11 curve of the first antenna in the comparative example, the dashed line shows the return loss curve of this application. Figure 16 The return loss S11 curve of the first antenna in the embodiment. Figure 19 This is a schematic diagram comparing the efficiency of the first antenna 1 in free space systems in the embodiments and comparative examples of this application. Figure 19 The solid line in the middle represents this application. Figure 17 The system efficiency curve of the first antenna in the comparative example, with the dashed line representing the present application. Figure 16 The system efficiency curve of the first antenna in the embodiment is shown. Figure 18 As shown, in this embodiment, the first antenna 1 generates only one main resonance within the first operating frequency band, while in the comparative example, the first antenna 1 generates two resonances within the first operating frequency band. Specifically, the third branch 1111 generates one resonance within the first operating frequency band, and the fourth branch 1112 also generates one resonance within the first operating frequency band. The main resonance generated by the first antenna 1 in the first operating frequency band in this embodiment is quite close to the single resonance in the comparative example. In the comparative example, tuning the first antenna 1 requires multiple tuning circuits, while in this embodiment, tuning of the first antenna 1 can be achieved using only a first tuning circuit 15. Figure 16 The first antenna 1 provided in the middle and Figure 17 The first antenna 1 in the comparative example shown can operate in the same frequency band. And as... Figure 19 As shown, the first antenna 1 in this embodiment can achieve high system efficiency in a wide frequency band. Therefore, this embodiment can improve the system efficiency of the first antenna 1 and expand the bandwidth to a certain extent.

[0142] In this embodiment, the first main radiator 11 and the parasitic radiator 12 of the first antenna 1 may each include a portion of the conductive structure of the frame of the housing, making the first antenna 1 a frame antenna. Specifically, in some embodiments, the frame is a metal frame, and the first main radiator 11 and the parasitic radiator 12 are each a portion of the structure of the metal frame. Alternatively, in some embodiments, the frame is a non-metallic frame, which includes a portion of the metal structure, and this portion of the structure can serve as the first main radiator 11 and the parasitic radiator 12.

[0143] In one implementation of the first antenna in this application, the frame, primarily composed of conductive material, can be referred to as the conductive frame or metal frame of the communication terminal, suitable for industrial design (ID) with a metallic appearance. In another implementation, the outer surface of the frame is primarily made of conductive material, such as metal, thus forming the appearance of a metal frame. In these implementations, the conductive portion of the frame, including its outer surface, can be used as a radiator of the communication terminal, such as the first main radiator 11 and parasitic radiator 12 of the first antenna 1 described above, and is commonly referred to as a frame antenna.

[0144] In another implementation, the outer surface of the frame is primarily made of a non-conductive material, such as plastic, forming a non-metallic frame appearance suitable for non-metallic IDs. In another implementation, the inner surface of the frame may include a conductive material, such as a metallic material. In this implementation, the conductive portion of the inner surface of the frame can be used as a radiator, such as the first main radiator 11 and the parasitic radiator 12 of the first antenna 1. It should be understood that the radiators (or the conductive material of the inner surface) disposed on the inner surface of the frame can be attached to the non-conductive material of the frame to minimize the volume occupied by the radiators and to be closer to the outside of the communication terminal, achieving better signal transmission performance, and can also be referred to as frame antennas. It should be noted that "the antenna radiator is attached to the non-conductive material of the frame" means that the antenna radiator can be tightly attached to the inner surface of the non-conductive material, or it can be embedded inside the non-conductive material, or it can be close to the inner surface of the non-conductive material. For example, there can be a certain small gap between the antenna radiator and the inner surface of the non-conductive material. It should be understood that both the conductive material and the non-conductive material can be considered as part of the frame.

[0145] Figure 20 This is a partial structural diagram of a communication terminal in an embodiment of this application, such as... Figure 16 and Figure 20 As shown in the embodiment of this application, a portion of the structure of the first main radiator 11 extends to one side of the parasitic radiator 12 in the first direction Y, which is perpendicular to the extension direction X of the parasitic radiator 12. In this embodiment, the parasitic radiator 12 and the first main radiator 11 have a partial overlap region A along the extension direction, which is beneficial for further reducing the size of the first antenna and increasing the system efficiency of the first antenna.

