Terminal antenna

Abstract

The embodiment of the invention discloses a terminal antenna, relates to the technical field of antennas, and achieves the effect of high radiation performance under the condition that the wavelength of a radiator is smaller than 1 / 2. According to the specific scheme, the antenna comprises a first radiator, the length of the first radiator is smaller than a first value, and the first value corresponds to 1 / 2 wavelength of the working frequency of the antenna. Two ends of the first radiator are respectively provided with a first feeding point and a second feeding point, the first feeding point and the second feeding point are respectively connected with two signal output ends of the differential mode feeding structure, the two signal output ends have different polarities, and the two signals are equal in amplitude and opposite in phase.

Description

A terminal antenna

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on October 14, 2022, with application number 202211261353.8 and invention name “A Terminal Antenna”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of antenna technology, and in particular to a terminal antenna. Background Art

[0003] Electronic devices can provide wireless communication capabilities through their antennas. With the development of electronic devices, the requirements for wireless communication quality are becoming increasingly stringent. At the same time, the increasing concentration of electronic devices has left increasingly limited design space for antennas. Consequently, the antennas in electronic devices need to provide better radiation performance and be smaller in size.

[0004] Summary of the Invention

[0005] The present invention provides a terminal antenna. The antenna solution achieves high radiation performance when the radiator is smaller than 1 / 2 wavelength through the antenna design of the present invention.

[0006] In order to achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0007] In a first aspect, a terminal antenna is provided, which is used in an electronic device. The antenna includes a first radiator, the length of which is less than a first value corresponding to half the wavelength of the antenna's operating frequency. A first feeding point and a second feeding point are provided at each end of the first radiator, respectively. The first feeding point and the second feeding point are respectively connected to two signal output terminals of a differential mode feeding structure. The two signal output terminals have different polarities, and the two signals are equal-amplitude and opposite-phase signals.

[0008] Thus, based on the technical solution provided in this example, by feeding signals through differential-mode feeds at both ends, it is possible to excite the antenna on a radiator with a length less than 1 / 2 wavelength. In some implementations, port matching can be performed before the differential-mode feed is fed into the radiator to ensure that the feed signal matches the antenna port, achieving better radiation performance within the operating frequency band.

[0009] Optionally, the feed signal output by the differential mode feeding structure and then input to the first radiator has a high impedance port characteristic. The high impedance port characteristic is achieved by a series capacitor. In this way, by connecting a series capacitor, the application of the differential mode feeding structure that outputs a low impedance feed signal in the solution provided in the present application can be achieved. The capacitor can be used to adjust the impedance characteristics of the signal so that the signal input to the radiator can have a high impedance characteristic. Of course, in other embodiments, other methods can also be used to make the signal input to the radiator have a high impedance characteristic.

[0010] Optionally, the length of the first radiator is less than or equal to 1 / 4 wavelength of the operating frequency.

[0011] Optionally, the length of the first radiator is less than or equal to 1 / 8 wavelength of the operating frequency.

[0012] It is understood that the smaller the length of the radiator, the smaller the maximum current amplitude difference on the radiator. In this example, when the first radiator (or the electrical length of the first radiator) is less than 1 / 4 wavelength or 1 / 8 wavelength, the maximum current amplitude difference can be adjusted to a smaller range, thereby achieving a better radiation effect.

[0013] Optionally, the differential mode feeding structure includes: a first feed source and a second feed source, wherein the first pole of the first feed source is coupled to the first feeding point, and the second pole of the second feed source is coupled to the second feeding point. The first pole is a positive pole, and the second pole is a negative pole. Alternatively, the first pole is a negative pole, and the second pole is a positive pole.

[0014] Optionally, the differential mode feeding structure includes a third feed source, a first pole of the third feed source is coupled to the first feeding point, and the first pole of the third feed source is coupled to the second feeding point through an inverting component, and the inverting component is used to provide a 180-degree inverting function.

[0015] In this way, the first radiator in the present application can be excited by a differential-mode feeding structure with a single feed source or a differential-mode feeding structure with a dual feed source.

[0016] Optionally, a matching circuit is provided between the differential-mode feeding structure and the first radiator, and the matching circuit is used to adjust the feeding signal output by the differential-mode feeding structure to a high-impedance port characteristic.

[0017] Optionally, when the antenna is operating, the antenna operates in a 0.5 times wavelength mode. Thus, the antenna can operate in a fundamental mode.

[0018] Optionally, when the antenna is working, the maximum current amplitude difference on the first radiator is less than a second value, the second value is the maximum current amplitude difference on the radiator when the dipole antenna is working, and the radiator length of the dipole antenna is the first value.

[0019] Optionally, the first radiator is in a long strip shape, and the straight line where the long side of the first radiator lies is parallel to the reference ground.

[0020] Optionally, the first radiator includes a first part, a second part and a third part connected in sequence, the first part and the third part are perpendicular to the reference ground, and the second part is arranged between the first part and the third part.

[0021] Optionally, the middle position of the first radiator also includes a grounding branch.

[0022] In the above examples, several different structural implementations of the radiator are provided. It is understandable that in any implementation, the electrical length of the radiator can be less than 1 / 2 of the operating wavelength.

[0023] Optionally, the first radiator is divided into at least two radiating units by at least one slot. Two ends of each radiating unit are respectively connected to two signal output ends of the differential mode feeding structure. The output ends of the differential mode feeding structure connected to the same side of any two radiating units have the same polarity.

[0024] Optionally, the size of the gap is within the range of [0.1 mm, 5 mm].

[0025] In this way, by dividing the radiator into multiple radiating units through the gap, the maximum current amplitude difference on each radiating unit can be further reduced, thereby improving the overall radiation performance of the antenna.

