Patent Description:
This disclosure generally relates to the field of terminal technologies, and the invention in particular relates to an antenna apparatus and an electronic device.

With development of information technologies, wireless performance of terminal products has been drawing more and more attention, and the wireless performance of an antenna directly affects actual user experience. However, after entering an era of <NUM>, an existing terminal mobile phone has developed towards a full screen and multi-antenna trend. As a result, a size of a radiator of the antenna becomes increasingly large, a radiation environment deteriorates, and antenna performance also becomes worse. In a plurality of frequency bands of the antenna, based on a relationship between a frequency band and wavelength resonance, the lower the frequency is, the longer the required radiator is, and the higher the space requirement is. Therefore, if a screen is a full screen, how to improve the antenna performance, especially low-frequency antenna performance, in a limited space environment and a radiator length, has become an important problem in research and design of a terminal antenna.

In an example in which an electronic device is a mobile phone, in a conventional technology, different antenna structures are generally designed at different spatial positions on the mobile phone. Specifically, different resonant antennas may be arranged at different positions in the mobile phone space to meet antenna requirements in different scenarios based on actual scenario requirements. In this way, if one of the antennas is blocked, an antenna distributed in another spatial position can be selected to operate, thereby satisfying a requirement of the terminal product for the antenna performance.

However, available space in the mobile phone is limited, and the antenna structure in the foregoing solution occupies an excessive design area in the mobile phone. This is unfavorable to a layout of another component in the mobile phone. Therefore, how to meet the requirement of the antenna performance in small space has become an important problem in research and design of an antenna.

<CIT> addresses the problem of a significant attenuation of antenna signals when a mobile terminal, such as a smartphone or tablet, is held in a user's hand (referred to as the "head-hand mode"), which affects the call quality and communication efficiency of the device. This issue is particularly important given how most current mobile terminals are designed with internal antennas used for external communication, and how user interaction can interfere with these antennas' performance. To solve this problem, it is here proposed to employ an antenna design specifically aimed at maintaining relatively good signal sending and receiving performance even when the device is operated in head-hand mode. The solution involves an antenna configuration that includes a feed stub, a parasitic stub, a feed branch, a grounding branch, and a grounding portion, all structured within the mobile terminal.

<CIT> addresses the challenge of designing high-performance Multiple-Input Multiple-Output (MIMO) mobile terminal antennas in a compact space while ensuring good isolation between the antennas. This issue is crucial due to the growing demand for larger channel transmission capacity and faster information transmission rates in wireless communication technologies. Traditional antenna designs and MIMO technologies face challenges such as mutual coupling between closely spaced antennas, which can degrade system performance. This problem is here solved by providing a dual-port mobile terminal antenna with self-decoupling characteristics. This antenna design allows two feeding ports to excite a single radiator simultaneously without the need for any additional decoupling structures, even when the ports are extremely close together. This design achieves good port isolation which is essential for effective MIMO communication.

<CIT> addresses the challenge of miniaturization and complexity in the design of mobile communication device antennas that need to operate across multiple frequency bands (e.g., <NUM>/<NUM>/<NUM>) covering low-frequency bands (around <NUM>~<NUM>) and high-frequency bands (around <NUM>~<NUM>). Typically, the resonance path of the low-frequency band and the resonance path of the high-frequency band overlap or have high coupling. This configuration makes the antenna's high-frequency band very susceptible to influence when adjusting its low-frequency band, and vice versa, which complicates the antenna component design and limits its miniaturization. Here, a solution to this problem is presented by using a communication device with a combined dual-bandwidth antenna element that addresses the issue of overlapping resonance paths and high coupling between the antenna's low- and high-frequency bands. This is achieved by separating the resonance paths, using dual-bandwidth operation with independent structures, inductor elements, and using specific design features for miniaturization such as special dimensions of metal parts and the placement of components in a clear space, which together contribute to the antenna's small size and effective operation in both frequency bands without mutual interference.

The object of the present invention is to provide an antenna apparatus and electronic device, to improve radiation efficiency of an antenna without occupying too much design space in a mobile phone and without affecting a resonance curve of an existing antenna, so as to improve actual user experience. This object is solved by the attached independent claims and further embodiments and improvements of the invention are listed in the attached dependent claims. Hereinafter, up to the "brief description of the drawings", expressions like ". aspect according to the invention", "according to the invention", or "the present invention", relate to technical teaching of the broadest embodiment as claimed with the independent claims. Expressions like "implementation", "design", "optionally", "preferably", "scenario", "aspect" or similar relate to further embodiments as claimed, and expressions like "example", ". aspect according to an example", "the disclosure describes", or "the disclosure" describe technical teaching which relates to the understanding of the invention or its embodiments, which, however, is not claimed as such.

A first aspect of the invention provides an antenna apparatus. The antenna apparatus is applied to an electronic device, and the antenna apparatus includes: at least one radiation unit, at least one feed unit, and at least one non-resonant unit, where the feed unit directly feeds the radiation unit and the non-resonant unit separately; and a size of the non-resonant unit is less than <NUM>/8λ, and λ is a wavelength corresponding to a resonance frequency of the radiation unit.

According to the antenna apparatus of the invention, the antenna apparatus is provided with the non-resonant unit and the feed unit, to respectively feed the radiation unit and the non-resonant unit. Through feeding power distribution design, the non-resonant unit can assist in exciting a floor characteristic mode. In addition, since the size of the non-resonant unit is much smaller than an electrical length required for resonance of an antenna on this frequency band, the non-resonant unit does not generate a resonance curve on a resonance curve and has no resonance point, to improve radiation efficiency of the antenna without generating new resonance, so as to improve a use effect of a user.

According to the invention, a feed point and a ground point of the feed unit are respectively electrically connected to the non-resonant unit and a metal middle plate used as a floor in the electronic device. Through a power distribution of a feed connection, the feed point of the feed unit is connected to the non-resonant unit, and the ground point of the feed unit is connected to the floor (that is, the metal middle plate), to assist in exciting a floor characteristic mode.

