CN115882218A - Terminal antenna system with high isolation - Google Patents
Terminal antenna system with high isolation Download PDFInfo
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- CN115882218A CN115882218A CN202111153412.5A CN202111153412A CN115882218A CN 115882218 A CN115882218 A CN 115882218A CN 202111153412 A CN202111153412 A CN 202111153412A CN 115882218 A CN115882218 A CN 115882218A
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Abstract
The embodiment of the application discloses terminal antenna system with high isolation, relates to the technical field of antennas, and can provide good radiation performance while providing good isolation. The specific scheme is as follows: the terminal antenna system comprises a first antenna pair, wherein the first antenna pair comprises a first antenna and a second antenna, and the first antenna and the second antenna are both current loop antennas or magnetic current loop antennas. The feed port of the first antenna is a first port, the feed port of the second antenna is a second port, and the feed signals fed into the first port and the second port simultaneously comprise a symmetric feed signal and an anti-symmetric feed signal.
Description
Technical Field
The application relates to the technical field of antennas, in particular to a terminal antenna system with high isolation.
Background
The electronic equipment can support the higher wireless communication requirement of the electronic equipment through the arrangement of a plurality of antennas. When multiple antennas are operated simultaneously, mutual interference may occur, thereby affecting the overall radiation performance. By improving the isolation between the antennas, the influence in the working process of the multiple antennas can be effectively improved.
Disclosure of Invention
The high-isolation terminal antenna system provided by the embodiment of the application provides a working mode of the antenna system based on different feeding forms, and the antenna in the antenna system has better isolation because the antenna pair in the antenna system can excite orthogonal current on the floor due to different feeding modes and can generate orthogonal spatial field distribution. In addition, the antenna system comprises a current loop antenna and/or a magnetic current loop antenna, so that better radiation performance, such as better bandwidth, radiation efficiency, system efficiency, lower SAR and better directional diagram, can be obtained in a limited space.
In order to achieve the above purpose, the embodiment of the present application adopts the following technical solutions:
in a first aspect, a terminal antenna system with high isolation is provided, and is applied to an electronic device, where the terminal antenna system includes a first antenna pair, the first antenna pair includes a first antenna and a second antenna, and both the first antenna and the second antenna are current loop antennas, or both the first antenna and the second antenna are magnetic current loop antennas. The feed port of the first antenna is a first port, the feed port of the second antenna is a second port, and the feed signals fed into the first port and the second port simultaneously comprise a symmetric feed signal and an anti-symmetric feed signal.
Based on the scheme, a scheme of an antenna system with high isolation characteristics is provided. In this example, at least one antenna pair (e.g., a first antenna pair) may be included in the antenna system, and the first antenna pair may be comprised of two antennas. The two antennas of the first antenna pair may be current loop antennas, or magnetic current loop antennas. When the two antennas of the first antenna pair work in a symmetric feeding state under the excitation of symmetric feeding and the two antennas of the first antenna pair work in an anti-symmetric feeding state under the excitation of anti-symmetric feeding, due to the high isolation characteristics of the two states, the two high isolation working characteristics are obtained under the condition that the first antenna pair is subjected to symmetric feeding and anti-symmetric feeding simultaneously, and therefore high isolation is obtained. Based on the scheme, the method comprises the following steps of,
in one possible design, when the feeding signals fed into the first port and the second port are symmetrical feeding signals, the first antenna pair operates in a symmetrical feeding state. When the feeding signals fed into the first port and the second port are antisymmetric feeding signals, the first antenna pair works in an antisymmetric feeding state. The current direction of the excitation floor in the symmetrical feeding state is a first direction, the current direction of the excitation floor in the anti-symmetrical feeding state is a second direction, and the first direction and the second direction are orthogonal. Based on the scheme, a specific limitation of high isolation characteristics in two feeding states is provided. For example, in the two states, a transverse current and a longitudinal current on the floor can be excited respectively, and due to the orthogonality of the currents exciting the floor, the two feeding states acquire corresponding high isolation characteristics.
In one possible design, the symmetric feed signal and the anti-symmetric feed signal are feed signals of equal amplitude and opposite phase. Based on this solution, a specific example of symmetric and anti-symmetric feeding signals is provided. For example, when symmetric feeding excitation is performed, feeding signals input to the two antenna ports may be equal-amplitude and in-phase signals. In the case of antisymmetric feed excitation, the feed signals input to the two antenna ports may be equal-amplitude and opposite-phase signals. In this example, the first antenna pair may be fed with both symmetric and anti-symmetric feeding in order to obtain two orthogonal operating states.
In one possible design, the first antenna and the second antenna are mirror symmetric in structure. Based on the scheme, a structural definition of the first antenna and the second antenna is provided. For example, the positions of the first antenna and the second antenna on the electronic device may be symmetrical to each other, and/or the structures of the first antenna and the second antenna themselves, such as the feeding structure, the radiating structure, and the like, may also have symmetrical features to each other.
In one possible design, the first antenna and the second antenna are fed directly or coupled. Based on this scheme, an example of a feeding form of a high isolation antenna pair is provided.
In a possible design, when the first antenna and the second antenna are both directly fed, the feeding ports of the first antenna and the second antenna are disposed at the ends of the antenna radiators close to each other or disposed at the ends of the antenna radiators far away from each other. Based on the scheme, the high-isolation antenna is used for setting and limiting the feeding point under the condition of direct feeding. For example, the two feeding points may be located close to each other, or, for example, the two feeding points may be located far from each other.
In a possible design, the first antenna and the second antenna are disposed on the same side of the electronic device, and when the first antenna and the second antenna are both directly fed, the feeding point of the first antenna is disposed at the left end of the radiator of the first antenna, and the feeding point of the second antenna is disposed at the left end of the radiator of the second antenna. Or the feeding point of the first antenna is arranged at the right end of the radiator of the first antenna, and the feeding point of the second antenna is arranged at the right end of the radiator of the second antenna. Or the feeding point of the first antenna is arranged at the upper end of the radiator of the first antenna, and the feeding point of the second antenna is arranged at the upper end of the radiator of the second antenna. Alternatively, the feeding point of the first antenna is disposed at a lower end of the radiator of the first antenna, and the feeding point of the second antenna is disposed at a lower end of the radiator of the second antenna. Based on this scheme, an example of the setting position of the feeding point in still another direct feeding case is provided. For example, when the two antennas are at the top edge or the bottom edge, the feeding point may be on the same left side or right side of the two radiators. When the two antennas are on the side, the feeding point can be on the upper side or the lower side of the two radiators.
In a possible design, when the first antenna and the second antenna are both coupled-feed current loop antennas, the first antenna includes a first radiation branch and a first feed branch, the first feed branch is used for coupled-feed to the first radiation branch, and at least one end of the first radiation branch is grounded through a capacitor. Based on the scheme, the limitation to the antenna itself is provided when the antenna pair is formed by the current loop of the coupling feed. In some embodiments, the second antenna may also have the same structural features as the first antenna.
In a possible design, when the first antenna and the second antenna are both coupled-feed magnetic current loop antennas, the first antenna includes a second radiation branch and a second feed branch, the second feed branch is used for coupled-feed of the second radiation branch, and at least one end of the second radiation branch is grounded through an inductor. Based on the scheme, the limitation on the antenna is provided when the magnetic current loop for coupling feeding forms the antenna pair. In some embodiments, the second antenna may also have the same structural features as the first antenna.
In a possible design, the first antenna and the second antenna are both current loop antennas, and radiators of the current loop antennas are connected in parallel with at least one first capacitor to be grounded. Or, the first antenna and the second antenna are both current ring slot antennas, and at least one second capacitor is connected in series on a radiator of each current ring slot antenna. Based on this scheme, a specific example of a current loop antenna is provided. The uniform magnetic field distribution can be obtained by connecting the capacitors in parallel on the line antenna or connecting the capacitors in series on the slot antenna, so that the distribution characteristics of the current loop antenna can be obtained. In this example, the first antenna and the second antenna may be the same type of current loop antenna, or different types of current loop antennas.
In one possible design, the first antenna and the second antenna have the same antenna form, the antenna form comprising any one of: a current loop monopole antenna, a current loop dipole antenna, a current loop left-handed antenna, and a current loop slot antenna. Based on this approach, several specific examples of current loop antennas are provided.
In one possible design, the first antenna and the second antenna are both a magnetic current loop antenna, and a radiator of the magnetic current loop antenna is connected in parallel with at least one first inductor and grounded. Or, the first antenna and the second antenna are both magnetic current ring slot antennas, and at least one second inductor is connected in series on a radiating body of each magnetic current ring slot antenna. Based on this scheme, a specific example of a magnetic current loop antenna is provided. The uniform electric field distribution can be obtained by connecting the inductor in parallel on the line antenna or connecting the inductor in series on the slot antenna, so that the distribution characteristics of the magnetic current loop antenna can be obtained. In this example, the first antenna and the second antenna may be the same type of magnetic current loop antenna, or may be different types of magnetic current loop antennas.