[0146] For example, the side of the frame of the communication terminal facing inward may also include a suspended baffle structure 700, which is a metal structure. In this embodiment, the suspended baffle structure 700 is connected to a portion of the conductive structure of the frame, allowing the portion of the metal structure of the frame and the portion of the suspended baffle structure 700 to jointly serve as the first main radiator 11. For example, as the first main radiator 11, the parasitic radiator 12 is specifically a portion of the conductive structure of the frame. The parasitic radiator 12 and the portion of the suspended baffle structure 700 at least partially overlap along the extending direction, that is, the parasitic radiator 12 and the first main radiator 11 have a partial overlap area A along the extending direction. The overlapping portion of the first main radiator 11 and the parasitic radiator 12 is located on the side of the parasitic radiator 12 facing inward, with a gap between them. The architecture of the first antenna in this scheme can support the use of the suspended baffle structure 700 as a portion of the radiator of the first antenna, which is beneficial for further reducing the space occupied by the first antenna 1.

[0147] In some embodiments, the first antenna of the communication terminal of this application may also be a support antenna. Specifically, the first main radiator and the parasitic radiator are located on the support and disposed within the housing of the communication terminal. Alternatively, in some embodiments, the first antenna of the communication terminal of this application may also be located on a circuit board. Specifically, the first main radiator and the parasitic radiator are located on the circuit board, specifically as a metal layer structure disposed on the circuit board.

[0148] The feeding structure 14 is connected to the floating barrier structure 700 of the first main radiator 11, which facilitates the architectural design of the first antenna 1 and helps to optimize the environment of the first antenna 1.

[0149] Figure 21 This is a schematic diagram of the antenna structure of a communication terminal in an embodiment of this application, as shown below. Figure 21 As shown, in one embodiment, the communication terminal further includes a second antenna 2, which operates in a second operating frequency band, different from the first operating frequency band. This allows the communication terminal to achieve communication across different frequency bands; for example, the first operating frequency band may be a low-frequency band, and the second operating frequency band may be a mid-to-high-frequency band. The aforementioned second antenna 2 includes a second main radiator 21, and the second main radiator 21 and the parasitic radiator 12 share some branches. This embodiment helps reduce the space occupied by the antenna of the communication terminal and enriches the communication scenarios of the communication terminal.

[0150] like Figure 21As shown, in a specific embodiment, the parasitic radiator 12 is grounded between the second connection point 121 of the resonant circuit and the ground terminal through a first capacitor 22, and the second main radiator 21 is grounded on the side away from the ground terminal of the parasitic radiator 12 through a second capacitor 23. The capacitance of the first capacitor 22 is smaller than the capacitance of the second capacitor 23. For example, the smaller capacitance of the first capacitor 22 effectively creates an open circuit for the first operating frequency band, thus having no impact on the operation of the first antenna 1, while creating a short circuit for the second operating frequency band, thereby grounding the second antenna 2. The larger capacitance of the second capacitor 23 creates an open circuit for the second operating frequency band, and the resonance generated by the second capacitor 23 occurs before the resonant frequency of the main resonance of the first antenna 1, which is beneficial for further improving the system efficiency of the first antenna 1.

[0151] In one specific embodiment, the architecture of the second antenna 2 can be the same as that of the first antenna 1 in any embodiment of this application, that is, it can also include a parasitic radiator, thereby having a larger aperture and higher system efficiency. Of course, the specific structures of the first antenna and the second antenna in the communication terminal can be different.

[0152] Figure 22 This is a schematic diagram of one structure of the first antenna 1 in an embodiment of this application, as shown below. Figure 22 As shown, in one embodiment, one end of the parasitic radiator 12 can be grounded through the sixth tuning circuit 122, and the other end can be grounded through the seventh tuning circuit 123, thereby tuning more current modes, further shortening the size of the first antenna 1, and improving the efficiency of the first antenna 1.