According to the invention, the non-resonant unit is configured to assist in exciting a floor characteristic mode; and when the radiation unit is a low-frequency radiation unit, the non-resonant unit assists in exciting a floor longitudinal characteristic mode; or when the radiation unit is a medium-high frequency radiation unit, the non-resonant unit assists in exciting a floor transverse characteristic mode. A current flow direction of the low-frequency radiation unit is in a longitudinal mode, and a current flow direction of the medium-high frequency radiation unit is in a transverse mode, so that high antenna efficiency at a corresponding frequency can be obtained by exciting a required floor characteristic mode. That is, for the low-frequency radiation unit, high radiation efficiency can be obtained by sufficiently exciting the floor longitudinal mode; and for the medium-high frequency radiation unit, high radiation efficiency can also be obtained by sufficiently exciting the transverse mode.

According to the invention, an orthographic projection that is of the non-resonant unit and that is in a first direction is located in the metal middle plate; and the first direction is the direction perpendicular to a plane in which the metal middle plate is located. Through a power distribution of a feed connection, the feed unit is connected to each of the non-resonant unit and a floor (that is, the metal middle plate) below the non-resonant unit, thereby assisting in exciting the floor characteristic mode.

In a possible implementation, the feed unit is electrically connected to each of the non-resonant unit and the metal middle plate by using a feed line. Through a line power distribution of the feed line for the feed connection, the feed unit is connected to each of the non-resonant unit and a floor (that is, the metal middle plate) below the non-resonant unit through the feed line, thereby assisting in exciting the floor characteristic mode.

In a possible implementation, each feed line includes a main feed line and a sub-feed line, the main feed line and the sub-feed line each include a signal line and a ground line, a signal line at a first end of the main feed line is electrically connected to the feed unit, and a signal line at a second end of the main feed line is electrically connected to the radiation unit; and the ground line of the main feed line is grounded; and a signal line and a ground line at a first end of the sub-feed line are electrically connected to the signal line and the ground line of the main feed line, and a signal line and a ground line at a second end of the sub-feed line are electrically connected to the non-resonant unit and the metal middle plate respectively.

In this way, the feed unit can separately feed the radiation unit and the non-resonant unit, and efficiency of the antenna can be effectively improved through a power distribution at a feed location and a connection to the non-resonant unit and the floor (that is, the metal middle plate) at the non-resonant unit.

In a possible implementation, the sub-feed line is a coaxial line and includes an outer conductor and an inner conductor; the outer conductor is wrapped outside the inner conductor, the inner conductor is the signal line, and the outer conductor is the ground line; and one end of the inner conductor is electrically connected to the signal line of the main feed line, and the other end of the inner conductor is electrically connected to the non-resonant unit; and one end of the outer conductor is electrically connected to the ground line of the main feed line, and the other end of the outer conductor is electrically connected to the metal middle plate.

The inner conductor of the sub-feed line is electrically connected to the non-resonant unit, and the outer conductor of the sub-feed line is electrically connected to the floor (that is, the metal middle plate) at the non-resonant unit, so that while assisting in exciting the floor characteristic mode, the metal middle plate connected to the outer conductor can provide a specific shielding effect for the non-resonant unit connected to the inner conductor.

In a possible implementation, the main feed line is a microstrip line including a first conductor and a second conductor, the first conductor is the signal line, the second conductor is the ground line, and the first conductor is separated from the second conductor. In this way, transmission of a power supply signal and a ground signal between the feed unit and the radiation unit can be ensured.

In a possible implementation, a quantity of non-resonant units is one; a quantity of feed lines is at least two; the at least one feed unit includes a first feed unit and a second feed unit; and a feed point and a ground point of the first feed unit are respectively electrically connected to the non-resonant unit and the metal middle plate by using a first feed line of the at least two feed lines, and a feed point and a ground point of the second feed unit are respectively electrically connected to the non-resonant unit and the metal middle plate by using a second feed line of the at least two feed lines.

In a possible implementation, the at least one radiation unit includes a first radiation unit and a second radiation unit; the signal line at the first end of the main feed line of the first feed line is electrically connected to the first feed unit, and the signal line at the second end of the main feed line of the first feed line is electrically connected to the first radiation unit; the ground line of the main feed line of the first feed line is grounded; and the signal line and the ground line at the first end of the sub-feed line of the first feed line are electrically connected to the signal line and the ground line of the main feed line of the first feed line, and the signal line and the ground line at the second end of the sub-feed line of the first feed line are electrically connected to the non-resonant unit and the metal middle plate respectively; and
the signal line at the first end of the main feed line of the second feed line is electrically connected to the second feed unit, and the signal line at the second end of the main feed line of the second feed line is electrically connected to the second radiation unit; the ground line of the main feed line of the second feed line is grounded; and the signal line and the ground line at the first end of the sub-feed line of the second feed line are electrically connected to the signal line and the ground line of the main feed line of the second feed line, and the signal line and the ground line at the second end of the sub-feed line of the second feed line are electrically connected to the non-resonant unit and the metal middle plate respectively.

In this way, the first feed unit is connected to the first radiation unit, the non-resonant unit, and the floor below the non-resonant unit (that is, the metal middle plate) by using the first feed line, the second feed unit is connected to the second radiation unit, the non-resonant unit, and the floor below the non-resonant unit (that is, the metal middle plate) by using the second feed line. That is, through a line power distribution, the first feed unit feeds the first radiation unit and the non-resonant unit by using the first feed line, and the second feed unit feeds the second radiation unit and the non-resonant unit by using the second feed line, so that the non-resonant unit can assist the first radiation unit and the second radiation unit in exciting the floor characteristic mode.

In a possible implementation, a quantity of non-resonant units is two; the at least one non-resonant unit includes a first non-resonant unit and a second non-resonant unit; a quantity of feed lines is at least two; the at least one feed unit includes a first feed unit and a second feed unit; and the first feed unit is electrically connected to each of the first non-resonant unit and the metal middle plate by using a first feed line of the at least two feed lines, and the second feed unit is electrically connected to each of the second non-resonant unit and the metal middle plate by using a second feed line of the at least two feed lines.

In a possible implementation, the at least one radiation unit includes a first radiation unit and a second radiation unit; the signal line at the first end of the main feed line of the first feed line is electrically connected to the first feed unit, and the signal line at the second end of the main feed line of the first feed line is electrically connected to the first radiation unit; the ground line of the main feed line of the first feed line is grounded; and the signal line and the ground line at the first end of the sub-feed line of the first feed line are electrically connected to the signal line and the ground line of the main feed line of the first feed line, and the signal line and the ground line at the second end of the sub-feed line of the first feed line are electrically connected to the first non-resonant unit and the metal middle plate respectively; and
the signal line at the first end of the main feed line of the second feed line is electrically connected to the second feed unit, and a signal line at a second end of the main feed line of the second feed line is electrically connected to the second radiation unit; the ground line of the main feed line of the second feed line is grounded; and the signal line and the ground line at the first end of the sub-feed line of the second feed line are electrically connected to the signal line and the ground line of the main feed line of the second feed line, and the signal line and the ground line at the second end of the sub-feed line of the second feed line are electrically connected to the second non-resonant unit and the metal middle plate respectively.

