WO2021127932A1

WO2021127932A1 - Handheld terminal

Info

Publication number: WO2021127932A1
Application number: PCT/CN2019/127647
Authority: WO
Inventors: 朱玉飞; 郑磊
Original assignee: 瑞声声学科技(深圳)有限公司; 瑞声科技(新加坡)有限公司
Priority date: 2019-12-23
Filing date: 2019-12-23
Publication date: 2021-07-01

Abstract

The present invention relates to the field of wireless technologies. Provided is a handheld terminal. The mobile terminal comprises a metal midframe. The metal midframe comprises two side edge frames opposite each other and a bottom edge frame connected to the two side edge frames. The mobile terminal also comprises a mainboard and a metal slot antenna in proximity to the bottom edge frame. A first gap and a second gap cutting the bottom edge frame are provided on the bottom edge frame. A third gap is provided at where the bottom edge frame is connected to either of the side edge frames. The second gap is located between the first gap and the third gap. A first metal strip is formed by the bottom edge frame between the first gap and the second gap and a second metal strip is formed by the bottom edge frame between the second gap and the third gap. Provided on the mainboard are a feed point, a ground point, a mainboard reference ground, and, a first switch and a second switch used for controlling the tuning and switching of the metal slot antenna. The present invention improves the low-frequency performance of the antenna in a left-handed grip.

Description

Handheld Terminal

Technical field

The present invention relates to the field of wireless technology, and in particular to a handheld terminal.

Background technique

Mobile terminals with metal casings, such as smart phones, are becoming more and more mainstream. At the same time, using metal casing frames to design antennas has become a current popular trend. Metal frame slot antennas use mobile phone frame slots and feeder circuits to form terminal antennas. The prior art In this method, the entire metal frame or part of the metal frame is used as the radiating unit of the antenna. When the user holds the smart terminal while using it, the hand will affect the antenna signal of the smart terminal, and the antenna performance will decrease, affecting the normal use of the terminal antenna.

technical problem

Aiming at the problem that the antenna performance of the antenna solution in the prior art decreases when the terminal is held by hand, the present invention provides a handheld terminal.

Technical solutions

A handheld terminal, the mobile terminal includes a metal middle frame, the metal middle frame includes two opposite side frames and a bottom frame connecting the two side frames, the mobile terminal further includes a main board adjacent to the bottom frame and For a metal slot antenna, the bottom frame is provided with a first slit and a second slit for cutting the bottom frame, and a third slit is provided at the junction of the bottom frame and one of the side frames. The second slit is located between the first slit and the third slit. The first metal strip is formed by the bottom frame between the first slit and the second slit, and the second slit and the The bottom frame between the third slits forms a second metal strip; the main board is provided with a feed point, a ground point, a main board reference ground, and a first switch and a second switch for controlling the tuning and switching of the metal slot antenna The metal slot antenna further includes a radiating sheet spaced apart from the first metal strip and adjacent to the second slit, and the radiating sheet is connected to the reference ground of the main board through the ground point; the first metal strip and The radiating sheets are all connected to the feeding point, and the first metal strip, the second metal strip and the radiating sheet are the radiators of the metal slot antenna.

Preferably, a first switch connection point connected to the first switch and a second switch connection point connected to the second switch are further provided on the main board, and the metal slot antenna further includes a connection point connected to the first switch. The switch connection point and the first spring foot of the first metal strip and the second spring foot that connects the second switch connection point and the second metal strip.

Preferably, the metal slot antenna further includes a second radiating sheet opposed to the second metal strip at intervals, and the second radiating sheet is electrically connected to the second elastic leg.

Preferably, the metal slot antenna further includes a third elastic leg connecting the radiating sheet and the ground point, and a fourth elastic leg connecting the radiating sheet and the feeding point.

Preferably, when the second switch is switched to the short-circuit state, the second metal strip is connected to the reference ground of the main board, and the second metal strip, the first metal strip and the radiating sheet are coupled to each other to generate mid-high frequency resonance, and the second metal strip One switch switches different state tuning, so that the antenna resonance covers the mid-to-high frequency band.

Preferably, when the second switch is switched to the open state, the second metal strip is in a disconnected state with the reference ground of the main board, and the first metal strip and the radiating sheet are used as the radiator of the antenna, and different switches are switched through the first switch. The antenna state is tuned so that the antenna resonance covers the low frequency band.

Preferably, the radiation sheet adopts laser-direct-structuring (LDS) or flexible printed circuit board (Flexible Printed) technology. Circuit, FPC) metal antenna pattern formed by the process.

