EP3159963B1

EP3159963B1 - Antenna and terminal

Info

Publication number: EP3159963B1
Application number: EP14895302.9A
Authority: EP
Inventors: Qun Li
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2014-06-20
Filing date: 2014-12-08
Publication date: 2021-01-20
Anticipated expiration: 2034-12-08
Also published as: WO2015192614A1; EP3159963A1; EP3159963A4; CN105281014A; WO2015192594A1; CN105281014B

Description

TECHNICAL FIELD

The present disclosure relates to the field of mobile communications, and more particularly, to an antenna and a terminal.

BACKGROUND

Antennas are indispensable components in communications systems, and antenna performance may have a direct bearing on quality in receiving and transmitting signals. Nowadays, sizes of smart terminals trend towards thinner and smaller. Therefore, sizes of antennas built-in the terminals need to be smaller and smaller, and a traditional PIFA (Planar Inverted-F Antenna) needs to have a height of at least 7mm. However, the wider the frequency band needs to be supported by an antenna is, the greater the height and the area of the antenna are. A monopole antenna is required to have a certain clearance area, and the wider the frequency band of the antenna is, the larger the clearance area of the antenna is. Conventional antennas are generally attached to housings in forms of FPC (flexible printed circuit) or steel sheets and then are connected with a mainboard via spring plates or pins to form a passage. However, in this manner, it is required that enough areas are kept in housing structures for the antennas. Meanwhile, generally in order that the antenna may have excellent radiation performances, the antenna need to be installed in housing areas as far as possible from the mainboard. In this way, space of the antenna occupying in the terminal is increased, which may cause sizes of the terminal to be increased. WO 2013/011339 A1 describes a multi-band wireless communication terminal comprising a metal backplate defining a slot between spaced-apart regions thereof, a grounding element bridging the slot between the spaced-apart regions, and a coupling feed element bridging a portion of the slot. US 2013/0181871 describes an antenna device for a portable terminal having first and second antenna elements. The first antenna element includes one or more metal members electrically connected with a ground surface of the PCB and has a slot. The second antenna element is disposed in proximity to the slot spaced from and electromagnetically coupled to the first antenna element. CN103441329 describes an LCD metal plate radiating antenna of a smartphone. The antenna comprises an LCD metal plate, a coupling element and a feeder line. The LCD metal plate is located below a circuit board and on a plane parallel to the circuit board. The coupling element is connected with the LCD metal plate through a grounding circuit.

SUMMARY

A technical problem to be solved by the present disclosure is a problem that a traditional antenna occupies a relatively large space of a terminal.
To solve the above technical problem, the invention provides an antenna in a terminal according to claim 1.
In an embodiment, the terminal further includes another antenna arranged on the housing of the terminal.
In an embodiment, one side of the open cavity is provided with another cavity.
In an embodiment, the open cavity is in shape of a rectangle.
In an embodiment, the antenna has a radiation frequency of 1710 MHz to 2200 MHz.
In an embodiment, the extended portion of the support plate is connected with a ground feed point of the mainboard of the terminal, and the radiator is connected with a signal feed point of the mainboard of the terminal.
In an embodiment, the support plate is made from aluminum magnesium alloy, zinc alloy or stainless steel.
In an embodiment, the support plate or the extended portion of the support plate and the radiator are respectively connected with a ground feed point of the mainboard of the terminal and a signal feed point of the mainboard of the terminal via a pin or a spring plate.
In the embodiments of the present disclosure, the extended portion of the support plate and the radiator are employed to form a coupled fed antenna. In this way, internal space of the terminal may be fully utilized, and a utilization rate of the internal space of the terminal may be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a layout of a metal support plate inside a mobile phone according to embodiments of the present disclosure;
FIG. 2 is a schematic diagram illustrating an antenna according to embodiments of the present disclosure;
FIG. 3 is a schematic side view illustrating interior of a terminal provided with the antenna according to embodiments of the present disclosure;
FIG. 4 is a chart of return loss generated when an antenna according to embodiments of the present disclosure is used as an individual antenna;
FIG. 5 is an efficiency curve chart of an antenna according to embodiments of the present disclosure within a frequency range of 1710 MHz to 2160 MHz;
FIG. 6 is an efficiency curve chart of an antenna according to embodiments of the present disclosure within a frequency range of 710 MHz to 890 MHz;
FIG. 7 is an efficiency curve chart depicted, with a combination of an antenna according to embodiments of the present disclosure and an antenna built-in the terminal, within a frequency range of 1710 MHz to 2160 MHz; and
FIG. 8 is an efficiency curve chart depicted, with a combination of an antenna according to embodiments of the present disclosure and an antenna built-in the terminal, within a frequency range of 710 MHz to 890 MHz.

