CN110673164A

CN110673164A - Mobile terminal

Info

Publication number: CN110673164A
Application number: CN201910871980.5A
Authority: CN
Inventors: 张生; 潘璐
Original assignee: TCL Mobile Communication Technology Ningbo Ltd
Current assignee: TCL Mobile Communication Technology Ningbo Ltd
Priority date: 2019-09-16
Filing date: 2019-09-16
Publication date: 2020-01-10
Anticipated expiration: 2039-09-16
Also published as: CN110673164B

Abstract

The application relates to a mobile terminal, which comprises a circuit board and a front shell positioned on the circuit board, wherein the circuit board comprises a substrate, a radio frequency power amplifier and a shielding cover, wherein the radio frequency power amplifier and the shielding cover are positioned on the substrate; the front shell comprises a conductive grounding plate with a flat surface and an insulating layer positioned between the conductive grounding plate and the substrate, wherein the insulating layer is provided with an opening to expose the conductive grounding plate, and a shielding cover is embedded in the opening and is electrically connected with the conductive grounding plate, so that a radio frequency power amplifier is arranged in the shielding cover, and the shielding cover is electrically connected with the conductive grounding plate with the flat surface, thereby avoiding resonance points caused by uneven surface of the conductive grounding plate in the front shell, further reducing the interference of antenna harmonic radiation on GPS signal reception, and improving the GPS positioning precision.

Description

Mobile terminal

Technical Field

The application relates to the technical field of electronic equipment, in particular to a mobile terminal.

Background

The AGPS (Assisted Global Positioning System) technology is a technology that combines network base station information and GPS (Global Positioning System) information to locate a mobile station, and can be used in Global System for mobile communications/general packet radio service (GSM/GPRS), Wideband Code Division Multiple Access (WCDMA), code division multiple access 2000(CDMA2000), and Long Term Evolution (LTE) networks.

However, when the frequency band 13 or the frequency band 14 of LTE is used for AGPS positioning, since the frequency band 13 or the frequency band 14 of LTE and GPS work simultaneously, the second harmonic generated by the frequency band 13 or the frequency band 14 may just fall within the GPS receiving range, interfering with GPS receiving, and further causing the GPS to fail positioning or fail to perform correct positioning.

Disclosure of Invention

The application aims to provide a mobile terminal to reduce interference of antenna harmonic radiation on GPS signal reception, and then improve GPS positioning accuracy.

In order to solve the above problem, an embodiment of the present application provides a mobile terminal, which includes a circuit board and a front case located on the circuit board, where the circuit board includes a substrate, and a radio frequency power amplifier and a shielding cover located on the substrate, and the shielding cover covers the radio frequency power amplifier; the front shell comprises a conductive grounding plate with a smooth surface and an insulating layer positioned between the conductive grounding plate and the substrate, wherein an opening is formed in the insulating layer to expose the conductive grounding plate, and the shielding cover is embedded in the opening and is electrically connected with the conductive grounding plate.

And conductive foam is arranged between the shielding cover and the conductive grounding plate.

The radio frequency power amplifier is a multi-mode multi-band power amplifier.

The conductive grounding plate is made of aluminum alloy, magnesium-aluminum alloy or zinc alloy.

Wherein, the insulating layer is made of plastic.

The circuit board further comprises a GPS receiving circuit positioned on the substrate.

The GPS receiving circuit and the radio frequency power amplifier are arranged at the two opposite side edges of the substrate at intervals.

The mobile terminal further comprises a rear shell matched with the front shell in size and shape, and the circuit board is installed between the front shell and the rear shell.

The mobile terminal further comprises a display screen, and the display screen is located on the front shell.

The circuit board further comprises a duplexer and a low-frequency filter which are positioned on the substrate.

