Hybrid polarized antenna and communication equipment

Abstract

The invention provides a hybrid polarized antenna and communication equipment, the hybrid polarized antenna comprises a PCB and six branches arranged on the PCB, the center of the top layer of the PCB is provided with a feeding point, the feeding point is connected with a radio frequency port of the antenna through an impedance matching circuit, the top layer of the PCB is also provided with a reference ground plane, and the impedance matching circuit is connected with the radio frequency port of the antenna through an impedance matching circuit. Each branch knot comprises a straight line wire located on the top layer of the PCB and an oblique line wire located on the bottom layer of the PCB, the straight line wires and the oblique line wires are connected to form a continuous spiral broken line structure, and a tuning device is connected in series in the middle of a spiral broken line of each branch knot. The six branches comprise two feed branches and four ground branches, the head ends of the feed branches are jointly connected to the feed point, and the tail ends of the feed branches are suspended; the head ends of the four ground branches are jointly connected to the reference ground plane, and the tail ends of the four ground branches are suspended. Through the broken line type routing design of the six branches, the multi-band and circular polarization characteristics of the antenna are realized, and the debugging flexibility of the antenna is improved.

Description

Technical Field

[0001] This application relates to the field of wireless communication technology, and in particular to a hybrid polarization antenna and communication device. Background Technology

[0002] In the field of wireless communication, antennas are key components for transmitting and receiving electromagnetic waves in space, and their performance directly affects communication quality. Based on their polarization, antennas can be classified into three types: linear polarization, circular polarization, and elliptical polarization. Circularly polarized antennas are widely used in satellite communication because they effectively reduce the impact of interference signals such as reflections, thereby improving communication quality. For example... Figure 1 The image shows a commonly used traditional circularly polarized microstrip antenna, consisting of a bottom base plate and an upper square antenna plate, both made of metal. The feed point is located slightly below the center of the antenna plate. Two corners along one diagonal of the antenna plate are beveled to achieve circular polarization. The choice of bevel angle depends on whether the radiated electromagnetic wave requires left-hand or right-hand circular polarization. However, while this traditional circularly polarized microstrip antenna has a relatively simple structure, it suffers from large size and difficulties in subsequent debugging. Summary of the Invention

[0003] In view of this, this application proposes a hybrid polarization antenna and communication device, which realizes multi-band and circular polarization characteristics of the antenna through a six-segment zigzag routing design, thereby improving the flexibility of antenna tuning.

[0004] In a first aspect, this application provides a hybrid polarization antenna, including a PCB board and six branches disposed on the PCB board. A feed point is disposed at the center of the top layer of the PCB board, and the feed point is connected to the radio frequency port of the antenna through an impedance matching circuit. A reference ground plane is also disposed on the top layer of the PCB board. Each branch includes a straight trace located on the top layer of the PCB board and a diagonal trace located on the bottom layer of the PCB board, and they are connected to form a continuous spiral zigzag structure through vias at both ends of the traces. A tuning device is connected in series in the middle of the spiral zigzag of each branch. The six branches include two power supply branches and four ground branches, with two ground branches distributed on both sides of each power supply branch. The beginning ends of the two power supply branches are connected to the power supply point, and their ends are suspended. The beginning ends of the four ground branches are connected to the reference ground plane, and their ends are suspended. After the two feed stubs are energized, an alternating electromagnetic field is generated around them, which excites their corresponding two ground stubs, forming different antenna operating states to achieve circular polarization radiation in multiple frequency bands.

[0005] From the above, the application provides a mixed polarized antenna, which comprises six branches composed of two feeding branches and four ground branches on a double-sided PCB, each branch adopts a unique spiral broken line structure and a series tuning device, each feeding branch corresponds to two ground branches, the first ends of the two feeding branches are connected to a feeding point and the second ends are suspended, the first ends of the four ground branches are connected to a reference ground plane and the second ends are suspended, the unique asymmetric suspended-ground structure enables each feeding branch to excite its corresponding two ground branches and form different antenna working states and realize circular polarization radiation, which helps to improve the radiation performance and circular polarization characteristics of the antenna, and the tuning device in the middle of each branch can be used to adjust the resonant frequency, so that the antenna supports multiple frequency bands.

[0006] Optionally, the impedance matching circuit comprises at least one parallel tuning branch and at least one series tuning branch. The parallel tuning branch comprises a first inductor and a first capacitor connected in parallel between the signal path and the reference ground. The series tuning branch comprises a second inductor and a second capacitor connected in series on the signal path.

