Multiband integrated antenna for a smartphone and method for designing the same

Abstract

The application discloses a multi-band integrated antenna for a smart phone and a design method thereof. The antenna comprises a first ground feed point, a second ground feed point, a feed point and a radiation branch structure. The radiation branch structure comprises a main branch, a first branch and a second branch. The feed point is connected with the main branch, the first ground feed point is connected with the first branch, and the second ground feed point is connected with the second branch. The main branch and the first branch generate a first resonant frequency band through electromagnetic coupling. The first resonant frequency band is a 2.4 GHz frequency band. The second branch generates a second resonant frequency band in the form of a parasitic main branch. The second resonant frequency band is a frequency band corresponding to a GPS signal. The second branch and the main branch generate a third resonant frequency band through electromagnetic coupling. The third resonant frequency band is a 5 GHz frequency band. The antenna can realize efficient transmission and reception of multi-band signals in a limited space. The antenna has simple wiring, strong controllability of single-band, wide range of each frequency band and high practicability.

Description

Technical Field

[0001] This application relates to the field of smartphone antenna design technology, and in particular to a multi-band integrated antenna for smartphones and its design method. Background Technology

[0002] With the development of mobile communication technology, candybar smartphones are constantly upgrading towards ultra-thin and full-screen designs. Under this trend, the space available for antenna placement inside the phone is greatly reduced, and the antenna clearance area is limited, which brings great challenges to the design of multi-band antennas.

[0003] In related technologies, smartphones typically use inverted F-shaped antennas (IFA) and loop antennas (LOOP). These antennas all adopt a design with one feed point and one ground feed point. Some solutions will add parasitic antennas on this basis. Most of the antennas are attached to the internal frame of the phone.

[0004] However, in the antenna design schemes mentioned above, the antenna wiring VSWR is relatively poor and the impedance matching effect is not good within the limited installation space, which makes it impossible to achieve efficient signal radiation and reception. Summary of the Invention

[0005] The purpose of this application is to at least partially solve one of the aforementioned technical problems.

[0006] Therefore, the first objective of this application is to propose a multi-band integrated antenna for smartphones. This antenna can achieve efficient transmission and reception of multi-band signals within a limited space, has simple and easy wiring, strong controllability of single bands, good anti-interference performance, and covers a wide range of frequency bands. It is effectively adapted to the internal space layout of ultra-thin, full-screen candybar smartphones and has strong practicality.

[0007] The second objective of this application is to propose a design method for a multi-band integrated antenna for smartphones.

[0008] The third objective of this application is to provide a non-transitory computer-readable storage medium.

[0009] To achieve the above objectives, a first aspect of this application provides a multi-band integrated antenna for smartphones, comprising:

[0010] The structure includes a first ground feed point, a second ground feed point, a feed point, and a radial branch structure; among which...

[0011] The radial branch structure includes a main branch, a first branch, and a second branch. The feed point is connected to the main branch via a wiring, the first ground feed point is connected to the first branch via a wiring, and the second ground feed point is connected to the second branch via a wiring.

[0012] The main branch and the first branch generate a first resonant frequency band through electromagnetic coupling, and the first resonant frequency band is the 2.4GHz band;

[0013] The second branch generates a second resonant frequency band by parasitizing the main branch. In the case of generating the two resonant frequency bands, the second branch resonates independently. The second resonant frequency band is the frequency band corresponding to the Global Positioning System (GPS) signal.

[0014] The second branch and the main branch generate a third resonant frequency band through electromagnetic coupling, and the third resonant frequency band is the 5GHz band;

[0015] The tuning matching circuit includes multiple matching bits, each of which corresponds to a tunable device. The number of multiple matching bits is ≥3. The multiple tunable devices are connected in a corresponding series-parallel hybrid connection method based on antenna design requirements. The multiple tunable devices are used to adjust the impedance and resonant point of the multi-band integrated antenna.

[0016] Optionally, in some embodiments, the plurality of tunable devices include: capacitors, inductors, antenna switches, and antenna tuners.

[0017] Optionally, in some embodiments, the shielding opening on the motherboard of the multi-band integrated antenna is provided with a copper foil sealing structure, which is used to suppress interference signals inside the shielding cover.

[0018] Optionally, in some embodiments, the frequency range of the first resonant frequency band is 2400MHz to 2500MHz, and the first resonant frequency band is used to transmit and receive Bluetooth signals and 2.4GHz WiFi signals; the frequency of the second resonant frequency band is 1575.42MHz; and the frequency range of the third resonant frequency band is 5150MHz to 5850MHz, and the third resonant frequency band is used to transmit and receive 5GHz WiFi signals.

