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CN-120545666-B - Antenna structure and mobile terminal

CN120545666BCN 120545666 BCN120545666 BCN 120545666BCN-120545666-B

Abstract

The application provides an antenna structure and a mobile terminal. The antenna structure comprises a radiator and an impedance matching circuit, wherein the radiator comprises a first branch and a second branch which are connected, one end, deviating from the second branch, of the first branch is an open end, the first branch comprises a feed point, one end, deviating from the first branch, of the second branch is grounded, and a connecting point of the first branch and the second branch is grounded through an inductive structure. The physical length L1 of the first branch and the physical length L2 of the second branch are equal to or less than 4/5 and equal to or less than 1/L2 and equal to or less than 4/3, and the distance d between the feeding point and one end of the first branch, which is far away from the second branch, is equal to or less than 1/4 multiplied by L1. The impedance matching circuit is electrically connected with the feed point and comprises an inductor. According to the application, the antenna structure is constructed as the homodromous slot antenna, so that electric fields generated by all parts of the radiator of the antenna structure are homodromous, and the directional diagram of the antenna structure facing to one side of the display screen is convenient to tune, so that the handheld performance of the antenna structure is optimized.

Inventors

  • WANG JIAMING
  • LEI LIBIN
  • ZHAO FANGCHAO
  • YU DONG
  • ZHAO GE
  • LIU DAN

Assignees

  • 华为技术有限公司

Dates

Publication Date
20260505
Application Date
20240304

Claims (13)

  1. 1. The mobile terminal comprises a frame and an antenna structure, wherein the frame is circumferentially arranged around the periphery of the mobile terminal, the antenna structure comprises a radiator and an impedance matching circuit, the radiator is arranged on one side edge of the frame, The radiator comprises a first branch and a second branch which are connected, one end of the first branch, which is far away from the second branch, is an open end, the first branch comprises a feed point, one end of the second branch, which is far away from the first branch, is grounded, the connection point of the first branch and the second branch is grounded through an inductive structure, and the currents of the first branch and the second branch are in the same direction; The physical length L1 of the first branch and the physical length L2 of the second branch are 4/5-1/L2-4/3; the distance d between the feeding point and one end of the first branch, which is far away from the second branch, is less than or equal to 1/4 multiplied by L1; The impedance matching circuit is electrically connected with the feed point and comprises serially connected inductors; The sum of the electric length lambda 1 of the first branch and the electric length lambda 2 of the second branch meets the condition that lambda 1+ lambda 2 is more than or equal to 1/2 multiplied by lambda, wherein lambda is the wavelength corresponding to resonance generated by the antenna structure.
  2. 2. The mobile terminal of claim 1, wherein the antenna structure is configured to operate in a low frequency band comprising at least one communication band within 600MHz-1 GHz.
  3. 3. The mobile terminal of claim 2, wherein the inductance of the inductor has an inductance value of greater than or equal to 15nH.
  4. 4. The mobile terminal of any one of claims 1-3, wherein the antenna structure further comprises a tuning circuit, one end of the tuning circuit is grounded, the other end of the tuning circuit is electrically connected between the impedance matching circuit and the feed point, and the tuning circuit comprises at least one capacitor.
  5. 5. The mobile terminal of claim 4, wherein a capacitance value of the at least one capacitor is less than or equal to 2pF.
  6. 6. The mobile terminal of claim 4, wherein the tuning circuit comprises a plurality of the capacitors, the plurality of capacitors being arranged in parallel.
  7. 7. A mobile terminal according to any of claims 1-3, wherein the antenna structure further comprises a feed circuit, the impedance matching circuit being electrically connected between the feed circuit and the feed point.
  8. 8. The mobile terminal according to any one of claims 1 to 3, further comprising a middle frame, wherein the middle frame is located in a section formed by surrounding the frame, one end of the second branch, which is away from the first branch, is connected with the middle frame, and a connection point of the first branch and the second branch is connected with the middle frame through the inductive structure.
  9. 9. The mobile terminal of claim 8, wherein the middle frame includes a battery compartment, the radiator is located on a side of one of the sides of the frame facing the battery compartment, and a connection point of the first and second branches is lower than a top of the battery compartment in a direction from the second branch to the first branch.
  10. 10. The mobile terminal of claim 9, wherein the inductive structure includes a ground connection rib between the battery compartment and the radiator, one end of the ground connection rib being connected to a connection point of the first branch and the second branch, and the other end of the ground connection rib being connected to the middle frame.
  11. 11. The mobile terminal of claim 10, wherein the ground connection bar, the center frame, and the bezel are an integrally formed structure.
  12. 12. The mobile terminal of claim 9, wherein the inductive structure is a separate structure, and wherein the inductive portion of the inductive structure is connected to a connection point of the first leg and the second leg and to the center.
  13. 13. The mobile terminal of claim 8, wherein a clear gap exists between the radiator and the center.

