TW202239057A - Dual feed-in antenna capable of maintaining up-tilt omni-directional pattern and achieving high isolation level - Google Patents

Abstract

A dual feed-in antenna comprises a ground plane, an extension rack, a first inverted-F antenna, and a second inverted-F antenna. The extension rack is disposed on the ground plane and vertical to the ground plane. The first inverted-F antenna is disposed on the extension rack and connected with the extension rack through a first feed-in end and a first short circuit end; and, the second inverted-F antenna is disposed on the extension rack and connected with the extension rack through a second feed-in end and a second short circuit end, wherein the second short circuit end is adjacent to the first short circuit end.

Description

Dual Feed Antenna

A dual-feed antenna, more specifically, a dual-feed antenna with an up-tilt omni-directional pattern.

Generally speaking, existing wireless communication products (such as ceiling-mounted WiFi machines, etc.) increase the number of antennas in order to improve functions, but in order to maintain the same product size, the space that can be used by each antenna is severely compressed, which affects the performance of the antenna. function or feature.

In more detail, the energy coupling between antennas is mainly through the electromagnetic wave (radiation) distribution in space and the surface wave (surface wave) distribution on the physical structure, where changing the electromagnetic wave in space will change the radiation energy distribution, which may lead to failure Obtain the desired elevation radiation pattern. But on the other hand, For antenna structures such as monopole antennas (Monopole antennas), dipole antennas (Dipole antennas) or planar inverted F antennas (PIFAs) commonly used in conventional technologies, the surface waves on the structures will interact with each other when the distances between the plurality of antennas are close. Coupling results in poor isolation. Therefore, how to provide a dual-feed antenna capable of maintaining an elevation-angle radiation pattern and having high isolation has become an urgent problem to be solved in the industry.

In order to solve various problems of the aforementioned prior art, one object of the present invention is to provide a dual-feed antenna capable of maintaining the elevation radiation pattern and having high isolation.

In order to achieve the aforementioned purpose, the dual-feed antenna of the present invention includes a ground plane, an extension frame, a first inverted-F antenna and a second inverted-F antenna. The extension frame is arranged on the ground plane, and the extension frame is perpendicular to the ground plane; the first inverted F antenna is arranged on the extension frame, and the first inverted F antenna includes a first feed-in end and a first short-circuit end, the first feed-in end and the first short-circuit end. The first short-circuit end is connected to the extension frame; and the second inverted F antenna is arranged on the extension frame, the second inverted F antenna includes a second feed-in end and a second short-circuit end, and the second feed-in end and the second short-circuit end are connected to the extension frame. frame connection, and the second short-circuit end is adjacent to the first short-circuit end.

In one embodiment of the present invention, the dual-feed antenna of the present invention further includes a first antenna parallel plate, a second antenna parallel plate, a first extended parallel plate, and a second extended parallel plate. The first antenna parallel plate is arranged on the end of the first inverted F antenna close to the first feeding end; the second antenna parallel plate is arranged on the second inverted F antenna near the end of the second feeding end; the first extending parallel plate is arranged at one end of the extension frame and parallel to the first antenna parallel plate; The position of the antenna parallel plate and the second extending parallel plate corresponds to the second antenna parallel plate.

In an implementation form of the present invention, the first antenna parallel plate or the second antenna parallel plate is parallel to the ground plane.

In an implementation form of the present invention, the distance between the first feeding point and the second feeding point is 1/2 of the carrier wavelength.

In an implementation form of the present invention, the operating frequency of the first inverted-F antenna is the same as or different from the operating frequency of the second inverted-F antenna.

In one implementation form of the present invention, the first inverted-F antenna further includes a first radiator, and the second inverted-F antenna further includes a second radiator, and the length of the first radiator is equal to the length of the second radiator. same or not.

Compared with the prior art, the dual-feed antenna of the present invention has an extension frame arranged on the ground plane, and the first inverted F antenna and the second inverted F antenna are arranged on the extension frame, and the first inverted F antenna is lifted by the extension frame. The first feeding end and the second feeding end of the inverted-F antenna and the second inverted-F antenna reduce the surface wave distribution formed on the ground plane, so the isolation can be effectively improved, and the radiation pattern at the elevation angle is still maintained. In addition, the first antenna parallel plate, the second antenna parallel plate, the first extended parallel plate, and the second extended parallel plate can be added to form a capacitor structure, so that the equivalent circuit of the double-feed antenna of the present invention Like a band-stop filter, the isolation can be further improved.

The implementation of the present invention is described below through specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various modifications and changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention.

Please refer to FIG. 1 . FIG. 1 is a schematic structural diagram of a dual-feed antenna according to a first embodiment of the present invention. As shown in the figure, the dual-feed antenna of the present invention includes a ground plane 10 , an extension frame 11 , a first inverted-F antenna 12 and a second inverted-F antenna 13 .