[0019] Optionally, in some embodiments, the multi-band integrated antenna is made of flexible printed circuit board (FPC) material, and the multi-band integrated antenna is fixed to the inner wall of the mid-frame of the smartphone based on positioning holes.

[0020] To achieve the above objectives, a second aspect of the present invention provides a design method for a multi-band integrated antenna for a smartphone, applied to the multi-band integrated antenna for a smartphone described in the first aspect. The method includes:

[0021] Set up a first ground feed point, a second ground feed point, and a power feed point. Run a line from the power feed point to the main branch, and run a line from the first ground feed point around the main branch to one side to the first branch, and run a line from the second ground feed point around the main branch to the other side to the second branch.

[0022] By adjusting the parameters and connection methods of multiple tunable devices in the tuning matching circuit, a preliminary tuning design is carried out for the multi-band integrated antenna so that the impedance of each resonant frequency band generated by each branch coupling is matched with the target characteristic impedance of the mobile phone radio frequency system.

[0023] Multiple operating parameters of the pre-tuned multi-band integrated antenna are detected, and the pre-tuned multi-band integrated antenna is cyclically tuned based on the multiple operating parameters until the multiple operating parameters meet the requirements.

[0024] Optionally, in some embodiments, after setting the first ground feed point, the second ground feed point, and the power feed point, the method further includes: designing the gap width between two adjacent traces based on the electromagnetic coupling strength between each stub; and designing the arm width of each trace based on the preset occupied space and radiation effect of the multi-band integrated antenna.

[0025] Optionally, in some embodiments, the preliminary tuning design of the multi-band integrated antenna includes: detecting the original input impedance of each of the resonant frequency bands; determining the impedance deviation type corresponding to each of the resonant frequency bands based on the original input impedance and preliminarily determining the parameters and connection methods of the plurality of tunable devices based on the Smith circle; and iteratively adjusting the parameters and connection methods of the plurality of tunable devices based on the impedance of each resonant frequency band.

[0026] Optionally, in some embodiments, the plurality of operating parameters include reflection loss and radiation efficiency. The step of cyclically tuning the multi-band integrated antenna after preliminary tuning based on the plurality of operating parameters includes: if the reflection loss or radiation efficiency does not reach the target value, re-determining the parameters of the plurality of tunable devices, and cyclically performing operating parameter detection and tunable device parameter adjustment until each of the operating parameters reaches the corresponding target value.

[0027] To achieve the above objectives, a third aspect of the present invention provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the design method for a multi-band integrated antenna for a smartphone as described in any of the second aspects of the present invention.

[0028] The technical solutions provided by the embodiments of this application bring at least the following beneficial effects:

[0029] This application utilizes a structural design combining a single feed point and two independent ground feed points, along with differentiated coupling through multiple branches, to achieve integrated radiation and reception of multi-band signals (GPS, 2.4GHz WiFi / BT, and 5GHz WiFi) within a limited space. This design is adaptable to the internal space layout of ultra-thin, full-screen smartphones, making it highly practical for these devices. Furthermore, the feed point and two ground feed points employ independent coupling routing, simplifying the routing process. The gaps and arm widths of each routing line can be precisely designed according to resonance requirements. Each frequency band's resonance forms an independent control unit, offering strong single-band controllability and allowing for individual performance optimization to avoid inter-band interference. Moreover, the tuning and matching circuit in this application allows for precise tuning of the resonant frequency and impedance matching of each antenna band through different combinations of tuning components, adapting to various internal environments of mobile phones and enhancing the antenna's versatility and adaptability.

[0030] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0031] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0032] Figure 1 This is a schematic diagram of the structure of a multi-band integrated antenna for a smartphone according to an embodiment of this application;

[0033] Figure 2 This is a schematic diagram of the structure of a tuning matching circuit proposed in an embodiment of this application;

[0034] Figure 3 This is a schematic diagram of the arrangement of a multi-band integrated antenna according to an embodiment of this application;

[0035] Figure 4 This is a flowchart illustrating a design method for a multi-band integrated antenna for a smartphone, as proposed in an embodiment of this application.

[0036] Figure 5 This is a schematic diagram illustrating the measured results of a specific S11 parameter according to an embodiment of this application.