Preferably, the handheld terminal further includes a plastic body, the metal middle frame is formed by in-mold injection molding, and the first metal strip and the second metal strip are embedded in the plastic body.

Beneficial effect

Compared with the prior art, the present invention breaks the side wall of the metal frame at three slits to form two independent metal strips. The metal strip and the radiating sheet are tuned and switched through two switches, so as to ensure that the medium and high frequency At the same time of performance, it improves the antenna performance of the handheld terminal held by the hand at low frequency.

Description of the drawings

In order to explain the technical solutions in the embodiments of the present invention more clearly, the following will briefly introduce the drawings needed in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative work, other drawings can be obtained based on these drawings, among which:

FIG. 1 is a schematic diagram of the structure of a terminal and a metal slot antenna according to Embodiment 1 of the present invention;

FIG. 2 is a schematic structural diagram of a part of the structure shown in FIG. 1;

Figure 3 is a partially separated front schematic view of the partial structure shown in Figure 1;

Fig. 4 is a schematic back view of part of the structure shown in Fig. 1;

FIG. 5 is a schematic diagram of the structure of the radiator shown in FIG. 2;

FIG. 6 is a schematic diagram of the structure of the second radiating sheet shown in FIG. 2;

7 is a schematic diagram of a terminal structure including a plastic body provided by Embodiment 1 of the present invention;

FIG. 8 is the performance data of FS, BHHL, and BHHR in state 1 provided by the first embodiment of the present invention;

FIG. 9 is the performance data of FS, BHHL, and BHHR in state 2 provided by the first embodiment of the present invention;

FIG. 10 is the comparison data of the antenna FS performance in the state 1 and the state 2 in the LTE B8 frequency band provided by the first embodiment of the present invention;

FIG. 11 is the comparison data of the antenna BHHL performance in the state 1 and the state 2 in the LTE B8 frequency band provided by the first embodiment of the present invention;

FIG. 12 is the comparative data of the antenna BHHR performance in the state 1 and the state 2 in the LTE B8 frequency band provided by the first embodiment of the present invention;

FIG. 13 is the comparison data of the antenna FS performance in the state 1 and the state 2 in the LTE B7 frequency band provided by the first embodiment of the present invention;

FIG. 14 is the comparison data of the LTE B7 frequency band provided by the first embodiment of the present invention, and the performance of the antenna BHHL in the state 1 and the state 2;

FIG. 15 is the comparison data of the antenna BHHR performance in the state 1 and the state 2 in the LTE B7 frequency band provided by the first embodiment of the present invention.

Embodiments of the present invention

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

Please refer to Figure 1 to Figure 4 together. The present invention provides a handheld terminal 100, the handheld terminal 100 includes a metal middle frame 10, the metal middle frame 10 includes two opposite side frames 11 and a bottom frame 12 connecting the two side frames 11, the handheld terminal 100 also includes a main board 20 adjacent to the bottom frame 12 and a metal slot antenna, wherein the bottom frame 12 is provided with a first slit 121 and a second slit 122 that cut the bottom frame, and the bottom frame 12 is provided with a first slit 121 and a second slit 122. A third slit 123 is provided at the junction of the frame 12 and one of the side frames 11. Specifically, the junction of the bottom frame 12 and one of the side frames 11 is the position where the handheld terminal holds the terminal. The junction can be the junction with either side, that is, it may be the place where the left hand is held or the place where the right hand is held. In this embodiment, the third slit 123 is provided at the left-hand grip.

The second slit 122 is located between the first slit 121 and the third slit 123, and a first metal strip is formed by the bottom frame between the first slit 121 and the second slit 122 31 and a second metal strip 32 formed by the bottom frame between the second slit 122 and the third slit 123; the main board 20 is provided with a feed point 41, a ground point 42, a main board reference ground, and a control station The metal slot antenna is a first switch and a second switch for tuning and switching; the metal slot antenna further includes a radiating sheet 61 spaced apart from the first metal strip 31 and adjacent to the second slit 122, the radiating sheet 61 is connected to the reference ground of the mainboard through the ground point 42; the first metal strip 31 and the radiating sheet 61 are both connected to the feeding point 41, and the first metal strip 31, the second metal strip 32 and the radiation The sheet 61 is the radiator of the metal slot antenna.

The main board 20 is also provided with a first switch connection point 51 connected to the first switch 512 and a second switch connection point 52 connected to the second switch 522. The metal slot antenna further includes The first switch connection point 51 and the first spring leg 511 of the first metal strip 31 and the second spring leg 521 that connects the second switch connection point 52 and the second metal bar 32.