The ground plane 10 can be, for example, a metal plate, and its area is much larger than that of the extension frame 11 , the first inverted-F antenna 12 and the second inverted-F antenna 13 . The extension frame 11 is disposed on the ground plane 10 , and the extension frame 10 can be, for example, a metal conductor in the shape of a rectangular plate, and is perpendicular to the ground plane 10 .

The first inverted-F antenna 12 is disposed on the extension frame 11 , and the first inverted-F antenna 12 is connected to the extension frame 11 through the first feeding end 120 and the first short-circuit end 121 . Similarly, the second inverted-F antenna 13 is arranged on the extension frame 11, the second inverted-F antenna 13 is connected with the extension frame 11 through the second feeding end 130 and the second short-circuit end 131, and the second short-circuit end 131 is adjacent to the first Short circuit terminal 121 . In other words, the first inverted-F antenna 12 and the second inverted-F antenna 13 are relatively disposed on the extension frame 11, and the distance between the second short-circuit end 131 and the first short-circuit end 121 is smaller than the distance between the second short-circuit end 131 and the second short-circuit end 131. A distance between feeding ends 120 .

In the conventional technology, antenna structures such as monopole antennas, dipole antennas, or planar inverted F antennas are directly placed on the ground plane, so that part of the energy of one of the antennas will reach the adjacent antenna via surface waves on the ground plane. Another antenna, the energy coupling between the antennas will interfere with each other and affect the transmission performance, which is not conducive to the demand for increasing the number of antennas in wireless communication products.

In comparison, the dual-feed antenna of the present invention lifts the first feed end 120 and the second feed end 130 of the first inverted-F antenna 12 and the second inverted-F antenna 13 through the extension frame 11, and the first feed The end 120 and the second feeding end 130 are not in direct contact with the ground plane 10, which will reduce the surface wave distribution formed on the ground plane 10 due to the energy fed into the first feeding end 120 or the second feeding end 130, Therefore, the degree of isolation can be effectively improved. On the other hand, the first inverted-F antenna 12 and the second inverted-F antenna 13 still maintain the elevation radiation pattern, which meets the design requirements of wireless communication products.

Please refer to FIG. 2 . FIG. 2 is a schematic diagram of a three-dimensional structure of a dual-feed antenna according to a second embodiment of the present invention. In one embodiment, the dual feed antenna of the present invention further includes a first antenna parallel plate 122 , a second antenna parallel plate 132 , a first extending parallel plate 110 and a second extending parallel plate 111 . The first antenna parallel plate 122 is disposed at an end of the first inverted-F antenna 12 close to the first feeding end 120 . The second antenna parallel plate 132 is disposed at an end of the second inverted-F antenna 13 close to the second feeding end 130 . The first extended parallel plate 110 is disposed on one end of the extension frame 11 and parallel to the first antenna parallel plate 122 , and the second extended parallel plate 111 is disposed on the other end of the extension frame 11 and parallel to the second antenna parallel plate 132 . Wherein, the position of the first extending parallel plate 110 corresponds to the first antenna parallel plate 122 , and the position of the second extending parallel plate 111 corresponds to the second antenna parallel plate 132 . The first antenna parallel plate 122 , the second antenna parallel plate 132 , the first extending parallel plate 110 and the second extending parallel plate 111 can be, for example, rectangular plate-shaped metal conductors, but not limited thereto.

In a further embodiment, the first antenna parallel plate 122 or the second antenna parallel plate 110 is parallel to the ground plane 10 (not shown in FIG. 2 ).

In more detail, the first antenna parallel plate 122 is parallel to and corresponding to the first extending parallel plate 110 to form a capacitor structure. Similarly, the second antenna parallel plate 132 is parallel to and corresponding to the second extending parallel plate 111 to form a capacitor structure.

Please refer to FIG. 3 . FIG. 3 is a schematic diagram of an equivalent circuit of a dual-feed antenna according to a second embodiment of the present invention. In more detail, FIG. 3 is an equivalent circuit of the first inverted-F antenna 12 and the second inverted-F antenna 13 viewed from the first feeding end 120a or the second feeding end 130a. Wherein, the equivalent circuit model formed by the first antenna parallel plate 122 and the first extended parallel plate 110 is capacitor C1, and the equivalent circuit model formed by the conductor between the first feed-in end 120 and the first short-circuit end 121 For the inductance L1. Similarly, the equivalent circuit model formed by the second antenna parallel plate 132 and the second extended parallel plate 111 is the capacitor C2, and the equivalent circuit formed by the conductor between the second feed-in end 130 and the second short-circuit end 131 The model is inductor L2.

As shown in Figure 3, the equivalent circuit model formed by the first antenna parallel plate 122, the first extended parallel plate 110, and the first inverted-F antenna 12 is the same as the band rejection filter (Band rejection filter), and the second antenna The parallel plate 132 , the second extended parallel plate 111 and the second inverted-F antenna 13 form another band rejection filter. Therefore, the equivalent circuit observed by the first feed-in terminal 120a or the second feed-in terminal 130a is two band-rejection filters, and this circuit structure can improve the frequency between the first inverted-F antenna 12 and the second inverted-F antenna 13. isolation.