[0007] From the above, the combination of parallel and series tuning branches (L-type, Π-type, etc.) can finely adjust the input impedance of the antenna, so that it can better match the standard impedance (such as 50Ω) in the working frequency band, thereby minimizing signal reflection loss and improving energy transmission efficiency.

[0008] Optionally, the tuning device is an inductor, a capacitor, or a combination of an inductor and a capacitor.

[0009] From the above, the tuning device can be an inductor, a capacitor, or a combination thereof, and by replacing or adjusting these devices, the resonant frequency and coupling strength of each branch can be independently and accurately fine-tuned, providing a physical basis for subsequent implementation of multi-frequency, circular polarization, etc.

[0010] Optionally, the two feeding branches are a first feeding branch and a second feeding branch, and the four ground branches are a first ground branch, a second ground branch, a third ground branch, and a fourth ground branch. The first ground branch and the third ground branch are a pair of ground branches symmetrically distributed on both sides of the first feeding branch and jointly form a first antenna working state. The second ground branch and the fourth ground branch are a pair of ground branches symmetrically distributed on both sides of the second feeding branch and jointly form a second antenna working state.

[0011] From the above, the four ground branches are clearly divided into two pairs, and each pair corresponds to a pair of feeding branches arranged symmetrically. This symmetrical layout in space is conducive to exciting electric field components with equal amplitude and a certain angle in space, thereby providing an ideal structure for generating high-quality circularly polarized waves. Moreover, the symmetrical structure can also help to achieve symmetry in the antenna radiation pattern and avoid directional distortion. At the same time, the grouping mode provides a clear physical basis for independent regulation of dual-band or dual-mode operation.

[0012] Optionally, when the lengths of the ground branches in a pair are the same and the parameters of the tuning devices connected in series are configured to have a preset difference, the pair of ground branches and the corresponding feeding branches together generate two resonant modes with a preset phase difference at a target frequency band, thereby enabling the antenna to exhibit circularly polarized radiation characteristics at the target frequency band.

[0013] From the above, by setting the parameters of the tuning devices of a pair of symmetrical ground branches to a "preset difference", the two resonant modes generated by the coupling of the pair of branches and the feeding branches can be artificially split slightly (one is slightly higher and the other is slightly lower). At the center frequency, these two modes naturally form the required phase difference at a certain angle, thereby reliably converting the antenna from linear polarization to circular polarization operation.

[0014] Optionally, the positive and negative relationship of the preset difference is used to control the handedness of the circularly polarized radiation characteristics. Specifically: When the parameter value of the tuning device of the first ground branch is greater than that of the third ground branch paired with it, the antenna exhibits a first circular polarization characteristic at the corresponding target frequency band. When the parameter value of the tuning device of the first ground branch is less than that of the third ground branch, the antenna exhibits a second circular polarization characteristic opposite to the first circular polarization characteristic at the corresponding target frequency band.

[0015] From the above, the positive and negative relationship of the preset difference directly determines the circular polarization handedness (left-handed LHCP or right-handed RHCP), which means that simply exchanging the parameter values of the tuning devices of a pair of ground branches can reverse the circular polarization direction of the antenna. This allows the same antenna platform to adapt to different polarization requirements of communication systems, greatly improving the versatility and application range of the antenna.

[0016] Optionally, the four ground branches are configured to have at least two different resonant frequencies, enabling the antenna to achieve a mixed polarization operating mode at at least two different frequency bands. At least one frequency band is a circular polarization operating mode, and the remaining frequency bands are linear polarization operating modes.

[0017] As described above, by configuring the four ground stubs with different resonant frequencies, the antenna can operate in multiple frequency bands, and each band can independently select its polarization (e.g., band A is right-hand circular polarization, and band B is linear polarization). This allows a single antenna to simultaneously meet the needs of multiple different communication modules within a complex wireless device (such as GPS circular polarization reception and Wi-Fi linear polarization transceiver), achieving ultimate integration and design flexibility.

[0018] Optionally, the tuning device is a switching tuning circuit, which is composed of a third inductor and a switching device connected in series, and then connected in parallel with a fourth inductor. The switching device is controlled by a controller, and the equivalent inductance value of the ground stub is adjusted by switching the on and off state of the switching device, so that the antenna switches between multiple frequency bands.

[0019] As described above, by replacing fixed tuning devices with controlled switching tuning circuits, the equivalent inductance of each stub can be switched in real time via electrical signals, thereby adjusting the resonant frequency of each stub. This upgrades the antenna from fixed multi-frequency to reconfigurable multi-frequency. By controlling all switches, the antenna can be selected to operate in up to eight preset frequency bands, or these frequency points can be combined to form an extremely wide bandwidth, dynamically adapting to different communication standards or frequency band requirements.

