TW201717479A - Antenna structure - Google Patents

Abstract

The present disclosure provides an antenna structure comprising a ground plane, a radiating metal plate, a feeding connection metal, a first ground metal, a second ground metal and an inductor. The radiating metal plate is vertically disposed above an edge of the ground plane with a vertical spacing distance. The radiating metal generates a first mode which is a quarter wavelength resonant mode. A side of the radiating metal plate is disposed with a feeding connection terminal, a first shorting connection terminal and a second shorting connection terminal. The first shorting connection terminal and the second shorting connection terminal are respectively at opposite side of the feeding connection terminal. The feeding connection metal connected with the feeding connection terminalis coupled to a RF input signal. The first ground connection metal connects the first shorting connection terminal to the ground plane. The second ground connection metal and the inductor connect the second shorting connection terminal to the ground plane.

Description

Antenna structure

The present invention relates to an antenna, and more particularly to an antenna structure integrated with a handheld mobile communication device.

The popularity of handheld mobile communication devices allows people to communicate with each other anytime and anywhere, thus increasing the convenience of everyday life. For handheld mobile communication devices, such as common handheld mobile phones, they use RF circuitry in conjunction with appropriate antenna elements to provide good voice or data communication quality. In the design of the wireless communication system, the characteristics of the antenna component substantially affect the signal transmission capability of the wireless communication system, and actually the user's evaluation of the communication quality.

However, in recent years, there has been an increasing demand for the functionality and appearance of handheld mobile communication devices. Therefore, antenna design developers often need to design the appropriate antenna structure for the structural body of the handheld mobile communication device and its materials. Therefore, it is a basic challenge for the antenna design and development personnel to provide good antenna characteristics while integrating the antenna structure into the appearance structure or internal components of the handheld mobile communication device as much as possible.

Embodiments of the present invention provide an antenna structure for providing an antenna structure capable of being highly integrated with a handheld mobile communication device.

Embodiments of the present invention provide an antenna structure including a grounded metal surface, a radiating metal piece, a feed connection metal, a first ground metal, a second ground metal, and an inductor. The radiating metal piece is vertically disposed above the edge of the grounded metal surface, and is opposite to the side The edge maintains a vertical clearance distance, and the vertical projection of the radiating metal piece on the grounded metal surface overlaps the edge of the grounded metal surface, wherein the radiating metal piece generates a first mode, and the first mode is a quarter-wave resonant mode state. The side of the radiating metal piece away from the grounded metal surface is provided with a feeding connection point, a first short circuit connection point and a second short circuit connection point, and the first short circuit connection point and the second short circuit connection point are respectively located at two sides of the feeding connection point . The feed connection metal has one end connected to the feed connection point and the other end connected to the RF input signal. The first grounding metal has one end connected to the first short-circuit connection point and the other end connected to the ground metal surface. The second grounding metal is connected in series with the inductor to be electrically connected between the second short-circuit connection point and the grounded metal surface.

In summary, the embodiment of the present invention provides an antenna structure in which a radiating metal piece perpendicular to a grounded metal surface is used, and a radiating metal piece is disposed on an edge of the grounded metal surface, and two of the two are disposed at the feeding connection point. The grounding design on the side enables an antenna structure that is highly integrated with the handheld mobile communication device.

The detailed description of the present invention and the accompanying drawings are to be understood by the claims The scope is subject to any restrictions.

1‧‧‧Antenna structure

11‧‧‧Grounded metal surface

111‧‧‧ edge

12‧‧‧radiation metal sheet

121‧‧‧ side

d‧‧‧Vertical headroom

f‧‧‧Feeding connection point

S1‧‧‧ first short-circuit connection point

S2‧‧‧Second short-circuit connection point

13‧‧‧Feed connection metal

14‧‧‧First grounded metal

15‧‧‧Second grounding metal

17‧‧‧RF circuit

Ant1, Ant2, Ant3‧‧‧ antenna structure

Ls‧‧‧Inductance

L‧‧‧ Length of second grounded metal

M1, M1’‧‧‧ first mode

MH‧‧‧high-order mode

FIG. 1 is a conceptual diagram of an antenna structure according to an embodiment of the present invention.