DETAILED DESCRIPTION

To solve the problem in the prior art that an antenna occupies a relatively large internal space of a terminal, the present disclosure provides an antenna and a terminal. The following further describes in detail the present disclosure with reference to the accompanying drawings and the embodiments. It should be understood that the embodiments described herein are merely used to explain the present disclosure, and are not intended to limit the present disclosure.
The terminal as mentioned in this embodiment takes a mobile phone as an example, generally an internal structural layout thereof is as shown in FIG. 1. To a structure whose printed circuit board (PCB) of a mainboard is smaller than a liquid crystal display (LCD) in size, a metal support plate needs to be added to increase stability of the mainboard and the LCD. To provide better radiation performance of the antenna, generally no metal structural part extends below the antenna of the mobile phone, and generally a gap of about 1-2mm is provided between the PCB and the metal support plate. In the antenna provided by the embodiments of the present disclosure, a coupled feeding antenna (hereinafter referred to as antenna) is formed, based on the support plate, with an extended portion of the support plate exceeding a joint between the support plate and a housing of the terminal, or with a part of the support plate itself.
FIG. 2 is a schematic diagram illustrating an antenna according to embodiments of the present disclosure.
As shown in FIG. 2, the antenna is composed of extended portions 7 and 8 of a support plate 2 inside the terminal and a radiator 6, where the support plate may be made from aluminum magnesium alloy, zinc alloy or stainless steel. The extended portion of the support plate 2 refers to a portion of the support plate exceeding a joint 3 between the support plate 2 and a housing of the terminal. Dashed areas as shown in FIG. 2 are representative of the support plate 2 inside the terminal and the extended portion of the support plate. In an embodiment, the radiator 6 may be implemented by means of a sheet radiator from the extended portion of the support plate, or also may be implemented by means of other radiators made from materials different from the support plate 2. The support plate 2 is connected with a mainboard 1 of the terminal, and the extended portions of the support plate are used for forming a coupled feeding with the radiator 6 to constitute a coupled fed antenna. The extended portion 7 and 8 of the support plate are connected with a ground feed point 4 of the mainboard 1 of the terminal, and the radiator 6 is connected with a signal feed point 5 of the mainboard of the terminal. As a high-band radiator combined with the extended portion of the support plate, the radiator 6 may radiate energy within a waveband of 1710 MHz to 2200 MHz. A resonance generating higher frequency points may also be designed according to the needs. The extended portion 7 and 8 of the support plate are mainly used to couple with the radiator 6 to generate a low-band resonance, where a wire arrangement mode thereof is not limited to what is shown in FIG. 2. Different wire arrangements may be designed and formed for purpose of generating excitation.
It is to be noted that a structure of the antenna in the embodiments of the present disclosure is not limited to the concrete structure as shown in FIG. 2. The structure of the antenna may be any antenna structure as long as following conditions are satisfied. The extended portion of the support plate inside the terminal is provided with an open cavity, one side of the open cavity is provided with another cavity, and the radiator is arranged in the open cavity. The open cavity as shown in FIG. 2 is in shape of a rectangle, which is merely a specific implementation form of the antenna as mentioned in the embodiments of the present disclosure.
FIG. 3 is a schematic side view illustrating interior of a terminal provided with the antenna according to embodiments of the present disclosure. In this figure, the terminal takes a mobile phone as an example to make a further description of the antenna provided by the embodiments of the present disclosure.
The mobile phone as shown in FIG. 3 internally includes a PCB 1 and a metal support plate 2. The antenna involved in this embodiment may further include another antenna 9, which may be an antenna built-in the mobile phone and may be arranged on the housing of the terminal. The antenna constituted by the extended portions 7 and 8 of the support plate inside the terminal is connected to the mainboard via the ground feed point 4 and the signal feed point 5. Specifically, the extended portion of the support plate and the radiator 6 are respectively connected with the ground feed point and the signal feed point of the mainboard of the terminal via a pin and a spring plate. It is to be noted that the radiator 6 and the extended portions 7 and 8 inside the support plate are in the same plane. Concrete structures of the radiator 6 and the extended portions 7 and 8 of the support plate are not shown in a test chart as shown in FIG. 3. The reference sign 3 as shown in the figure represents a joint between the metal support plate and a plastic part of a front housing of the mobile phone. In a conventional mobile phone, a length of the support plate reaches the position of the reference sign 3 or slightly stretches downward by 1-2mm to increase stability. In this embodiment, the support plate is properly prolonged, and the extended portion thereof are used to form a coupled fed antenna which is designed by adopting a coupled feeding manner to obtain an antenna having a wider frequency band within a smaller area. However, the antenna is relatively narrow in a low-frequency bandwidth and is not high enough in radiation efficiency. Therefore, in addition to meeting design needs, the extended portion of the grounded metal support plate positioned at the bottom of the mobile phone is as short as possible. Accordingly, an antenna 9 is additionally designed on the housing of the mobile phone to meet the needs. The design and the performance of the antenna 9 may be adversely affected if the extended portions of the support plate are prolonged downward excessively, and a coupling effect may exist therebetween, which is relatively difficult for debugging. The antenna may be used to generate a part of resonance which may be a high-band resonance. The antenna may be used as an individual high-band antenna and may be connected with the antenna 9 on the housing of the mobile phone to generate a resonance of another frequency band, which may be a low frequency.
FIG. 4 is a chart of return loss generated when the antenna according to embodiments of the present disclosure is used as an individual antenna. As can be seen, it is somewhat difficult to cover a low frequency range. FIG. 5 is an antenna efficiency curve chart of an antenna according to embodiments of the present disclosure within a frequency range of 1710 MHz to 2160 MHz. As can be seen from FIG. 5, a high frequency efficiency can basically meet the design needs. FIG. 6 is an efficiency curve chart of an antenna according to embodiments of the present disclosure within a frequency range of 710 MHz to 2160 MHz. As can be seen from FIG. 6, a low frequency is not high in efficiency, nearby the intermediate 800MHZ is a little better, the antenna efficiency may reach about 14%, and a high frequency part is better in covering 1710 MHz to 2300 MHz. FIG. 7 is an efficiency curve chart depicted, with a combination of an antenna according to embodiments of the present disclosure and an antenna built-in the terminal, within a frequency range of 1710 MHz to 2160 MHz, while FIG. 8 is an efficiency curve chart depicted, with a combination of an antenna according to embodiments of the present disclosure and an antenna built-in the terminal, within a frequency range of 710 MHz to 890 MHz. As can be seen from FIG. 7 and FIG. 8, the antenna efficiency is greatly improved within a low frequency range.
The embodiments of the present disclosure further provide a terminal, where the terminal may include any one of following antennas. The antenna is composed of an extended portion of a support plate inside the terminal and a radiator, the support plate is connected with a mainboard of the terminal, the extended portion of the support plate is used for forming a coupled feeding with the radiator, and the extended portion of the support plate refers to a portion of the support plate exceeding a joint between the support plate and a housing of the terminal.
The antenna further includes another antenna, which is arranged on the housing of the terminal.
The extended portion of the support plate is provided with an open cavity, one side of which is provided with another cavity, the radiator is arranged in the open cavity, and the antenna is composed of the open cavity and the radiator arranged in the open cavity. The open cavity may also be in shape of a rectangle.
The antenna built-in the terminal has a radiation frequency of 1710 MHz to 2200 MHz.
The extended portion of the support plate may be connected with a ground feed point of the mainboard of the terminal, while the radiator may be connected with a signal feed point of the mainboard of the terminal.
The support plate may be made from aluminum magnesium alloy, zinc alloy or stainless steel.
The extended portion of the support plate and the radiator may be respectively connected with the ground feed point of the mainboard of the terminal and the signal feed point of the mainboard of the terminal via a pin or a spring plate.
The antenna provided by the embodiments of the present disclosure not only can fully utilize internal space of the terminal, but also can ensure that the antenna keeps away from a human body when a user is using the terminal, which may reduce a specific absorption rate (SAR) of the antenna and reduce a loss of the antenna efficiency when the terminal is in a usage status. Therefore, when the antenna provided by the embodiments of the present disclosure is combined with the antenna built-in the terminal, the overall efficiency of the antennas may be improved.
Although preferred embodiments of the present disclosure have been disclosed for illustrative purposes, those skilled in the art will realize that various improvements, increases and substitutions are also possible. Therefore, the scope of the present disclosure shall be not limited to the foregoing embodiments.