In one possible design, the first antenna and the second antenna have the same antenna form, the antenna form comprising any one of: magnetic current loop monopole antenna, magnetic current loop dipole antenna, magnetic current loop left-hand antenna and magnetic current loop slot antenna. Based on this scheme, several specific examples of magnetic current loop antennas are provided.
In a second aspect, there is provided an electronic device provided with at least one processor, a radio frequency module, and a terminal antenna system as described in the first aspect and any one of its possible designs. When the electronic equipment transmits or receives signals, the radio frequency module and the terminal antenna system transmit or receive the signals.
It should be understood that, technical features of the solutions provided by the second aspect may all correspond to the solutions provided by the first aspect and possible designs thereof, so that similar beneficial effects can be achieved, and further description thereof is omitted here.
Drawings
FIG. 1 is a schematic diagram of a multi-antenna operating scenario;
fig. 2 is a schematic composition diagram of an electronic device according to an embodiment of the present disclosure;
fig. 3 is a schematic composition diagram of a metal shell according to an embodiment of the present disclosure;
fig. 4 is a schematic composition diagram of an electronic device according to an embodiment of the present disclosure;
fig. 5 is a schematic diagram illustrating an operation of a current loop antenna according to an embodiment of the present disclosure;
fig. 6 is a schematic diagram of an implementation of a current loop antenna according to an embodiment of the present disclosure;
fig. 7 is a schematic diagram of a coupled-feed current loop antenna according to an embodiment of the present application;
fig. 8 is a schematic diagram illustrating an operation of a magnetic current loop antenna according to an embodiment of the present disclosure;
fig. 9 is a schematic diagram of an implementation of a magnetic current loop antenna according to an embodiment of the present disclosure;
fig. 10 is a schematic diagram of a magnetic current loop antenna with coupled feed according to an embodiment of the present application;
FIG. 11 is a schematic diagram of an antisymmetric feed provided by an embodiment of the present application;
fig. 12 is a schematic diagram of a pair of high isolation antennas formed by a current loop antenna according to an embodiment of the present application;
fig. 13 is a schematic diagram of different feeding states provided by the embodiment of the present application;
FIG. 14 is a comparative illustration of a current distribution provided by an embodiment of the present application;
FIG. 15 is a comparative diagram of a distribution of electric field of a floor provided by an embodiment of the present application;
FIG. 16 is a comparison of far field patterns provided by embodiments of the present application;
fig. 17 is a schematic simulation diagram of an S parameter provided in an embodiment of the present application;
FIG. 18A is a schematic diagram of an efficiency simulation according to an embodiment of the present application;
fig. 18B is a schematic diagram of a high isolation antenna pair formed by another current loop antenna according to an embodiment of the present application;
fig. 19 is a schematic diagram of a high isolation antenna pair formed by a magnetic current loop antenna according to an embodiment of the present application;
fig. 20 is a schematic diagram of different feeding states provided by the embodiment of the present application;
FIG. 21 is a comparison of magnetic flux distribution profiles provided in accordance with an embodiment of the present application;
FIG. 22 is a comparative illustration of a distribution of electric field in a floor provided by an embodiment of the present application;
FIG. 23 is a comparison of far field patterns provided by embodiments of the present application;
fig. 24 is a schematic simulation diagram of an S parameter provided in an embodiment of the present application;
FIG. 25A is a schematic diagram of an efficiency simulation according to an embodiment of the present application;
fig. 25B is a schematic diagram of a high isolation antenna pair formed by another magnetic current loop antenna according to an embodiment of the present application;
fig. 26 is a schematic diagram of an antenna pair formed by a conventional left-hand antenna according to an embodiment of the present application;
fig. 27 is a schematic diagram illustrating a directional diagram comparison of a left-hand antenna pair according to an embodiment of the present application;
fig. 28 is a schematic diagram of an antenna pair formed by a conventional IFA antenna according to an embodiment of the present application;
fig. 29 is a diagram illustrating a pattern comparison of an IFA antenna pair according to an embodiment of the present application;
fig. 30 is a schematic diagram of an antenna pair formed by an ILA antenna according to the present embodiment;
fig. 31 is a schematic diagram illustrating a directional diagram comparison of an ILA antenna pair according to an embodiment of the present application.
Detailed Description
With the development of wireless communication technology, a plurality of antennas are generally required to be disposed in an electronic device to meet the requirements of the electronic device for wireless communication functions. The working frequency bands of the partial antennas can be partially overlapped or completely overlapped, so that the communication capacity of the corresponding frequency bands is improved.
For example, referring to fig. 1, an example is that an antenna provided in an electronic device includes E1 and E2, and operating frequency bands of E1 and E2 are overlapped. When the electronic device performs wireless communication using the operating frequency bands corresponding to E1 and E2, E1 and E2 may operate simultaneously. For example, when E1 works, the signal of the electronic device may be emitted in the form of electromagnetic wave, and the corresponding resonant frequency of the electromagnetic wave may be included in the operating frequency band of E1, thereby implementing the emission of the signal. E2 may convert the electromagnetic wave in the external space into a signal (e.g., an analog signal) that can be processed by the electronic device, thereby implementing reception of the signal.
It can be understood that since the operating frequency bands of E1 and E2 are the same, the signal received by E2 may include the signal sent by E1. This part of the signal is obviously not required to be received by the electronic device and therefore may be an invalid signal for the E2 to work. That is, when E1 and E2 operate simultaneously, the two antennas may affect each other, thereby reducing the wireless communication efficiency of the antennas.
In the above example, the scenario of E1 transmission and E2 reception is taken as an example, and in other scenarios, similar problems may exist, which reduces the wireless communication efficiency of the antenna. Illustratively, the same problem arises in the scenario of E1 reception, E2 transmission due to similar mechanisms. In addition, when the operating frequency bands of E1 and E2 are different, taking the operating frequency band of E1 lower than the operating frequency band of E2 as an example, although the operating frequency band of E1 does not overlap with E2, the frequency multiplication of the corresponding resonance may also affect the operation of E2 when E1 operates.
In order to solve the problem of mutual influence in a multi-antenna scene, the influence between the antennas can be reduced by improving the isolation (isolation) between the antennas. The better the isolation between the antennas, the less the interaction between the antennas. Wherein the degree of isolation may be identified by a normalized value. For example, taking the dual-port isolation as an example, the isolation may be identified by S21 (or S12) in the S parameter, and the values of S21 at different frequency points correspond to the dual-port isolation at the current frequency point. After normalization, the maximum value of the isolation does not exceed 0, and the larger the absolute value of the isolation is, the better the isolation is, and the smaller the influence between the antennas is. Correspondingly, the smaller the absolute value of the isolation, the worse the isolation, the greater the influence between the antennas. For convenience of explanation, in the following examples, the absolute value of the isolation is simply referred to as the isolation. For example, the absolute value of the isolation is large, which is simply referred to as large isolation. For another example, the absolute value of the isolation is small, and is simply referred to as the isolation is small.
It should be understood that the strength of the radiation performance of the antennas also affects the isolation between the antennas. Continuing with the example shown in fig. 1, in the case where E1 and E2 have mutual influence, the better the radiation performance of the antennas, the smaller the isolation between the antennas, the greater the mutual influence, regardless of other influences. For example, the better the radiation performance of E1, the better the isolation from E2 in the frequency point or frequency band with good radiation performance will be relatively deteriorated. However, in order to ensure the wireless communication function of the electronic device, the antenna is required to provide a good radiation performance. That is, there is a need for antennas in electronic devices that provide both good radiation performance and good isolation between antennas. This also places high demands on the multi-antenna design in the electronic device.
In order to solve the above problem, embodiments of the present application provide a high-isolation antenna scheme. The scheme can be applied to an antenna system. Multiple antennas may be included in the antenna system. Wherein at least two of the plurality of antennas may form a high isolation antenna pair. At least one current loop antenna/magnetic loop antenna is included in the high isolation antenna pair. Through the control of feeding forms, such as symmetric feeding and anti-symmetric feeding, the antenna pair composed of two antennas in the plurality of antennas in the antenna system can form high isolation characteristic. For example, two antennas in an antenna pair can simultaneously operate in two states corresponding to feeding forms, such as a symmetric feeding state and an anti-symmetric feeding state, and the respective modes in the two states can have high isolation characteristics. For another example, the two antennas in the antenna pair may be both symmetrically fed, and the high isolation characteristic is achieved through the respective working characteristic difference of the two antennas. In the embodiment of the present application, when symmetric feeding and antisymmetric feeding are performed on two ports simultaneously, the symmetric feeding signal and the antisymmetric feeding signal are equal-amplitude and opposite-phase feeding signals, and two signals simultaneously feed the two antennas. . For example, two ports are respectively the port a of the antenna a and the port B of the antenna B. In the case of symmetric feeding, the feeding signals to the port a and the port B may have an amplitude X and a phase Y. In the case of anti-symmetric feeding, the feed signals to port a and port B may be of amplitude X and phase-Y.