[0037] Figure 6 This is a schematic diagram illustrating a specific measured result of radiation efficiency proposed in an embodiment of this application. Detailed Implementation

[0038] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0039] The following description, with reference to the accompanying drawings, describes an embodiment of a multi-band integrated antenna for a smartphone and its design method.

[0040] Figure 1 This is a schematic diagram of the structure of a multi-band integrated antenna for a smartphone according to an embodiment of this application, as shown below. Figure 1 As shown, the antenna includes: a first ground feed point G1, a second ground feed point G2, a feed point F, and a radiating stub structure.

[0041] The radial branch structure includes a main branch C, a first branch E, and a second branch H. The feed point F is connected to the main branch C through a wiring, the first ground feed point G1 is connected to the first branch E through a wiring, and the second ground feed point G2 is connected to the second branch H through a wiring.

[0042] The main branch C and the first branch E generate the first resonant frequency band through electromagnetic coupling. The first resonant frequency band is the 2.4 GHz band.

[0043] The second branch H generates a second resonant frequency band in the form of a parasitic main branch C. In the case of generating the two resonant frequency bands, the second branch resonates independently, and the second resonant frequency band is the frequency band corresponding to the Global Positioning System (GPS) signal.

[0044] The second branch H and the main branch C generate a third resonant frequency band through electromagnetic coupling. The third resonant frequency band is the 5GHz band.

[0045] The tuning matching circuit includes multiple matching bits, each of which corresponds to a tunable device. The number of matching bits is ≥3. The multiple tunable devices are connected in a series-parallel hybrid connection method based on the antenna design requirements. The multiple tunable devices are used to adjust the impedance and resonant point of the multi-band integrated antenna.

[0046] The multi-band integrated antenna in the above embodiments will be described in detail below.

[0047] In this application, the feed point F is the signal connection point between the antenna and the RF circuit of the mobile phone motherboard, serving as the channel for RF energy input and output. The ground feed point is the connection point between the antenna and the ground plane of the motherboard, acting as the reference point for antenna radiation. The antenna in this application includes two independent ground feed points, left and right. Each feed point and ground feed point has its own dedicated trace, and the traces corresponding to the feed point and ground feed point are coupled to generate resonance in a specific frequency band.

[0048] Among them, stubs are metal traces with specific lengths, widths, and orientations extending from the feed point or ground feed point; they are the functional arms of the antenna that enable signal radiation and resonance. For example, such as... Figure 1 As shown, the trace starts from feed point F, first connecting to stub D, and then from stub D connecting to main stub C. The first ground feed point G1 is traced around the stub of feed point F to the first stub E, and the second ground feed point G2 is traced around the stub of feed point F in the opposite direction to the second stub H.

[0049] Based on this, the feed point F is connected to the main stub C, and the first ground feed point G1 is connected to the first stub E, forming a coupling structure to generate the first resonant frequency band. The second ground feed point G2 is connected to the second stub H, independently generating the second resonant frequency band as a parasitic antenna. The main stub C of feed point F and the second stub H of the second ground feed point G2 are coupled again to generate the third resonant frequency band.

[0050] In one embodiment of this application, the first resonant frequency band has a frequency range of 2400MHz to 2500MHz and is used to transmit and receive Bluetooth signals and 2.4GHz WiFi signals; the second resonant frequency band has a frequency of 1575.42MHz, corresponding to the GPS frequency band; and the third resonant frequency band has a frequency range of 5150MHz to 5850MHz and is used to transmit and receive 5GHz WiFi signals.

[0051] In this embodiment, when generating the first resonant frequency band, energy is first input: the motherboard's RF module transmits an electrical signal of 2400MHz to 2500MHz to stub C through feed point F. Then, a ground reference is established: the first ground feed point G1 transmits the motherboard's ground plane signal to stub E, making stub E a stable ground reference arm. Next, electromagnetic coupling and resonance occur: based on the preset gap between stub C (carrying RF energy) and stub E (providing a ground reference), they form a "coupled structure." That is, when the electrical signal is transmitted in stub C, it will generate electromagnetic induction with stub E, ultimately exciting the entire coupled structure to produce an inherent oscillation (i.e., resonance) of 2400 MHz - 2500MHz. Finally, signal radiation or reception occurs: in the resonant state, stubs C and E efficiently convert the electrical signal into electromagnetic waves and radiate them into space, enabling the mobile phone to transmit Wi-Fi or Bluetooth signals, or receive electromagnetic waves of that frequency band in space and convert them into electrical signals, which are then transmitted back to the motherboard through feed point F.