In this way, the first feed unit is connected to the first radiation unit, the first non-resonant unit, and the floor below the first non-resonant unit (that is, the metal middle plate) by using the first feed line, the second feed unit is connected to the second radiation unit, the second non-resonant unit, and the floor below the second non-resonant unit (that is, the metal middle plate) by using the second feed line. That is, through a line power distribution, the first feed unit feeds the first radiation unit and the first non-resonant unit by using the first feed line, and the second feed unit feeds the second radiation unit and the second non-resonant unit by using the second feed line, so that the first non-resonant unit can assist the first radiation unit in exciting the floor characteristic mode, and the second non-resonant unit can assist the second radiation unit in exciting the floor characteristic mode.

In a possible implementation, the first radiation unit is a low frequency radiation unit, and the second radiation unit is a medium-high frequency radiation unit.

In a possible implementation, the sub-feed line is provided with a switch for selecting to turn on the non-resonant unit on the sub-feed line. The switch can control the main feed line and the non-resonant unit to be connected or disconnected, thereby ensuring flexible use. For example, if the non-resonant unit is not required to assist in exciting the floor characteristic mode, the switch can be turned on; or if the non-resonant unit is required to assist in exciting the floor characteristic mode, the switch can be turned off.

In a possible implementation, the radiation unit is a metal border frame antenna, and the non-resonant unit is disposed close to the metal border frame antenna. The non-resonant unit is disposed close to the metal border frame antenna, so that a length of the feed line can be reduced to some extent, thereby reducing costs and improving reliability.

A second aspect of the invention further provides an electronic device, where the electronic device includes at least a display, a rear housing, and a middle frame between the display and the rear housing, and further includes any one of the antenna apparatus.

According to the electronic device according to the invention, the electronic device includes at least an antenna apparatus. The antenna apparatus is provided with a non-resonant unit and a feed unit, to respectively feed a radiation unit and the non-resonant unit. Through feeding power distribution design, the non-resonant unit can assist in exciting a floor characteristic mode. In addition, since a size of the non-resonant unit is much smaller than an electrical length required for resonance of an antenna on this frequency band, the non-resonant unit does not generate a resonance curve on a resonance curve and has no resonance point, to improve radiation efficiency of the antenna without generating new resonance, so as to improve a use effect of a user.

In a possible implementation, the middle frame is a metal middle frame, the metal middle frame includes at least a metal border frame and a metal middle plate, and the metal border frame is disposed around an outer periphery of the metal middle plate; and the metal border frame forms a metal border frame antenna, and the metal border frame antenna is used as at least one radiation unit in the antenna apparatus.

Terms used in implementations of this application are only used to explain specific embodiments of this application, and are not intended to limit this application. The following clearly describes implementations in embodiments of this application with reference to accompanying drawings.

Embodiments of this application provide an electronic device that may include, but is not limited to, a mobile or fixed terminal having an antenna apparatus, such as a mobile phone, a tablet computer, a notebook computer, an ultra-mobile personal computer (ultra-mobile personal computer, UMPC), a handheld computer, a walkie-talkie, a netbook, a point of sales (Point of sales, POS), a personal digital assistant (personal digital assistant, PDA), a wearable device, a virtual reality device, a wireless USB flash, a Bluetooth speaker/headset, a factory-installed vehicle component, an event data recorder, or a security device.

In an embodiment of this application, an example in which a mobile phone <NUM> is the foregoing electronic device is used for description. The mobile phone <NUM> provided in the embodiment of this application may be a curved screen mobile phone or a flat screen mobile phone. In the embodiment of this application, the flat screen mobile phone is used as an example for description. <FIG> and <FIG> respectively show an overall structure and a split structure of the mobile phone <NUM>. A display <NUM> of the mobile phone <NUM> provided in this embodiment of this application may be a waterdrop screen, a notch screen, a full screen, or a punch-hole screen (as shown in <FIG>). For example, the display <NUM> is provided with an opening <NUM>. The following is described by using the punch-hole screen as an example.

Referring to <FIG>, the mobile phone <NUM> may include the display <NUM>, a rear housing <NUM>, and a middle frame <NUM> located between the display <NUM> and the rear housing <NUM>. In addition, the mobile phone <NUM> may further include a battery <NUM>, and the battery <NUM> is located between the middle frame <NUM> and the rear housing <NUM>. The battery <NUM> may be disposed on a surface that is of the middle frame <NUM> and that faces the rear housing <NUM> (as shown in <FIG>), or the battery <NUM> may be disposed on a surface that is of the middle frame <NUM> and that faces the display <NUM>. For example, the surface that is of the middle frame <NUM> and that faces the rear housing <NUM> may include a battery compartment (not shown in the figure), and the battery <NUM> is mounted in the battery compartment.

In some other examples, the mobile phone <NUM> may further include a circuit board <NUM>. The circuit board <NUM> may be disposed on the middle frame <NUM>, for example, the circuit board <NUM> may be disposed on the surface that is of the middle frame <NUM> and that faces the rear housing <NUM> (as shown in <FIG>), or the circuit board <NUM> may be disposed on the surface that is of the middle frame <NUM> and that faces the display <NUM>. The display <NUM> and the rear housing <NUM> are respectively located on two sides of the middle frame <NUM>.

The battery <NUM> may be connected to a charging management module and the circuit board <NUM> by using a power management module. The power management module receives an input of the battery <NUM> and/or an input of the charging management module, and supplies power to a processor, an internal memory, an external memory, the display <NUM>, a camera module, a communication module, and the like. The power source management module may be further configured to monitor parameters such as a capacity of the battery <NUM>, a cycle count of the battery <NUM>, and a state of health (leakage or impedance) of the battery <NUM>. In some other embodiments, the power management module may alternatively be disposed in a processor of the circuit board <NUM>. In some other embodiments, the power management module and the charging management module may be disposed in a same component.