[0020] Optionally, adjusting the equivalent inductance of the ground stub by switching the on / off state of the switching device specifically includes: When the switching device is turned on, the third inductor and the fourth inductor are connected in parallel to form the first equivalent inductance value; When the switching device is disconnected, only the fourth inductor is connected to the circuit to form the second equivalent inductance value; By switching the state of the switching device, the ground stub can be switched between two resonant frequencies.

[0021] As described above, by controlling the parallel inductor combination or the connection of a single inductor through a switch, two discrete and significantly different equivalent inductance values ​​can be obtained. This circuit structure has advantages such as simplicity, reliability, fast switching speed, and clear control logic, ensuring flexible adjustment of the equivalent inductance of each branch.

[0022] Secondly, this application provides a communication device including the aforementioned hybrid polarization antenna.

[0023] These and other aspects of this application will become more apparent in the description of the following embodiments(s). Attached Figure Description

[0024] Figure 1 This is a top view of the structure of a commonly used traditional circularly polarized microstrip antenna; Figure 2A top view of a hybrid polarization antenna provided in an embodiment of this application; Figure 3a This is a schematic diagram of the straight traces on the top layer of the PCB board in an embodiment of this application; Figure 3b This is a schematic diagram of the diagonal traces on the bottom layer of the PCB board in an embodiment of this application; Figure 4 A circuit diagram of a first hybrid polarization antenna provided for embodiments of this application; Figure 5 A circuit diagram of a second hybrid polarization antenna provided in an embodiment of this application; Figures 6a-6c A schematic diagram of the results of a simulation experiment provided in this application embodiment; Figure 7 This is a schematic diagram showing the results of another simulation experiment provided in an embodiment of this application.

[0025] It should be understood that the dimensions and shapes of the block diagrams in the above structural diagrams are for reference only and should not constitute an exclusive interpretation of the embodiments of this application. The relative positions and inclusion relationships between the block diagrams presented in the structural diagrams are only schematic representations of the structural relationships between the block diagrams, and are not intended to limit the physical connection methods of the embodiments of this application. Detailed Implementation

[0026] The technical solutions provided in this application will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the system architecture and business scenarios provided in the embodiments of this application are mainly for illustrating possible implementations of the technical solutions of this application and should not be construed as the sole limitation on the technical solutions of this application. Those skilled in the art will recognize that the technical solutions provided in this application are equally applicable to similar technical problems as system architectures evolve and new business scenarios emerge.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. In case of any inconsistency, the meaning set forth in this specification or derived from the content described herein shall prevail. Furthermore, the terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit the scope of this application.

[0028] The solutions provided in this application will now be described in detail with reference to the accompanying drawings and embodiments.

[0029] This application proposes a hybrid polarization antenna, specifically implementing an innovative antenna physical structure and tuning method. Utilizing double-sided printed circuit board (PCB) technology, the antenna is designed with six centrally symmetrically distributed spiral stubs. By connecting tunable passive devices or switchable circuit networks in series in each stub, flexible configuration and reconfiguration of the antenna's operating frequency, bandwidth, polarization mode (linear / circular polarization), and circular polarization direction are achieved. This solution effectively solves the problems of large size, difficult tuning, and limited functionality of traditional circular polarization antennas.

[0030] like Figures 2-3b As shown in the embodiment of this application, a hybrid polarization antenna is provided. This antenna is constructed based on a dielectric substrate (i.e., a PCB board). A feed point and a reference ground plane are respectively disposed on the top layer of the PCB board. The feed point is located on the top layer of the PCB board, and the reference ground plane is located near the feed point. Six sets of radially distributed straight traces (such as...) are etched on the top layer of the PCB board. Figure 3a As shown), six sets of diagonal traces corresponding to the top layer traces are etched on the bottom layer of the PCB board (e.g., Figure 3b As shown), each group of top-layer traces and the corresponding bottom-layer traces are electrically connected through metal vias at both ends, forming a continuous spiral zigzag structure with a spatial spiral feel. Each spiral zigzag structure is a branch, and a tuning device is connected in series in the middle of the spiral zigzag structure of each branch.

