TWI538302B - Dual polarized antenna - Google Patents

Description

Dual polarized antenna

The invention relates to an antenna, in particular to a dual-polarized antenna having different polarization directions.

With the evolution of communication technology, the design of the antenna is better to apply a wide range of practicality and ease of integration. The conventional single-polarized antenna can only receive/transmit signals in a single direction, but cannot receive/transmit signals in other directions. Therefore, it is limited in use. Therefore, in order to make the application of the antenna more extensive, so-called dual-polarized antennas can be started, and the antennas of the two-directional signals can be received/transmitted, but such dual-polarized antennas There is often a lack of isolation.

In addition, there are many ways to feed the antenna. The most widely used feed mode is the direct feed type microstrip antenna. As shown in Figure 1, the edge impedance of the microstrip antenna is about 100 Ω ~ 400 Ω, but The system impedance used in microwave measurement is mostly about 50Ω. Therefore, in order to improve the impedance mismatch, the microstrip antenna is often increased by a quarter-wavelength impedance converter 5 as shown in FIG. 2, or It is the impedance matching that is achieved by using the plug-in microstrip line 6 as shown in FIG.

Therefore, the object of the present invention is to provide an impedance A dual-polarized antenna that matches the isolation.

Therefore, the dual polarized antenna of the present invention is disposed on a substrate and includes a ground layer body and two feed arms.

The ground layer body is disposed on the substrate and includes a central vacant portion, an outer frame portion formed of a conductive material and surrounding the central vacant portion, and a notch that passes through the outer frame portion from the central vacant portion. The angle between the imaginary lines of the two notches extending in a direction extending outward from the central vacancy is less than 180°.

The two feeding arms are made of a conductive material and are disposed on the substrate and respectively include a radiating portion located in the central vacant portion, a main arm connected to the radiating portion and located in the one of the notches and not contacting the outer frame portion And a feeding portion connected to the one end of the radiating portion and connected to the signal.

Preferably, the ground layer body further comprises an isolation section extending from the outer frame portion toward the center of the central vacancy portion and separating the radiation portions.

Preferably, the orthographic shape of the isolation segment is an elongated shape.

Preferably, the angle of the imaginary connection of the two notches along the direction in which they extend outward from the central vacancy is 90°.

Preferably, the orthographic shape of the central vacancy is rectangular.

Preferably, the orthographic shape of the outer frame portion is a rectangular frame of equal width.

Preferably, the width of the orthographic projection of the outer frame portion is 60 mm.

Preferably, the distance between each radiating portion and the outer frame portion is 2.95 mm.

Preferably, the distance between one side of each main arm portion and one side adjacent to the outer frame portion is 0.3 mm.

Preferably, the orthographic shape of each of the radiating portions is a circular shape.

The effect of the present invention is to provide a dual-polarized antenna that satisfies impedance matching and can increase isolation characteristics and can have polarization characteristics in two different directions.

1‧‧‧Substrate

2‧‧‧ Grounding layer

21‧‧‧Central Vacancy

22‧‧‧Outer frame

23‧‧‧Isolated segment

24‧‧ ‧ gap

3‧‧‧Feeding arm

31‧‧‧ Radiation Department

32‧‧‧ main arm

33‧‧‧Feeding Department

34‧‧‧First feed arm

35‧‧‧second feed arm

4‧‧‧SMA connector

41‧‧‧First potential section

42‧‧‧Second potential

Other features and advantages of the present invention will be apparent from the embodiments of the present invention. FIG. 1 is a perspective view illustrating an embodiment of a conventional microstrip antenna. FIG. 2 is a perspective view illustrating a conventional The microstrip antenna utilizes a quarter-wavelength impedance converter to achieve impedance matching; FIG. 3 is a perspective view illustrating a conventional microstrip antenna using a plug-in microstrip line to achieve impedance matching; FIG. 4 is a front view illustrating the present invention An embodiment of a dual-polarized antenna; FIG. 5 is a side elevational view of the embodiment of the dual-polarized antenna of the present invention; and FIG. 6 is a front elevational view of the embodiment of the dual-polarized antenna of the present invention Geometry; and FIG. 7 is a graph illustrating S11 and S22 simulated and measured reflection loss maps of the embodiment of the dual polarized antenna of the present invention; FIG. 8 is a surface current distribution diagram illustrating the dual polarized antenna of the present invention having The surface current distribution trend of an isolated segment; 9 is a surface current distribution diagram illustrating that the dual-polarized antenna of the present invention does not have a surface current distribution tendency of the isolation section; FIG. 10 is a graph illustrating that the embodiment of the dual-polarized antenna of the present invention has the isolation section A reflection loss simulation diagram of S21 isolation; and FIG. 11 is a graph illustrating a reflection loss simulation diagram of the embodiment of the dual polarized antenna of the present invention without the S21 isolation of the isolation section.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals.