When the mobile phone <NUM> is a flat screen mobile phone, the display <NUM> may be an organic light-emitting diode (Organic Light-Emitting Diode, OLED) display, or may be a liquid crystal display (Liquid Crystal Display, LCD). When the mobile phone <NUM> is a curved screen mobile phone, the display <NUM> may be an OLED display.

Still referring to <FIG>, the middle frame <NUM> may be a metal middle frame, the metal middle frame may include at least a metal middle plate <NUM> and a metal border frame <NUM>, and the border frame <NUM> is disposed around an outer periphery of the metal middle plate <NUM> for one cycle. Generally, the border frame <NUM> may include a top border frame <NUM>, a bottom border frame <NUM>, a left border frame <NUM>, and a right border frame <NUM>, and the top border frame <NUM>, the bottom border frame <NUM>, the left border frame <NUM>, and the right border frame <NUM> surround the frame <NUM> having a square ring structure. A material of the metal middle plate <NUM> includes, but is not limited to, an aluminum plate, aluminum alloy, stainless steel, a steel-aluminum composite die-casting plate, titanium alloy, magnesium alloy, or the like. The border frame <NUM> may be a metal border frame, a ceramic border frame, or a glass border frame. When the border frame <NUM> is the metal border frame, a material of the metal border frame includes, but is not limited to, aluminum alloy, stainless steel, a steel-aluminum composite die-casting plate, titanium alloy, or the like. The metal middle plate <NUM> may be connected to the border frame <NUM> through clamping, welding, bonding, or integral molding, or the metal middle plate <NUM> may be fixedly connected to the border frame <NUM> through injection molding.

Referring to <FIG>, the top border frame <NUM> is disposed opposite to the bottom border frame <NUM>, the left border frame <NUM> is disposed opposite to the right border frame <NUM>, the top border frame <NUM> is separately connected to one end of the left border frame <NUM> and one end of the right border frame <NUM> at a rounded corner, and the bottom border frame <NUM> is separately connected to the other end of the left border frame <NUM> and the other end of the right border frame <NUM> at a rounded corner, to jointly form a round-cornered rectangular region. A surface that is of a rear housing and that is grounded is disposed in the round-cornered rectangular region, and is separately connected to the top border frame <NUM>, the bottom border frame <NUM>, the left border frame <NUM>, and the right border frame <NUM>. It may be understood that the surface that is of the rear housing and that is grounded may be the rear housing <NUM> of the mobile phone <NUM>.

The rear housing <NUM> may be a metal rear housing, a glass rear housing, a plastic rear housing, or a ceramic rear housing. In the embodiment of this application, a material of the rear housing <NUM> is not limited, and is not limited to the foregoing examples either.

It should be noted that, in some examples, the rear housing <NUM> of the mobile phone <NUM> may be connected to the border frame <NUM> to form a unibody (Unibody) rear housing. For example, the mobile phone <NUM> may include the display <NUM>, the metal middle plate <NUM>, and a rear housing. The rear housing may be a unibody (Unibody) rear housing including the border frame <NUM> and the rear housing <NUM>. In this way, the circuit board <NUM> and the battery <NUM> are located in space surrounded by the metal middle plate <NUM> and the rear housing.

It may be understood that the structures illustrated in embodiments of this application do not constitute a specific limitation on the mobile phone <NUM>. In some other embodiments of this application, the mobile phone <NUM> may include more or fewer components than those shown in the figure, or combine some components, or split some components, or have different component arrangements. The components shown in the figure may be implemented by hardware, software, or a combination of software and hardware.

To implement a communication function of the mobile phone <NUM>, an antenna may be disposed on the mobile phone <NUM>, to transmit and receive signals through the antenna. An antenna performance level of the mobile phone <NUM> in an actual use scenario is directly related to actual user experience. Currently, most of the mobile phones <NUM> are industry design (Industry Design, ID) using a metal border frame and glass rear housing. A size of the metal border frame is limited and an antenna environment is limited. In a plurality of frequency bands of the antenna, based on a relationship between a frequency band and wavelength resonance, the lower the frequency is, the longer the required radiator is, and the greater the space requirement is. Therefore, how to improve antenna performance, especially low-frequency antenna performance, in a limited space environment and a radiator length, has become an important problem in research and design of a terminal antenna.

A theory of a characteristic mode is a very important theory during design of the antenna. <FIG> and <FIG> show current distributions of a floor characteristic mode of the antenna. It may be learned from the figures that due to resonance, the floor (that is, the metal middle plate <NUM>) has different current distribution on different frequency bands, that is, the floor characteristic modes of a low-frequency antenna and a medium-high-frequency antenna on different frequency bands have respective characteristics. A current flow direction of the low-frequency antenna is in a longitudinal mode (as shown in <FIG>), and a current flow direction of the medium-high-frequency antenna is in a transverse mode (as shown in <FIG>). A characteristic mode of the floor is an inherent characteristic of the floor. Based on a frequency requirement, a required floor characteristic mode is excited, to obtain high antenna efficiency at a corresponding frequency. For example, for a low frequency antenna, high free space (FS) efficiency can be obtained by sufficiently exciting the floor longitudinal mode; and for a medium-high frequency antenna, high FS efficiency can also be obtained by sufficiently exciting the lateral mode.

A conventional terminal antenna has many use scenarios. For example, common use scenarios include besides head and hand (besides head and hand, BHH), besides head (besides head, BH), and hand (hand, H). These scenarios are also common test scenarios for national authentication or operator admission. For example, <FIG> is a schematic diagram of a besides head and hand scenario. However, in these scenarios, the antenna performance changes compared with FS performance. For example, for FS of the low frequency antenna, a good floor longitudinal characteristic mode is needed when the antenna is designed, but the longitudinal characteristic mode in this case will result in great reduction in the hand. However, if the low-frequency antenna has a good floor transverse characteristic mode, small reduction in the hand may be obtained, and hand performance is good, but the FS deteriorates in this case.

Through analysis, for the low frequency antenna, efficiency of the low frequency antenna is improved if the floor longitudinal characteristic mode is additionally assisted and excited. Similarly, for the medium-high frequency antenna, efficiency of the medium-high frequency antenna is improved if the floor transverse characteristic mode is additionally assisted and excited. Based on this, embodiments of this invention provide an antenna apparatus and an electronic device having the antenna apparatus. The antenna apparatus may be used in the electronic device (for example, the mobile phone <NUM>). The antenna apparatus is provided with a non-resonant unit and a feed unit, to respectively feed a radiation unit and a non-resonant unit. Through feeding power distribution design, the non-resonant unit can assist in exciting the floor characteristic mode. In addition, since a size of the non-resonant unit is much smaller than an electrical length required for resonance of an antenna on this frequency band, the non-resonant unit does not generate a resonance curve on a resonance curve and has no resonance point, to improve radiation efficiency of the antenna without generating new resonance, so as to improve a use effect of a user.