[0052] When generating the second resonant frequency band, the second stub H resonates independently as a parasitic radiating unit, while the main stub C only provides the energy source and does not participate in the frequency determination of this resonance. The second stub H is adapted to the GPS frequency band based on its own size parameters. First, energy is acquired: the feed point F inputs radio frequency energy to the main stub C. The main stub C carries energy and generates an alternating electromagnetic field. The second stub H is located in this electromagnetic field and acquires induced energy through electromagnetic induction (without direct electrical connection). Then, independent resonance occurs: the length and arm width of the second stub H are precisely designed to adapt to the GPS frequency band. Its own metal trace structure possesses the inherent resonant frequency of this band. After acquiring energy, it independently resonates, realizing the transmission and reception of GPS signals.

[0053] Therefore, when the second branch H generates the second resonant frequency band, it can resonate independently without interfering with the main frequency band. It also does not require a separate power supply line and can obtain power only through coupling, which simplifies the design and reduces the space occupied by the line.

[0054] When generating the third resonant frequency band, stub H and stub C form a coupled double-stub structure, the overall electrical characteristics of which are adapted to the 5GHz band. First, direct energy input: the feed point F directly inputs radio frequency energy to stub C. A precisely designed gap exists between stub C and stub H, forming a strongly electromagnetically coupled double-stub structure. Then, coordinated resonance occurs: stub C and stub H form a unified resonant unit through electromagnetic coupling. The equivalent electrical length of this unit perfectly matches the frequency band requirements of 5150MHz to 5850MHz, thus generating resonance together. The 5GHz resonant frequency is determined by the dimensions of stub C and stub H, as well as the gap between them.

[0055] Because the same stub H in this application can participate in resonance in two different frequency bands without mutual interference, after dual-band adaptation design, the physical dimensions of stub H not only meet the requirement that its independent resonance is 1 / 4 wavelength of the GPS frequency band, but also, after coupling with stub C, allow the equivalent electrical length of the overall structure to adapt to the wavelength requirement of the 5GHz frequency band. The embodiments of this application can achieve precise control of stub dimensions through fine wiring technology, allowing the same physical structure to possess two different electrical resonance characteristics.

[0056] This application implements a dual-band antenna for GPS and WIFI within a limited space. The main frequency bands include the 2.4GHz band and the 5GHz band, and the auxiliary frequency band is the GPS band.

[0057] In one embodiment of this application, the plurality of tunable devices in the tuning matching circuit include capacitors, inductors, antenna switches, and antenna tuners.

[0058] Specifically, this embodiment can set up a tuning matching circuit according to the actual antenna design needs. The antenna can be tuned by various tunable devices in the tuning matching circuit in a series and parallel combination, thereby fine-tuning the antenna's equivalent impedance, resonant frequency and radiation efficiency and other parameters, so that the antenna performance can reach the design target.

[0059] As one possible implementation, such as Figure 2 As shown, the tuning matching circuit includes multiple matching bits, i.e. Figure 2 In the diagram, A, B, I, L, and O represent parallel grounding points, B and L represent serial tunable devices, and ANT201 is the antenna spring. When reserving these matching points, the hybrid series-parallel connection method is as follows: A and B are connected in parallel, I and L are connected in parallel, these two parallel structures are then connected in series, and finally O is connected in series. L201 to L203, R201, and R202 on each matching point can be capacitors, inductors, antenna switches, and antenna tuners, etc. The type, parameters, and connection method of each tunable device can be set according to actual needs to achieve the goal of bringing the reactance part of the antenna complex impedance close to zero, ultimately matching the antenna input impedance with the target characteristic impedance of the mobile phone RF system (e.g., a 50Ω pure resistance). That is, based on meeting the goal of matching the antenna input impedance with the target characteristic impedance of the mobile phone RF system, the appropriate hybrid series-parallel connection method of the tunable devices can be selected according to the actual needs of the antenna design; this application does not impose any restrictions on this.

[0060] It should be noted that the number of matching bits reserved in this application is determined based on the actual situation after the preliminary antenna design is completed. At least 3 matching bits are reserved to meet basic tuning requirements, that is, the number of matching bits is ≥3. For example, at least 3 matching bits are reserved. Figure 2 In the case of A, B, and I, A and B are connected in parallel and then I is connected in series.

