CN101409381A - Wireless transmission/receiving unit, wideband antenna and method for increasing antenna bandwidth - Google Patents

Abstract

The invention discloses a wireless transmission/receiving unit, a broadband antenna and a method for increasing the bandwidth of the antenna, which are used for transmitting/receiving an electromagnetic wave, wherein the wireless transmission/receiving unit comprises a radiation element and a feed-in connecting wire; the radiating element further comprises a metal plane and a plurality of cutting grooves; the metal plane has a first edge and a second edge separated from each other, wherein the length of the first edge is greater than that of the second edge; the plurality of cutting grooves are positioned on the metal plane and have a plurality of staggered opening directions, so that the metal plane forms a tortuous shape; the feed-in connecting wire is electrically connected with the second edge. By applying the method and the device of the invention, the effect of broadband is achieved by utilizing a plurality of different resonant frequencies, thereby not only improving the problem of insufficient bandwidth of the known printed antenna, but also providing better return loss and overcoming the problem of central frequency offset; the area of the antenna is not enlarged, and an additional process with high cost is not needed.

Description

Wireless transmission/reception unit, broadband antenna and method for increasing antenna bandwidth

technical field

The present invention relates to a method and device for a broadband antenna, more particularly to a wireless transmission receiving unit and device, a broadband antenna and a method for increasing the bandwidth of the antenna.

Background technique

The use of the general wireless network card antenna must be determined according to the size of the space, the characteristics of the antenna and the cost. The wireless network card is often limited by the limited area and height of the erection device, and the chip antenna is used. Although the area of the chip antenna is small, the cost is high, and its bandwidth is narrow. When it is actually used on a printed circuit board, the actual measured bandwidth is easily affected by the difference in the circuit layout, making the actual bandwidth than expected. Small.

Printed antennas can be selected when device space permits. Printed antennas can be divided into monopole antennas, double dipole antennas, planar inverted F-shaped antennas, and loop antennas according to their structures. Most of the current printed antennas are implemented with planar inverted F-shaped antennas, which can effectively reduce the antenna area, but its disadvantage is that due to the inherent structural limitations of the antenna, it cannot achieve a larger antenna bandwidth. When the bandwidth of the antenna itself is insufficient, it often results in that when the location of the wireless network card is too close to the surrounding sheltered objects, the electromagnetic waves emitted by the antenna are easily reflected by a large amount, and the return loss of the antenna is easy to change accordingly. Even lead to the shift of the center frequency. Therefore, it is necessary to provide a larger bandwidth and better return loss in a certain area without additional antenna cost, and then overcome the influence of surrounding objects on the return loss and center frequency offset.

Contents of the invention

The technical problem to be solved by the present invention is to provide a wireless transmission/reception unit, a broadband antenna and a method for increasing the bandwidth of the antenna. By changing the configuration of the radiation element of the monopole antenna, the antenna can be increased without increasing the area of the antenna. Receive/transmit bandwidth with reduced center frequency offset.

In order to solve the above problems, the present invention provides a wireless transmission/reception unit for transmitting/receiving an electromagnetic wave, comprising:

A radiating element comprising:

a metal plane having a first and a second edge separated from each other, wherein the length of the first edge is greater than the length of the second edge; and

A plurality of cutting grooves, located on the metal plane, have a plurality of staggered opening directions, so that the metal plane forms a meandering shape; and

A feed-in connecting line electrically connects the second edge.

Further, the wireless transmission/reception unit may further include that the metal plane is one of an inverted triangular metal plane and an inverted trapezoidal metal plane.

Further, the wireless transmission/reception unit may further include:

The length of the first edge is 1/4 of the wavelength of the electromagnetic wave;

The length of the radiating element is 1/2 of the wavelength of the electromagnetic wave; and/or

The sum of the lengths of each cutting groove is 1/2 of the wavelength of the electromagnetic wave.

Further, the wireless transmission/reception unit further includes a ground plane, and a gap is provided between the ground plane and the feeding connection line; the wireless transmission/reception unit further includes a substrate made of a dielectric material, located on the ground plane In the gap with the feeding connection line; and the dielectric material is glass fiber.

The present invention also provides a broadband antenna for transmitting/receiving an electromagnetic wave, comprising:

A radiating metal wire, having a first end point and a second end point, at least includes:

a first radiating metal line segment connected to the first end point;

a second radiating metal line segment connected to the first radiating metal line segment via a first bending point; and

A third radiating metal line segment, connected to the second radiating metal line segment via a second bending point, and connected to the second end point, wherein the third radiating metal line segment is longer than the first radiating metal line segment the length of

a feed connection line connected to the first terminal.

Further, the broadband antenna may further include that the radiating metal wire has at least two bends, so that the radiating metal wire forms one of an S-shaped bent inverted triangle and an inverted trapezoid.