It should be noted that the antenna apparatus provided in this application is used in an electronic device using any one or more of the following communication technologies, for example, a long term evolution (long term evolution, LTE) communication technology, a Wi-Fi communication technology, a <NUM> communication technology, a SUB-<NUM> communication technology, and another communication technology in the future.

The following describes a specific structure of the antenna apparatus with reference to specific accompanying drawings (the following embodiments do not highlight a need for a communication network, and describe an operation characteristic of the antenna apparatus only based on a frequency).

As shown in <FIG>, an embodiment of this application provides an antenna apparatus <NUM>. The antenna apparatus <NUM> is used in a mobile phone <NUM>. The mobile phone <NUM> may include a display <NUM>, a rear housing <NUM>, and a middle frame <NUM> (referring to <FIG>) located between the display <NUM> and the rear housing <NUM>. The antenna apparatus <NUM> includes at least one radiation unit <NUM>, at least one feed unit <NUM>, and at least one non-resonant unit <NUM>, and the feed unit <NUM> separately feeds the radiation unit <NUM> and the non-resonant unit <NUM>.

A size of the non-resonant unit <NUM> is less than <NUM>/8λ, where λ is a wavelength corresponding to a resonance frequency of the radiation unit <NUM>. It should be noted that the size of the non-resonant unit <NUM> is much smaller than an electrical length required for resonance of the radiation unit <NUM> on this frequency band, to ensure that the non-resonant unit <NUM> does not generate a resonance curve on a reflection coefficient curve (S <NUM>) and has no resonance point. Therefore, even if the non-resonant unit <NUM> is removed, the resonance curve and a quantity of resonance points on S11 do not change.

For example, as shown in <FIG>, the size of the non-resonant unit size <NUM> may be <NUM> x <NUM>, which is less than a resonant length of the radiation unit <NUM> on this frequency band. A <NUM>/<NUM> wavelength at a low frequency is <NUM> @ <NUM>. It may be understood that the non-resonant unit <NUM> may be a metal layer or may be a border frame metal branch, and this is not limited in this embodiment of this application, and is not limited to the foregoing example either.

In this embodiment of this application, a border frame <NUM> may be a metal border frame, the metal border frame may form a metal border frame antenna, and the metal border frame antenna is used as the at least one radiation unit <NUM> in the antenna apparatus <NUM>. Specifically, the metal border frame antenna may be a radiator located on the metal border frame, and the radiator is formed by opening a slot in the metal border frame, in other words, the metal border frame antenna is a slot antenna formed by slotting in the metal border frame. The slot antenna may include a first part, a second part, and a third part separated by slots, and a non-conductive material may be filled between the first part and the second part, between the second part and the third part, and between the third part and the first part.

In an actual application, positions of the slots may be varied as required, and the slots may be filled with a non-conductive material (such as plastic), to ensure integrity of the metal border frame in appearance. By flexibly providing opening positions of the slots on the metal border frame, appearance design with different requirements may be implemented while ensuring radiation performance of the antenna, thereby improving product quality of the mobile phone <NUM>.

A feed point and a ground point of the feed unit <NUM> are respectively electrically connected to the non-resonant unit <NUM> and a metal middle plate <NUM> used as a floor in the mobile phone <NUM>. It may be understood that the non-resonant unit <NUM> is configured to assist in exciting the floor characteristic mode, and the non-resonant unit <NUM> assists in exciting the floor longitudinal characteristic mode when the radiation unit <NUM> is a low frequency radiation unit. The non-resonant unit <NUM> assists in exciting the floor transverse characteristic mode when the radiation unit <NUM> is a medium-high frequency radiation unit.

A current flow direction of the low-frequency radiation unit is in a longitudinal mode, and a current flow direction of the medium-high frequency radiation unit is in a transverse mode, so that high antenna efficiency at a corresponding frequency can be obtained by exciting a required floor characteristic mode. That is, for the low-frequency radiation unit, high radiation efficiency can be obtained by sufficiently exciting the floor longitudinal mode; and for the medium-high frequency radiation unit, high radiation efficiency can also be obtained by sufficiently exciting the transverse mode.

An orthographic projection that is of the non-resonant unit <NUM> and that is in a first direction L1 is located in the metal middle plate <NUM>, and the first direction L1 is the direction perpendicular to a plane in which the metal middle plate <NUM> is located. For example, the non-resonant unit <NUM> may be located above the metal middle plate <NUM>, so that the feed unit <NUM> is separately connected to the non-resonant unit <NUM> and a floor (that is, the metal middle plate <NUM>) below the non-resonant unit <NUM> through a power distribution of a feed connection, thereby assisting in exciting the floor characteristic mode.

As an optional implementation, the feed unit <NUM> may be electrically connected to the non-resonant unit <NUM> and the metal middle plate <NUM> by using a feed line <NUM>. Through a line power distribution of the feed line <NUM> for the feed connection, the feed unit <NUM> is connected to each of the non-resonant unit <NUM> and the floor (that is, the metal middle plate <NUM>) below the non-resonant unit <NUM> by using the feed line <NUM>, thereby assisting in exciting the floor characteristic mode.

As shown in <FIG> and <FIG>, each feed line <NUM> may include a main feed line <NUM> and a sub-feed line <NUM>. The main feed line <NUM> and the sub-feed line <NUM> each include a signal line and a ground line. A signal line at a first end <NUM> of the main feed line is electrically connected to the feed unit <NUM>, a signal line at a second end <NUM> of the main feed line is electrically connected to the radiation unit <NUM>, and a ground line of the main feed line <NUM> is grounded. A signal line and a ground line at a first end <NUM> of the sub-feed line are electrically connected to the signal line and the ground line of the main feed line <NUM>, and a signal line and a ground line at a second end <NUM> of the sub-feed line are electrically connected to the non-resonant unit <NUM> and the metal middle plate <NUM> respectively. In this way, the feed unit <NUM> can separately feed the radiation unit <NUM> and the non-resonant unit <NUM>, and efficiency of the antenna can be effectively improved through a power distribution at a feed location and a connection to the non-resonant unit <NUM> and the floor (that is, the metal middle plate <NUM>) at the non-resonant unit <NUM>.