It should be noted that, the radiation performance referred to in the embodiments of the present application may refer to radiation efficiency of the corresponding antenna and/or system efficiency. The radiation efficiency may be used to identify the maximum radiation capability of the antenna system, and the system efficiency is used to identify the current environment and the efficiency condition that the antenna can provide under the port matching.
First, an implementation scenario of the high-isolation antenna scheme provided in the embodiment of the present application is described below.
The antenna scheme provided by the embodiment of the application can be applied to electronic equipment of a user and is used for supporting the wireless communication function of the electronic equipment. For example, the electronic device may be a portable mobile device such as a mobile phone, a tablet computer, a Personal Digital Assistant (PDA), an Augmented Reality (AR) \ Virtual Reality (VR) device, and a media player, and the electronic device may also be a wearable electronic device such as a smart watch. The embodiment of the present application does not specifically limit the specific form of the apparatus.
Please refer to fig. 2, which is a schematic structural diagram of an electronic device 200 according to an embodiment of the present disclosure. As shown in fig. 2, the electronic device 200 according to the embodiment of the present disclosure may sequentially include a screen and a cover 201, a metal housing 202, an internal structure 203, and a rear cover 204 from top to bottom along a z-axis.
The screen and the cover 201 may be used to implement a display function of the electronic device 200. The metal housing 202 may serve as a main frame of the electronic device 200, providing rigid support for the electronic device 200. The internal structure 203 may include a collection of electrical components as well as mechanical components that implement various functions of the electronic device 200. For example, the internal structure 203 may include a shield, screws, ribs, etc. The back cover 204 may be a back appearance of the electronic device 200, and the back cover 204 may use a glass material, a ceramic material, a plastic material, etc. in various implementations.
The antenna scheme provided by the embodiment of the application can be applied to the electronic device 200 shown in fig. 2, and is used for supporting the wireless communication function of the electronic device 200. In some embodiments, the antenna involved in the antenna scheme may be disposed on the metal housing 202 of the electronic device 200. In other embodiments, the antenna involved in the antenna scheme may be disposed on the back cover 204 of the electronic device 200, or the like.
As an example, taking the metal housing 202 having a metal frame structure as an example, fig. 3 shows a composition schematic of the metal housing 202. In this example, the metal housing 202 may be made of a metal material, such as an aluminum alloy. As shown in fig. 3, the metal housing 202 may be provided with a reference ground. The reference ground may be a metallic material with a large area for providing most of the rigid support while providing a zero potential reference for the various electronic components. In the example shown in fig. 3, a metal bezel may also be provided around the reference ground. The metal frame may be a complete closed metal frame, and the metal frame may include a part or all of the metal strips suspended in the air. In other implementations, the metal bezel may also be a metal bezel broken by one or more slits as shown in fig. 3. For example, in the example shown in fig. 3, the slits 1, 2 and 3 may be disposed at different positions on the metal frame. These gaps can break the metal border, thereby obtaining independent metal branches. In some embodiments, part or all of the metal branches can be used as radiation branches of the antenna, so that structural multiplexing in the antenna setting process is realized, and the antenna setting difficulty is reduced. When the metal branch is used as a radiation branch of the antenna, the position of the gap corresponding to one end or two ends of the metal branch can be flexibly selected according to the setting of the antenna.
In the example shown in fig. 3, one or more metal pins may also be disposed on the metal bezel. In some examples, the metal pins may be provided with screw holes for fixing other structural members by screws. In other examples, a metal pin may be coupled to the feed point so that the antenna is fed through the metal pin when the metal stub to which the metal pin is connected is used as a radiating stub of the antenna. In other examples, the metal pins may also be coupled with other electronic components to achieve corresponding electrical connection functions.
In this example, a schematic diagram of the placement of a Printed Circuit Board (PCB) on a metal case is also shown. The main board (main board) and the small board (sub board) are designed as an example. In other examples, the motherboard and platelet may also be connected, such as an L-type PCB design. In some embodiments of the present application, a motherboard (e.g., PCB 1) may be used to carry electronic components that implement various functions of the electronic device 200. Such as a processor, memory, radio frequency module, etc. A small board, such as a PCB2, may also be used to carry electronic components. Such as a Universal Serial Bus (USB) interface and associated circuitry, a sound cavity (speak box), etc. As another example, the small board may be used to carry a radio frequency circuit corresponding to an antenna disposed on the bottom (i.e., the negative y-axis portion of the electronic device).
The antenna schemes provided by the embodiments of the present application can be applied to electronic devices having the compositions shown in fig. 2 or fig. 3.
It should be noted that the electronic device 200 in the above example is only one possible component. In other embodiments of the present application, the electronic device 200 may also have other logical compositions. For example, in order to realize the wireless communication function of the electronic device 200, a communication module as shown in fig. 4 may be provided in the electronic device. The communication module may include an antenna, a radio frequency module in signal interaction with the antenna, and a processor in signal interaction with the radio frequency module. For example, the signal interaction between the radio frequency module and the antenna may be an interaction of an analog signal. The signal interaction between the radio frequency module and the processor can be an analog signal or a digital signal. In some implementations, the processor may be a baseband processor.
In this example, the antenna provided in the electronic device may be a plurality of constituent antenna systems. For example, as shown in fig. 4, the antenna system may include antennas 1 to n. Among the n antennas, one or more magnetic current loop antennas and/or current loop antennas may be included.
First, a magnetic current loop antenna and a current loop antenna will be briefly described with reference to the drawings.
For example, the current loop antenna involved in the solution provided in the embodiment of the present application may be configured such that the antenna has current and magnetic field distributions as shown in fig. 5 during operation. In the embodiments of the present application, the radiation characteristic having the current distribution and/or the magnetic field distribution as shown in fig. 5 may also be referred to as a current loop radiation characteristic.
As shown in fig. 5, the current direction on the radiating stub of the current loop antenna may be opposite to the current direction on the ground as a reference (e.g., the side of the ground near the current loop antenna). Thereby forming a current loop formed by the radiation branch and the floor and carrying out radiation with the radiation characteristic of the current loop antenna. In some embodiments, the current loop radiation characteristic may be obtained by placing series and/or parallel capacitors on the radiation stubs. For example, in connection with fig. 5, a capacitor or the like may be provided at position 1. It should be understood that, through the energy storage characteristic of the capacitor to the electric energy, the change of the current on the radiation branch node tends to be flat, and the magnetic field corresponds to the current, so that the change of the magnetic field in the area near the radiation branch node (such as the area between the radiation branch node and the reference ground) tends to be flat, and a more uniformly distributed magnetic field is obtained. It should be noted that, in the embodiment of the present application, the capacitor may be a lumped capacitor or a distributed capacitor. In other embodiments of the present application, the function of the capacitor may be implemented in other forms, for example, by providing a structure having the same or similar distributed capacitance values. As a possible implementation, the distributed capacitance structure may be an interdigital structure or the like.
Experiments prove that the current loop antenna with uniform magnetic field distribution can provide better radiation performance under the same space condition. Such as better radiation efficiency, system efficiency, bandwidth, etc.
As an example, fig. 6 shows several possible current loop antenna implementations. It should be noted that, in different implementations of the present application, the current loop antenna may be divided into a current loop antenna and a current loop slot antenna according to a difference in a composition structure of the current loop antenna. The current loop antenna may include a current loop monopole antenna, a current loop dipole antenna, and the like. The current-loop antennas may include current-loop left-handed antennas, current-loop slot antennas, and the like.
On the current loop antenna, a first capacitor connected in parallel may be provided, thereby implementing the operation mechanism as shown in fig. 5. In some implementations, one or more capacitors may also be connected in series with the radiator of the current loop antenna, thereby improving the radiation performance of the current loop antenna.
A second capacitor connected in series may be provided on the current loop slot antenna corresponding to the current loop antenna, thereby implementing the operation mechanism as shown in fig. 5. In some implementations, more capacitors may be connected in series to the radiators of the current loop antenna, thereby improving the radiation performance of the current loop antenna.