[0153] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication terminal, characterized in that, The first antenna includes a first antenna that operates in a first operating frequency band. The first antenna includes a first main radiator, a parasitic radiator, and a first tuning circuit, wherein: A first gap exists between the first main radiator and the parasitic radiator. The first main radiator includes a feed point, and the end of the first main radiator facing away from the parasitic radiator is a ground terminal, as is the end of the parasitic radiator facing away from the first main radiator. A first tuning circuit is electrically connected between the first connection point of the first main radiator and the parasitic radiator, wherein the distance S1 between the first connection point and the feed point satisfies: Wherein, L1 is the length of the parasitic radiator; The first main radiator is used to form a main resonance corresponding to the first operating frequency band, and the parasitic radiator is used to form a parasitic resonance; the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance satisfy: |f1-f2|≥30%*f1.

2. The communication terminal as described in claim 1, characterized in that, The first operating frequency band is any frequency band within the range of 600MHz to 960MHz, and the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance satisfy: |f1-f2|≥200MHz.

3. The communication terminal as described in claim 1, characterized in that, The first operating frequency band is any frequency band within the range of 1.7GHz to 2.7GHz, and the resonant frequency f1 of the main resonance and the resonant frequency f2 of the parasitic resonance satisfy: |f1-f2|≥1GHz.

4. The communication terminal as described in any one of claims 1 to 3, characterized in that, The length L1 of the parasitic radiator satisfies: Wherein, λ is the wavelength in free space corresponding to the resonant frequency of the main resonance of the first main radiator.

5. The communication terminal as described in any one of claims 1 to 4, characterized in that, The length L2 of the first main radiator satisfies: Wherein, λ is the wavelength in free space corresponding to the resonant frequency of the main resonance of the first main radiator.

6. The communication terminal as described in any one of claims 1 to 5, characterized in that, The first connection point and the power supply point are the same point.

7. The communication terminal as described in claim 6, characterized in that, The distance S1 between the first connection point and the feed point satisfies: Wherein, λ is the wavelength in free space corresponding to the resonant frequency of the main resonance of the first main radiator.

8. The communication terminal as described in any one of claims 1 to 7, characterized in that, The distance S2 between the first connection point and the first gap satisfies: Wherein, λ is the wavelength in free space corresponding to the resonant frequency of the main resonance of the first main radiator.

9. The communication terminal as described in any one of claims 1 to 8, characterized in that, The first tuning circuit is electrically connected to the parasitic radiator at a second connection point, and the distance S3 between the second connection point and the first gap satisfies: Wherein, λ is the wavelength in free space corresponding to the resonant frequency of the main resonance of the first main radiator.

10. The communication terminal according to any one of claims 1 to 9, characterized in that, The first tuning circuit includes a switch and a plurality of tuning devices. The switch is used to switch the tuning devices that are turned on, thereby switching the capacitance and / or inductance of the first tuning circuit.

11. The communication terminal according to any one of claims 1 to 10, characterized in that, The first tuning circuit includes a capacitor, the capacitance of which is less than or equal to 3pF.

12. The communication terminal as described in any one of claims 1 to 11, characterized in that, The first tuning circuit includes an inductor with an inductance value greater than or equal to 8nH.

13. The communication terminal as described in any one of claims 1 to 12, characterized in that, The communication terminal includes a housing, and the first main radiator and the parasitic radiator each include a portion of the conductive structure of the frame of the housing.

14. The communication terminal as described in any one of claims 1 to 13, characterized in that, The first main radiator is also grounded via an inductor between the first gap and the grounding terminal of the first main radiator.

15. The communication terminal according to any one of claims 1 to 13, characterized in that, The first main radiator includes a first branch and a second branch, a second gap is provided between the first branch and the second branch, and the first branch and the second branch are electrically connected through a second tuning circuit; The second branch is located on the side of the first branch away from the parasitic radiator. The two ends of the first branch are open ends. The end of the second branch facing the first branch is an open end, and the end away from the first branch is a grounded end.

16. The communication terminal according to any one of claims 1 to 13, characterized in that, The end of the first main radiator facing the parasitic radiator is the open end, and the end away from the parasitic radiator is the grounded end.

17. The communication terminal as described in any one of claims 1 to 16, characterized in that, A portion of the structure of the first main radiator extends to one side of the parasitic radiator in a first direction, which is perpendicular to the extension direction of the parasitic radiator.

18. The communication terminal as described in any one of claims 1 to 17, characterized in that, It also includes a second antenna, which operates in a second operating frequency band, which is a different frequency band from the first operating frequency band; the second antenna includes a second main radiator, and the second main radiator and the parasitic radiator share a branch.

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