Further, the above broadband antenna may also include,

The length of the third radiating metal line segment is 1/4 of the wavelength of the electromagnetic wave;

The length of the radiating metal wire is 1/2 of the wavelength of the electromagnetic wave; and/or

Each of the metal radiating wire segments has a distance of 5.08 cm.

The present invention also provides a method for increasing the bandwidth of the antenna, comprising the following steps,

providing a radiating element comprising at least a first edge and a second edge, wherein the length of the first edge is greater than the length of the second edge; and

A plurality of cutting grooves are formed on the radiating element to generate a plurality of horizontal electric fields parallel to each of the cutting grooves, and a plurality of vertical electric fields perpendicular to each of the cutting grooves, wherein each of the horizontal electric fields cancels each other out, and each of the cutting grooves Vertical electric fields add to each other.

Further, the above method may also include,

The radiating element has a shape of one of an inverted triangle and an inverted trapezoid;

Each of the cutting grooves is formed by one of mechanical cutting and etching; and/or

Each of the cutting slots has a width of preferably 5.08 cm.

Compared with the prior art, the application of the method and device of the present invention utilizes multiple different resonant frequencies to achieve broadband effects, which not only improves the problem of insufficient bandwidth of known printed antennas, but also provides better return loss and overcomes the center The problem of frequency offset; the area of the antenna does not increase because of this, and no additional process with high cost is required.

Description of drawings

Fig. 1 is a schematic diagram of a multi-mode resonant broadband antenna according to a first preferred embodiment of the present invention;

2 is an enlarged view of a radiation element according to a first preferred embodiment of the present invention;

3a and 3b are XZ plane antenna field diagrams according to the first preferred embodiment of the present invention;

4a and 4b are XY plane antenna field diagrams according to the first preferred embodiment of the present invention; and

FIG. 5 is a measurement diagram of the antenna return loss (return loss) according to the first preferred embodiment of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

The present invention discloses a multi-mode resonant broadband antenna and method, the content of which will be described as follows through preferred specific implementations, but these specific implementations are only the preferred ones, and the implementation of the present invention is not limited to these preferreds Specific implementation methods, those skilled in the art can still deduce other specific implementation modes according to the spirit of the disclosed specific implementation modes, and all these specific implementation modes shall belong to the scope of the present invention.

Please refer to FIG. 1 , which is a schematic diagram of a multi-mode resonant broadband antenna according to a first preferred embodiment of the present invention. The multi-mode resonant broadband antenna 01 of the present invention includes a radiating element 11 , a feeding connection line 12 , a substrate 13 and a ground plane 14 . Wherein the radiation element 11 is a triangular metal plane, the metal plane has a first edge 113 and a second edge 114, and the metal plane further includes a plurality of etching grooves 111 (only one of them is illustrated in the figure) , the number of these etching grooves can be adjusted as required, and in this preferred embodiment, five etching grooves 111 are included. The metal plane is cut into a plurality of radiating metal line segments 112 (only one of which is illustrated in the figure) by the etching grooves 111 , wherein the opening directions of the etching grooves 111 are staggered and parallel to each other.

In order to achieve the best and most suitable transmission/reception effect, the side length of the triangular metal plane can be adjusted according to the wavelength of the electromagnetic wave to be transmitted/received. In this preferred embodiment, the side length of the triangle is about 1/4 A 2.45GHz wavelength. Meanwhile, the width and depth of each etching groove 111 can also be adjusted according to the required performance. In this preferred embodiment, the width of each of the etching grooves 111 is 20 mils, which can be easily realized according to current printed circuit technology. At the same time, the depth of each of the etching grooves 111 is adjusted so that the sum of the lengths of each of the radiating metal line segments 112 , that is, the total length of the entire radiating element 11 is about half of the 2.45 GHz wavelength.

Further please refer to FIG. 2 , which is an enlarged view of the radiation element according to the first preferred embodiment of the present invention. The radiation element 11 includes a plurality of etching grooves 111 , a plurality of radiation metal line segments 112 , a first end point 115 , a second end point 116 , a first bending point 117 , a second bending point 118 and a fourth bending point 119 . As shown in Figure 2, for each of the etching grooves 111, when the current flows from the first terminal 115 to the second terminal 116, a horizontal current component (-x/+x) and another vertical current component will be generated respectively. The current component in the direction (+y) creates a horizontal electric field (-x/+x) and a vertical electric field (+y). Similarly, a horizontal electric field (+x or -x) and a vertical electric field (+y) will be formed at other etching grooves 111 respectively, wherein the horizontal electric fields cancel each other out due to their opposite directions, and the electric fields in the vertical direction will mutually cancel each other out. addition. When the sum of the lengths of each radiating metal line segment 112 is about 1/2 of the wavelength of the electromagnetic wave to be received, the corner of the etching groove 111 where the fourth bending point 119 is located has the maximum resonant current, that is, the place is the antenna energy the main radiation location. Please refer to FIG. 3a and FIG. 3b , which are the field diagrams of the XZ plane antenna according to the first preferred embodiment of the present invention. In Figure 3a, frequency (MHz): 2450.00, antenna polarity: Horizontal, average value (dB): -3.30, maximum value (dB): 1.45, maximum value (degree): 28, minimum value (dB): -33.70 , minimum value (degree): 269; in Figure 3b, frequency (MHz): 2450.00, antenna polarity: Vertical, average value (dB): -8.32, maximum value (dB): 1.40, maximum value (degree): 258 , minimum value (dB): -2.63, minimum value (degree): 180.