Fig. 6 (a) shows a schematic of a current loop monopole antenna. The current loop monopole antenna may include a radiator B1, and the length of the radiator B1 may correspond to 1/4 of the operating wavelength in a case where the current loop monopole antenna operates in a fundamental mode (e.g., a 1/4 wavelength mode). For example, the length of B1 may be less than 1/4 of the operating wavelength. One end of B1 can be electrically connected with the feeding point, and the other end of B1 can pass through a first capacitor (such as a capacitor C) M1 ) And (4) grounding.
Fig. 6 (b) shows a schematic of a current loop dipole antenna. The current loop dipole antenna may include radiators B2 and B3. B2 and B3 can be connected through a feed point, and the end of B2 far away from B3 can be connected through a capacitor C D1 The end of B3 far away from B2 can pass through a capacitor C D2 And is grounded. In case the current loop dipole antenna operates in a fundamental mode (e.g. 1/4 wavelength mode), the length of the radiator B2 and the length of B3 may correspond to 1/4 of the operating wavelength, respectively. For example, the length of B2 may beAt less than 1/4 of the operating wavelength. As another example, the length of B3 may be less than 1/4 of the operating wavelength. That is, the radiating stubs (e.g., B2 plus B3) of the current-loop dipole antenna may be less than 1/2 of the operating wavelength in length. The sum of the lengths of B2 and B3 may be greater than 1/4 of the operating wavelength in some embodiments. It will be appreciated that the capacitance C D1 And a capacitor C D2 May correspond to a first capacitance on the current loop antenna.
Fig. 6 (c) shows a schematic of a current loop left-hand antenna. The current loop left hand antenna may comprise a radiator B4. A capacitor C can be connected in series with the B4 C1 . One end of B4 can be grounded, and the other end can be connected with left-hand feed. In this example, the left-hand feed may include a feed point, and a left-hand capacitor in series with the feed point. This left-handed capacitance can be used to excite the left-handed mode generated on B4. The structure and the working mechanism of the left-handed antenna can refer to CN201380008276.8 and CN201410109571.9, which are not described herein again. It will be appreciated that the capacitance C C1 It can correspond to a second capacitance on the current-slot antenna.
Fig. 6 (d) shows a schematic of a current loop slot antenna. The current loop slot antenna may include radiators B5 and B6. B5 and B6 may be connected by a feeding point. The end of B5 away from B6, and the end of B6 away from B5 may be grounded, respectively. Thus B5 and B6 and the reference ground can form a gap for radiation. In this example, a capacitor C may be connected in series with B5 S1 And a capacitor C can be connected in series on B6 S2 . It will be appreciated that the capacitance C C1 And a capacitor C S2 It can correspond to a second capacitance on the current-slot antenna.
In the example shown in fig. 6, the power feeding is performed by direct power feeding. In other implementations of the present application, the current loop antenna may also be excited by a form of coupled feed. Illustratively, fig. 7 shows a schematic of a coupled-feed current-loop monopole antenna.
As shown in fig. 7, the current loop monopole antenna may include a radiating stub and a feed stub. The radiation branches may comprise spokesTwo ends of the emitters B12 and B12 pass through a capacitor C respectively CM1 And C CM2 And (4) grounding. The feed branch may be used for coupling feed, and the feed branch may include a first feed portion CB12 and a second feed portion CB13, the CB13 and the CB12 may be connected by a feed point, and the other ends of the CB12 and the CB13 are both grounded. The feed stub may be disposed between the radiating stub and a reference ground. Thereby exciting the radiating stub to radiate with the characteristics of current loop radiation.
It will be appreciated that for other current loop antennas, excitation may also be by way of a coupled feed. The structure of the feed stub may also be varied. Reference may be made in particular to the following patent applications: application No. 202110961752.4, application No. 202110963510.9, application No. 202110961755.8, and application No. 202110962491.8. And will not be described in detail herein.
The current loop antenna is exemplarily described in fig. 5, 6, and 7, and the magnetic loop antenna is briefly described below with reference to fig. 8 and 9.
Illustratively, in conjunction with FIG. 8, a schematic of a magnetic current loop antenna is provided. As shown in fig. 8, the magnetic current loop antenna may include at least one radiating branch. The radiating stub may be used to radiate with the radiation characteristics of a magnetic current loop antenna. The radiation characteristics of the magnetic current loop antenna described in the embodiment of the present application may include: a uniform electric field distribution is generated between the radiation branch and the reference ground. For example, as shown in fig. 8, a downward electric field may be uniformly distributed between the antenna radiating stub and the reference ground. Of course, in other scenarios, the electric field may be uniformly distributed upward due to the constant change of the feeding signal.
As a possible implementation, the magnetic current loop antenna provided in the embodiment of the present application may be based on an existing electric field type antenna, and an inductor is connected in series and/or in parallel to the radiation branch, so that a position with a higher electric potential on the radiator can return to the ground through the inductor, thereby reducing the electric potential of the part, and further reducing the electric field near the high electric potential; correspondingly, the energy storage characteristic of the inductor to the magnetic energy is set, so that the time difference between the electric field change and the current change of the lower area of the electric field is generated, and further when the current is enhanced according to the current provided by the feeding point, the electric field of the original low electric field area can be rapidly enhanced, and the electric field of the original high electric field area still keeps the high electric field in a subsequent period of time. Thereby obtaining an electric field uniformly distributed near the radiation branch. Similarly to the foregoing description about the capacitor, in the embodiments of the present application, the setting of the inductor is described by taking the inductor in a lumped form as an example. In other embodiments of the present application, the function of the inductor may also be implemented in other forms, such as a distributed inductor.
It should be understood that with uniformly distributed electric field characteristics, a magnetic current loop with closed characteristics may be formed in the space near the radiation branch. That is, the radiation characteristics of the magnetic current loop antenna according to the embodiment of the present application may also include: a closed magnetic current loop distribution is generated near the radiation branch. For example, as shown in fig. 8, a closed magnetic current loop in a counterclockwise direction may be formed near the antenna radiation branch. Similar to the above description of the electric field distribution, in other scenarios, the magnetic current loop may also be distributed in a clockwise closed manner because the feeding signal is in constant change.
Based on the above description of the characteristics of the magnetic current loop antenna provided in this embodiment in the operating process (for example, with the radiation characteristics of the magnetic current loop antenna), since the magnetic current loop antenna provided in this embodiment can generate a uniform electric field (or a closed magnetic current loop) to radiate when operating, in combination with the foregoing description, the magnetic current loop antenna can provide better radiation performance than a general electric field type antenna having a non-uniform electric field.
Fig. 9 shows a schematic of several possible magnetic current loop antennas. It should be noted that, in different implementations of the present application, the magnetic current loop antenna may be divided into a magnetic current loop antenna and a magnetic current loop slot antenna according to a difference in a composition structure of the magnetic current loop antenna. The magnetic current loop antenna can comprise a magnetic current loop monopole antenna, a magnetic current loop dipole antenna and the like. The magnetic current ring slot antenna can comprise a magnetic current ring left-hand antenna, a magnetic current ring slot antenna and the like.
On the magnetic current loop antenna, a parallel first inductor may be provided, thereby implementing the operation mechanism as shown in fig. 8. In some implementations, one or more inductors may be connected in series to the radiator of the magnetic flux loop antenna, thereby improving the radiation performance of the magnetic flux loop antenna.
A second inductor connected in series may be provided on the magnetic current loop antenna corresponding to the magnetic current loop antenna, thereby implementing the working mechanism as shown in fig. 8. In some implementations, more inductors can be connected in series to the radiator of the magnetic current loop antenna, so that the radiation performance of the magnetic current loop antenna is improved.
Fig. 9 (a) shows a magnetic current loop monopole antenna. The magnetic current loop monopole antenna can comprise a radiator B1, wherein one end of the B1 can pass through an inductor L M1 The other end of B1 may be connected to the feed point. In the case where the antenna operates in the fundamental mode, the length of B1 may be related to 1/4 of the operating wavelength. For example, the length of B1 may be less than 1/4 of the operating wavelength. It can be understood that the inductance L M1 It may correspond to a first inductance on the magnetic loop antenna.
Fig. 9 (b) shows a magnetic current loop dipole antenna. The magnetic current loop dipole antenna may include radiators B2 and B3. B2 may be connected to B3 via a feed point. One end of B2 far away from B3 can pass through an inductor L D1 The end of B3 far away from B2 can pass through an inductor L D2 And (4) grounding. In some embodiments, the arrangement of B2 and B3 may be symmetrical about the feed point. In the case where the antenna operates in the fundamental mode, the length of B2 (or B3) may be related to 1/4 of the operating wavelength. For example, the length of B2 may be less than 1/4 of the operating wavelength. As another example, the length of B3 may be less than 1/4 of the operating wavelength. As another example, B2 and B3 may form the antenna with a direct length of radiation that is less than 1/2 of the operating wavelength and greater than 1/4 of the operating wavelength. It can be understood that the inductance L D1 Inductor L D2 May correspond to a first inductance on the magnetic flux loop antenna.