[0026] Optionally, at least one capacitor is connected in series with the first radiator. When multiple capacitors are connected in series with the first radiator, at least a portion of the first radiator is included between any two of the capacitors.

[0027] In this example, the energy storage properties of capacitors further reduce the maximum current amplitude difference on the radiator. It's understood that when multiple capacitors are connected in series on the first radiator, any two capacitors can be disconnected. For example, any two capacitors can be connected through a portion of the first radiator. This allows for better adjustment of the maximum current amplitude difference. The greater the number of capacitors, the better the corresponding effect.

[0028] In a second aspect, a terminal antenna is provided, which is used in an electronic device. The antenna includes a first radiator having a length of a first value corresponding to half the wavelength of the antenna's operating frequency. A first feeding point and a second feeding point are provided at each end of the first radiator, respectively. The first feeding point and the second feeding point are respectively connected to two signal output terminals of a differential mode feeding structure. The two signal output terminals have different polarities, and the two signals are equal-amplitude and opposite-phase signals.

[0029] Optionally, the feeding signal output by the differential mode feeding structure and then input to the first radiator has a high-impedance port characteristic, wherein the high-impedance port characteristic is achieved by connecting a capacitor in series.

[0030] This example provides a new feeding method, such as high-impedance differential mode feeding at both ends of the radiator. Based on this feeding method, it is also possible to excite the 0.5 wavelength mode of the dipole antenna.

[0031] In a third aspect, an electronic device is provided, wherein the electronic device is provided with a terminal antenna as provided in the first aspect and any one of its possible designs, or a terminal antenna as provided in the second aspect. When the electronic device transmits or receives a signal, the signal is transmitted or received via the terminal antenna.

[0032] It should be understood that the technical solutions provided in the second and third aspects above have technical features that correspond to the solutions provided in the first aspect and its possible designs, so the beneficial effects that can be achieved are similar and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG1 is a schematic diagram of an antenna link in an electronic device;

[0034] FIG2 is a schematic diagram of feeding a dipole antenna;

[0035] FIG3 is a schematic diagram of feeding a dipole antenna;

[0036] FIG4 is a schematic diagram of a terminal antenna solution provided in an embodiment of the present application;

[0037] FIG5 is a schematic diagram of eigenmode current distribution of a dipole antenna provided in an embodiment of the present application;

[0038] FIG6 is a schematic diagram of current amplitude distribution of a dipole antenna provided in an embodiment of the present application;

[0039] FIG7 is a schematic diagram of current amplitude distribution of a two-terminal differential-mode fed dipole antenna provided in an embodiment of the present application;

[0040] FIG8 is a matching diagram of a two-terminal differential-mode fed dipole antenna provided in an embodiment of the present application;

[0041] FIG9 is a schematic diagram of current amplitude differences of a dipole antenna provided in an embodiment of the present application;

[0042] FIG10 is a schematic diagram of current amplitude differences of an antenna with two-terminal differential-mode feeding provided by an embodiment of the present application;

[0043] FIG11 is a simulation diagram of an antenna solution provided in an embodiment of the present application;

[0044] FIG12 is a schematic diagram of an S11 simulation in an unmatched state provided by an embodiment of the present application;

[0045] FIG13 is a schematic diagram of an S-parameter simulation of a port in a high-impedance matching state provided by an embodiment of the present application;

[0046] FIG14 is a schematic diagram of a current distribution simulation in a high-impedance matching state of a port provided in an embodiment of the present application;

[0047] FIG15 is a schematic diagram of a magnetic field simulation in a high-impedance matching state of a port provided in an embodiment of the present application;

[0048] FIG16 is a schematic diagram of a directional pattern simulation in a high-impedance matching state of a port provided in an embodiment of the present application;

[0049] FIG17 is a simulation diagram of an antenna solution provided in an embodiment of the present application;

[0050] FIG18 is a schematic structural diagram of two terminal antennas provided in an embodiment of the present application;

[0051] FIG19 is a schematic structural diagram of a terminal antenna provided in an embodiment of the present application;

[0052] FIG20 is a schematic structural diagram of a terminal antenna provided in an embodiment of the present application;

[0053] FIG21 is a schematic structural diagram of a terminal antenna provided in an embodiment of the present application;

[0054] Figure 22 is a structural schematic diagram of a terminal antenna provided in an embodiment of the present application. DETAILED DESCRIPTION

[0055] Currently, most electronic devices can provide wireless communication capabilities.

[0056] As an example, referring to Figure 1 , assuming the electronic device is a mobile phone, the electronic device may be provided with at least one antenna connected to a feed source. Under the stimulation of the feed source, the antenna can radiate or receive electromagnetic waves, thereby enabling the electronic device to provide the aforementioned wireless communication function.

[0057] It is understood that the antennas provided in electronic devices may be of various types. However, these different antenna types can all be derived from several basic antennas, such as dipole antennas, monopole antennas, and slot antennas.

[0058] Antennas that radiate through a radiator, such as dipole and monopole antennas, are also called wire antennas. Similarly, antennas that radiate through a gap formed by a metal material, such as slot antennas, are also called slot antennas.

[0059] For example, Figure 2 illustrates an example of an excitation method for a dipole antenna. In this example, the dipole antenna's radiator may include radiator 21 and radiator 22, each having a size corresponding to a quarter wavelength of the operating frequency band. The long sides of radiators 21 and 22 may be arranged parallel, such as on the same straight line. Feed points may be provided at the adjacent ends of radiators 21 and 22.