Referring to FIG. 4 and FIG. 5, an embodiment of the dual-polarized antenna of the present invention is disposed on a square substrate 1 and includes a ground layer body 2 and two feed arms 3.

The ground layer body 2 is disposed on the substrate 1 and includes a central vacant portion 21, an outer frame portion 22 formed of a conductive material and surrounding the central vacant portion 21, and an outer frame portion 22 toward the central vacant portion An isolated section 23 extending from the center of the 21, and a notch 24 passing through the outer frame portion 22 from the central vacant portion 21, wherein the orthographic projection shape of the central vacant portion 21 is a rectangle, and the outer frame portion 22 is The orthographic projection shape is a rectangular frame of equal width, and the angle of the imaginary connection of the two notches 24 along the direction in which the two notches 24 extend outward from the central vacant portion 21 is 90°. The orthographic projection shape of the isolation segment is a long strip shape, and The angle between the sides of the two notches 24 extends obliquely diagonally.

Each of the feeding arms 3 is made of a conductive material and is disposed on the substrate 1 and includes a radiating portion 31 located in the central recess 21, and is connected to the radiating portion 31 and located in the one of the notches 24 and is not in contact with the outer portion Frame portion 22 The main arm portion 32 and a feeding portion 33 connected to one end of the radiating portion 31 opposite to the main arm portion 32 for signal input, wherein the orthographic projection shape of each of the radiating portions 31 is a circular shape.

When the SMA (Sub-Miniature-A) connector 4 is electrically connected to the feeding portion 33 of the two feed arms 3 to receive signals, each SMA connector 4 includes two first wires electrically connected to the outer frame portion 22. a potential portion 41, and a second potential portion 42 electrically connected to each of the feed portions 33, such that each feed arm 3 of the embodiment of the dual polarized antenna of the present invention forms a coplanar waveguide with the adjacent ground portion (CPW, Coplanar Waveguide) feed structure, therefore, the embodiment of the dual-polarized antenna of the present invention can have a large impedance bandwidth and achieve good impedance matching, and can improve the conventional antenna by adding an additional four points One wavelength impedance converter or plug-in microstrip line is used to achieve the advantages of impedance matching, as well as the advantages of low radiation loss and easy combination.

In addition, the electrical characteristics of the conventional feed structure are susceptible to the dielectric or thickness of the substrate. Therefore, the dual polarized antenna of the present invention is designed to be fed by a coplanar waveguide that is less susceptible to the medium or thickness of the substrate. Therefore, the antenna structure can be arbitrarily used for the FR4 printed circuit board (PCB), a higher-order printed circuit board, or a copper plating method to achieve the antenna application without limitation. The scope will be more extensive.

At the same time, when the signals are respectively fed from the SMA connector 4 into the two feed arms 3, they are transmitted to each of the radiating portions 31 via each corresponding main arm portion 32 to respectively excite one parallel to one of the feed arms 3 First in the direction of extension Linear polarization, and a second linear polarization parallel to the direction in which the other feed arm 3 extends, so that the antenna of the present invention can achieve the characteristics of dual polarization, in particular, in this embodiment, because the two feeds The arms 3 extend in a direction orthogonal to each other, so the excitation directions of the first linear polarization and the second linear polarization are also orthogonal to each other.

Referring to FIG. 6, FIG. 6 is a geometrical structural diagram of a dual-polarized antenna according to the present invention. In the figure, the width and length of the whole antenna are represented by W and L, respectively, and the feeding portion 33 and the main arm are represented by W1. The width of the portion 32 represents the width of the orthographic shape of the outer frame portion 22 by W2, and the isolation portion 23 represents the length and width thereof by LS and WS, respectively, and the two feed arms 3 are respectively marked as the first Feeding arm 34 and second feeding arm 35, the radius of the orthographic shape of the radiating portion 31 is denoted by r, the radiating portion 31 of the first feeding arm 34 and the second feeding arm 35 and the outer frame portion The distance of 22 is denoted by t, and the distance between one side of the main arm portion 32 of the first feed arm 34 and the second feed arm 35 and one side adjacent to the outer frame portion 22 is indicated by gap, the above-mentioned related parameters The specifications are shown in Table 1 below.