Fig. 9 (c) shows a magnetic current loop left-hand antenna. The flux ring left hand antenna may include a radiator B4. One end of the B4 can be grounded, and the other end can be connected with left-hand feed. The left-hand feeding formReference may be made to left hand feeding as shown in figure 6. An inductor L can be connected in series with B4 C1 . It can be understood that the inductance L C1 It may correspond to a second inductance on the magnetic flux ring slot antenna.
Fig. 9 (d) shows a magnetic current loop slot antenna. The magnetic current loop slot antenna may include radiators B5 and B6. The B5 and B6 may be connected by a feeding point. The end of B5 away from B6 may be grounded, and the end of B6 away from B5 may be grounded. Thus, B5 and B6 and the reference ground can be radiated to form a gap. In this example, an inductor L may be connected in series with B5 S1 And an inductor L can be connected in series on B6 S2 . It can be understood that the inductance L S1 Inductor L S2 It may correspond to a second inductance on the magnetic flux ring slot antenna.
In the example of fig. 9, the excitation is performed by direct feeding, and in other embodiments of the present application, the magnetic current loop antenna may also be excited by coupled feeding. Illustratively, fig. 10 shows a schematic diagram of a coupled-feed magnetic current loop monopole antenna. As shown in fig. 10, both ends of the radiator B11 of the antenna may pass through an inductor (e.g., L) CM1 And L CM2 ) And (4) grounding. A feeding branch CB11 may be disposed between the radiating branch and the reference ground, two ends of the CB11 may be disposed in the air, and the CB11 may be connected to a feeding point, for example, the feeding point may be disposed at a central position of the CB 11. Therefore, excitation of the magnetic current loop antenna can be realized, so that B11 carries out radiation with the magnetic current loop radiation characteristic. It will be appreciated that for other magnetic current loop antennas, excitation may also be by way of a coupled feed. The structure of the feed stub may also be varied. Reference may be made in particular to the following patent applications: application No. 202111034604.4, application No. 202111034603.X, application No. 202111034611.4, and application No. 202111033384.3. And will not be described in detail herein.
In the antenna scheme with high isolation provided by the embodiment of the application, the antenna scheme can be used in an antenna system comprising a plurality of antennas. Antenna pairs having high isolation characteristics may be included in the antenna system. The high isolation antenna pair is described below in conjunction with specific embodiments.
In the embodiment of the present application, the feeding mode of the antenna may be direct feeding or coupled feeding. Wherein, whether the feed is direct feed or coupled feed, the signal can be input to the feed point of the antenna by adopting a symmetrical feed or an anti-symmetrical feed mode so as to excite the antenna.
The symmetrically fed feed signal (shortly called symmetric feed signal) and the antisymmetrically fed feed signal (shortly called antisymmetric feed signal) may have an anti-phase characteristic. For example, the symmetric feed signal and the anti-symmetric feed signal may be 180 degrees out of phase.
In some embodiments, the symmetric feed signal and the anti-symmetric feed signal may also be from the same feed. The signal of the feed source can be used as a symmetrical feed signal and directly input to a port needing symmetrical feed. The signal of the feed source can also realize the phase reversal through devices such as a phase inverter and the like, so that a corresponding antisymmetric feed signal is obtained, and the antisymmetric feed signal can be input into a corresponding port to realize antisymmetric feed.
For example, in connection with fig. 11, the feed 1 may provide the original feed signal. The original feed signal can be directly transmitted to the port A of the antenna A and the port B of the antenna B without inversion processing, and symmetric feed of the antenna A and the antenna B is realized. In addition, the original feed signal can be processed by an inverter before being transmitted to the port a of the antenna a and the port B of the antenna B, so as to obtain an anti-symmetric signal after phase inversion, and transmit the anti-symmetric signal to the port a and the port B, thereby realizing anti-symmetric feeding to the antenna a and the antenna B.
Similarly, the two states (e.g. the symmetric feeding state of the antenna a and the antenna B, and the anti-symmetric feeding state of the antenna a and the antenna B) can excite the transverse current and the longitudinal current on the floor respectively, so that the field distribution has orthogonality, and thus better isolation is obtained.
It should be noted that the symmetric feeding and the anti-symmetric feeding may be relative, for example, the symmetric feeding and the anti-symmetric feeding may indicate that the two feeding signals have equal-amplitude and opposite-phase characteristics. In the case where two or more antennas are symmetrically fed, it can indicate that the feeding signals of these antennas have the characteristics of equal amplitude and same phase.
The following describes the scheme provided by the embodiments of the present application with reference to specific examples.
The antenna scheme provided by the embodiment of the application can be used for covering at least one working frequency band. The covered operating band may include overlapping coverage bands for respective antennas in a pair (e.g., antenna pair consisting of antenna a and antenna B).
The operating band may include a Low Band (LB), a Medium Band (MB), and/or a High Band (HB), among others. Wherein in some embodiments the low frequency may comprise a frequency band range of 450M-1 GHz. The intermediate frequency may comprise a frequency band range of 1G-3 GHz. The high frequency may comprise a frequency band range of 3GHz-10GHz. It is understood that, in various embodiments, the low, medium, and high frequency bands may include operating bands required by, but not limited to, bluetooth (BT) communication technology, global Positioning System (GPS) communication technology, wi-Fi (wireless fidelity) communication technology, global system for mobile communications (GSM) communication technology, wideband Code Division Multiple Access (WCDMA) communication technology, long Term Evolution (LTE) communication technology, 5G communication technology, SUB-6G communication technology, and other future communication technologies. As an example, the LB band may cover 450MHz-1GHz, the MB band may cover 1GHz-3GHz, and the HB band may cover 3GHz-10GHz. In some implementations, the LB, MB, and HB can include the common bands of 5G nr, wifi 6e, uwb, and the like.
Please refer to fig. 12, which is a schematic diagram of a high isolation antenna pair according to an embodiment of the present application. In this example, the high isolation antenna pair may include antenna 1 and antenna 2. The antennas 1 and 2 may be current loop antennas. The current loop antenna may have any of the possible implementations of the current loop antenna described in the above examples.
In the following, a current loop monopole antenna in which both the antenna 1 and the antenna 2 are directly fed is taken as an example. For example, the antenna 1 may be a current loop antenna 1, and the antenna 2 may be a current loop antenna 2. For example, referring to fig. 12, the antenna 1 may include a radiator B11, and one end of the radiator B11 may be provided with a port 1, where the port 1 may be used to feed the radiator B11. The other end of B11 may be grounded through a capacitor CM 11. In case the antenna 1 operates in the fundamental mode, the length of the B11 may be less than 1/4 of the corresponding operating wavelength. Correspondingly, the antenna 2 may include a radiator B12, and one end of the radiator B12 may be provided with a port 2, and the port 2 may be used to feed the radiator B12. The other end of B12 may be grounded through capacitor CM 12. In case the antenna 2 operates in the fundamental mode, the length of the B12 may be less than 1/4 of the corresponding operating wavelength.
The antenna 1 and the antenna 2 can be respectively operated in a symmetrical feeding state and an anti-symmetrical feeding state. Exemplarily, in connection with fig. 13. As shown in fig. 13 (a), in the symmetric feeding state, the port 1 of the antenna 1, and the port 2 of the antenna 2 can be excited by the symmetric feeding signal. In the antisymmetric feeding state, as shown in fig. 13 (b), the port 1 of the antenna 1 and the port 2 of the antenna 2 can be excited by the antisymmetric feeding signal. The symmetrical feeding signal and the anti-symmetrical feeding signal can be obtained as described with reference to fig. 11 and 12. In some embodiments, antennas 1 and 2 may operate in both a symmetrically fed state and an anti-symmetrically fed state. That is, port 1 can be excited by a symmetric feed while also receiving an anti-symmetric feed signal. Similarly, port 2 may be excited by a symmetric feed while also receiving an anti-symmetric feed signal. Thus, the antenna pair composed of the antenna 1 and the antenna 2 can provide both a mode of a symmetric feeding state and a mode of an anti-symmetric feeding state.
In the example shown in fig. 12 and 13, the antenna 1 and the antenna 2 are provided as mirror images. As can be seen from the examples of fig. 12 and 13, the feeding point may be located close to each other, that is, the feeding point of the antenna 1 may be located on one side of the antenna 1 close to the center of the electronic device, and the feeding point of the antenna 2 may be located on one side of the antenna 2 close to the center of the electronic device. In other embodiments of the application, the feed point of the antenna 1 and/or the antenna 2 may also be arranged on another side than the example shown in fig. 12. Alternatively, the feeding point can be flexibly set according to the specific design of the current loop antenna.