Specifically, in this embodiment, the metal slot antenna further includes a second radiating sheet 62 spaced and opposed to the second metal strip 32, and the second radiating sheet 62 is electrically connected to the second elastic leg 521. The second radiating sheet 62 is used to enhance the radiation effect. When the structure of the second metal strip 32 is sufficient to meet the performance requirements, the second radiating sheet 62 can be removed.

The metal slot antenna further includes a third elastic leg 421 connecting the radiating sheet 61 and the ground point 42 and a fourth elastic leg 411 connecting the radiating sheet 61 and the feeding point 41. Please refer to FIGS. 5 and 6 together, which are schematic diagrams of the radiating sheet 61. The radiating sheet 61 includes a radiating metal sheet 611 and a ground terminal 612 for connecting the third elastic leg 421 and a fourth elastic Pin 411 of the feeder terminal 613. The structure of the second radiating sheet 62 is shown in FIG. 6. The second radiating sheet 62 includes a radiating metal sheet 621 and a ground terminal 622 connected to the second spring leg 521. The radiating sheet 61 and the second radiating sheet 62 are laser-direct-structuring (LDS) or flexible printed circuit boards (Flexible Printed). Circuit, FPC) metal antenna pattern formed by the process.

Please refer to FIG. 7, the handheld terminal 100 further includes a plastic body 70, the metal middle frame is formed by in-mold injection molding, and the first metal strip 31 and the second metal strip 32 are embedded in the plastic In the body 70, the first slit 121, the second slit 122, and the third slit 123 are all filled with a plastic body.

Referring again to FIGS. 1 to 4, when the metal slot antenna is working, the first metal strip 31, the second metal strip 32, and the radiating sheet 61 serve as the radiator of the antenna, and pass through the first switch and the second switch. Perform tuning. When the second switch is switched to the short-circuit state, the second metal strip 32 is connected to the reference ground of the main board. The second metal strip 32, the first metal strip 31 and the radiating sheet 61 are coupled to each other to generate mid-to-high frequency resonance. The first switch switches different state tuning, so that the antenna resonance covers the mid-to-high frequency band. When the second switch is switched to the open state, the second metal strip 32 is disconnected from the reference ground of the main board. The first metal strip 31 and the radiating sheet 61 are used as the radiator of the antenna, and the first switch is used to switch between different The antenna state is tuned so that the antenna resonance covers the low frequency band.

Specifically, when the antenna is working in the mid-to-high frequency band (1710~2690MHz), through the second switch, the second metal strip is connected to the reference ground of the main board, and the second metal strip and the first metal strip are coupled with the radiating sheet to generate medium and high frequency resonance. Through the first switch to switch different antenna state tuning, the antenna resonance can cover the middle and high frequency bands (1710~2690MHz).

When the antenna works in the low frequency band (699~960MHz), through the second switch, the second metal strip is disconnected from the reference ground of the main board. When the second metal strip is disconnected from the reference ground of the main board, the first metal The strip and the radiator are the main radiators of the antenna, and the first switch is used to switch different antenna state tuning, so that the antenna resonance can cover the low frequency band (699~960MHz). In this state, when holding by hand, the position of the second metal strip is relatively close to the hand, but the coupling effect between the second metal strip and the first metal strip and the radiation sheet is small. At this time, the first metal strip and the radiating sheet are the main radiators of the antenna, which are relatively far away from the hand, and the energy absorbed by the hand is relatively small. Therefore, the antenna performance loss is correspondingly reduced when the antenna is held in the left hand.

Please refer to Fig. 8 and Fig. 9. Specifically, in the embodiment, LTE B8 low frequency band and LTE Comparison of passive performance of B7 high frequency antenna:

The data shown in Fig. 8 is the data of state 1, which means: when the first switch is -15nH to ground, the second switch is switched in the closed state; where nH is the unit of inductance, nanohenry.

The data shown in Figure 9 is the data of state 2. State 2 refers to the data when the first switch is -15nH to ground and the second switch is switched in the open state.

Figure 8 and Figure 9 specifically show the following data in the passive test state:

FS performance: As shown by the curve F in Figure 8 and Figure 9, FS refers to the free state (Free Space, FS), that is, the antenna performance of the mobile phone in the air download (Over The Air, OTA) state;

BHHL performance: As shown by the curve L in Figure 8 and Figure 9, BHHL refers to the left-hand holding state (Beside Head and Hand Left Side, BHHL), that is, the mobile phone is in the United States Wireless Communications and Internet Association (Cellular Telecommunication Industry Association (CITA) standard head and the antenna performance under the wide hand holding on the left;

BHHR performance: as indicated by the curve R in Figure 8 and Figure 9, BHHR refers to the right-hand holding state (Beside Head and Hand Right Side, BHHR), that is, the mobile phone is held in the CITA standard head and the right wide hand (Wide Hand) Lower antenna performance.