The beneficial effect of this application is: different from the prior art, the mobile terminal provided by the application comprises a circuit board and a front shell positioned on the circuit board, wherein the circuit board comprises a substrate, a radio frequency power amplifier and a shielding cover, the radio frequency power amplifier and the shielding cover are positioned on the substrate, and the shielding cover covers the radio frequency power amplifier; the front shell comprises a conductive grounding plate with a flat surface and an insulating layer positioned between the conductive grounding plate and the substrate, wherein the insulating layer is provided with an opening to expose the conductive grounding plate, and a shielding cover is embedded in the opening and is electrically connected with the conductive grounding plate, so that a radio frequency power amplifier is arranged in the shielding cover, and the shielding cover is electrically connected with the conductive grounding plate with the flat surface, thereby avoiding resonance points caused by uneven surface of the conductive grounding plate in the front shell, further reducing the interference of antenna harmonic radiation on GPS signal reception, and improving the GPS positioning precision.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a mobile terminal provided in an embodiment of the present application;

fig. 2 is a schematic structural view of the front case of fig. 1;

fig. 3 is another schematic structural diagram of a mobile terminal according to an embodiment of the present application;

FIG. 4 is a schematic diagram of the structure of the circuit board of FIG. 1;

fig. 5 is a schematic flow diagram of the path of generation of the second harmonic in fig. 4.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. It is to be noted that the following examples are only illustrative of the present application, and do not limit the scope of the present application. Likewise, the following examples are only some examples and not all examples of the present application, and all other examples obtained by a person of ordinary skill in the art without any inventive step are within the scope of the present application.

Currently, the AGPS (Assisted Global Positioning System) technology is a technology that combines network base station information and GPS (Global Positioning System) information to locate a mobile station, and can be used in Global System for mobile communications/general packet radio service (GSM/GPRS), Wideband Code Division Multiple Access (WCDMA), code division multiple access 2000

(CDMA2000), and Long Term Evolution (LTE) networks. However, when the frequency band 13 or 14 of LTE is used for AGPS positioning, since the frequency band 13 or 14 of LTE and GPS work simultaneously, the second harmonic generated by the frequency band 13 or 14 may just fall within the GPS receiving range, interfering with GPS receiving, and further causing a problem that GPS cannot perform positioning or cannot perform correct positioning. In order to solve the above problems, the present application provides a mobile terminal to reduce interference of antenna harmonic radiation on GPS signal reception, and further improve GPS positioning accuracy.

Referring to fig. 1 and fig. 2, fig. 1 is a schematic structural diagram of a mobile terminal according to an embodiment of the present application, and fig. 2 is a schematic structural diagram of a front case in fig. 1. As shown in fig. 1 and 2, the mobile terminal 10 includes a wiring board 11, and a front case 12 on the wiring board 11. The circuit board 11 includes a substrate 111, and a radio frequency power amplifier 112 and a shielding cover 113 disposed on the substrate 111, and the shielding cover 113 covers the radio frequency power amplifier 112. Further, the front case 12 includes a conductive ground plate 121 having a flat surface, and an insulating layer 122 disposed between the conductive ground plate 121 and the substrate 111, an opening 122A is disposed on the insulating layer 122 to expose the conductive ground plate 121, and the shielding lid 113 of the circuit board 11 is embedded in the opening 122A and electrically connected to the conductive ground plate 121.

In the present embodiment, the rf power amplifier 112 of the antenna is disposed in the sealed cavity formed by the shielding lid 113 and the substrate 111, so that the rf power amplifier 112 does not affect other electronic components or external interference signals when operating, and the shielding lid 113 is grounded through the conductive grounding plate 121, so that the return path of the rf signal emitted by the rf power amplifier 112 can be shortened, thereby reducing radiation.

Specifically, the inventor of the present application found in long-term research and development that, when the surface of the conductive ground plate of the front case of the mobile terminal is uneven, for example, there are some ribs formed by the conductive protrusions, the conductive ground plate may generate resonance points in some frequency ranges, that is, if the shielding cover 113 is grounded through the conductive ground plate with uneven surface, the conductive ground plate with uneven surface will not serve as ground, but serve as an antenna to radiate interference signals, thereby affecting the reception of GPS signals.