[0060] In this example, by feeding the feeding points on the radiator 21 and the radiator 22 respectively through a differential mode (DM) feeding form of equal amplitude and opposite phase, the dipole antenna can be excited. For example, as shown in Figure 2, the differential mode feeding can include two feed sources, such as feed 23 and feed 24. The positive pole of one feed source (such as feed 23) in the differential mode feeding can be connected to the feeding point of a radiator (such as radiator 21). The negative pole of another feed source (such as feed 24) in the differential mode feeding can be connected to the feeding point of another radiator (such as radiator 22). The ends of the two feed sources away from the radiator are respectively coupled to the ground. In this way, when the antenna operates in the fundamental mode, a current distribution in the same direction can be formed on the radiator 21 and the radiator 22.

[0061] As shown in Figure 3, another conventional excitation method for a dipole antenna is provided. In this example, the dipole antenna's radiator can include radiator 21 and radiator 22, each with a size corresponding to a quarter wavelength of the operating frequency band. The long sides of radiators 21 and 22 can be arranged parallel, such as on the same straight line. Feed points can be provided at the adjacent ends of radiators 21 and 22.

[0062] In this example, the positive and negative electrodes of the feed source can be coupled to the feed points of radiator 21 and radiator 22, respectively. For example, the positive electrode of feed source 25 can be coupled to the feed point of radiator 21, and the negative electrode of feed source 25 can be coupled to the feed point of radiator 22. In this way, when the antenna operates in the fundamental mode, a current distribution similar to that in the antenna shown in Figure 2 can be formed on radiators 21 and 22 in the same direction.

[0063] In combination with the above description, the dipole antenna can be excited by the excitation method shown in Figure 2 or Figure 3. Therefore, when the dipole antenna or other antenna forms derived from the dipole antenna are set in an electronic device, it can operate in the fundamental mode (such as 1 / 2 wavelength mode) or higher-order mode (such as 1x wavelength mode, 3 / 2x wavelength mode, etc.) through the excitation method shown in Figure 2 or Figure 3, achieving coverage of the operating frequency band.

[0064] It's understandable that for a dipole antenna to function properly, the radiator length must be equal to half the wavelength of the operating frequency band. The smaller the operating frequency band, the longer the corresponding wavelength, and the higher the radiator length requirement.

[0065] Thus, new antenna forms are needed that provide better radiation performance and have smaller size.

[0066] To solve the above problems, the present invention provides a new terminal antenna. The antenna can have a radiator size smaller than 1 / 2 wavelength while providing good radiation performance.

[0067] As an example, Figure 4 is a schematic diagram of a terminal antenna provided in an embodiment of the present application. In this example, the antenna can adopt the form of differential mode feeding, feeding from both ends of the radiator to stimulate the operation of the antenna. In addition, the radiator of the antenna may include a radiator 31 having a size smaller than 1 / 2 wavelength of the operating frequency band. Among them, differential mode feeding can be interpreted as: simultaneously feeding equal-amplitude and anti-phase feeding signals into the two feeding points of the antenna to stimulate the antenna. In this example, the two feeding points of the antenna can be respectively set at the ends of the radiator 31.

[0068] The following describes in detail the implementation and effects of the terminal antenna solution provided in the embodiments of the present application in conjunction with the accompanying drawings.

[0069] The following first provides an exemplary description of the differential mode feeding scheme mechanism in the antenna scheme provided in the embodiment of the present application from the perspective of the antenna eigenmode.

[0070] It should be understood that any radiator of any form has corresponding eigenmode distributions in different wavelength modes. For example, the eigenmode distribution includes the eigenmode current distribution.

[0071] As an example, FIG5 shows a schematic diagram of the eigenmode current distribution of a dipole antenna, and the dipole antenna is shown in FIG2 or FIG3. In this example, the antenna radiator is taken as radiator 11, and the length corresponds to 1 / 2 wavelength of the working frequency band as an example. In the example of FIG5, the eigenmode current distribution of the dipole antenna in 1 / 2 wavelength mode (fundamental mode), 1 wavelength mode, 1.5 wavelength mode, and 2 wavelength mode are respectively given. Among them, the current amplitude schematic curve represents the current distribution on the radiator. As analyzed in the figure, the farther the curve is from the radiator, the larger the corresponding current amplitude and the larger the current. Conversely, the closer the current amplitude schematic curve is to the radiator, the smaller the corresponding current amplitude and the smaller the current.

[0072] As shown in Figure 5, in the 1 / 2 wavelength (i.e., half wavelength) mode, the antenna radiator may include two points with smaller current amplitudes (hereinafter referred to as the smaller current points) and one point with larger current amplitudes (hereinafter referred to as the larger current point). The larger current point may be located in the middle of the radiator, while the smaller current points may be located at both ends of the radiator.

[0073] In 1x wavelength mode, the antenna radiator can include three low current points and two high current points. The high current points are located in the middle of the left half and the right half of the radiator, respectively. The low current points can be located at both ends of the radiator and in the middle of the two high current points.

[0074] In 1.5x wavelength mode, the antenna radiator can include four low current points and three high current points. The low current points are located at both ends of the radiator. The low current points and high current points are distributed alternately on the radiator.

[0075] In the 2x wavelength mode, the antenna radiator can include five low current points and four high current points. The low current points are located at both ends of the radiator. The low current points and high current points are alternately distributed on the radiator.

[0076] Based on the characteristics of the eigenmode current distribution in the above different modes, in the 1 / 2M-times (i.e., 1 / 2 × M times, where M is an odd number) wavelength mode, the center of the radiator has the highest current. Correspondingly, in the N-times wavelength mode, the center of the radiator has the lowest current. N is a positive integer.