[0031] Of the six branches, the one located directly above (with) Figure 2 Taking the orientation shown as an example, the two feed stubs are defined as feed stub 1 and feed stub 2, respectively. The remaining four stubs are evenly distributed around these two feed stubs in the circumference and are defined as ground stub 1, ground stub 2, ground stub 3, and ground stub 4, respectively. Among them, ground stub 1 and ground stub 3 are symmetrically distributed on both sides of feed stub 1, and have the same trace width and spacing. This three-stub structure constitutes the first operating state of the antenna. Ground stub 2 and ground stub 4 are symmetrically distributed on both sides of feed stub 2, and have the same trace width and spacing. This three-stub structure constitutes the second operating state of the antenna. This symmetrical layout provides the hardware physical basis for achieving good circular polarization characteristics.

[0032] In some embodiments, in order to achieve multi-frequency design, the trace width and spacing of the two sets of three-stub structures can be different in the antenna operating state. That is, the total trace length of one set of three-stub structures is shorter and is suitable for high-frequency antenna operating state, while the total trace length of the other set of three-stub structures is longer and is suitable for low-frequency antenna operating state, so as to ensure good antenna performance.

[0033] The two feed stubs (i.e., the starting points of the spiral-shaped structure, near the center of the PCB board) are connected to a feed point located at the center of the top layer of the PCB board. This feed point is connected to an external RF port through an impedance matching circuit to match the antenna's input impedance to the system's standard impedance (typically 50Ω). The ends of the two feed stubs (i.e., the ending points of the spiral-shaped structure) are left floating. The four ground stubs are connected to the reference ground plane, and their ends are left floating.

[0034] When the antenna is operating, the radio frequency signal directly excites the two feed stubs through the impedance matching circuit and the feed point, causing them to generate alternating current and electromagnetic fields, respectively. This electromagnetic field, through a near-field coupling mechanism, excites the currents on the two adjacent ground stubs, thus forming effective radiation. Feed stub 1, together with its symmetrically distributed ground stubs 1 and 3 on either side, constitutes one antenna operating mode (referred to as Mode A); feed stub 2, together with its symmetrically distributed ground stubs 2 and 4 on either side, constitutes another antenna operating mode (referred to as Mode B). Since the physical lengths and trace spacing of the two sets of three-stub structures can be designed independently, Mode A and Mode B can resonate at different frequencies, thus achieving dual-frequency operation.

[0035] To achieve good signal transmission, the impedance matching circuit in this application embodiment has been preferably designed. For example... Figure 4 As shown, the matching circuit can be specifically implemented as a two-stage tuning network.

[0036] First, a parallel tuning branch is set up immediately adjacent to the feed point. This branch consists of an inductor L1 connected in parallel to ground and a capacitor C1 connected in parallel to ground. This parallel structure is mainly used for coarse adjustment of the antenna's input impedance. Second, after the parallel branch, a series tuning branch is connected in series on the signal path. This branch consists of a series inductor L2 and a series capacitor C2. This series structure is mainly used for fine adjustment of the input resistance and further impedance compensation. By properly selecting the values ​​of L1, C1, L2, and C2, the impedance flowing from Port1 (i.e., the RF port) to the antenna within the target operating frequency band can be made close to the standard impedance of 50Ω, thereby maximizing power transmission efficiency and improving the antenna's VSWR and return loss performance.

[0037] In some embodiments, the series tuning branch of the impedance matching circuit is further provided with an inductor L3 connected in parallel to ground at the rear end, which works in conjunction with the two-stage matching network at the front end to perform "final compensation" on the impedance after the first two stages of transformation. By carefully selecting the value of L3, an additional parallel inductance can be provided at a specific frequency to accurately cancel the small capacitive reactance that may remain at the antenna port at that frequency, or it can be used to fine-tune the real part of the input resistance, thereby making the return loss more deeply and widely recessed in the target frequency band.

[0038] In some embodiments, the tuning devices in each branch can be selected as inductors, capacitors, or a combination of inductors and capacitors. For example... Figure 4 As shown, the tuning device can be an inductor, where L02 is the tuning device for feed stub 1, L03 is the tuning device for feed stub 2, and L04, L05, L06, and L07 correspond to the tuning devices for feed stubs 1, 2, 3, and 4, respectively. Port1 is connected to the antenna feed point through an impedance matching circuit. In practical use, the length and spacing of the broken lines are designed first based on the target antenna operating frequency and the required antenna size. The broken line spacing mainly affects the overall length of the antenna broken line trace. The lower the target antenna operating frequency, the longer the broken line trace needs to be. Therefore, the smaller the spacing, the more bends the trace can make, and the longer the trace. The closer the resonant frequency of the antenna trace is to the target frequency, the more it can be adjusted to the target operating frequency by supplementing it with a tuning device connected in series in the middle. However, the smaller the spacing, the longer the trace, and the denser the trace, the worse the antenna radiation effect. The supplement value of the tuning device can be smaller, and the device loss performance is lower. Conversely, the larger the spacing of the trace, the shorter the trace, and the better the radiation performance of the trace. However, a larger tuning device is required, and the device loss is greater. In actual use, the approximate antenna spacing is determined by comparing the best antenna radiation effect after different spacings and device supplementation. The length of the trace is determined by the size of the antenna board. Try to fill the board as much as possible to make the trace area larger, and the antenna radiation effect will be better.