In a possible implementation, still referring to <FIG>, the sub-feed line <NUM> may be a coaxial line. Specifically, the sub-feed line <NUM> may include an outer conductor <NUM> and an inner conductor <NUM>, the outer conductor <NUM> is wrapped outside the inner conductor <NUM>, the inner conductor <NUM> is the signal line of the sub-feed line <NUM>, and the outer conductor <NUM> is the ground line of the sub-feed line <NUM>. One end of the inner conductor <NUM> is electrically connected to the signal line of the main feed line <NUM>, and the other end of the inner conductor <NUM> is electrically connected to the non-resonant unit <NUM>. One end of the outer conductor <NUM> is electrically connected to the ground line of the main feed line <NUM>, and the other end of the outer conductor <NUM> is electrically connected to the metal middle plate <NUM>. The inner conductor <NUM> of the sub-feed line <NUM> is electrically connected to the non-resonant unit <NUM>, and the outer conductor <NUM> of the sub-feed line <NUM> is electrically connected to the floor (that is, the metal middle plate <NUM>) at the non-resonant unit <NUM>, so that while assisting in exciting the floor characteristic mode, the metal middle plate <NUM> connected to the outer conductor <NUM> can provide a specific shielding effect for the non-resonant unit <NUM> connected to the inner conductor <NUM>.

In addition, as shown in <FIG>, the main feed line <NUM> may be a microstrip line. Specifically, the main feed line <NUM> may include a first conductor <NUM> and a second conductor <NUM>. The first conductor <NUM> is the signal line of the main feed line <NUM>, the second conductor <NUM> is the ground line of the main feed line <NUM>, and the first conductor <NUM> is separated from the second conductor <NUM>. In this way, transmission of a power supply signal and a ground signal between the feed unit <NUM> and the radiation unit <NUM> can be ensured.

It should be noted that the first end <NUM> of the main feed line may include a first end of the first conductor <NUM> and a first end of the second conductor <NUM>. For ease of identification, in <FIG>, the first end of the first conductor <NUM> is used as an example to show the first end <NUM> of the main feed line.

In this embodiment of this application, the non-resonant unit <NUM> may be disposed at a position as shown in <FIG>, or may be disposed at a position as shown in <FIG> or <FIG>. A specific position of the non-resonant unit <NUM> is not limited in this embodiment of this application, and is not limited to the forgoing example either. It should be noted that the radiation unit <NUM> may be a low-frequency radiation unit.

<FIG> and <FIG> are respectively a diagram of a current distribution and a pattern of an antenna in a conventional technology. <FIG> and <FIG> are respectively a diagram of an overall current distribution and an overall pattern of an antenna apparatus <NUM> when a non-resonant unit <NUM> is introduced into the antenna apparatus <NUM> according to an embodiment of this application. <FIG> and <FIG> are respectively a diagram of a current distribution and a pattern of a non-resonant unit <NUM> introduced into an antenna apparatus <NUM> according to an embodiment of this application. Through comparison, it can be learned that the non-resonant unit <NUM> introduced into the antenna apparatus <NUM> in this embodiment of this application does not change the overall current distribution and pattern characteristic of the antenna apparatus <NUM>, but the current distribution on the non-resonant unit <NUM> significantly excites the floor characteristic mode better, and excitation of such characteristic mode is beneficial for improving antenna efficiency.

<FIG> shows a comparison of each of reflection coefficient curves and radiation efficiency curves of an antenna of an electronic device on B28/B5/B8 in a conventional technology. In <FIG>, A1 is a reflection coefficient curve obtained by tuning an antenna on the B28 band, B1 is a radiation efficiency curve obtained by tuning the antenna on the B28 band, A2 is a reflection coefficient curve obtained by tuning an antenna on the B5 band, B2 is a radiation efficiency curve obtained by tuning the antenna on the B5 band, A3 is a reflection coefficient curve obtained by tuning an antenna on the B8 band, and B3 is a radiation efficiency curve obtained by tuning the antenna on the B8 band. A frequency band covered by B28 is <NUM> to <NUM>, a frequency band covered by B5 is <NUM> to <NUM>, and a frequency band covered by B8 is <NUM> to <NUM>.

<FIG> and <FIG> show a comparison of radiation efficiency and system efficiency of an antenna after a non-resonant unit <NUM> is introduced according to an embodiment of this application and radiation efficiency and system efficiency of an antenna without using a solution in an embodiment of this application. In <FIG>, C1 is a radiation efficiency curve of an antenna in a conventional technology, and C2 is a radiation efficiency curve of an antenna apparatus <NUM> according to an embodiment of this application. In <FIG>, D1 is a system efficiency curve when the antenna apparatus <NUM> in this embodiment of this application is on the B28 band, D2 is a system efficiency curve when the antenna apparatus <NUM> in this embodiment of this application is on the B5 band, D3 is a system efficiency curve when the antenna apparatus <NUM> in this embodiment of this application is on the B8 band, E1 is a system efficiency curve when the antenna in the conventional technology is on the B28 band, E2 is a system efficiency curve when the antenna in the conventional technology is on the B5 band, and E3 is a system efficiency curve when the antenna in the conventional technology is on the B8 band.

Through comparison, it may be apparently seen that the non-resonant unit <NUM> is introduced, so that antenna efficiency can be effectively improved through a power distribution at a feed location and a connection of the non-resonant unit <NUM> and the floor (the metal middle plate <NUM>) at the non-resonant unit <NUM>. Specifically, at <NUM>, the radiation efficiency of the antenna apparatus <NUM> in this embodiment of this application is <NUM> dB higher than the radiation efficiency of the antenna in the conventional technology. At <NUM>, the radiation efficiency of the antenna apparatus <NUM> in this embodiment of this application is <NUM> dB higher than the radiation efficiency of the antenna in the conventional technology. At <NUM>, the radiation efficiency of the antenna apparatus <NUM> in this embodiment of this application is <NUM> dB higher than the radiation efficiency of the antenna in the conventional technology.