[0077] It should be noted that, in this application, the positional relationship between the high current point and the low current point does not determine the direction of the current flow. For example, in some cases, the current intensity can vary periodically, while the current flow direction can remain unchanged. In other cases, as the current intensity varies periodically, the current flow direction can also have an inversion point.

[0078] In combination with the eigenmode current distribution of the dipole antenna in different modes shown in FIG. 5 , corresponding feed sources can be set to achieve excitation of the corresponding modes.

[0079] For example, by connecting a low-resistance (e.g., less than 100 ohms) feed source at a point with high current corresponding to the eigenmode distribution, the corresponding wavelength mode can be excited on the radiator. For example, the low-resistance feed source can include a 50 ohm feed source or a 75 ohm feed source.

[0080] Specifically for each mode, take the fundamental mode (1 / 2 wavelength) as an example. The radiator 11 can be divided into two radiators of 1 / 4 wavelength size from the middle position, such as the radiator 21 and the radiator 22 in the aforementioned example. As shown in Figure 6, a single feed source (such as feed source 23) can be connected at the point where the current of the fundamental mode corresponding to the eigenmode is large (such as between the radiator 21 and the radiator 22), or a differential mode feed can be connected as shown in Figure 2, thereby exciting the dipole antenna to operate in the 1 / 2 wavelength mode. In this way, the dipole antenna can generate a resonance of the 1 / 2 wavelength mode corresponding to the electrical length of its radiator to cover the working frequency band. In this way, the dipole antenna solution shown in Figure 2 or Figure 3 can be obtained.

[0081] In an embodiment of the present application, based on the eigenmode current distribution of the dipole antenna as shown in FIG5 , a high-impedance (e.g., greater than 100 ohms) differential mode feed can be connected to two different current low points corresponding to the eigenmode distribution to achieve excitation of the corresponding mode. The high impedance can be an impedance state corresponding to an impedance matching condition close to an open circuit. For example, the high-impedance feed can include a 200 ohm feed or a 500 ohm feed.

[0082] For example, let's continue with the fundamental mode as an example. As shown in Figure 7, a high-resistance differential mode feed source can be connected to each of the points where the intrinsic mode current corresponding to the fundamental mode is small (such as the two ends of the radiator 11). The two differential mode feed sources can constitute a differential mode feeding structure for the radiator 11. In this way, by setting the differential mode feeding as shown in Figure 7, a current distribution with a large current in the middle and small currents on both sides can be excited on the radiator 11, which is the same as the intrinsic mode current distribution of the fundamental mode as shown in Figure 5. In other words, by setting the differential mode feeding as shown in Figure 7, the excitation of the 1 / 2 wavelength mode of the dipole antenna can be achieved.

[0083] It should be noted that in the embodiment of the present application, the high-impedance feed source may include any of the following two types:

[0084] 1. Signal source with high impedance port characteristics;

[0085] 2. By setting up a matching circuit between the low-impedance feed and the radiator, the port characteristics of the signal source emitted by the low-impedance feed are matched to a high-impedance state through the matching circuit. For example, components such as capacitors can be connected in series in the matching circuit to achieve adjustment to increase the port impedance.

[0086] For example, in conjunction with Figure 8, taking the example of obtaining a high-impedance feed source through a matching circuit, the setting of the high-impedance differential mode feeding in the embodiment of the present application is exemplified. In this example, the differential mode feeding structure may include a feed source 81 and a feed source 82 that output a feed signal of equal amplitude and opposite phase to the radiator. Matching circuits can be respectively set between the two feed sources and the radiator that respectively provide equal amplitude and opposite phase. For example, a matching circuit M1 is set between the feed source 81 and one end of the radiator 11. A matching circuit M2 is set between the feed source 82 and the other end of the radiator 11. Through the tuning of the matching circuit M1 and the matching circuit M2, the signals emitted by the feed source 81 and the feed source 82 have high-impedance port characteristics and are connected to the two ends of the radiator 11. In this way, the setting of high-impedance differential mode feeding at both ends of the radiator (such as the radiator 11) of the dipole antenna is realized.

[0087] It should be understood that Figures 7 and 8 above are merely schematic illustrations of excitation for the fundamental mode of a dipole antenna. For other higher-order modes, the high-impedance differential-mode feed provided in the embodiments of this application can also be used to effectively excite the corresponding mode's eigenmode current at its lowest point. The configuration described in Figures 7 and 8 above is omitted here.

[0088] This high-impedance differential-mode feeding mechanism differs from conventional feeding mechanisms, further diversifying existing antenna excitation methods. Other derivative antenna forms corresponding to dipole antennas can also refer to the high-impedance differential-mode feeding scheme provided in this application for low eigenmode current, allowing for flexible selection of feeding mechanisms. In the following examples, high-impedance differential-mode feeding is referred to as differential-mode feeding.

[0089] In the above example, the differential-mode feeding scheme mechanism provided in the embodiment of the present application is exemplified from the perspective of the antenna eigenmode. Based on this differential-mode feeding mechanism, the implementation of the antenna scheme with a smaller size (e.g., less than 1 / 2 wavelength) provided in the embodiment of the present application will be described below.

[0090] It can be understood that, in combination with the eigenmode current distribution shown in FIG5 , when the length of the radiator corresponds to 1 / 2 wavelength of the operating frequency band, currents of different intensities can be distributed on the radiator regardless of the operating mode.

[0091] 9 , which illustrates the distribution of current intensity on the radiator of a dipole antenna operating in fundamental mode (i.e., 1 / 2 wavelength mode), shows that the dipole antenna can be excited by differential mode feeds provided at both ends.

[0092] As shown in FIG9 , when the dipole antenna is working, the current amplitude at the middle position of the radiator 11 , whose length corresponds to 1 / 2 wavelength of the working frequency band, is the largest, and the current amplitude at both ends is the smallest.