In the present example, the mode of the symmetric feeding state may be simply referred to as a symmetric feeding mode, and the mode of the anti-symmetric feeding state may be simply referred to as an anti-symmetric feeding mode. The symmetric feeding mode and the anti-symmetric feeding mode can respectively excite orthogonal currents on the floor. For example, as shown in fig. 14, in the symmetric feeding mode, a longitudinal (e.g., upward) current may be excited on the floor. In the antisymmetric feed mode, a transverse (e.g., rightward) current can be excited on the floor. This current may correspond to the electric field distribution shown in fig. 15. As shown in fig. 15, in the symmetric feeding mode, the electric field direction of the head of the electronic device may be a direction pointing to the electronic device from the outside. Whereas in the anti-symmetric feeding mode the electric field direction of the head of the electronic device may be a direction pointing from the left side of the electronic device to the right side of the electronic device. Excitation with current distribution and electric field distribution as shown in fig. 14 or fig. 15 can make the spatial field distribution orthogonal also in two different modes. For example, referring to fig. 16, a far field distribution diagram is shown. In the antisymmetric feed mode, the far field distribution may approach a longitudinal distribution. In a symmetric feeding mode, the far field distribution may approach a lateral distribution. Therefore, when the antenna pair works in an antisymmetric feeding mode and an antisymmetric feeding mode, orthogonal field distribution can be obtained in the two modes, and therefore better isolation is obtained.
The following is further described in connection with S-parameters and efficiency simulations.
As shown in fig. 17, both the antisymmetric feed mode and the symmetric feed mode can operate around 1.8GHz, with the deepest point of S11 exceeding-10 dB. At the same time, the bandwidth is sufficient to cover at least one operating band. Furthermore, in the isolation diagram shown in fig. 17, although the antenna 1 is excited by the symmetric feeding signal and excited by the anti-symmetric feeding signal, and the antenna 2 is excited by the symmetric feeding signal and excited by the anti-symmetric feeding signal, in both operation modes, the symmetric feeding mode formed by the symmetrically fed antenna 1 and the symmetrically fed antenna 2, and the anti-symmetric feeding mode formed by the anti-symmetrically fed antenna 1 and the anti-symmetrically fed antenna 2, still have very good isolation, and the highest point thereof is lower than-120 dB. Therefore, the two working modes have very good isolation, and basically cannot influence each other in the working process.
Fig. 18A shows an efficiency simulation schematic in two operating modes. As shown in (a) of fig. 18A, the radiation efficiency of the antisymmetric feeding mode is already over-1 dB in terms of radiation efficiency, and the radiation efficiency of the symmetric feeding mode is over-4 dB. As shown in (b) of fig. 18A, the system efficiency of the antisymmetric feeding mode has exceeded-2 dB, approaching-1 dB, while the system efficiency of the symmetric feeding mode has exceeded-4 dB, approaching-3 dB. Both modes can provide better radiation performance.
From the above description of fig. 12 to 18A, it can be seen that in the antenna pair including the antenna 1 and the antenna 2 having the composition shown in fig. 12, it is possible to operate in the symmetric feeding mode and the anti-symmetric feeding mode by symmetric feeding and anti-symmetric feeding, and the radiation performance in both modes can be ensured due to the better radiation performance of the current loop antenna, and at the same time, the isolation in both modes is also very good, thereby forming a high isolation antenna pair.
In the above example, a current loop monopole antenna in which a current loop antenna is a direct feed is taken as an example for explanation. In other embodiments of the present application, the current loop antenna corresponding to the antenna 1 and/or the antenna 2 may also be in the form of other current loop antennas provided in the above examples. For example, a direct-fed current loop dipole antenna, a direct-fed current loop slot antenna, and a direct-fed current loop left-handed antenna. For another example, a current loop monopole antenna for coupling feeding, a current loop dipole antenna for coupling feeding, a current loop slot antenna for coupling feeding, and a current loop left-handed antenna for coupling feeding. For specific implementation, reference may be made to the foregoing examples, which are not described herein again.
Illustratively, fig. 18B shows a schematic of a high isolation antenna pair formed by a coupled-feed current loop antenna. The current loop antenna fed by this coupling has a configuration shown in fig. 7 as an example. As shown in fig. 18B, the antenna 1 in the electronic device may be a coupling-fed current loop antenna 1-1. Correspondingly, the antenna 2 in the electronic device may be a coupled-feed current loop antenna 1-2. The current loop antenna 1-1 may include a radiation branch B12-1, and both ends of the radiation branch may be grounded through capacitors, respectively. For example, C can be respectively arranged at two ends of the radiation branch CM1-1 And C CM2-1 And (4) grounding. The current loop antenna 1-1 may further include a feed stub consisting of CB12-1 and CB 13-1. The CB12-1 and CB13-1 have respective ends grounded, and the opposite ends of the CB12-1 and CB13-1 are connected through a feed port (e.g., port 1). Similarly, the current loop antenna 1-2 may include a radiating stub B12-2, which may be capacitively grounded at each end. For example, C can be respectively arranged at two ends of the radiation branch CM1-2 And C CM2-2 And (4) grounding. The current loop antenna 1-2 can also comprise a feed branch consisting of CB12-2 and CB 13-2. The CB12-2 and CB13-2 have respective ends grounded, and the opposite ends of the CB12-2 and CB13-2 are connected via a feed port (e.g., port 2).
It should be understood that the high isolation and high radiation performance characteristics of the pair of high isolation antennas composed of the current loop antenna having the direct feed similar to those described above are illustrated, and the pair of antenna based on the coupled feed having the composition shown in fig. 18B also has the effects of high isolation and good radiation characteristics.
In the above example, the antenna pair including two current loop antennas is described as an example. In other embodiments of the present application, the antenna pair may further include two magnetic current loop antennas, and the two magnetic current loop antennas may also operate in a symmetric feeding mode and an anti-symmetric feeding mode, respectively, to form a high isolation antenna pair.
Fig. 19 is a schematic diagram of a high-isolation antenna pair according to an embodiment of the present application. In this example, the high isolation antenna pair may include antenna 3 and antenna 4. The antennas 3 and 4 may be magnetic current loop antennas. The magnetic current loop antenna may have any of the possible implementations of the magnetic current loop antenna described in the above examples.
Hereinafter, a magnetic current loop monopole antenna in which the antenna 3 and the antenna 4 are both directly fed will be taken as an example. For example, referring to fig. 19, the antenna 3 (i.e., the magnetic current loop antenna 1) may include a radiator 13, and one end of the B13 may be provided with a port 3, and the port 3 may be used to feed the B13. The other end of B13 may be grounded through inductor LM 11. In case the antenna 3 operates in the fundamental mode, the length of the B13 may be less than 1/4 of the corresponding operating wavelength. Correspondingly, the antenna 4 (i.e. the magnetic current loop antenna 2) may include a radiator B14, and one end of the radiator B14 may be provided with a port 4, and the port 4 may be used for feeding the radiator B14. The other end of B14 may be grounded through inductor LM 12. In the case where the antenna 4 operates in the fundamental mode, the length of the B14 may be less than 1/4 of the corresponding operating wavelength.
The antenna 3 and the antenna 4 can be operated in a symmetrically fed state and in an anti-symmetrically fed state, respectively. Exemplarily, in connection with fig. 20. As shown in fig. 20 (a), in the symmetric feeding state, the port 3 of the antenna 3, and the port 4 of the antenna 4 can be excited by a symmetric feeding signal. As shown in fig. 20 (b), in the antisymmetric feeding state, the port 3 of the antenna 3 and the port 4 of the antenna 4 can be excited by the antisymmetric feeding signal. The symmetrical feeding signal and the anti-symmetrical feeding signal can be obtained as described with reference to fig. 11 and 12. In some embodiments, antennas 3 and 4 may operate in both a symmetrically fed state and an anti-symmetrically fed state. That is, the port 3 can be excited by a symmetric feed while also receiving an anti-symmetric feed signal. Similarly, the port 4 may be excited by a symmetric feed, while also receiving an anti-symmetric feed signal. Thus, the antenna pair consisting of the antenna 3 and the antenna 4 can provide both a mode of a symmetric feeding state and a mode of an anti-symmetric feeding state.
Note that, in the examples shown in fig. 19 and 20, the antenna 3 and the antenna 4 are provided as mirror images. As can be seen from the examples of fig. 19 and 20, the feeding point may be located close to each other, that is, the feeding point of the antenna 3 may be located on a side of the antenna 3 close to the center of the electronic device, and the feeding point of the antenna 4 may be located on a side of the antenna 4 close to the center of the electronic device. In other embodiments of the application, the feed point of the antenna 3 and/or the antenna 4 may also be arranged on another side than the example shown in fig. 19. Alternatively, the feeding point can be flexibly arranged according to the specific design of the magnetic current loop antenna.