[0061] In one embodiment of this application, the shielding cover opening on the motherboard of the multi-band integrated antenna is provided with a copper foil sealing structure, which is used to suppress interference signals inside the shielding cover.

[0062] Specifically, in this embodiment, copper foil is used to cover and seal the openings of the shielding cover near the motherboard of the mobile wireless network (WCN) corresponding to the multi-band integrated antenna, thereby forming an electromagnetic shielding structure to prevent stray electromagnetic fields generated by various devices inside the shielding cover from interfering with the antenna signal.

[0063] In one embodiment of this application, the multi-band integrated antenna is made of flexible printed circuit board (FPC) material and is fixed to the inner wall of the mid-frame of the smartphone based on positioning holes.

[0064] Specifically, the multi-band integrated antenna in this embodiment is made entirely of flexible printed circuit board (FPC). Leveraging the fine wiring capabilities of FPC, it ensures resonant performance across the 2.4GHz, GPS, and 5GHz bands. Furthermore, the copper foil traces of the FPC allow for seamless connection with the copper foil covering layer described in the previous embodiment, forming a complete shielding structure. In addition, when the multi-band integrated antenna in this embodiment is actually installed in a smartphone, it can be attached to the inner wall of the phone's frame, with positioning holes added to the inner wall of the frame to secure the antenna. For example, as... Figure 3 As shown, this multi-band integrated antenna can be attached to the back cover of a smartphone.

[0065] In summary, the multi-band integrated antenna for smartphones in this application embodiment, through a structural design combining a single feed point and two independent ground feed points, coupled with differentiated coupling of multiple branches, achieves integrated radiation and reception of multi-band signals (GPS, 2.4GHz WiFi / BT, and 5GHz WiFi) within a limited space. This design is adaptable to the internal space layout of ultra-thin, full-screen smartphones, making it highly practical for these devices. Furthermore, the antenna's feed point and two ground feed points employ independent coupling routing, simplifying the routing process. The gaps and arm widths of each routing line can be precisely designed according to resonance requirements. Each frequency band's resonance forms an independent control unit, providing strong single-band controllability and allowing for individual performance optimization to avoid inter-band interference. Moreover, the tuning and matching circuit within the antenna can precisely tune the resonant frequency and impedance matching of each frequency band through different combinations of tuning components, adapting to different internal environments of mobile phones and enhancing the antenna's versatility and adaptability.

[0066] To more clearly illustrate the specific implementation process of designing the aforementioned multi-band integrated antenna for smartphones, this application also proposes a design method for a multi-band integrated antenna for smartphones. This method is applied to the multi-band integrated antenna for smartphones in the above embodiments; that is, this method can design a multi-band integrated antenna capable of achieving the aforementioned functions. The various components of the antenna involved in this method are as described in the above embodiments and will not be repeated here.

[0067] Figure 4 A flowchart illustrating a design method for a multi-band integrated antenna for a smartphone, as proposed in this application, is shown below. Figure 4 As shown, the method includes the following steps:

[0068] Step S101: Set up a first ground feed point, a second ground feed point, and a power feed point. Run a line from the power feed point to the main branch, and run a line from the first ground feed point around the main branch to one side to the first branch. Run a line from the second ground feed point around the main branch to the other side to the second branch.

[0069] Specifically, this step involves wiring design, referring to... Figure 1 As shown, a trace runs from feed point F directly to stubs D and C. The first ground feed point G1 runs a trace to the left around the stub of feed point F to stub E, and the second ground feed point G2 runs a trace to the right around the stub of feed point F to stub H. This achieves coupling between the traces at the feed point and the traces at the two ground feed points.

[0070] In one embodiment of this application, after setting the first ground feed point, the second ground feed point and the power feed point, the method further includes: designing the gap width between two adjacent traces based on the electromagnetic coupling strength between each branch; and designing the arm width of each trace based on the preset occupied space and radiation effect of the multi-band integrated antenna.