2A is a schematic diagram of an equivalent circuit of a partial antenna structure according to an embodiment of the present invention.

FIG. 2B is a schematic diagram of an equivalent circuit of a partial antenna structure according to an embodiment of the present invention.

2C is a schematic diagram of an equivalent circuit of an antenna structure according to an embodiment of the present invention.

FIG. 3A is a schematic structural diagram of a practical application of an antenna structure according to an embodiment of the present invention.

FIG. 3B is a schematic structural diagram of a practical application of an antenna structure according to an embodiment of the present invention.

FIG. 3C is a schematic structural diagram of a practical application of an antenna structure according to an embodiment of the present invention.

4 is a diagram showing reflection loss of an antenna structure and a partial antenna structure thereof according to an embodiment of the present invention.

FIG. 5 is a diagram showing reflection loss when the length of the second grounding metal of the antenna structure is changed according to an embodiment of the present invention.

FIG. 6 is a diagram showing reflection loss of an antenna structure according to an embodiment of the present invention when the inductance value of the second ground metal is different.

[Embodiment of Antenna Structure]

Please refer to FIG. 1. FIG. 1 is a conceptual diagram of an antenna structure according to an embodiment of the present invention. The antenna structure 1 includes a grounded metal surface 11, a radiating metal piece 12, and a feed connection metal 13, a first ground metal 14, a second ground metal 15, and an inductance Ls for connection to the radiating metal piece 12. The second grounding metal 15 and the inductor Ls are electrically connected in series with each other. The grounded metal surface 11 can be, for example, a metal casing of a hand-held mobile communication device, but the invention is not so limited. Moreover, the radiating metal piece 12 may be disposed on at least one of the side casings of the handheld mobile communication device. That is to say, the antenna structure 1 can be realized by integrating with the metal casing and the side casing of the handheld mobile communication device. The metal casing is connected to the ground of the system circuit of the handheld mobile communication device.

The component connection relationship of the antenna structure 1 is as follows. The radiating metal piece 12 is vertically disposed above the edge 111 of the grounded metal surface 11 and maintains a vertical clearance distance d with the edge 111. The radiating metal piece 12 is perpendicular to the grounded metal surface 11 The projection overlaps the edge 111 of the grounded metal surface 11. The side of the radiant metal piece 12 away from the grounded metal surface 11 is provided with a feed connection point f, a first short circuit connection point S1 and a second short circuit connection point S2. The first short-circuit connection point S1 and the second short-circuit connection point S2 are respectively located on both sides of the feed connection point f. The feed connection metal 14 has one end connected to the feed connection point f. The other end is connected to a radio frequency (RF) input signal, which is typically provided by a radio frequency circuit 17, such as a radio frequency integrated circuit. It should be noted that the ground of the RF circuit 17 is electrically connected to the grounded metal surface 11, and the system circuit of the handheld mobile communication device (including the RF circuit 17) can be disposed in the metal casing of the handheld mobile communication device. The board, the schematic diagram of Figure 1, does not show the board. Further, the first ground metal 14 has one end connected to the first short-circuit connection point S1 and the other end connected to the ground metal surface 11. The second grounding metal 15 has one end connected to the second short-circuit connection point S2, and the other end and the inductor Ls are electrically connected in series with each other and connected to the ground metal surface 11.