[0093] Then, in this state, the maximum current amplitude difference distributed on the radiator 11 is the amplitude difference 91 shown in Figure 9. It can be understood that the larger the maximum current amplitude difference is, the more the energy distribution in the space near the radiator will tend to converge toward the middle position (such as the middle position in the area between the radiator 11 and the reference ground). This tendency of energy to converge in space is obviously not conducive to antenna radiation. For example, as energy converges in space, the dielectric loss in areas with higher energy density (such as the space near the middle position of the radiator 11) will increase significantly, thereby reducing the radiation performance of the antenna (such as radiation efficiency, system efficiency, etc.).

[0094] In the embodiment of the present application, the length of the radiator provided between the two feed sources of differential-mode feeding can be less than 1 / 2 wavelength, thereby reducing the maximum current amplitude difference distributed on the radiator. This prevents the aforementioned energy from converging toward the middle position between the radiator 11 and the reference ground, thereby improving the antenna radiation performance.

[0095] For example, in conjunction with Figure 10. In the antenna solution provided in the embodiment of the present application, the length of the antenna radiator can be less than 1 / 2 wavelength corresponding to the working frequency band. For example, the radiator can be the radiator 31 shown in Figure 10. The feed source is still set at both ends of the radiator 31. It should be understood that in the working state of the fundamental mode, no matter what the length of the radiator is, the current intensity distribution conforms to the characteristics of being large in the middle and small on both sides. Then, in this example, as the length of the radiator is less than 1 / 2 wavelength of the working frequency band, the corresponding current amplitude schematic curve will also move downward on the basis of the example shown in Figure 9. Alternatively, the current amplitude schematic curve shown in Figure 10 corresponds to the middle part of the curve shown in Figure 9. Therefore, in the example as shown in Figure 10, the maximum current amplitude difference of the distributed current on the effective radiation area is reduced from the maximum current amplitude difference 91 to the maximum current amplitude difference 92, wherein the maximum current amplitude difference 91 is the maximum current amplitude difference of the distributed current on the effective radiation area of ​​the radiator 11 whose length corresponds to 1 / 2 wavelength of the working frequency band when the dipole antenna is working; the maximum current amplitude difference 92 is the maximum current amplitude difference of the distributed current on the effective radiation area of ​​the radiator 11 whose length is less than 1 / 2 wavelength of the working frequency band.

[0096] That is, in the example of FIG10 , as the amplitude difference of the current intensity on the radiator decreases, the energy distribution in the space near the radiator becomes more dispersed, thereby effectively improving the radiation performance of the antenna.

[0097] Figures 9 and 10 above illustrate the implementation mechanism of the antenna solution provided in the embodiments of the present application from the perspective of current intensity. In the example shown in Figure 10, the length of the radiator 31 is less than 1 / 2 of the operating wavelength. It is understood that as the radiator length decreases, the corresponding maximum current amplitude difference also decreases. For example, when the radiator length is less than or equal to 1 / 4 of the operating wavelength, or when the radiator length is less than or equal to 1 / 8 of the operating wavelength, the maximum current amplitude difference on the radiator can be less than a preset amplitude threshold. Therefore, it can also be roughly assumed that when the radiator length is less than or equal to 1 / 4, the current on the radiator tends to be uniform, and the corresponding radiation performance is also better. It is understood that when the current on the radiator tends to be uniform, the energy distribution in the space near the radiator (such as between the radiator and the reference) is more uniform, thereby avoiding the situation where large losses caused by energy concentration occur. In other words, in the embodiments of the present application, the smaller maximum current amplitude difference corresponds to the more uniform current on the radiator, which can improve the radiation performance of the antenna.

[0098] The following will illustrate the working conditions of the antenna solution with a radiator size less than 1 / 2 wavelength and differential mode high-impedance feeding provided in the embodiment of the present application in combination with specific simulation diagrams.

[0099] 11 is a schematic diagram of a simulation model of an antenna solution provided in an embodiment of the present application. In this example, the antenna may include a radiator 31, the length of which may be less than 1 / 2 wavelength of the operating frequency band.

[0100] For example, if the operating frequency band is higher than 700 MHz (e.g., 800 MHz), the dielectric constant (DK) of the antenna material is 3.2, and the dielectric loss factor (DF) of the antenna material is 0.01, the radiator size corresponding to 1 / 2 wavelength can be close to 120 mm. The length of the radiator 31 can be less than 120 mm. For example, the length of the radiator 31 can be equivalent to 1 / 4 wavelength of the operating frequency band, such as 60 mm.

[0101] As shown in Figure 11, feed sources 1301 and 1302 may be provided at both ends of the radiator 31, respectively. Feed sources 1301 and 1302 may form a differential mode feed structure. For example, the positive electrode of feed source 1301 may be coupled to one end of the radiator 31, and the negative electrode of feed source 1301 may be grounded. The negative electrode of feed source 1302 may be coupled to the other end of the radiator 31, and the positive electrode of feed source 1302 may be grounded.

[0102] It should be noted that, in conjunction with the above description of high-impedance differential mode feeding, in some embodiments of the present application, corresponding matching circuits (not shown in FIG. 11 ) may be provided between the positive electrode of the feed source 1301 and the radiator 31, and between the negative electrode of the feed source 1302 and the radiator 31. By tuning the matching circuits, the feed sources 1301 and 1302 can transmit a feed signal having a high-impedance port characteristic to the radiator 31.

[0103] In different scenarios, the devices in the matching circuit for providing high-impedance port characteristics may be different, thereby enabling the resonance position excited on the radiator 31 to correspond to and cover the operating frequency bands in different scenarios.