[0039] The following is based on Figure 2 Antenna structure and Figure 4 The circuit structure is used to illustrate how to achieve dual-mode circular polarization in a specific target frequency band: Based on the above design, the routing design for the target antenna operating frequencies f1 and f2 is completed. Since f1 is a higher frequency than f2, a lower frequency is achieved by using an antenna operating mode consisting of feed stub 1, ground stub 1, and ground stub 3 to complete the design of the f1 band. This group of routing is shorter and the routing spacing is larger. Then, another antenna operating mode consisting of feed stub 2, ground stub 2, and ground stub 4 is used to complete the design of the f2 band. This group of routing is longer and the routing spacing is smaller. Next, adjust the tuning devices in the middle of the stubs. First, connect only feed stub 1 and ground stub 1, disconnecting all other feed stubs 2 and ground stubs 2, 3, and 4. Determine the values ​​of the tuning device L02 in the middle of the fold line of feed stub 1 and the tuning device L04 in ground stub 1 based on the target antenna operating frequency f1. Record the inductance values ​​(usually inductors) as LF1, ensuring the antenna operating frequency is at the target operating frequency f1. Then, based on the target circular polarization characteristics and rotation requirements, determine whether the antenna needs left-hand or right-hand circular polarization. If it's a right-hand circular polarization antenna design, change the value of the tuning device L04 in ground stub 1 to an inductance value slightly larger than LF1, based on the tuning device value LF1. The value of the tuning device L06 in the ground branch 3 is determined to be a device inductance value slightly smaller than the inductance value LF1. With this design, the first antenna, composed of feed stub 1, ground stub 1, and ground stub 3, forms two antenna resonant modes with similar operating frequencies f1. The antenna resonant mode formed by feed stub 1 and ground stub 1 operates at a frequency slightly lower than the target operating frequency f1 by f1-k (k is greater than zero and very small), lagging behind the target frequency f1. The antenna resonant mode formed by feed stub 1 and ground stub 3 operates at a frequency slightly higher than the target operating frequency f1 by f1+k (k is greater than zero and very small), leading the target frequency f1. Furthermore, the two resonant modes rotate 120 degrees. This achieves the design of a right-hand circularly polarized antenna scheme with the operating frequency of the antenna formed by feed stub 1, ground stub 1, and ground stub 3 in the f1 frequency band.

[0040] Similarly, disconnect feed stub 1 from ground stub 1 and ground stub 3, and reconnect feed stub 2 and ground stub 2. Then, adjust the values ​​of the tuning devices L03 and L05 of feed stub 2 to be similar to the inductance value LF2, adjusting them to the operating frequency f2 of the antenna resonant mode formed by feed stub 2 and ground stub 2. Then, based on the desired circular polarization direction of the antenna, determine whether the antenna needs left-hand or right-hand circular polarization. If it is a right-hand circular polarization antenna design, change the value of the tuning device L05 of ground stub 2 to an inductance value slightly larger than LF2. The value of the tuning device L07 in the ground branch 4 is determined to be a device inductance value slightly smaller than the inductance value LF2. With this design, the second antenna formed by feed stub 2, ground stub 2, and ground stub 4 will each form two antenna resonant modes with similar operating frequencies f2. The antenna resonant mode formed by feed stub 2 and ground stub 2 will have an operating frequency slightly lower than the target operating frequency f2 by f2-k (k is greater than zero and very small), with phase lag at f2 frequency. The antenna resonant mode formed by feed stub 2 and ground stub 4 will have an operating frequency slightly higher than the target operating frequency f2 by f2+k (k is greater than zero and very small), with phase lead at f2 frequency. Furthermore, the two resonant modes will rotate 120 degrees. Thus, this scheme can achieve the design of a right-hand circularly polarized antenna scheme with the operating frequency of the antenna formed by feed stub 2, ground stub 2, and ground stub 4 in the f2 frequency band.