[0071] Specifically, the gaps and arm widths of each trace differ, resulting in varying resonance effects. Wider gaps lead to shallower standing waves, insufficient coupling, and failure to generate the target resonance. Smaller gaps result in stronger coupling, but excessively small gaps can cause frequency band overlap and signal interference. Arm width (the width of a stub) affects the antenna's impedance matching and power carrying capacity. Larger antenna areas result in better radiation, while narrower arms can lead to signal attenuation; therefore, it's necessary to maximize the trace arm width. However, the arm width is determined by preset parameters such as antenna length and area. Excessively wide arms occupy more space, conflicting with the pre-allocated limited space. Therefore, in this embodiment, before routing, based on the above analysis, the gap width between adjacent traces and the arm width of each trace are accurately designed according to the expected electromagnetic coupling strength, space occupation, and radiation effect between each stub. This ensures the multi-band integrated antenna in the above embodiment achieves the desired effect, balancing space constraints and performance. One possible implementation is to connect the antenna to a network analyzer. When designing the slot and arm width, experiments can be conducted to increase or decrease the size of the antenna slots. The coupling strength values ​​corresponding to different slot spacings can then be observed in the network analyzer to determine which slot spacing provides the most suitable coupling effect. Similarly, the values ​​displayed by the network analyzer can be used to determine which trace arm width provides the radiation effect that meets the radiation intensity requirements within the preset space requirements.

[0072] Step S102: By adjusting the parameters and connection methods of multiple tunable devices in the tuning matching circuit, a preliminary tuning design is carried out for the multi-band integrated antenna so that the impedance of each resonant frequency band generated by each branch coupling is matched with the target characteristic impedance of the mobile phone radio frequency system.

[0073] Specifically, because even small errors in stub dimensions have a significant impact on performance within a limited space, the routing design in the previous step alone may not be able to completely eliminate these errors. Therefore, this step utilizes tuning design to quickly correct these errors using tunable devices. Furthermore, antenna tuning design is integrated throughout the entire antenna design process in this application. In this step, during the FPC design phase, multiple solder pads for tunable devices are reserved. Simulation software is used to simulate the effects of different device combinations, initially determining the optimal device parameters (such as the selected capacitor and inductor values) and how the various devices should be connected in series and parallel.

[0074] In one embodiment of this application, preliminary tuning design of a multi-band integrated antenna includes: detecting the original input impedance of each resonant frequency band; determining the impedance deviation type corresponding to each resonant frequency band based on the original input impedance and using Smith circles to preliminarily determine the parameters and connection methods of multiple tunable devices; and iteratively adjusting the parameters and connection methods of the preliminarily determined multiple tunable devices for the impedance of each resonant frequency band.

[0075] Specifically, in this embodiment, when the antenna impedance is not adequately matched, tuning design is performed using the Smith Chart. In the antenna tuning and matching circuit, the reserved matching positions (i.e., the soldering positions of the tuning components) are used for component selection, parameter adjustment, and series-parallel combination to achieve precise matching between the antenna's input impedance and the 50Ω characteristic impedance of the RF system. This is achieved through the following steps:

[0076] The first step is to measure the native impedance: using equipment such as a network analyzer to connect the antenna's feed point and ground feed point, measure the native input impedance of the three frequency bands of GPS, 2.4GHz and 5GHz, and map the impedance data onto the Smith chart to mark the impedance points of each frequency band (at this time, the impedance points are far away from the 50Ω center).

[0077] The second step is to determine the type of impedance deviation: On the circle graph, based on the position of the impedance point, determine whether the deviation is biased towards inductive (closer to the upper half of the circle graph) or capacitive (closer to the lower half of the circle graph), and whether the resistance part is too large or too small.

[0078] Furthermore, if the impedance is biased towards inductive, a series capacitor or a parallel inductor will pull the impedance point downwards; if the impedance is biased towards capacitive, a series inductor or a parallel capacitor will pull the impedance point upwards.

[0079] The third step is to perform trial soldering of the matching parts: On the reserved matching parts, solder the patch components according to the component types and parameters indicated by the circular diagram. For example, if the 5G band of the antenna is far from 50 ohms, first connect a 1.5nH inductor in series and then connect a 0.3pF capacitor in parallel.

[0080] The fourth step is to retest and trace the Smith chart trajectory: measure the impedance again with a network analyzer and check whether the impedance point on the Smith chart has moved toward the 50Ω center. If it has not moved, change the component parameters (for example, change the 1.5nH inductor to 1.8nH) or change the matching method (for example, change the series connection to the parallel connection).

[0081] The fifth step is to perform iterative debugging of the three frequency bands: Since the antenna of this application is multi-band coupled, the GPS, 2.4GHz and 5GHz frequency bands need to be debugged one by one. Priority is given to ensuring the matching accuracy of 2.4G and 5G (Wi-Fi dual-band), and then the GPS (parasitic resonance) is finely adjusted. Finally, the impedance points of the three frequency bands are stabilized in the acceptable range of the 50Ω center of the Smith chart.