[0104] As an example, FIG12 shows a schematic diagram of S11 generated when the antenna shown in FIG11 is excited by a differential mode feeding structure in the case where no matching is performed.

[0105] Figure 13 illustrates the effects of high-impedance port matching. As shown in Figure 13, this port matching allows the antenna's excitation resonance to be tuned to cover 800 MHz. As shown in the efficiency simulation in Figure 13, the antenna's radiation efficiency peaks at over -0.5 dB near 800 MHz, and the system efficiency peak also exceeds -0.5 dB.

[0106] FIG14 shows a schematic diagram of the current simulation on the radiator and the surrounding floor when the antenna is working. The direction of the arrow is used to indicate the current flow direction at the current moment, and the deeper the arrow, the larger the current amplitude. It can be seen that the differential mode feeding provided in the embodiment of the present application can effectively excite the same-phase current on the radiator. There is no significant change in the current intensity on the radiator, which corresponds to the aforementioned description that the maximum current amplitude difference on the radiator is reduced. FIG15 shows a schematic diagram of the magnetic field simulation on the radiator and the surrounding floor when the antenna is working. The direction of the arrow is used to indicate the direction of the magnetic flux lines at the current moment, and the deeper the arrow, the larger the magnetic field intensity. It can be seen that the differential mode feeding provided in the embodiment of the present application can excite magnetic fields of similar intensity in the space around the radiator (such as in the area between the radiator and the reference ground) for radiation, thereby reducing the maximum magnetic field amplitude difference corresponding to the maximum current amplitude difference on the radiator.

[0107] Therefore, based on the simulations performed from the perspectives of current and magnetic field, respectively, as shown in Figures 14 and 15, it can be shown that the antenna solution provided in the embodiment of the present application can achieve energy excitation with small amplitude differences in the space near the antenna radiator by connecting differential mode feeding at both ends of the radiator (such as radiator 31), thereby achieving the effect of improving radiation performance. In addition, Figure 16 also shows a schematic diagram of the directional pattern simulation of the antenna solution provided in the embodiment of the present application when operating at 800 MHz.

[0108] In the description of Figures 11 to 16 above, the example of the radiator length being equivalent to 1 / 4 of the working wavelength is taken. As shown in Figure 17, an example of a simulation model is shown in which the radiator length is 30 mm, which is equivalent to 1 / 8 of the working wavelength. It can be understood that in this example, the radiator length is further reduced, the corresponding maximum current amplitude difference is smaller, the current distribution on the radiator is more uniform, and the radiation performance is also better. In the specific implementation process, as the radiator length decreases, the resonant bandwidth may deteriorate slightly due to the reduction in the area of ​​the radiation medium. Therefore, in the specific implementation process, the radiator length can be flexibly selected according to the required radiation performance and bandwidth requirements. In some implementations, multiple antenna schemes with shorter lengths as described in Figure 17 can also be set to achieve coverage of the same frequency band, thereby improving the overall coverage bandwidth.

[0109] Based on the description of Figures 10 to 17, those skilled in the art should be able to have a detailed understanding of the working mechanism and effect of the antenna solution provided in the embodiment of the present application (such as the antenna solution shown in Figure 4).

[0110] The embodiments of the present application also provide several examples of antenna forms that are different from the structure shown in FIG. 4 .

[0111] For example, please refer to Figure 18, which shows several further implementations of terminal antennas provided in embodiments of the present application. Each implementation provided in this example has similar structural features to the antenna shown in Figure 4: the radiator length is less than 1 / 2 wavelength of the operating frequency band, and two differential-mode feed sources are coupled to each end of the radiator. The two differential-mode feed sources can be connected to the radiator through high impedance to feed the antenna.

[0112] As shown by 1910 in Figure 18 , the antenna radiator in this example may include radiator 1911. Radiator 1911 may include a first portion parallel to (or nearly parallel to) the floor. The electrical length of this first portion may be less than half the wavelength of the operating frequency band. A branch 1912 may be provided at the center of the first portion, i.e., the point where the fundamental mode current is maximum, as the second portion of radiator 1911. One end of this second portion is connected to the center of the first portion, and the other end of the second portion is grounded. Two feed sources for high-impedance differential mode feeding are provided at each end of the first portion.

[0113] 1920 in FIG18 shows a schematic diagram of the structure of another antenna. In this example, the antenna radiator may include a radiator 1921. The electrical length of the radiator 1921 may be less than 1 / 2 wavelength of the operating frequency band. Two symmetrical L-shaped bending structures may be provided on the radiator 1921. The two L-shaped bending structures divide the radiator 1921 into a first part parallel to (or approximately parallel to) the floor, a second part perpendicular to (or approximately perpendicular to) the floor, and a third part. The first part is located between the second part and the third part, and is connected end to end. One end of the radiator 1921 on the second part and the other end on the third part are on the same side of the first part. High-impedance differential mode feed is fed into both ends of the radiator 1921 for excitation.

[0114] It is understood that the two structures shown in FIG18 are merely examples, and the antenna solutions provided in the embodiments of the present application may also have other variations. Among the various variations, antenna forms in which the electrical length of the radiator is less than 1 / 2 wavelength of the operating frequency band and high-impedance differential mode feeds are connected at both ends should be included in the scope of the technical solutions provided in the embodiments of the present application.

[0115] In this way, by setting up an antenna with a size smaller than 1 / 2 wavelength of the working frequency band and high-impedance differential mode feeding at both ends, an energy distribution with a smaller maximum amplitude difference can be obtained between the antenna radiator and the floor, thereby obtaining better radiation performance.

