CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Stage of International Patent Application No. PCT/CN2018/124150 filed on Dec. 27, 2018, which claims priority to Chinese Patent Application No. 201810554555.9 filed on Jun. 1, 2018. The disclosures of the aforementioned applications are hereby incorporated by reference in their entireties.

TECHNICAL FIELD

This application relates to the communications field, and in particular, to an antenna and a mobile terminal including the antenna.

BACKGROUND

Most of current mobile terminals have a call function, and are internally provided with antennas used to communicate with the outside. When a user makes a call, a mobile terminal is usually in a head-hand mode, and antenna signal attenuation is relatively serious when the mobile terminal is in the head-hand mode, affecting a call effect of the mobile terminal.

SUMMARY

An objective of this application is to provide an antenna that can still maintain relatively good signal sending and receiving performance in a head-hand mode. The following technical solutions are included:

An antenna is provided, and includes a feed stub, a parasitic stub, a feed branch, a grounding branch, and a grounding portion. The antenna apparatus is disposed in a mobile terminal, the mobile terminal includes a radiation portion and a circuit board, the circuit board includes a lateral side, the grounding portion is disposed on the whole or a part of a grounding layer on the circuit board, the lateral side is located on an edge of the grounding portion, a gap is formed between the radiation portion and the lateral side, the radiation portion is provided with an insulating slot, the insulating slot divides the radiation portion into the feed stub and the parasitic stub, the feed branch extends from the feed stub to the gap, an end that is of the feed branch and that is far away from the feed stub is a feed point, the grounding branch extends from the parasitic stub to the gap and is electrically connected to the grounding portion, the lateral side is located between an end that is of the feed stub and that is far away from the insulating slot and an end that is of the parasitic stub and that is far away from the insulating slot, and the end that is of the feed stub and that is far away from the insulating slot and the end that is of the parasitic stub and that is far away from the insulating slot both are electrically connected to the grounding portion.

Specifically, a resonance generated by the antenna on the grounding portion, the feed stub, and the parasitic stub excites an induced current loop winding around the gap.

According to the antenna in this application, the gap is encompassed by the radiation portion and the lateral side, the insulating slot divides the radiation portion into the feed stub and the parasitic stub, and the feed branch and the grounding branch are respectively extended in a direction in which the feed stub faces the gap and in a direction in which the parasitic stub faces the gap. The end that is of the feed branch and that is far away from the feed stub is the feed point, configured to conduct a radio frequency signal. An end that is of the grounding branch and that is far away from the parasitic stub is electrically connected to the grounding portion, to maintain a zero potential of the grounding branch. When the feed point starts feeding the antenna, the feed branch is coupled to the grounding branch, and an induced current extending in a length direction of the gap is excited on the lateral side. The current passes through the lateral side, the feed stub, and the parasitic stub to form a current loop cycling around the gap. The feed branch and the grounding branch may form a resonance to the current at a position having a relatively large induced current, so that radiation power of the antenna is enlarged, thereby improving signal sending and receiving performance of the antenna.

A transmit frequency of the antenna includes a low frequency band of 617 MHz to 960 MHz, and further includes LTE and GPS frequency bands close to low frequencies, such as an LTE B11/21/32 frequency band (1427 MHz to 1511 MHz) and a GPS L1/L2/L5 frequency band (1575.42 MHz/1227.6 MHz/1176.45 MHz).

The grounding portion, the feed stub, and the parasitic stub jointly constitute an electrical length that is a half of a wavelength of an operating frequency of the antenna, so that the resonance that is generated by the grounding portion, the feed stub, and the parasitic stub excites the induced current that winds around the gap and that has a relatively large value, thereby helping improve radiation efficiency.

A size range of the insulating slot in the length direction of the radiation portion is greater than or equal to 0.2 mm and less than or equal to 2 mm, to ensure that the feed stub is coupled to the parasitic stub. The length direction of the radiation portion is a direction in which the radiation portion extends from the feed stub to the parasitic stub.

The coupling between the feed branch and the grounding branch may be further adjusted through a capacitance generated by two parallel planes formed by the insulating slot.