Next, the design principle and concept of the antenna structure of the embodiment of the present invention will be described. First, considering that the radiation metal piece 12 has not been connected to the first ground metal 14 and the second ground metal 15, referring to the equivalent circuit diagram shown in FIG. 2A, the radiation metal piece 12 and the ground metal surface 11 constitute a capacitive impedance. The radiating metal sheet 12 itself can generate a first mode by feeding a radio frequency input signal fed by the connecting metal 13, the first mode being a quarter-wave resonant mode. For convenience of explanation, the case here is referred to as an antenna structure Ant1. In practical applications, the antenna structure Ant1 is implemented, for example, by the structure of FIG. 3A. However, the present invention does not limit the shape of the radiating metal sheet 12 and its bending, and only needs to make the radiating metal sheet 12 perpendicular to the grounded metal surface 11 That is to say, the radiating metal piece can be disposed in one of the side casings of the handheld mobile communication device or two or more adjacent side casings. It should be noted that FIG. 2A is only a simplified diagram drawn from the viewpoint of antenna design, and is intended to help explain an embodiment of the present invention, in which the RF circuit 17 is usually not directly disposed on a metal machine as a handheld mobile communication device. On the grounded metal surface 11 of the casing, the ground of the RF circuit 17 is generally connected to the grounded metal surface 11 through a system circuit (circuit board) of the handheld mobile communication device. The present invention also does not limit the structure and shape of the grounded metal surface 11. For example, the grounded metal surface 11 may be an integrally formed metal structure, or a metal material may be coated on the formed insulating plastic material to form a metallic appearance. After the shell and the side casing are assembled, they become the outer casing of the handheld mobile communication device, and the built-in system Functional modules such as circuit boards. However, the present invention does not limit the manner in which the metal casing, the side casing, and the internal functional modules of the handheld mobile communication device are assembled with each other.

According to the embodiment of FIG. 2A, please refer to the Return Loss diagram of FIG. 4, the frequency of the first mode M1 of the antenna structure Ant1 is approximately 0.75 GHz, and the high-order mode MH is the first mode M1. Higher order mode. Next, referring to FIG. 2B, when the first short-circuit connection point S1 of the radiating metal piece 12 is connected to the first grounding metal 14 to generate a short-circuit grounding, the short-circuited grounding design introduces an inductive impedance and becomes the antenna structure Ant2. Briefly, the first short-circuit connection point S1 is electrically connected to the ground metal surface 11 to form an inductive impedance near the resonant frequency of the first mode M1. In an embodiment, the distance between the first short-circuit connection point S1 and the feed-in connection point f is less than one tenth of the wavelength corresponding to the first mode M1, but the invention is not limited thereto. In practical applications, the antenna structure Ant2 is realized, for example, by the structure of FIG. 3B, but the present invention is not limited thereto. According to this embodiment, referring to FIG. 4 together, the antenna structure Ant2 is designed to compensate the capacitance of the first modality M1 of the antenna structure Ant1 by introducing inductivity, thereby improving the impedance matching of the first modality M1. In addition, the higher order mode MH is not affected.

Next, referring to FIG. 2C, based on the antenna structure Ant2, when the radiating metal piece 12 is further connected to the second short-circuit connection point S2 by the second grounding metal 15 connected in series with the inductor Ls to generate another short-circuit grounding, it becomes an antenna. Structure Ant3. In detail, the second short-circuit connection point S2 is electrically connected to the ground metal surface 11 through the second ground metal 15 and the inductor Ls connected in series to each other, so that the ground connection metal surface is fed from the connection point f to the second short-circuit connection point S2. 11 constitutes a loop, and the second short-circuit connection point S2 is used to increase a loop resonance whose resonance frequency is lower than M1, and the frequency of the resonance frequency is used to adjust the M1 frequency (becomes the first mode M1'). In an embodiment, the distance between the second short-circuit connection point S2 and the feed-in connection point f is greater than the distance between the first short-circuit connection point S1 and the feed-in connection point f, but the invention is not limited thereby. In practical applications, the antenna structure Ant3 is implemented, for example, by the structure of FIG. 3C, but the present invention is not limited thereto.