Therefore, in the present application, the front case 12 of the mobile terminal 10 employs the conductive ground plate 121 with a flat surface, and considering that a rib structure is still required to be disposed on the conductive ground plate 121 to support the electronic component in the mobile terminal, the insulating layer 122 is disposed on the conductive ground plate 121 with a flat surface, and the insulating layer 122 is provided with the opening 122A, so that the electronic component, such as the shielding cover 113, can be embedded and fixed in the opening 122A to obtain the support of the insulating layer 122, that is, the insulating layer 122 can replace the rib formed by the conductive bump, and is equivalent to replace the rib formed by the conductive bump that would originally generate the resonance point with the rib formed by the insulating bump that would not generate the resonance point.

The circuit board 11 may be a printed circuit board, the substrate 111 may be a flexible substrate or a rigid substrate, and the corresponding circuit board 11 may be a flexible printed circuit board or a rigid printed circuit board. The rf power amplifier 112 may be a multi-mode multi-band power amplifier, which can have better performance and integration. The conductive ground plate 121 may be made of a metal conductive material such as aluminum alloy, magnesium aluminum alloy, or zinc alloy. The insulating layer 122 may be made of an insulating material such as plastic or rubber.

The material of the shielding lid 113 may be a metal material such as copper, iron, aluminum, zinc, etc., and the thickness of the shielding lid 113 should be sufficiently thick to ensure the electromagnetic shielding effect of the shielding lid 113, for example, the thickness of the shielding lid 113 may be 0.4 to 0.8 mm. In addition, a conductive adhesive may be coated between the shield cover 113 and the substrate 111 to enable the shield cover 113 to be closely attached to the substrate 111.

In order to prevent the shielding cover 113 from moving in the opening 122A of the insulating layer 122, the shape and size of the shielding cover 113 may be matched with the shape and size of the opening 122A, so that the shielding cover 113 can be seamlessly embedded in the corresponding opening 122A.

In some embodiments, as shown in fig. 3, a conductive foam 13 may be disposed between the shielding cover 113 and the conductive ground plate 121, wherein the conductive foam 13 is a material integrating the conductive and electromagnetic shielding functions, and may be attached between the shielding cover 113 and the conductive ground plate 121 in a double-sided adhesive manner, so as to increase the adhesion between the shielding cover 113 and the conductive ground plate 121 and improve the shielding performance of the shielding cover 113.

In one embodiment, as shown in fig. 4, the circuit board 11 may further include a GPS receiving circuit 114 located on the substrate 111, wherein the GPS receiving circuit 114 is configured to receive a GPS signal when the mobile terminal 10 uses the GPS signal for positioning.

The location of the GPS receiving circuit 114 on the substrate 111 should be far away from the location of the rf power amplifier 112, so as to reduce coupling interference of the rf signal transmitted by the rf power amplifier 112 to the signal received by the GPS receiving circuit 114. For example, the GPS receiving circuit 114 and the rf power amplifier 112 may be disposed at opposite side edges of the substrate 111 at intervals, and specifically, as shown in fig. 4, the GPS receiving circuit 114 may be disposed at an upper edge of the substrate 111, and the rf power amplifier 112 covered by the shield cover 113 may be disposed at a lower edge of the substrate 111.

With reference to fig. 4, the circuit board 11 may further include a duplexer 115 and a low-frequency filter 116 on the substrate 111, and specifically, as shown in fig. 5, when performing AGPS positioning using the LTE band 13 or 14, there is a path for generating the second harmonic of the band 13 or 14: the rf power amplifier 112 to the duplexer 115 to the low frequency filter 116 to the antenna port T, and, in particular, the proper type of duplexer 115, low frequency filter 116 and rf power amplifier 112 may be selected to ensure that the second harmonic energy tested at the antenna port T is lower than-85 dBm/MHz, thereby reducing the interference of the second harmonic of the LTE antenna on the GPS signal reception.