[0041] Conversely, if the target antenna polarization is a left-hand circular polarization antenna in the f1 band, simply reversing the tuning devices of ground stub 1 and ground stub 3 will make the six-stub circular polarization antenna a left-hand circular polarization antenna at the operating frequency f1. Similarly, if the target antenna polarization is a left-hand circular polarization antenna in the f2 band, simply reversing the tuning devices of ground stub 2 and ground stub 4 will make the six-stub circular polarization antenna a left-hand circular polarization antenna at the operating frequency f2.

[0042] In this embodiment, the six-segment antenna operates in both the f1 and f2 frequency bands. The direction of their circular polarization characteristics can be the same or different, and can be arbitrarily adjusted according to the above method. The two frequency bands do not affect each other. After the six-segment antenna is designed using the above dual-band dual-circular polarization antenna scheme, the characteristic impedance of the antenna can be adjusted to match the 50Ω input impedance through the impedance matching circuit connected to the feed point, thus completing the design of the six-segment dual-band dual-circular polarization antenna scheme.

[0043] In some embodiments, ground branch 1 and ground branch 3 have different lengths, or the values ​​of the intermediate connecting tuning devices are not similar, and can also be determined solely according to... Figure 4 As shown, by welding a tuning device with its own inductance value to each of the two sections, two antenna frequency bands can be directly formed with feed stub 1. Similarly, if ground stub 2 and ground stub 4 have different lengths, or if the values ​​of the tuning devices connected in the middle are not similar, they can be adjusted according to... Figure 4 As shown, by soldering a tuning device with its own inductance value to each of the four ground stubs, two additional antenna bands can be formed directly with feed stub 2, resulting in a six-stub, four-band design. However, the antenna polarization in this case is linear. Therefore, by configuring the four ground stubs with different resonant frequencies, the antenna can operate in multiple bands, and each band can independently select its polarization mode, supporting a hybrid polarization mode of circular and linear polarization. For example, feed stub 1 can be configured to operate in circular polarization mode with ground stub 1 and ground stub 3 in band f1, while feed stub 2 can be configured with different lengths or device values ​​with ground stub 2 and ground stub 4, allowing it to operate in linear polarization mode in bands f2 and f3. This allows a single antenna to simultaneously meet the needs of multiple different communication modules within a complex wireless device, achieving ultimate integration and design flexibility.

[0044] To further enhance the flexibility and intelligence of antennas, this invention proposes a scheme to replace fixed tuning devices with switched tuning circuits, such as... Figure 5As shown, taking ground stub 1 as an example, its fixed inductor L04 is replaced by a switching tuning circuit. This switching tuning circuit includes an inductor L62 connected in series with the stub trace and a branch connected in parallel with the inductor L62. This branch consists of an inductor L61 and a single-pole single-throw (SPST) switch S3 connected in series. The switch S3 is controlled by a GPIO pin of the controller (such as the CPU) U1. Based on the structure of this switching tuning circuit, when the controller U1 outputs a control signal to open the switch S3, the branch of inductor L61 is not connected, and only inductor L62 is connected in series with ground stub 1. Let the equivalent inductance at this time be Leq_off = L62, corresponding to a resonant frequency F_off; when the controller U1 outputs a control signal to open the switch S3, inductors L61 and L62 form a parallel relationship. The total equivalent value of the parallel inductors, Leq_on, is equal to (L61*L62) / (L61+L62), which is less than L62. Therefore, the equivalent inductance of ground stub 1 decreases, corresponding to a higher resonant frequency, F_on.

[0045] By designing a switching tuning circuit, a single stub can electrically switch between two preset frequencies. Applying this switching circuit to all six stubs and independently controlling each switch using binary control, theoretically, the antenna can switch between up to 2^6 = 64 different frequency combinations. Through careful design of the values ​​of the two inductors in the switching tuning circuit, it can be made to operate stably on four, eight, or even more practically valuable frequency bands.

[0046] In some embodiments, by controlling the on / off states of each switch, a design can be created where some frequency bands are circularly polarized and others are linearly polarized. For example, ground stubs 1 and 3, together with feed stub 1, form a circularly polarized antenna characteristic operating in the f1 frequency band. Then, ground stubs 2 and 4, with different lengths or different tuning devices than feed stub 2, can form two more antenna operating frequency bands, f2 and f3. In this way, a six-stub antenna can achieve a tri-band antenna design that simultaneously supports the circularly polarized antenna characteristic requirement in the f1 frequency band and the linearly polarized antenna characteristics in the f2 and f3 frequency bands. Similarly, ground stubs 2 and 4, together with feed stub 2, can form a circularly polarized antenna characteristic operating at the f1 frequency. Ground stubs 1 and 3, together with feed stub 1, can form two more antenna operating frequency bands, f2 and f3. To ensure good performance of the antennas in each frequency band, only appropriate antenna lengths and tuning device values ​​need to be selected for balancing. The antenna stubs can be interchanged. Based on this, the six-segment antenna of this embodiment can be extended to support antenna design schemes that support up to 8 frequency bands.