Description

Antenna structure and mobile terminal The present application is a divisional application, the application number of which is 202410259371.5, the application date of which is 2024, 03, 04, and the entire contents of which are incorporated herein by reference. Technical Field The present application relates to the field of communications technologies, and in particular, to an antenna structure and a mobile terminal. Background With the development of mobile communication, the use rate of mobile terminals is increasing. The network coverage of a mobile cellular network is the key place for mobile communications, while the key devices used by mobile cellular networks to achieve network coverage are antennas. In the current mobile terminal, a frame antenna for radiating a low frequency signal is generally disposed at one side of a battery compartment of the mobile terminal, and a length of a radiator thereof is about one quarter of a wavelength corresponding to a center frequency of a resonant frequency of the antenna. The radiation efficiency of the antenna in the free space is higher, but in the state that a user holds the mobile terminal, as the energy radiated to the rear shell side of the mobile terminal by the frame antenna is covered by hands, the radiation energy of the frame antenna is greatly reduced in the holding state, so that the radiation performance of the frame antenna is influenced. Based on this, how to ensure the radiation efficiency of the antenna in the free space and simultaneously reduce the radiation energy of the antenna in the handheld state of the mobile terminal effectively has become a difficult problem to be solved by those skilled in the art. Disclosure of Invention The application provides an antenna structure and a mobile terminal, which are used for optimizing the handheld performance of the antenna structure on the basis of guaranteeing the radiation efficiency of the antenna structure in a free space, so that the communication performance of the mobile terminal is improved. In a first aspect, the present application provides an antenna structure comprising a radiator and an impedance matching circuit. The radiator comprises a first branch and a second branch which are connected, one end, deviating from the second branch, of the first branch is an open end, the first branch comprises a feed point, one end, deviating from the first branch, of the second branch is grounded, and a connecting point of the first branch and the second branch is grounded through an inductive structure. In addition, the physical length L1 of the first branch and the physical length L2 of the second branch are 4/5-4/3. And the distance d between the feeding point and one end of the first branch, which is far away from the second branch, is less than or equal to 1/4 multiplied by L1. In addition, an impedance matching circuit is electrically connected to the feed point, the impedance matching circuit including an inductance. In the application, the antenna structure is constructed as the homodromous slot antenna, so that the purpose of enabling electric fields generated by all parts of the radiator of the antenna structure to be in the same direction is achieved, thereby being convenient for tuning the directional diagram of the antenna structure towards one side of the display screen, ensuring the radiation efficiency of the antenna structure in free space and simultaneously optimizing the hand holding performance of the antenna structure. The antenna structure provided by the application can be used for working in a low-frequency band, wherein the low-frequency band comprises at least one communication frequency band within 600MHz-1 GHz. In addition, the inductor in the impedance matching circuit can be used for carrying out impedance matching on the antenna structure so as to achieve the purpose of adjusting the resonance frequency generated by the antenna structure. In one possible implementation, the inductance of the inductor in the impedance matching circuit has an inductance value of 15nH or greater to meet the impedance matching requirements of the antenna structure to facilitate the antenna structure to produce a slot-like antenna pattern. In one possible implementation of the present application, the antenna structure further includes a tuning circuit, one end of the tuning circuit is grounded, and the other end of the tuning circuit is electrically connected between the impedance matching circuit and the feeding point. In addition, the tuning circuit includes at least one capacitor. Wherein at least one capacitor of the tuning circuit is operable to perform a frequency tuning function, that is, when the corresponding capacitor is electrically connected between the impedance matching circuit and the feed point, the antenna structure is operable in a corresponding communication frequency band. In the application, the capacitance value of at least one capacitor of the tuning circuit is less th