In addition, it should be noted that a result consistent with a simulation result can be obtained through debugging and verifying on an actual project. <FIG> is a schematic diagram of an experimental fixture for verifying on an actual project. In <FIG>, the power distribution is performed at the feed location, the inner conductor <NUM> of the feed line <NUM> is connected to the non-resonant unit <NUM>, the outer conductor <NUM> of the feed line <NUM> is connected to a middle frame of the floor at the non-resonant unit <NUM>, and the non-resonant unit <NUM> may be a copper sheet of <NUM> x <NUM>.

<FIG> and <FIG> respectively show a reflection coefficient curve and a radiation efficiency curve actually measured by an actual fixture. In <FIG>, F1 is a reflection coefficient curve of an antenna in a conventional technology, and F2 is a reflection coefficient curve of an antenna apparatus <NUM> according to an embodiment of this application. In <FIG>, G1 is a radiation efficiency curve of an antenna in a conventional technology, and G2 is a radiation efficiency curve of an antenna apparatus <NUM> according to an embodiment of this application. An actual measurement result shows that the non-resonant unit <NUM> introduced in this embodiment of this application can effectively improve the antenna efficiency without increasing resonance of S11. A frequency-deviation phenomenon occurring therein because a distributed capacitor of the non-resonant unit <NUM> and the middle frame of floor (the metal middle plate <NUM>) is loaded to the feed location and cause capacitor loading, and this frequency deviation can be easily adjusted through tuning.

In addition, the method for improving the antenna efficiency by introducing the non-resonant unit to assist in exciting the floor characteristic mode mentioned in this invention patent can also be applied to a medium-high frequency antenna. As shown in <FIG> or <FIG>, a non-resonant unit is added to the medium-high frequency antenna, and an excited floor characteristic mode current is shown in <FIG>. The floor characteristic mode current assisted and excited by the non-resonant unit <NUM> is completely consistent with a medium-high frequency floor characteristic mode current shown in <FIG>.

<FIG> shows a comparison of efficiency benefits of introducing a non-resonant unit <NUM> into an antenna apparatus <NUM> (that is, a structure shown in <FIG> or <FIG>) according to an embodiment of this application. In <FIG>, L1 is a reflection coefficient curve of an antenna in a conventional technology, L2 is a reflection coefficient curve of the antenna apparatus <NUM> according to an embodiment of this application, M1 is a radiation efficiency curve of the antenna in the conventional technology, M2 is a radiation efficiency curve of the antenna apparatus <NUM> according to an embodiment of this application, N1 is a system total efficiency curve of the antenna in the conventional technology, and N2 is a system total efficiency curve of the antenna apparatus <NUM> according to an embodiment of this application. It may be apparently seen from the efficiency curve, compared with the conventional technology, in the antenna apparatus <NUM> provided in this embodiment of this application, the antenna efficiency of the medium-high frequency can also be significantly improved, and the antenna efficiency can be improved by <NUM> dB at <NUM>, thereby improving antenna performance.

It should be noted that, in this embodiment of this application, the radiation unit <NUM> may be a metal border frame antenna, and the non-resonant unit <NUM> may be disposed close to the metal border frame antenna. The non-resonant unit <NUM> is disposed close to the metal border frame antenna, so that a length of the feed line <NUM> can be reduced to some extent, thereby reducing costs and improving reliability.

In addition, in some embodiments, a quantity of non-resonant units <NUM> is one, and a quantity of feed lines <NUM> may be at least two. As shown in <FIG>, the at least one feed unit <NUM> may include a first feed unit <NUM> and a second feed unit <NUM>. A feed point and a ground point of the first feed unit <NUM> may be electrically connected to the non-resonant unit <NUM> and the metal middle plate <NUM> by using a first feed line <NUM> of the at least two feed lines <NUM>, and a feed point and a ground point of the second feed unit <NUM> may be electrically connected to the non-resonant unit <NUM> and the metal middle plate <NUM> by using a second feed line <NUM> of the at least two feed lines <NUM>.

The at least one radiation unit <NUM> may include a first radiation unit <NUM> and a second radiation unit <NUM>. The signal line at the first end <NUM> of the main feed line of the first feed line <NUM> is electrically connected to the first feed unit <NUM>, the signal line at the second end <NUM> of the main feed line of the first feed line <NUM> is electrically connected to the first radiation unit <NUM>, and the ground line of the main feed line <NUM> of the first feed line <NUM> is grounded. The signal line and the ground line at the first end <NUM> of the sub-feed line of the first feed line <NUM> are electrically connected to the signal line and the ground line of the main feed line <NUM> of the first feed line <NUM>, and the signal line and the ground line at the second end <NUM> of the sub-feed line of the first feed line <NUM> are electrically connected to the non-resonant unit <NUM> and the metal middle plate <NUM> respectively.

The signal line at the first end <NUM> of the main feed line of the second feed line <NUM> is electrically connected to the second feed unit <NUM>, the signal line at the second end <NUM> of the main feed line of the second feed line <NUM> is electrically connected to the second radiation unit <NUM>, and the ground line of the main feed line <NUM> of the second feed line <NUM> is grounded. The signal line and the ground line at the first end <NUM> of the sub-feed line of the second feed line <NUM> are electrically connected to the signal line and the ground line of the main feed line <NUM> of the second feed line <NUM>, and the signal line and the ground line at the second end <NUM> of the sub-feed line of the second feed line <NUM> are electrically connected to the non-resonant unit <NUM> and the metal middle plate <NUM> respectively.

In this way, the first feed unit <NUM> is connected to the first radiation unit <NUM>, the non-resonant unit <NUM>, and the floor below the non-resonant unit <NUM> (that is, the metal middle plate <NUM>) by using the first feed line <NUM>, the second feed unit <NUM> is connected to the second radiation unit <NUM>, the non-resonant unit <NUM>, and the floor below the non-resonant unit <NUM> (that is, the metal middle plate <NUM>) by using the second feed line <NUM>. That is, through a line power distribution, the first feed unit <NUM> feeds the first radiation unit <NUM> and the non-resonant unit <NUM> by using the first feed line <NUM>, and the second feed unit <NUM> feeds the second radiation unit <NUM> and the non-resonant unit <NUM> by using the second feed line <NUM>, so that the non-resonant unit <NUM> can assist the first radiation unit <NUM> and the second radiation unit <NUM> in exciting the floor characteristic mode.

As an optional implementation, in <FIG>, the first radiation unit <NUM> may be a low-frequency radiation unit, and the second radiation unit <NUM> may be a medium-frequency radiation unit. Certainly, in some other embodiments, the first radiation unit <NUM> and the second radiation unit <NUM> may be low frequency radiation units, or the first radiation unit <NUM> and the second radiation unit <NUM> may be medium-high frequency radiation units.