7 is a simulation and actual measurement result of the embodiment of the dual-polarized antenna of the present invention according to the actual size of Table 1 above, wherein S11 represents the input reflection loss of the first feed arm 34, and S22 represents the second. The input reflection loss of the feed arm 35, and the impedance bandwidth of the antenna is reflected loss When defined by 10 dB, the impedance bandwidth of the first feed arm 34 during simulation is 1.34 GHz (5.01 GHz to 6.35 GHz), and the impedance bandwidth during actual measurement is 1.685 GHz (4.955 GHz to 6.64 GHz), and the second feed is The impedance bandwidth of the arm 35 is 1.35 GHz (5.005 GHz to 6.355 GHz), and the impedance bandwidth when measured is 1.855 GHz (4.8 GHz to 6.655 GHz). Therefore, it can be confirmed that the dual-polarized antenna of the present invention can achieve good performance. The impedance is matched and applied to the 5.8 GHz band.

In order to clearly illustrate the importance of the isolation section 23 of the dual-polarized antenna of the present invention, the following will explain the presence or absence of the surface current distribution and the S21 isolation of the isolation section 23, respectively, wherein S21 represents the first The isolation of the feed arm 34 and the second feed arm 35. Referring to FIG. 8 and FIG. 9, FIG. 8 and FIG. 9 respectively show the surface current distribution when the isolation section 23 and the isolation section 23 are not provided, and the surface of the first feeding arm 34 can be clearly seen from FIG. The current has a tendency to concentrate on the main arm portion 32. It is apparent that the first feed arm 34 is affected by the second feed arm 35, and it can be seen from FIG. 9 that the isolation segment 23 is added. The surface current distributions of the first feed arm 34 and the second feed arm 35 are not affected by each other, because the isolation section 23 of the embodiment is from the outer frame portion 22 toward the central vacancy portion 21 The center extension extends the first radiating arm 34 and the second radiating arm 35 such that the surface current density of the first feed arm 34 is not affected by the interference of the second feed arm 35.

The S21 isolation of the dual-polarized antenna of the present invention having the isolation section 23 can be more clearly compared by the simulation diagrams of the S21 isolation of the isolation section 23 and the isolation section 23 of FIGS. 10 and 11. -22.39dB) is obvious The ground is better than the S21 isolation (-16.25dB) of the isolated segment 23, so that the two feed arms 3 of the dual polarized antenna of the present invention have high isolation characteristics by the isolation segment 23. .

In summary, the dual-polarized antenna of the present invention replaces the conventional direct feed mode by the feeding mode of the coplanar waveguide, and thus can have a large impedance bandwidth and is not affected by the medium and thickness of the substrate 1. Further, the isolation section 23 prevents the two feed arms 3 from interacting with each other to achieve good isolation characteristics, so that the object of the present invention can be achieved.

However, the above is only the embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the patent application scope and the patent specification of the present invention are still It is within the scope of the patent of the present invention.

1‧‧‧Substrate

2‧‧‧ Grounding layer

21‧‧‧Central Vacancy

22‧‧‧Outer frame

23‧‧‧Isolated segment

24‧‧ ‧ gap

3‧‧‧Feeding arm

31‧‧‧ Radiation Department

32‧‧‧ main arm

33‧‧‧Feeding Department

34‧‧‧First feed arm

35‧‧‧second feed arm

4‧‧‧SMA connector

41‧‧‧First potential section

42‧‧‧Second potential

Claims (9)

A dual-polarized antenna is disposed on a substrate, comprising: a ground layer body disposed on the substrate and including a central vacant portion, an outer frame portion formed of a conductive material and surrounding the central vacant portion, and The central vacant portion passes through the notch of the outer frame portion, the imaginary connection angle of the two notches extending in a direction extending outward from the central vacant portion is less than 180°; and the two feeding arms are formed of a conductive material and are disposed And a radiation portion located at the central vacant portion, a main arm portion connected to the radiation portion and located not in contact with the outer frame portion, and a main arm portion opposite to the main arm portion One end of the radiation portion is connected to the feed portion for signal input, and the ground layer body further includes an isolation portion extending from the outer frame portion toward the center of the central cutout portion and separating the radiation portions. The dual-polarized antenna of claim 1, wherein the orthographic shape of the isolated segment is an elongated shape. The dual-polarized antenna according to claim 1, wherein an angle of the imaginary connection of the two notches along a direction in which the two notches extend outward from the central vacant portion is 90°. The dual-polarized antenna of claim 1, wherein the orthographic shape of the central vacant portion is a rectangle. The dual-polarized antenna according to claim 1, wherein the orthographic shape of the outer frame portion is a rectangular frame of equal width. The dual-polarized antenna according to claim 5, wherein the width of the orthographic projection of the outer frame portion is 60 mm. The dual-polarized antenna according to claim 1, wherein a distance between each of the radiating portions and the outer frame portion is 2.95 mm. The dual-polarized antenna according to claim 1, wherein a distance between one side of each main arm portion and one side adjacent to the outer frame portion is 0.3 mm. The dual-polarized antenna according to claim 1, wherein the orthographic shape of each of the radiating portions is a circular shape.