In one embodiment, the distance between the first feeding point 120 and the second feeding point 130 is 1/2 of the carrier wavelength.

In one embodiment, the operating frequency of the first inverted-F antenna 12 and the operating frequency of the second inverted-F antenna 13 are the same or different. In order to meet the requirements of wireless communication products for multiple operating frequencies, the operating frequencies of the first inverted-F antenna 12 and the second inverted-F antenna 13 can be designed to be different frequencies.

Please refer to FIG. 4 . FIG. 4 is a schematic structural diagram of a dual-feed antenna according to a third embodiment of the present invention. In one embodiment, the first inverted-F antenna 12 further includes a first radiator 123, and the second inverted-F antenna 13 further includes a second radiator 133, and the length of the first radiator 123 is the same as that of the second radiator 133. The lengths are the same or different.

Since factors such as the radiator length of the inverted-F antenna, the distance from the feed end to the short-circuit end and the like will affect the operating frequency, when the operating frequencies of the first inverted-F antenna 12 and the second inverted-F antenna 13 are designed to be different frequencies, the first The length of the radiator 123 and the length of the second radiator 133 may be different, and the area of the first inverted-F antenna 12 and the area of the second inverted-F antenna 13 may be different.

In summary, the dual-feed antenna of the present invention has an extension frame arranged on the ground plane, and the first inverted F antenna and the second inverted F antenna are arranged on the extension frame, and the first inverted F antenna is lifted by the extension frame. The first feeding end and the second feeding end of the antenna and the second inverted-F antenna reduce the surface wave distribution formed on the ground plane, so the isolation can be effectively improved, and the radiation pattern at the elevation angle is still maintained. In addition, the first antenna parallel plate, the second antenna parallel plate, the first extended parallel plate, and the second extended parallel plate can be added to form a capacitor structure, so that the equivalent circuit of the double-feed antenna of the present invention Like a band-stop filter, the isolation can be further improved.

The above-mentioned embodiments are only for illustrating the principles and effects of the present invention, but not for limiting the present invention. Anyone skilled in the art can modify and change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the rights of the present invention should be listed in the scope of the patent application described later.

10: Ground plane 11: Extension frame 110: The first extended parallel plate 111: the second extended parallel plate 12: First Inverted F Antenna 120: The first feed-in terminal 120a: the first feed-in terminal 121: the first short-circuit terminal 122: The first antenna parallel plate 123: The first radiator 13: Second inverted F antenna 130: the second feed-in terminal 130a: the second feed-in terminal 131: the second short-circuit terminal 132: Second antenna parallel plate 133: Second Radiator C1, C2: capacitance L1, L2: inductance

FIG. 1 is a schematic structural diagram of a dual-feed antenna according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of a three-dimensional structure of a dual-feed antenna according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram of an equivalent circuit of a dual-feed antenna according to a second embodiment of the present invention.

FIG. 4 is a schematic structural diagram of a dual-feed antenna according to a third embodiment of the present invention.

10: Ground plane

11: Extension frame

12: First Inverted F Antenna

120: The first feed-in terminal

121: the first short-circuit terminal

13: Second inverted F antenna

130: the second feed-in terminal

131: the second short-circuit terminal

132: Second antenna parallel plate

Claims (6)

A dual-feed antenna comprising: ground plane; an extension frame is arranged on the ground plane, and the extension frame is perpendicular to the ground plane; A first inverted-F antenna is arranged on the extension frame, the first inverted-F antenna includes a first feed-in end and a first short-circuit end, and the first feed-in end and the first short-circuit end are connected to the extension frame; as well as The second inverted-F antenna is arranged on the extension frame, the second inverted-F antenna includes a second feed-in end and a second short-circuit end, the second feed-in end and the second short-circuit end are connected to the extension frame, And the second short-circuit end is adjacent to the first short-circuit end. The dual-feed antenna as described in claim 1, further comprising: The first antenna parallel plate is arranged at one end of the first inverted-F antenna close to the first feeding end; The second antenna parallel plate is arranged at one end of the second inverted-F antenna close to the second feeding end; a first extended parallel plate, disposed at one end of the extension frame and parallel to the first antenna parallel plate; and the second extended parallel plate is arranged at the other end of the extension frame and parallel to the second antenna parallel plate, Wherein, the position of the first extending parallel plate corresponds to the first antenna parallel plate, and the position of the second extending parallel plate corresponds to the second antenna parallel plate. The dual-feed antenna as claimed in claim 2, wherein the first antenna parallel plate or the second antenna parallel plate is parallel to the ground plane. The dual-feed antenna according to claim 1, wherein the distance between the first feed end and the second feed end is 1/2 of the carrier wavelength. The dual-feed antenna as claimed in claim 1, wherein the operating frequency of the first inverted-F antenna is the same as or different from the operating frequency of the second inverted-F antenna. The dual-feed antenna as claimed in item 1, wherein the first inverted-F antenna further includes a first radiator, and the second inverted-F antenna further includes a second radiator, and the length of the first radiator is the same as The lengths of the second radiators are the same or different.

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