[0082] Therefore, the embodiments of this application employ a Smith chart combined with a reserved matching bit debugging method, which eliminates the need to modify the core antenna structure (such as stub dimensions and feed point positions). Impedance optimization is achieved solely through the debugging of small matching bit components, simplifying the design process. Furthermore, the three frequency bands can be debugged independently, avoiding frequency band interference problems caused by multi-resonant coupling.

[0083] Step S103: Detect multiple operating parameters of the multi-band integrated antenna after preliminary tuning, and perform cyclic tuning design on the multi-band integrated antenna based on multiple operating parameters until multiple operating parameters meet the requirements.

[0084] Specifically, this step involves actual measurement and tuning during the antenna sample stage. For example, after producing the antenna sample and assembling it into the phone's mid-frame, multiple operating parameters of the antenna are measured. If any performance parameter fails to meet the standard, the tuning design is redesigned, and repeated testing is performed until the performance meets the standard. Therefore, this application allows for rapid component replacement, avoids redesigning the antenna structure, and ensures the accuracy of the final tuning result.

[0085] In one embodiment of this application, multiple operating parameters include reflection loss and radiation efficiency. Based on multiple operating parameters, the multi-band integrated antenna after initial tuning is cyclically tuned, including: if the reflection loss or radiation efficiency does not reach the target value, the parameters of multiple tunable devices are re-determined, and the operating parameters are cyclically detected and the tunable device parameters are adjusted until each operating parameter reaches the corresponding target value.

[0086] Specifically, this embodiment uses equipment such as a network analyzer and an anechoic chamber to measure the antenna's reflection loss (Scattering Parameter 11, or S11) and radiation efficiency. If a performance parameter is found to be substandard, for example, if the S11 parameter test determines that the VSWR of a certain frequency band is greater than 2.0, the tuning design is redesigned, including soldering components with different parameters (such as changing the capacitance value of the parallel capacitor). Then, the operating parameters are repeatedly tested and the parameters of the tunable components are adjusted until each operating parameter meets the standard. The process of determining the parameter values ​​of the replaced components can be referred to the tuning process in step S102, and will not be repeated here.

[0087] Therefore, the multi-band integrated antenna finally designed in this application detects the following S11 parameters: Figure 5 As shown, the results can be obtained by calculating the detected radiation efficiency. Figure 6 The attenuation values ​​shown are, where, Figure 5 The horizontal axis represents the frequency range, and the vertical axis represents the reflection loss; Figure 6 The horizontal axis represents the frequency range, and the vertical axis represents the antenna attenuation value. The attenuation value is calculated based on the antenna's radiation efficiency. For example, assuming the antenna radiation efficiency is 10%, the corresponding antenna attenuation value can be calculated using the following formula: 10 × log(10%) = -10. Figure 5 and Figure 6 It can be seen that the antenna S11 designed in this application has a lower value and higher radiation efficiency, which is superior to the antenna in the related embodiments.

[0088] In summary, the design method for a multi-band integrated antenna for smartphones according to the embodiments of this application enables efficient transmission and reception of multi-band signals within a limited space. The antenna has simple and easy wiring, strong single-band controllability, good anti-interference performance, and covers a wide range of frequency bands. It is effectively adapted to the internal space layout of ultra-thin, full-screen candybar smartphones and has strong practicality.

[0089] To implement the above embodiments, this application also proposes a non-transitory computer-readable storage medium storing a computer program that, when executed by a processor, implements the design method for a multi-band integrated antenna for a smartphone as proposed in the second aspect of the present application.

[0090] It should be noted that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0091] Furthermore, in the description of this application, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0092] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0093] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0094] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0095] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this invention.