In this example, the symmetric feed mode and the anti-symmetric feed mode may separately excite orthogonal currents on the floor, similar to the antenna pair of current loop antennas described above. For example, as shown in fig. 21, in the symmetric feeding mode, a longitudinal (e.g., upward) current may be excited on the floor. In the anti-symmetric feeding mode, a transverse (e.g., leftward) current can be excited in the floor. This current may correspond to the electric field distribution shown in fig. 22. As shown in fig. 22, in the symmetric feeding mode, the electric field direction of the electronic device head may be a direction pointing from the electronic device to the outside of the electronic device. Whereas in the anti-symmetric feeding mode the electric field direction of the head of the electronic device may be a direction pointing from the left side of the electronic device to the right side of the electronic device. Excitation with current distribution and electric field distribution as shown in fig. 21 or fig. 22 can make the spatial field distribution orthogonal also in two different modes. For example, referring to fig. 23, a far field distribution diagram is shown. In the antisymmetric feed mode, the far field distribution may approach a longitudinal distribution. In a symmetric feeding mode, the far field distribution may approach a lateral distribution. Therefore, when the antenna pair works in an antisymmetric feeding mode and an antisymmetric feeding mode, orthogonal field distribution can be obtained in the two modes, and therefore better isolation is obtained.
The following is further described in connection with S-parameters and efficiency simulations.
As shown in fig. 24, the operation can be performed around 1.8GHz in both the anti-symmetric feeding mode and the symmetric feeding mode, with the deepest point of S11 exceeding-15 dB. At the same time, the bandwidth is sufficient to cover at least one operating band. Furthermore, in the isolation diagram of fig. 24, although antenna 3 is excited by both the symmetrically and antisymmetrically fed signals and antenna 4 is excited by both the symmetrically and antisymmetrically fed signals, the symmetrically fed mode formed by symmetrically fed antenna 3 and symmetrically fed antenna 4 and the antisymmetrically fed mode formed by antisymmetrically fed antenna 3 and antisymmetrically fed antenna 4 still have very good isolation and peak below-120 dB in both modes of operation. Therefore, the two working modes have very good isolation, and basically no mutual influence is generated in the working process.
Fig. 25A shows an efficiency simulation in two operating modes. As shown in (a) of fig. 25A, the radiation efficiency of the antisymmetric feeding mode is close to-1 dB in terms of radiation efficiency, and the radiation efficiency in the symmetric feeding mode also exceeds-4 dB. As shown in (b) of fig. 25A, the system efficiency of the antisymmetric feeding mode is already over-2 dB, close to-1 dB, while the system efficiency of the symmetric feeding mode is also over-4 dB, close to-3 dB. Both modes can provide better radiation performance.
From the above description of fig. 19 to 25A, it can be seen that in the antenna pair including the antenna 3 and the antenna 4 having the composition shown in fig. 19, by symmetrically feeding and asymmetrically feeding, operating in the symmetrically feeding mode and the antisymmetrically feeding mode, the radiation performance in both modes can be ensured due to the better radiation performance of the magnetic current loop antenna, and the isolation in both modes is also very good, thereby forming a high isolation antenna pair.
In the above example, a magnetic current loop monopole antenna in which a magnetic current loop antenna is a direct feed is taken as an example for explanation. In other embodiments of the present application, the magnetic current loop antenna corresponding to the antenna 3 and/or the antenna 4 may also be in the form of other magnetic current loop antennas provided in the above examples. For example, a direct-fed magnetic current loop dipole antenna, a direct-fed magnetic current loop slot antenna, and a direct-fed magnetic current loop left-hand antenna. For another example, a magnetic current loop monopole antenna for coupling feeding, a magnetic current loop dipole antenna for coupling feeding, a magnetic current loop slot antenna for coupling feeding, and a magnetic current loop left-handed antenna for coupling feeding. For specific implementation, reference may be made to the foregoing examples, which are not described herein again.
Illustratively, fig. 25B shows a schematic of a high isolation antenna pair formed by coupled-feed magnetic current loop antennas. The magnetic current loop antenna fed by this coupling has a configuration shown in fig. 10 as an example. As shown in fig. 25B, the antenna 3 in the electronic device may be a coupling-fed magnetic current loop antenna 1-1. Correspondingly, the antenna 4 in the electronic device may be a coupled feed magnetic current loop antenna 1-2. The magnetic current loop antenna 1-1 may include a radiation branch B11-1, and both ends of the radiation branch may be grounded through inductors, respectively. For example, L may be respectively disposed at two ends of the radiation branch CM1-1 And L CM2-1 And (4) grounding. The magnetic current loop antenna 1-1 may further include a feed branch CB11-1. Two ends of the feed branch CB11-1 can be suspended, and a feed point can be arranged at the center of the feed branch and is connected with the port 3. Similarly, the magnetic current loop antenna 1-2 may include a radiating branch B11-2, at both ends of which may be grounded via an inductor, respectively. For example, L can be respectively arranged at two ends of the radiation branch knot CM1-2 And L CM2-2 And is grounded. The magnetic current loop antenna 1-2 may further include a feed stub CB11-2. Two ends of the feed branch CB11-2 can be suspended, and a feed point can be arranged at the center of the feed branch and is connected with the port 4.
It should be understood that the characteristics of high isolation and high radiation performance of the pair of high isolation antennas composed of the magnetic current loop antenna having the direct feed similar to those described above illustrate that the pair of antennas based on the coupled feed having the composition shown in fig. 25B also has the effects of high isolation and good radiation performance.
From the above description, it should be understood by those skilled in the art that two operation states with better isolation, such as a symmetric feeding state and an anti-symmetric feeding state, can be obtained in a limited space by performing symmetric feeding and anti-symmetric feeding on the antenna pair composed of the current loop antenna or the antenna pair composed of the magnetic current loop antenna, respectively. In combination with the analysis of the floor current in the two embodiments (e.g. the current distribution shown in fig. 14 and the far-field pattern distribution shown in fig. 16 for the antenna pair composed of the current loop, and the current distribution shown in fig. 21 and the far-field pattern distribution shown in fig. 23 for the antenna pair composed of the magnetic current loop), the high isolation effect can be demonstrated from the perspective of the current distribution and the far-field pattern.
The following provides a directional diagram of the conventional antenna corresponding to two states of symmetric feeding and anti-symmetric feeding, and compared with the scheme provided by the present invention, the effect produced by the scheme provided by the present invention will be further described.
Illustratively, fig. 26 is a schematic representation of a symmetrically distributed left-hand antenna pair. The left-hand antenna pair may include a left-hand antenna a and a left-hand antenna B. The left hand antenna a may be fed through port 5A. The port 5A may be provided with a feeding point 5A and a left-hand capacitor 5A. The left hand antenna B may be fed through port 5B. The port 5B may be provided with a feeding point 5B and a left-hand capacitor 5B.
In some implementations, with reference to the preceding description of symmetric feeding and anti-symmetric feeding, the ports 5A and 5B may be fed with symmetric feeding signals, respectively, so that the left-hand antenna pair operates in a symmetric feeding state. In addition, the ports 5A and 5B may be fed with anti-symmetric feeding signals, respectively, so that the left-hand antenna pair operates in an anti-symmetric feeding state. The symmetrical feeding state and the anti-symmetrical feeding state can have better isolation. Illustratively, fig. 27 shows far field patterns in two states. It can be seen that the left-hand antenna pair having the composition of fig. 26 is in a far-field pattern, and in the anti-symmetric feeding state, the regions of stronger gain are distributed at the upper and lower edges of the floor. In the symmetrical feeding state, the area with stronger gain is distributed at the lower part of the floor.
Figure 28 is a schematic of a symmetrically distributed pair of IFA antennas. The pair of IFA antennas may include an IFA antenna a and an IFA antenna B. The IFA antenna a may be fed through the port 6A. The port 6A may be provided with a feeding point 6A. IFA antenna B may be fed through port 6B. The port 6B may be provided with a feeding point 6B.
In some implementations, with reference to the description of symmetric feeding and anti-symmetric feeding previously described, the ports 6A and 6B may be fed with symmetric feeding signals, respectively, so that the pair of IFA antennas operates in a symmetric feeding state. In addition, the ports 6A and 6B may be fed with anti-symmetric feeding signals, respectively, so that the pair of IFA antennas operates in an anti-symmetric feeding state. The symmetrical feeding state and the anti-symmetrical feeding state can have better isolation. Illustratively, fig. 29 shows far field patterns in two states. It can be seen that the pair of IFA antennas having the configuration of figure 28 has a far field pattern in which the region of higher gain is distributed at the lower edge of the floor and a region near the middle of the floor has a stronger gain distribution in the anti-symmetric feed condition. In the symmetrical feeding state, the area with stronger gain is distributed at the lower part of the floor.