[0116] It should be noted that in some implementations, the high-impedance differential-mode feed can also be set on the radiator, rather than all on the end face of the radiator. In this way, the above technical effects can be achieved between the radiator and the reference ground between the high-impedance differential-mode feed.

[0117] In other embodiments of the present application, based on the antenna structure shown in FIG. 4 or FIG. 18 , further optimization design may be performed to obtain better radiation performance.

[0118] Exemplarily, in some embodiments, taking the antenna structure shown in FIG4 as an example, the radiator 31 can be split into multiple radiating units (such as greater than or equal to 2 radiating units). The radiators of the multiple radiating units are arranged in parallel, for example, the long sides of the radiators of the multiple radiating units are arranged on the same straight line. Any two adjacent radiating units of the multiple radiating units are separated by a gap. The size of the gap can be [0.1mm-5mm]. Both ends of each radiating unit are respectively connected to the high-impedance differential mode feed in the aforementioned embodiment. Corresponding to the radiator 31, the total length of the multiple radiating units is less than 1 / 2 wavelength of the working frequency band.

[0119] As an example, consider splitting radiator 31 into four radiating elements. Referring to FIG19 , a schematic diagram of another antenna solution provided in an embodiment of the present application is shown. In this example, the radiating elements may include radiator 2001, radiator 2002, radiator 2003, and radiator 2004. The long sides of radiators 2001, radiator 2002, radiator 2003, and radiator 2004 are arranged on the same straight line, and their total length is less than 1 / 2 wavelength of the operating frequency band. As shown in FIG19 , the left ends of radiators 2001, radiator 2002, radiator 2003, and radiator 2004 are each coupled to one of the differential mode feed sources. Correspondingly, the right ends of radiators 2001, radiator 2002, radiator 2003, and radiator 2004 are each coupled to another of the differential mode feed sources. This achieves differential mode feeding for each radiating element. In a specific implementation, a matching circuit can be set on the link between each radiating unit and the feed source to achieve high-impedance port characteristic matching of the feed signal.

[0120] It can be understood that, in conjunction with the principle description of Figure 10, after the radiator 31 is split into multiple radiating units, by connecting each radiating unit to a high-impedance differential mode feed, a smaller maximum current amplitude difference is obtained on each radiating unit compared to the radiator 31. Therefore, when the antenna solution composed of multiple radiating units is in operation, the maximum current amplitude difference on the radiator is smaller, which can achieve a more significant improvement in radiation performance. Based on this description, the greater the number of radiating units obtained by splitting, the more significant the corresponding improvement effect.

[0121] The above examples illustrate differential-mode feeding using two feed sources. It will be appreciated that, in other embodiments, the technical solutions provided by the embodiments of the present application can also be implemented using a single feed source in combination with a component having a phase inversion function. For example, the antenna structure shown in FIG. 19 is used as an example. Please refer to FIG. 20 for a schematic diagram of the composition of another antenna provided by the embodiments of the present application. In this example, the example of splitting radiator 31 into four radiating elements is continued. As shown in FIG. 20 , this antenna solution can include a single feed source. For example, the feed source can be a high-impedance feed source. One end of the feed source can be grounded, and the other end can be coupled to the same end of radiators 2001 and 2004. For example, the positive electrode of the feed source can be coupled to the right ends of radiators 2001 and 2004, respectively. The positive electrode of the feed source can also be coupled to the left ends of radiators 2001 and 2004, respectively, through a 180° phase inverter. In this way, each radiating element can be fed with a differential-mode signal of equal amplitude and opposite phase at both ends. Similar to the solution illustrated in Figure 19, the antenna solution illustrated in Figure 20 has a smaller maximum current amplitude difference on the radiator, which can achieve a more significant improvement in radiation performance. Based on this description, the greater the number of radiating elements obtained by splitting, the greater the corresponding improvement effect.

[0122] 19 and 20 , by designing multiple differential-mode fed radiating units, a current distribution with a smaller maximum current amplitude difference can be obtained on the radiator, thereby improving the antenna radiation performance.

[0123] In other embodiments of the present application, the above-mentioned purpose can also be achieved through other means.

[0124] For example, please refer to FIG21 , which is a schematic diagram of another antenna solution provided in an embodiment of the present application, wherein a modification is made to the antenna solution shown in FIG4 .

[0125] As shown in Figure 21, in this antenna solution, the antenna radiator can be radiator 31, whose electrical length is less than half the wavelength of the operating frequency band. High-impedance differential-mode feeds can be connected to both ends of radiator 31. In this example, at least one capacitor can be connected in series with radiator 31. For example, in the example of Figure 21, series capacitor 2201 is used as an example. This creates a current distribution on radiator 31 with a smaller maximum current amplitude difference.

[0126] It is understood that capacitor 2201 can have energy storage characteristics. Under the excitation of differential-mode feeding, the current generated on radiator 31 can charge capacitor 2201. Therefore, when the phase of the feed signal changes over time, due to the presence of capacitor 2201, the current change near capacitor 2201 on radiator 31 will be significantly delayed compared to the change in the feed signal. For example, when the current at the feed source increases, the current near capacitor 2201 does not decrease; for another example, when the current at the feed source decreases, the current near capacitor 2201 does not increase. This makes the current amplitude distribution on the entire radiator 31 no longer follow the characteristic of large in the middle and small on both sides as shown in Figure 10. After adding capacitor 2201, the current amplitude distribution on radiator 31 is more regionally balanced. That is, the current amplitude at both ends of radiator 31 increases relatively, while the current amplitude near the location of capacitor 2201 on radiator 31 decreases relatively. This further reduces the current amplitude difference on radiator 31, and thus obtains a current distribution with a smaller maximum current amplitude difference. Corresponding to the magnetic field, a magnetic field distribution with a smaller maximum magnetic field amplitude difference can be obtained between the radiator 31 and the reference ground, thereby achieving better radiation performance based on the antenna solution shown in FIG4 .