Claims

1. A multi-band integrated antenna for smartphones, characterized in that, include: The structure includes a first ground feed point, a second ground feed point, a feed point, and a radial branch structure; among which... The radial branch structure includes a main branch, a first branch, and a second branch. The feed point is connected to the main branch via a wiring, the first ground feed point is connected to the first branch via a wiring, and the second ground feed point is connected to the second branch via a wiring. The main branch and the first branch generate a first resonant frequency band through electromagnetic coupling, and the first resonant frequency band is the 2.4GHz band; The second branch generates a second resonant frequency band by parasitizing the main branch. In the case of generating the two resonant frequency bands, the second branch resonates independently. The second resonant frequency band is the frequency band corresponding to the Global Positioning System (GPS) signal. The second branch and the main branch generate a third resonant frequency band through electromagnetic coupling, and the third resonant frequency band is the 5GHz band; A tuning matching circuit includes multiple matching bits, each matching bit corresponding to a tunable device. The number of multiple matching bits is ≥3. The multiple tunable devices are connected in a corresponding series-parallel hybrid connection method based on antenna design requirements. The multiple tunable devices are used to adjust the impedance and resonant point of the multi-band integrated antenna. Each power feed point and ground feed point has its own separate trace, and the traces corresponding to the power feed point and ground feed point are coupled. A stub is a metal trace segment with a certain length, width and direction that extends from the power feed point or ground feed point. The trace starts from the power feed point, connects to the stub first, and then connects from the stub to the main stub. The first ground feed point runs a trace around the stub of the power feed point to the first stub, and the second ground feed point runs a trace around the stub of the power feed point in the opposite direction to the second stub.

2. The multi-band integrated antenna for smartphones according to claim 1, characterized in that, The plurality of tunable devices include: capacitors, inductors, antenna switches, and antenna tuners.

3. The multi-band integrated antenna for smartphones according to claim 1, characterized in that, The shielding cover on the motherboard of the multi-band integrated antenna has a copper foil sealing structure at the opening, which is used to suppress interference signals inside the shielding cover.

4. The multi-band integrated antenna for smartphones according to claim 1, characterized in that, The first resonant frequency band has a frequency range of 2400MHz to 2500MHz, and is used to transmit and receive Bluetooth signals and 2.4GHz WiFi signals. The frequency of the second resonant band is 1575.42MHz; The third resonant frequency band has a frequency range of 5150MHz to 5850MHz and is used to transmit and receive 5GHz WiFi signals.

5. The multi-band integrated antenna for smartphones according to claim 1, characterized in that, The multi-band integrated antenna is made of flexible printed circuit board (FPC) material and is fixed to the inner wall of the smartphone's mid-frame based on positioning holes.

6. A design method for a multi-band integrated antenna for smartphones, characterized in that, The design method, applied to a multi-band integrated antenna for a smartphone as described in any one of claims 1-5, comprises the following steps: Set up a first ground feed point, a second ground feed point, and a power feed point. Run a line from the power feed point to the main branch, and run a line from the first ground feed point around the main branch to one side to the first branch, and run a line from the second ground feed point around the main branch to the other side to the second branch. By adjusting the parameters and connection methods of multiple tunable devices in the tuning matching circuit, a preliminary tuning design is carried out for the multi-band integrated antenna so that the impedance of each resonant frequency band generated by each branch coupling is matched with the target characteristic impedance of the mobile phone radio frequency system. Multiple operating parameters of the pre-tuned multi-band integrated antenna are detected, and the pre-tuned multi-band integrated antenna is cyclically tuned based on the multiple operating parameters until the multiple operating parameters meet the requirements.

7. The design method for a multi-band integrated antenna for a smartphone according to claim 6, characterized in that, After setting the first ground feed point, the second ground feed point, and the power feed point, the following is also included: Based on the electromagnetic coupling strength between each branch, the gap width between two adjacent traces is designed. Based on the pre-defined space requirements and radiation effect of the multi-band integrated antenna, the arm width of each trace is designed.

8. The design method for a multi-band integrated antenna for a smartphone according to claim 6, characterized in that, The preliminary tuning design of the multi-band integrated antenna includes: Detect the original input impedance for each of the resonant frequency bands; Based on the original input impedance, the impedance deviation type corresponding to each resonant frequency band is determined using the Smith circle method, and the parameters and connection methods of the multiple tunable devices are initially determined. For the impedance of each resonant frequency band, the parameters and connection methods of the initially determined multiple tunable devices are iteratively adjusted.

9. The design method for a multi-band integrated antenna for a smartphone according to claim 8, characterized in that, The multiple operating parameters include reflection loss and radiation efficiency. The step of cyclically tuning the pre-tuned multi-band integrated antenna based on these multiple operating parameters includes: If the reflection loss or radiation efficiency fails to reach the target value, the parameters of the plurality of tunable devices are redefined, and the working parameter detection and tunable device parameter adjustment are performed cyclically until each of the working parameters reaches the corresponding target value.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the design method for a multi-band integrated antenna for a smartphone as described in any one of claims 6-9.

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