Next, please refer to FIG. 5. FIG. 5 is an antenna structure according to an embodiment of the present invention. A reflection loss diagram when the length L of the two grounded metals 15 is changed. In the present embodiment, the change in the length L of the second grounding metal 15 is explained by using an embodiment of 19 mm to 26 mm. As can be seen from Fig. 5, by adjusting the length L of the second grounding metal 15, the frequency of the first mode M1' can be changed while the high frequency mode MH is not affected.

Furthermore, the inductance value of the inductor Ls is selectable in design. In FIG. 6, it can be seen that when the inductance value of the inductor Ls used is zero, 4.3 nH and 24 nH, respectively, the first mode M1' of the antenna resonance frequency (and The original first mode M1) also changes. As can be seen in Fig. 6, the higher the inductance value of the inductance Ls, the lower the frequency of the first mode M1'.

[Possible effects of the examples]

In summary, the antenna structure provided by the embodiment of the present invention uses a radiating metal piece perpendicular to the grounded metal surface, and the radiating metal piece is disposed at the edge of the grounded metal surface, and the two are disposed at the feeding connection point. The grounding design on both sides enables an antenna structure that is highly integrated with the handheld mobile communication device. In addition, based on this design, the metal casing of the handheld mobile communication device is used as the grounding metal surface, and the radiation metal surface is disposed on the side casing of the handheld mobile communication device, and the space occupied by the antenna can be reduced while still being able to reduce the space occupied by the antenna. Provides good antenna characteristics.

The above description is only an embodiment of the present invention, and is not intended to limit the scope of the invention.

1‧‧‧Antenna structure

11‧‧‧Grounded metal surface

111‧‧‧ edge

12‧‧‧radiation metal sheet

121‧‧‧ side

D‧‧‧ clearance distance

f‧‧‧Feeding connection point

S1‧‧‧ first short-circuit connection point

S2‧‧‧Second short-circuit connection point

13‧‧‧Feed connection metal

14‧‧‧First grounded metal

15‧‧‧Second grounding metal

17‧‧‧RF circuit

Ls‧‧‧Inductance

Claims (7)

An antenna structure includes: a grounded metal surface; a radiating metal piece vertically disposed above an edge of the grounded metal surface and maintaining a vertical clearance distance from the edge, the radiating metal piece being on the grounded metal surface Vertical projection is overlapped with the edge of the grounded metal surface, wherein the radiating metal sheet generates a first mode, the first mode is a quarter-wave resonant mode, and the radiating metal piece is away from the grounded metal surface a feed connection point, a first short circuit connection point and a second short circuit connection point are disposed on one side, the first short circuit connection point and the second short circuit connection point are respectively located at two sides of the feed connection point; The connection metal has one end connected to the feed connection point and the other end connected to an RF input signal; a first ground metal having one end connected to the first short connection point and the other end connected to the ground The metal surface is connected; an inductor; and a second grounding metal, in series with the inductor, electrically connected between the second shorting connection point and the grounded metal surface. The antenna structure according to Item 1, wherein the distance between the first short-circuit connection point and the feed connection point is less than one tenth of a wavelength corresponding to the first mode. The antenna structure of claim 1, wherein the second grounding metal in series with the inductor causes the feeding connection point to the second shorting connection point such that the grounded metal surface forms a loop to generate a resonance a mode having a lower frequency than the first mode, wherein an inductance value of the inductor connected to the second short-circuit connection point adjusts a frequency of the first mode. The antenna structure of claim 1, wherein the length of the second ground metal adjusts the frequency of the first mode. The antenna structure according to Item 1, wherein the distance between the second short-circuit connection point and the feed connection point is greater than the distance between the first short-circuit connection point and the feed connection point. The antenna structure of claim 1, wherein the grounded metal surface is a metal casing of a handheld mobile communication device. The antenna structure of claim 6, wherein the radiating metal piece is disposed on a side casing of the handheld mobile communication device.