Figure 30 is a schematic of a symmetrically distributed pair of ILA antennas. The ILA antenna pair may include an ILA antenna a and an ILA antenna B. ILA antenna a may be fed through port 7A. The port 7A may be provided with a feeding point 7A. ILA antenna B may be fed through port 7B. The port 7B may be provided with a feeding point 7B.
In some implementations, with reference to the previous description of symmetric feeding and anti-symmetric feeding, the port 7A and port 7B may be fed with symmetric feeding signals, respectively, so that the ILA antenna pair operates in a symmetric feeding state. In addition, the ILA antenna pair may also be caused to operate in an anti-symmetric feed state by feeding anti-symmetric feed signals to port 7A and port 7B, respectively. The symmetrical feeding state and the anti-symmetrical feeding state can have better isolation. Illustratively, fig. 31 shows far field patterns in two states. It can be seen that the ILA antenna pair having the composition of fig. 30 is in a far field pattern, and in the anti-symmetric feeding state, the region of stronger gain is distributed at the lower edge of the floor. In the symmetrical feeding state, the area with stronger gain is distributed at the lower part of the floor.
It can be seen that the above three antenna pairs consisting of the existing antennas, such as the left-handed antenna pair, the IFA antenna pair, and the ILA antenna pair. Better isolation can also be achieved by symmetric and anti-symmetric feeding. However, as can be seen from the directional diagram, due to poor excitation to the floor, the intensity distribution of the directional diagram is not uniform, there is a significant region with strong gain, and the radiation performance of the corresponding region with weak gain is poor.
In contrast, the directional diagram of the high isolation current loop antenna pair shown in fig. 16 provided by the present application is that in the anti-symmetric feeding state, since the current loop antenna can better excite the floor current, the magnitude of the gain is more uniformly distributed in the longitudinal direction, and there is no region with significantly lower gain. Correspondingly, in the symmetric feeding state, because the current loop antenna can better excite the floor current, the gain is more uniformly distributed in the transverse direction, and no region with obviously lower gain exists. That is to say, the directional diagram distribution of the current loop antenna pair provided by the embodiment of the present application is more uniform than the directional diagram distribution of the three existing antenna pairs, so that the radiation performance in each direction can be better, and better radiation performance is provided while better isolation is provided. For example, it has better bandwidth, efficiency, and SAR.
Similar to the current loop antenna pair described above, with reference to the far-field pattern of the current loop antenna pair provided in the present application as shown in fig. 23, since the current loop antenna can better excite the floor current, the gain distribution of the pattern in each direction is better in both operation modes, and thus better radiation performance can be provided while providing better isolation. For example, the bandwidth, efficiency, SAR and the like are better.
Although the present application has been described in conjunction with specific features and embodiments thereof, it will be evident that various modifications and combinations can be made thereto without departing from the spirit and scope of the application. Accordingly, the specification and figures are merely exemplary of the present application as defined in the appended claims and are intended to cover any and all modifications, variations, combinations, or equivalents within the scope of the present application. It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include such modifications and variations.
Claims (14)
1. A terminal antenna system with high isolation is characterized by being applied to electronic equipment and comprising a first antenna pair, wherein the first antenna pair comprises a first antenna and a second antenna, and the first antenna and the second antenna are both current loop antennas, or the first antenna and the second antenna are both magnetic current loop antennas;
the feed port of the first antenna is a first port, the feed port of the second antenna is a second port, and the feed signals fed into the first port and the second port simultaneously comprise a symmetric feed signal and an anti-symmetric feed signal.
2. The terminal antenna system of claim 1,
when the feeding signals fed into the first port and the second port are symmetrical feeding signals, the first antenna pair works in a symmetrical feeding state;
when the feeding signals fed into the first port and the second port are antisymmetric feeding signals, the first antenna pair works in an antisymmetric feeding state;
the current direction of the excitation floor under the symmetrical feeding state is a first direction, the current direction of the excitation floor under the antisymmetrical feeding state is a second direction, and the first direction is orthogonal to the second direction.
3. The terminal antenna system according to claim 1 or 2,
the symmetric feed signal and the anti-symmetric feed signal are feed signals with equal amplitude and opposite phase.
4. The terminal antenna system according to any of claims 1-3,
the first antenna and the second antenna are mirror symmetric in structure.
5. The terminal antenna system of claim 4,
the first antenna and the second antenna are in the form of a feed fed directly, or,
the first antenna and the second antenna are in the form of coupled feeds.
6. The terminal antenna system of claim 5,
when the first antenna and the second antenna are both direct fed,
the feed ports of the first antenna and the second antenna are arranged at the ends of the antenna radiators which are close to each other, or at the ends of the antenna radiators which are far away from each other.
7. The terminal antenna system according to any of claims 1-3,
the first antenna and the second antenna are disposed on the same side of the electronic device,
when the first antenna and the second antenna are both direct fed,
the feed point of the first antenna is arranged at the left end of the radiator of the first antenna, and the feed point of the second antenna is arranged at the left end of the radiator of the second antenna; alternatively, the first and second electrodes may be,
the feed point of the first antenna is arranged at the right end of the radiator of the first antenna, and the feed point of the second antenna is arranged at the right end of the radiator of the second antenna; alternatively, the first and second electrodes may be,
the feed point of the first antenna is arranged at the tail end of the upper side of the radiator of the first antenna, and the feed point of the second antenna is arranged at the tail end of the upper side of the radiator of the second antenna; alternatively, the first and second electrodes may be,
the feed point of the first antenna is arranged at the lower end of the radiator of the first antenna, and the feed point of the second antenna is arranged at the lower end of the radiator of the second antenna.
8. The terminal antenna system of claim 5,
when the first antenna and the second antenna are both feed-coupled current loop antennas,
the first antenna comprises a first radiation branch and a first feed branch, the first feed branch is used for coupling feed of the first radiation branch, and at least one tail end of the first radiation branch is grounded through a capacitor.
9. The terminal antenna system of claim 5,
when the first antenna and the second antenna are both coupled-feed magnetic current loop antennas,
the first antenna comprises a second radiation branch and a second feed branch, the second feed branch is used for coupling feed to the second radiation branch, and at least one tail end of the second radiation branch is grounded through an inductor.
10. The terminal antenna system according to any of claims 1-9,
the first antenna and the second antenna are both current loop antennas, and radiating bodies of the current loop antennas are connected with at least one first capacitor in parallel and grounded; alternatively, the first and second electrodes may be,
the first antenna with the second antenna is the current ring slot antenna, it has at least one second electric capacity to establish ties on the irradiator of current ring slot antenna.
11. The terminal antenna system according to claim 10, characterized in that the antenna forms of the first and second antennas are identical, the antenna forms comprising any of the following:
a current loop monopole antenna, a current loop dipole antenna, a current loop left-handed antenna, and a current loop slot antenna.
12. The terminal antenna system according to any of claims 1-9,
the first antenna and the second antenna are all magnetic current loop antennas, and radiating bodies of the magnetic current loop antennas are connected with at least one first inductor in parallel and grounded; alternatively, the first and second electrodes may be,
the first antenna with the second antenna is magnetic current ring slot antenna, it has at least one second inductance to establish ties on the irradiator of magnetic current ring slot antenna.
13. The terminal antenna system according to claim 12, wherein the first antenna and the second antenna have the same antenna form, the antenna form comprising any one of:
magnetic current loop monopole antenna, magnetic current loop dipole antenna, magnetic current loop left-hand antenna, magnetic current loop slot antenna.
14. An electronic device, characterized in that the electronic device is provided with at least one processor, a radio frequency module, and a terminal antenna system according to any one of claims 1-13;
when the electronic equipment transmits or receives signals, the radio frequency module and the terminal antenna system transmit or receive the signals.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111153412.5A CN115882218A (en) | 2021-09-29 | 2021-09-29 | Terminal antenna system with high isolation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111153412.5A CN115882218A (en) | 2021-09-29 | 2021-09-29 | Terminal antenna system with high isolation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115882218A true CN115882218A (en) | 2023-03-31 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111153412.5A Pending CN115882218A (en) | 2021-09-29 | 2021-09-29 | Terminal antenna system with high isolation |
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| Country | Link |
|---|---|
| CN (1) | CN115882218A (en) |
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2021
- 2021-09-29 CN CN202111153412.5A patent/CN115882218A/en active Pending
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