[0047] To verify the feasibility and effectiveness of this application, three-dimensional electromagnetic simulation software can also be used to establish, for example... Figure 2The six-segment antenna model shown has a PCB board diameter of 100mm. Two representative simulation experiments were conducted: For example, with the goal of achieving dual-band operation at 240MHz and 320MHz, both with left-hand circular polarization, by adopting... Figure 2 The PCB has a diameter of 100mm. The tuning components are surface-mount inductors with the following values: Mode A (240MHz): L02=62nH, L04=68nH, L06=62nH (according to the left-hand rule, L04>L06); Mode B (320MHz): L03=10nH, L05=15nH, L07=10nH (according to the left-hand rule, L05>L07); Impedance matching circuit: L1=36nH, C1=12pF (parallel); L2=75nH, C2=10pF (series).

[0048] The antenna evaluation results are obtained through simulation, such as Figures 6a-6c As shown, the antenna's reflection coefficient S11 at 240MHz and 320MHz ( Figure 6a All values ​​are less than -10dB, indicating good matching; the gain curves ( Figure 6b The left-hand circular polarization component and the maximum gain pattern are basically coincident; the axial ratio curve ( Figure 6c The value is 1.4 at 240MHz and 2.2 at 320MHz, which is much smaller than the 3dB circular polarization threshold, confirming the excellent left-hand circular polarization performance.

[0049] In another simulation experiment, with the goal of demonstrating the ability to achieve multi-band extension by adjusting the ground stub parameters, based on the above simulation experiment, keeping other components unchanged, only changing the inductor L06 of ground stub 3 to 24nH and the inductor L07 of ground stub 4 to 51nH, and correspondingly fine-tuning the matching circuit as follows: L1=33nH, C1=10pF; L2=62nH, C2=9pF.

[0050] Simulation results are as follows Figure 7 As shown, the antenna reflection coefficient S11 curve exhibits four distinct resonance valleys, located at 240MHz, 286MHz, 308MHz, and 323MHz, respectively. This indicates that by simply adjusting the tuning inductance value of the ground stub, the antenna's operating mode was successfully extended to four closely adjacent frequency bands, effectively broadening the antenna's operating bandwidth and making it suitable for scenarios requiring broadband coverage.

[0051] In summary, the hybrid polarization antenna provided in this application offers a highly compact, flexible, and high-performance multi-frequency circular polarization antenna solution through an innovative six-segment helical zigzag structure, a flexibly configurable tuning device network, and a clear circular polarization generation and control method. This antenna is not only easy to miniaturize and operate in dual / multi-frequency modes, but also possesses outstanding advantages such as independently configurable circular polarization direction and reconfigurable operating modes (fixed multi-frequency / switchable multi-frequency / hybrid polarization). It can be widely used in satellite communication, BeiDou / GPS navigation, RFID, and modern multimode wireless communication systems.

[0052] It should be noted that the embodiments described in this application are merely some embodiments, not all embodiments. The components of the embodiments of this application typically described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the above detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0053] The terms "first, second, third, etc." or similar terms such as module A, module B, module C, etc., used in the specification and claims are only used to distinguish similar objects and do not represent a specific ordering of objects. It is understood that a specific order or sequence may be interchanged where permitted so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0054] In the above description, the labels indicating the steps do not necessarily mean that the steps will be executed. They may include intermediate steps or be replaced by other steps. Where permissible, the order of the steps may be interchanged or executed simultaneously.

[0055] The term "comprising" as used in the specification and claims should not be construed as limiting itself to what follows; it does not exclude other elements or steps. Therefore, it should be interpreted as specifying the presence of the mentioned feature, integral, step, or component, but does not exclude the presence or addition of one or more other features, integrals, steps, or components, or groups thereof. Thus, the statement "device comprising means A and B" should not be limited to a device consisting solely of components A and B.

[0056] The terms "an embodiment" or "an embodiment" as used in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in at least one embodiment of this application. Therefore, the terms "in one embodiment" or "in an embodiment" appearing throughout this specification do not necessarily refer to the same embodiment, but may refer to the same embodiment. Furthermore, in the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions between different embodiments are consistent and can be mutually referenced. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0057] Note that the above are merely preferred embodiments and the technical principles employed in this application. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present application has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, all of which fall within the scope of protection of the present invention.