Claims

A terminal, comprising:
a support plate (2) inside the terminal and having a joint (3) between the support plate and a plastic part of a front housing of the terminal, the support plate (2) being connected with a mainboard (1) of the terminal, the support plate having an extended portion (7, 8) of the support plate (2), the extended portion (7, 8) of the support plate (2) being a portion of the support plate (2) extending beyond the joint (3);

an antenna, the antenna comprising the extended portion (7, 8) of the support plate and a radiator (6),

wherein:
the extended portion of the support plate is configured to form a coupled feeding with the radiator (6) and is provided with an open cavity, and

the radiator is arranged in the open cavity and in the same plane as the extended portion (7, 8).
The terminal according to claim 1, further comprising another antenna (9) arranged on the housing of the terminal.
The terminal according to claim 1, wherein one side of the open cavity is provided with another cavity.
The terminal according to claim 1, wherein the open cavity is in shape of a rectangle.
The terminal according to claim 1, wherein the antenna has a radiation frequency of 1710 MHz to 2200 MHz.
The terminal according to claim 1, wherein the extended portion (7, 8) of the support plate (2) is connected with a ground feed point (4) of the mainboard of the terminal, and the radiator (6) is connected with a signal feed point (5) of the mainboard of the terminal.
The terminal according to claim 1, wherein the support plate (2) is made from aluminum magnesium alloy, zinc alloy or stainless steel.
The terminal according to claim 1, wherein the support plate (2) or the extended portion (7, 8) of the support plate (2), and the radiator (6) are respectively connected with a ground feed point (4) of the mainboard of the terminal and a signal feed point (5) of the mainboard of the terminal via a pin or a spring plate.