The insulating slot further includes a conductive suspension section, the suspension section is located between the feed stub and the parasitic stub, and an insulating separation slot is separately disposed between the suspension section and the feed stub and between the suspension section and the parasitic stub. The suspension section may be used to arrange structures such as a key or an interface of the mobile terminal.

Relative to a grounding point of the feed stub, the feed branch is closer to an end of the insulating slot on the feed stub, and relative to the grounding point of the feed stub, the grounding branch is closer to the end of the insulating slot on the parasitic stub. Specifically, a first distance is less than a second distance, and a third distance is less than a fourth distance. The first distance is a distance between the insulating slot and a portion that connects the feed branch and the feed stub. The second distance is a distance between the portion that connects the feed branch and the feed stub and a position at which the feed stub is electrically connected to the grounding portion. The third distance is a distance between the insulating slot and a portion that connects the grounding branch and the parasitic stub. The fourth distance is a distance between the portion that connects the grounding branch and the parasitic stub and a position at which the parasitic stub is electrically connected to the grounding portion. A midpoint position of the lateral side is a position having a largest induced current, and after the suspension section is added, the feed branch and the grounding branch are close to each other, thereby implementing a better coupling effect.

A size range of the suspension section in the length direction of the radiation portion is greater than or equal to 12 mm and less than or equal to 18 mm. A size range of the separation slot in the length direction of the radiation portion is greater than or equal to 0.2 mm and less than or equal to 1.5 mm. This setting may match most keys or interfaces, and the coupling between the grounding branch and the feed branch is ensured.

A range of a length by which the feed branch extends to the gap is greater than or equal to ⅙ of the wavelength of the operating frequency of the antenna, and less than or equal to ⅛ of the wavelength of the operating frequency of the antenna. A length by which the grounding branch extends to the gap is ¼ of the wavelength of the operating frequency of the antenna, so that efficient coupling between the grounding branch and the feed branch can be further ensured.

A parasitic frequency modulation apparatus is disposed between the grounding branch and the grounding portion, and is configured to adjust a frequency of the grounding branch.

The feed branch is further provided with a feed frequency modulation branch, the feed frequency modulation branch is located in a direction in which the parasitic stub extends towards the feed stub, the feed frequency modulation branch also extends towards the gap, and the feed frequency modulation branch is electrically connected to the grounding portion. The feed frequency modulation branch may be configured to ground the feed stub.

A feed frequency modulation apparatus is further disposed between the feed frequency modulation branch and the grounding portion, and the feed frequency modulation apparatus is configured to adjust a frequency of the feed stub.

The lateral side includes a first segment and a second segment that intersect with each other. The feed stub or the parasitic stub bends synchronously along with the lateral side, to ensure a consistent cross-sectional width of the gap in the length direction. To be specific, the feed stub or the parasitic stub also includes two intersected shapes. A length of the gap may be extended by a combination of the first segment and the second segment, so that a matching range of the wavelength of the antenna is enlarged.

The lateral side further includes a third segment, the first segment is connected between the second segment and the third segment, the third segment intersects with the first segment, and the second segment and the third segment bend in a same direction from the first segment. The feed stub bends synchronously along with the third segment, and the parasitic stub bends synchronously along with the second segment. To be specific, the feed stub and the parasitic stub both include two intersected shapes. The third segment may be used to further extend the length of the gap, and cooperate with the first segment and the second segment to adjust a position of the insulating slot on the mobile terminal.

The third segment and the second segment are distributed symmetrically on two ends of the first segment, and the parasitic stub and the feed stub are distributed symmetrically on two sides of the insulating slot. A length of the third segment is equal to that of the second segment, so that the insulating slot is located at a center position of a frame on a side of the mobile terminal.

This application further relates to a mobile terminal, including a transceiver and the foregoing antenna. The transceiver is electrically connected to a feed point in the antenna, and the transceiver exchanges data with the outside through the antenna. It can be understood that the mobile terminal may implement a better call effect by using the antenna.

The lateral side is located at a bottom end of the mobile terminal, a short side close to a position at which an earpiece is disposed in the mobile terminal is a top end of the mobile terminal, and a position of the lateral side helps expose the antenna and avoid covering in a call status.