Further, in another embodiment, as shown in <FIG>, a quantity of non-resonant units <NUM> may be two, and the at least one non-resonant unit <NUM> may include a first non-resonant unit <NUM> and a second non-resonant unit <NUM>. A quantity of feed lines <NUM> may be at least two, and the at least one feed unit <NUM> may include a first feed unit <NUM> and a second feed unit <NUM>. A feed point and a ground point of the first feed unit <NUM> may be electrically connected to the first non-resonant unit <NUM> and the metal middle plate <NUM> by using a first feed line <NUM> of the at least two feed lines <NUM>, and a feed point and a ground point of the second feed unit <NUM> may be electrically connected to the second non-resonant unit <NUM> and the metal middle plate <NUM> by using a second feed line <NUM> of the at least two feed lines <NUM>.

Similarly, the at least one radiation unit <NUM> may include a first radiation unit <NUM> and a second radiation unit <NUM>. The signal line at the first end <NUM> of the main feed line of the first feed line <NUM> is electrically connected to the first feed unit <NUM>, the signal line at the second end <NUM> of the main feed line of the first feed line <NUM> is electrically connected to the first radiation unit <NUM>, and the ground line of the main feed line <NUM> of the first feed line <NUM> is grounded. The signal line and the ground line at the first end <NUM> of the sub-feed line of the first feed line <NUM> are electrically connected to the signal line and the ground line of the main feed line <NUM> of the first feed line <NUM>, and the signal line and the ground line at the second end <NUM> of the sub-feed line of the first feed line <NUM> are electrically connected to the first non-resonant unit <NUM> and the metal middle plate <NUM> respectively.

The signal line at the first end <NUM> of the main feed line of the second feed line <NUM> is electrically connected to the second feed unit <NUM>, the signal line at the second end <NUM> of the main feed line of the second feed line <NUM> is electrically connected to the second radiation unit <NUM>, and the ground line of the main feed line <NUM> of the second feed line <NUM> is grounded. The signal line and the ground line at the first end <NUM> of the sub-feed line of the second feed line <NUM> are electrically connected to the signal line and the ground line of the main feed line <NUM> of the second feed line <NUM>, and the signal line and the ground line at the second end <NUM> of the sub-feed line of the second feed line <NUM> are electrically connected to the second non-resonant unit <NUM> and the metal middle plate <NUM> respectively.

In this way, the first feed unit <NUM> is connected to the first radiation unit <NUM>, the first non-resonant unit <NUM>, and the floor below the first non-resonant unit <NUM> (that is, the metal middle plate <NUM>) by using the first feed line <NUM>, the second feed unit <NUM> is connected to the second radiation unit <NUM>, the second non-resonant unit <NUM>, and the floor below the second non-resonant unit <NUM> (that is, the metal middle plate <NUM>) by using the second feed line <NUM>. That is, through a line power distribution, the first feed unit <NUM> feeds the first radiation unit <NUM> and the first non-resonant unit <NUM> by using the first feed line <NUM>, and the second feed unit <NUM> feeds the second radiation unit <NUM> and the second non-resonant unit <NUM> by using the second feed line <NUM>, so that the first non-resonant unit <NUM> can assist the first radiation unit <NUM> in exciting the floor characteristic mode, and the second non-resonant unit <NUM> can assist the second radiation unit <NUM> in exciting the floor characteristic mode.

In addition, as an optional implementation, the sub-feed line <NUM> may be provided with a switch <NUM> (as shown in <FIG>), the switch <NUM> is configured to select to turn on the non-resonant unit <NUM> (that is, the first non-resonant unit <NUM> or the second non-resonant unit <NUM>) on the sub-feed line <NUM>. The switch <NUM> can control the main feed line <NUM> and the non-resonant unit <NUM> to be connected or disconnected, thereby ensuring flexible use. For example, if the non-resonant unit <NUM> is not required to assist in exciting the floor characteristic mode, the switch <NUM> can be turned on; or if the non-resonant unit <NUM> is required to assist in exciting the floor characteristic mode, the switch <NUM> can be turned off.

In descriptions of embodiments, it should be noted that, unless otherwise expressly specified and limited, the terms "installation", "connect", and "connection" should be understood in a broad sense, for example, may be a fixed connection, or may be an indirect connection by using an intermediate medium, or may be a communication between two elements or an interaction between two elements. A person of ordinary skill in the art can understand specific meanings of the foregoing terms in embodiments of this application based on a specific situation.

The apparatus or element referred to in or implied in embodiments of this application needs to have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation on embodiments of this specification. In the descriptions of embodiments of this application, "a plurality of" means two or more, unless otherwise specifically defined.

In the specification of embodiments, claims, and accompanying drawings of this application, the terms "first", "second", "third", "fourth", and the like (if existent) are intended to distinguish between similar objects but do not necessarily indicate a specific order or sequence. It should be understood that the data termed in such a way are interchangeable in proper circumstances, so that embodiments described herein can be implemented in orders except the order illustrated or described herein. In addition, the terms "may include" and "have", and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, a method, a system, a product, or a device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or are inherent to the process, method, product, or device.

Claim 1:
An antenna apparatus (<NUM>), applied to an electronic device, wherein the antenna apparatus (<NUM>) comprises:
at least one radiation unit (<NUM>), at least one feed unit (<NUM>), and at least one non-resonant unit (<NUM>, <NUM>), wherein the feed unit (<NUM>) is configured to directly feed the radiation unit (<NUM>) and the non-resonant unit (<NUM>, <NUM>) separately; and
a size of the non-resonant unit (<NUM>, <NUM>) is less than <NUM>/8λ, and λ is a wavelength corresponding to a resonance frequency of the radiation unit (<NUM>);
wherein a feed point and a ground point of the feed unit (<NUM>) are respectively electrically connected to the non-resonant unit (<NUM>, <NUM>) and a metal middle plate (<NUM>) configured to form a floor in the electronic device;
wherein the non-resonant unit (<NUM>, <NUM>) is configured to assist in exciting a floor characteristic mode;
wherein an orthographic projection that is of the non-resonant unit (<NUM>, <NUM>) and that is in a first direction is located in the metal middle plate (<NUM>); and
the first direction is the direction perpendicular to a plane in which the metal middle plate (<NUM>) is located.