[0127] It can be understood that the more capacitors are provided on the radiator 31, the smaller the current amplitude difference on the radiator 31, and the higher the radiation performance of the corresponding antenna. For example, as shown in Figure 22, two capacitors (such as capacitor 2201 and capacitor 2202) are connected in series on the radiator 31 as an example. The capacitor 2201 and the capacitor 2202 can divide the radiator 31 into three parts. The three parts are connected sequentially via the capacitor 2201 and the capacitor 2202. Thus, the maximum current amplitude difference is adjusted by the capacitor 2202 and the capacitor 2201 at the corresponding positions on the radiator, thereby obtaining a smaller maximum current amplitude difference as a whole.

[0128] Although the present application has been described with reference to specific features and embodiments thereof, it is apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the present application. Accordingly, this specification and the drawings are merely illustrative of the present application as defined by the appended claims and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the present application. Obviously, those skilled in the art may make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, the present application is intended to include such modifications and variations as fall within the scope of the claims of the present application and their equivalents.

Claims

1. A terminal antenna, characterized in that: The antenna is used in electronic equipment; The antenna includes a first radiator, the length of the first radiator is less than a first value, and the first value corresponds to 1 / 2 wavelength of the antenna operating frequency; A first feeding point and a second feeding point are respectively provided at both ends of the first radiator. The first feeding point and the second feeding point are respectively connected to two signal output ends of the differential mode feeding structure. The two signal output ends have different polarities, and the two signals are equal-amplitude and anti-phase signals.

2. The antenna according to claim 1, wherein The length of the first radiator is less than or equal to 1 / 4 wavelength of the operating frequency.

3. The antenna according to claim 1 or 2, characterized in that The length of the first radiator is less than or equal to 1 / 8 wavelength of the operating frequency.

4. The antenna according to any one of claims 1 to 3, characterized in that The differential mode feeding structure includes: a first feed source and a second feed source, The first pole of the first feed source is coupled to the first feed point, and the second pole of the second feed source is coupled to the second feed point; Wherein, the first electrode is a positive electrode and the second electrode is a negative electrode; or, the first electrode is a negative electrode and the second electrode is a positive electrode.

5. The antenna according to any one of claims 1 to 4, characterized in that The differential mode feeding structure includes a third feed source, The first pole of the third feed source is coupled to the first feeding point, and the first pole of the third feed source is coupled to the second feeding point via an inverting component, and the inverting component is used to provide a 180-degree inverting function.

6. The antenna according to any one of claims 1 to 5, characterized in that The feeding signal output by the differential mode feeding structure and then input to the first radiator has a high-impedance port characteristic; wherein the high-impedance port characteristic is achieved by a series capacitor.

7. The antenna according to claim 6, characterized in that A matching circuit is provided between the differential-mode feeding structure and the first radiator, and the matching circuit is used to adjust the feeding signal output by the differential-mode feeding structure to a high-impedance port characteristic.

8. The antenna according to any one of claims 1 to 7, characterized in that When the antenna is working, the antenna works in a 0.5 times wavelength mode.

9. The antenna according to any one of claims 1 to 8, characterized in that When the antenna is working, the maximum current amplitude difference on the first radiator is less than a second value, the second value is the maximum current amplitude difference on the radiator when the dipole antenna is working, and the radiator length of the dipole antenna is the first value.

10. The antenna according to any one of claims 1 to 9, characterized in that The first radiator is in a long strip shape, and the straight line where the long side of the first radiator lies is parallel to the reference ground.

11. The antenna according to any one of claims 1 to 9, characterized in that: The first radiator includes a first part, a second part and a third part connected in sequence, The first portion is perpendicular to the reference ground and the third portion is perpendicular to the reference ground, and the second portion is disposed between the first portion and the third portion.

12. The antenna according to claim 10 or 11, characterized in that: The middle position of the first radiator also includes a grounding branch.

13. The antenna according to any one of claims 1 to 12, characterized in that: The first radiator is divided into at least two radiating units by at least one gap; two ends of each radiating unit are respectively connected to two signal output ends of the differential mode feeding structure; The output terminals of the differential mode feeding structure connected to the same side of any two radiating elements have the same polarity.

14. The antenna according to claim 13, wherein: The size of the gap is included in the range of [0.1mm, 5mm].

15. The antenna according to any one of claims 1 to 14, characterized in that At least one capacitor is connected in series with the first radiator; When a plurality of capacitors are connected in series to the first radiator, at least a portion of the first radiator is included between any two of the capacitors.

16. A terminal antenna, characterized in that: The antenna is used in electronic equipment; The antenna includes a first radiator, the length of the first radiator is a first value, and the first value corresponds to 1 / 2 wavelength of the antenna operating frequency; A first feeding point and a second feeding point are respectively provided at both ends of the first radiator. The first feeding point and the second feeding point are respectively connected to two signal output ends of the differential mode feeding structure. The two signal output ends have different polarities, and the two signals are equal-amplitude and anti-phase signals.

17. The antenna according to claim 16, wherein: The feeding signal output by the differential mode feeding structure and then input to the first radiator has a high-impedance port characteristic; wherein the high-impedance port characteristic is achieved by a series capacitor.

18. An electronic device, characterized in that: The electronic device is provided with a terminal antenna as described in any one of claims 1 to 15, or a terminal antenna as described in claim 16 or 17; when the electronic device transmits or receives a signal, the signal is transmitted or received through the terminal antenna.

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