Claims

1. A hybrid polarized antenna, characterized by, The antenna comprises a PCB board and six branches arranged on the PCB board, a feeding point is arranged at the center of the top layer of the PCB board, the feeding point is connected to the RF port of the antenna through an impedance matching circuit, and a reference ground plane is arranged on the top layer of the PCB board, each branch comprises a straight line trace on the top layer of the PCB board and an oblique line trace on the bottom layer of the PCB board, and the two ends of the trace are connected to form a continuous spiral broken line structure through vias, and a tuning device is arranged in the middle of the spiral broken line of each branch. The six branches comprise two feeding branches and four ground branches, two ground branches are arranged on the two sides of each feeding branch, the first ends of the two feeding branches are connected to the feeding point, and the second ends of the two feeding branches are suspended; the first ends of the four ground branches are connected to the reference ground plane, and the second ends of the four ground branches are suspended. After the two feeding branches are powered on, an alternating electromagnetic field is generated around the two feeding branches, and the two ground branches corresponding to the two feeding branches are excited to form different antenna working states, so that circularly polarized radiation of multiple frequency bands is realized.

2. The hybrid polarized antenna of claim 1, wherein, The impedance matching circuit comprises at least one parallel tuning branch and at least one series tuning branch. The parallel tuning branch comprises a first inductor and a first capacitor connected in parallel between a signal path and a reference ground. The series tuning branch comprises a second inductor and a second capacitor connected in series on the signal path.

3. The hybrid polarized antenna of claim 1, wherein, The tuning device is an inductor, a capacitor, or a combination circuit of an inductor and a capacitor.

4. The hybrid polarized antenna of claim 1, wherein, The two feeding branches are a first feeding branch and a second feeding branch, and the four ground branches are a first ground branch, a second ground branch, a third ground branch, and a fourth ground branch. The first ground branch and the third ground branch are a pair of ground branches, are symmetrically arranged on the two sides of the first feeding branch, and jointly form a first antenna working state. The second ground branch and the fourth ground branch are a pair of ground branches, are symmetrically arranged on the two sides of the second feeding branch, and jointly form a second antenna working state.

5. The hybrid polarized antenna of claim 4, wherein, When the trace lengths of a pair of ground branches are the same and the parameters of the tuning devices connected in series are configured to have a preset difference, the pair of ground branches and the corresponding feeding branches jointly generate two resonant modes with a preset phase difference and a preset included angle at a target frequency band, so that the antenna exhibits circularly polarized radiation characteristics at the target frequency band.

6. The hybrid polarized antenna of claim 5, wherein, The positive and negative relationship of the preset difference is used to control the handedness of the circularly polarized radiation characteristics, and specifically: When the parameter value of the tuning device of the first ground branch is greater than the parameter value of the tuning device of the third ground branch, the antenna exhibits circularly polarized characteristics of a first handedness at the corresponding target frequency band. When the parameter value of the tuning device of the first ground branch is less than the parameter value of the tuning device of the third ground branch, the antenna exhibits circularly polarized characteristics of a second handedness opposite to the first handedness at the corresponding target frequency band.

7. The hybrid polarized antenna of claim 1, wherein, The four ground branches are configured to have at least two different resonant frequencies, so that the antenna realizes a mixed polarization working mode at at least two different frequency bands; at least one frequency band is a circularly polarized working mode, and the remaining frequency bands are linearly polarized working modes.

8. The hybrid polarized antenna of claim 1, wherein, The tuning device is a switch-type tuning circuit, which is composed of a third inductor and a switch device in series, and a fourth inductor in parallel with the series of the third inductor and the switch device, the switch device is controlled by a controller, and the on-off state of the switch device is switched to adjust the equivalent inductance value of the ground branch, so that the antenna switches between multiple frequency bands.

9. The hybrid polarized antenna of claim 8, wherein, The adjustment of the equivalent inductance value of the ground branch by switching the on-off state of the switch device specifically includes: When the switch device is turned on, the third inductor and the fourth inductor are in parallel to form a first equivalent inductance value; When the switch device is turned off, only the fourth inductor is connected to the circuit to form a second equivalent inductance value; By switching the state of the switch device, the switching of the ground branch between two resonant frequencies is realized.

10. A communication device, characterized by A hybrid polarized antenna comprising any one of claims 1 to 9.

Images