Please refer to Figure 10 to Figure 12 together, for the LTE B8 frequency band, the comparison of FS performance, BHHL performance, and BHHR performance in state 1 and state 2 under passive antenna conditions. The average efficiency is shown in Table 1:

Table 1:

It can be seen from Table 1 above that the BHHL performance of the low-frequency B8 in state 2 is improved by about 1.2 dB compared to state 1.

Please refer to Figure 13 to Figure 15 together for the comparison of FS performance, BHHL performance and BHHR performance in state 1 and state 2 under the passive condition of LTE B7 band antenna. The average efficiency is shown in Table 2:

Table 2:

It can be seen from Table 2 above that the performances of FS, BHHL and BHHR of the high frequency B7 in state 1 are improved by about 1.7dB, 0.7dB and 1.9dB respectively compared with state 2.

Compared with the prior art, the present invention breaks the side wall of the metal frame at three slits to form two independent metal strips. The metal strip and the radiating sheet are tuned and switched through two switches, so as to ensure that the medium and high frequency At the same time, it improves the performance of the antenna held by the low-frequency hand.

The above are only the embodiments of the present invention. It should be pointed out here that for those of ordinary skill in the art, improvements can be made without departing from the inventive concept of the present invention, but these all belong to the present invention. The scope of protection.

Claims

A handheld terminal, the mobile terminal includes a metal middle frame, the metal middle frame includes two opposite side frames and a bottom frame connecting the two side frames, the mobile terminal further includes a main board adjacent to the bottom frame and The metal slot antenna is characterized in that the bottom frame is provided with a first slit and a second slit for cutting the bottom frame, and a third slit is provided at the junction of the bottom frame and one of the side frames. The second slit is located between the first slit and the third slit, the first metal strip is formed by the bottom frame between the first slit and the second slit, and the first metal strip is formed by the first slit. The bottom frame between the second slot and the third slot forms a second metal strip; the main board is provided with a feed point, a ground point, a main board reference ground, and a first switch for controlling the tuning and switching of the metal slot antenna And a second switch; the metal slot antenna further includes a radiating sheet spaced apart from the first metal strip and adjacent to the second slit, and the radiating sheet is connected to the reference ground of the main board through the ground point; the first A metal strip and the radiating sheet are both connected to the feeding point, and the first metal strip, the second metal strip and the radiating sheet are the radiators of the metal slot antenna.
The handheld terminal according to claim 1, wherein the main board is further provided with a first switch connection point connected to the first switch and a second switch connection point connected to the second switch, so The metal slot antenna further includes a first spring foot connecting the first switch connection point and the first metal strip and a second spring foot connecting the second switch connection point and the second metal strip.
The handheld terminal according to claim 2, wherein the metal slot antenna further comprises a second radiating sheet opposite to the second metal strip, and the second radiating sheet and the second elastic foot Electric connection.
The handheld terminal according to claim 1, wherein the metal slot antenna further comprises a third elastic foot connecting the radiating sheet and the ground point, and a third elastic foot connecting the radiating sheet and the feeding point. Four snap feet.
The handheld terminal according to any one of claims 1 to 4, wherein when the second switch is switched to a short-circuit state, the second metal strip is connected to the reference ground of the main board, and the second metal strip, The first metal strip and the radiating sheet are coupled with each other to generate mid-high frequency resonance, and the first switch is used to switch different state tuning, so that the antenna resonance covers the mid-high frequency band.
The handheld terminal according to any one of claims 1 to 4, wherein when the second switch is switched to an open state, the second metal strip is in a disconnected state with the reference ground of the main board, and the first metal strip The radiator and the radiator are used as the radiator of the antenna, and the first switch is used to switch different antenna states for tuning, so that the antenna resonance covers the low frequency band.
The handheld terminal of claim 1, wherein the radiating sheet is a metal antenna pattern formed by laser-direct-structuring (LDS) or flexible printed circuit (FPC) technology .
The metal slot antenna according to claim 1, wherein the handheld terminal further comprises a plastic body, the metal middle frame is formed by in-mold injection molding, and the first metal strip and the second metal strip are embedded In the plastic body.