It should be noted that the insulating layer 122 of the front housing 12 may further have a plurality of grooves (not shown), and some electronic components disposed on the substrate 111, such as the duplexer 115 and the low frequency filter 116, may be accommodated in the grooves of the insulating layer 122, so that the electronic components may be effectively supported.

In one embodiment, the mobile terminal 10 may further include a rear case (not shown) matching the size and shape of the front case 12, and the circuit board 11 is mounted between the front case 12 and the rear case. The circuit board 11 and the front housing 12 or the rear housing may be fixed in any manner, specifically, may be fixed by a nut or a bolt, and may also be fixed by a snap.

The rear housing may be made of metal, such as aluminum alloy and stainless steel, and the rear housing made of metal has a better appearance.

Further, the mobile terminal 10 may further include a display screen (not shown) disposed on the front housing 12, and the front housing 12 may provide support for the display screen. Specifically, the display screen may adopt an LCD (Liquid crystal display) screen for displaying information, and the LCD screen may be a TFT (Thin Film Transistor) screen or an IPS (In-plane switching) screen or an SLCD (split Liquid crystal display) screen. In other embodiments, the display screen may further adopt an OLED (Organic Light-Emitting display) screen for displaying information, and the OLED screen may be an AMOLED (Active Matrix Organic Light-Emitting Diode) screen or a Super AMOLED (Super Active Matrix Organic Light-Emitting Diode) screen or a Super AMOLED Plus (Super Active Matrix Organic Light-Emitting Diode) screen.

In the above embodiments, the mobile terminal 10 includes, but is not limited to, a smart phone, a tablet computer, and the like.

Different from the prior art, the mobile terminal in this embodiment includes a circuit board and a front case located on the circuit board, where the circuit board includes a substrate, and a radio frequency power amplifier and a shielding cover located on the substrate, and the shielding cover covers the radio frequency power amplifier; the front shell comprises a conductive grounding plate with a flat surface and an insulating layer positioned between the conductive grounding plate and the substrate, wherein the insulating layer is provided with an opening to expose the conductive grounding plate, and a shielding cover is embedded in the opening and is electrically connected with the conductive grounding plate, so that a radio frequency power amplifier is arranged in the shielding cover, and the shielding cover is electrically connected with the conductive grounding plate with the flat surface, thereby avoiding resonance points caused by uneven surface of the conductive grounding plate in the front shell, further reducing the interference of antenna harmonic radiation on GPS signal reception, and improving the GPS positioning precision.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A mobile terminal is characterized by comprising a circuit board and a front shell positioned on the circuit board, wherein the circuit board comprises a substrate, a radio frequency power amplifier and a shielding cover, the radio frequency power amplifier and the shielding cover are positioned on the substrate, and the shielding cover covers the radio frequency power amplifier; the front shell comprises a conductive grounding plate with a smooth surface and an insulating layer positioned between the conductive grounding plate and the substrate, wherein an opening is formed in the insulating layer to expose the conductive grounding plate, and the shielding cover is embedded in the opening and is electrically connected with the conductive grounding plate.

2. The mobile terminal of claim 1, wherein a conductive foam is disposed between the shield cover and the conductive ground plate.

3. The mobile terminal of claim 1, wherein the radio frequency power amplifier is a multi-mode multi-band power amplifier.

4. The mobile terminal of claim 1, wherein the conductive ground plane comprises an aluminum alloy, a magnesium aluminum alloy, or a zinc alloy.

5. The mobile terminal of claim 1, wherein the insulating layer is made of plastic.

6. The mobile terminal of claim 1, wherein the wiring board further comprises a GPS receiving circuit located on the substrate.

7. The mobile terminal of claim 6, wherein the GPS receive circuit is spaced from the radio frequency power amplifier at opposite side edges of the substrate.

8. The mobile terminal of claim 1, further comprising a rear housing that matches the size and shape of the front housing, the circuit board being mounted between the front housing and the rear housing.

9. The mobile terminal of claim 1, further comprising a display screen located on the front housing.

10. The mobile terminal of claim 1, wherein the wiring board further comprises a duplexer and a low frequency filter on the substrate.