It can be seen from Fig. 3a and Fig. 3b that the sum of five current components in the +y direction makes the antenna of the present invention equivalent to an omnidirectional antenna in the XZ plane.

Next, please refer to FIG. 4a and FIG. 4b , which are the field diagrams of the XY plane antenna according to the first preferred embodiment of the present invention. In Figure 4a, frequency (MHz): 2450.00, antenna polarity: Horizontal, average value (dB): -0.30, maximum value (dB): 3.20, maximum value (degree): 228, minimum value (dB): -20.38 , minimum value (degree): 93; in Figure 4b, frequency (MHz): 2450.00, antenna polarity: Vertical, average value (dB): -19.25, maximum value (dB): -15.53, maximum value (degree): 297, minimum value (dB): -35.91, minimum value (degree): 165.

Since the etching width of the radiation element in the present invention is very small (20 mil, converted to 5.08 cm) relative to the metal part, the width of each radiation metal line segment 112 is very wide, which can reduce its impedance value and effectively increase antenna efficiency. It can be seen from FIG. 4a and FIG. 4b that the antenna structure of the present invention has an ideal performance of 3dBi in the peak gain of the XY plane.

In the multi-mode resonant broadband antenna structure provided by the present invention, because the width of each of the etched grooves 111 is not large (20 mil), a leakage electric field will be generated directly across each of the etched grooves 111 . It produces the effect equivalent to multiple electric field paths (the shortest path is about 1/4 wavelength, and the longest path is about 1/2 wavelength), so multiple different coupling paths can be used to generate a large resonance bandwidth. Please refer to FIG. 5 , which is a measurement diagram of the antenna return loss (return loss) according to the first preferred embodiment of the present invention. The vertical axis represents the return loss, and the horizontal axis represents the operating frequency. Compared with the previous figure 2, the equivalent antenna length of one-half wavelength, that is, the fourth bending point 119 has the largest vertical current, and because it is effectively far away from the ground plane 14 (reference ground), the ground plane 14 pairs of antennas are reduced Radiation effects can be produced as shown in Figure 5 The first one indicated corresponds to the resonant frequency (2.4GHz). In addition, there is a larger current at the equivalent coupling length of a quarter wavelength, that is, at the first end point 115 in FIG. Electric field coupling effect (coupling effect), so the second corresponding resonant frequency (2.5 GHz) can be found at the △ 3 mark in Figure 5 . It can also be seen from FIG. 5 that, through the provision of the multi-mode resonant broadband antenna structure of the present invention, under the definition of the operable range of return loss less than -20dB, the bandwidth of the antenna of the present invention is 200MHz. Under the definition of the operable range which is generally less than -10dB return loss, the bandwidth of the antenna of the present invention reaches 600MHz.

To sum up, the present invention mainly uses a monopole antenna as the main structure, through the special configuration of the radiation element, to realize the optimization of the characteristics of the antenna, the minimization of the area, and the use of multiple resonance frequencies to achieve broadband Effect. However, the specific implementation methods described in the above description are only for illustrating the principles and effects of the present invention, rather than limiting the present invention. Therefore, those who are familiar with this technology can modify and change the above-mentioned specific implementation methods without departing from the spirit of the present invention. The scope of rights of the present invention should be listed in the appended claims.

Claims (10)

1, a kind of wireless transmission/receive unit is used for transmission one electromagnetic wave, it is characterized in that, comprises:

One radiant element, it comprises:

One metal flat has one first and one second edge separated from one another, and wherein the length at this first edge is greater than the length at this second edge; And

A plurality of cutting grooves are positioned on the described metal flat, have staggered plurality of openings direction, make this metal flat form the shape of a circuitous bending; And

One feed-in connecting line is electrically connected described second edge.

2, wireless transmission/receive unit as claimed in claim 1 is characterized in that, described metal flat be a del metal flat and fall trapezoidal metal flat one of them.

3, wireless transmission/receive unit as claimed in claim 1 is characterized in that,

The length at described first edge is 1/4 of described electromagnetic wavelength;

The length of described radiant element is 1/2 of described electromagnetic wavelength; And/or

The length sum of each described cutting groove is 1/2 of a described electromagnetic wavelength.

4, wireless transmission/receive unit as claimed in claim 1 is characterized in that, further comprises a ground plane, is provided with a gap between this ground plane and described feed-in connecting line; Described wireless transmission/receive unit more comprises the substrate of a dielectric material, is positioned at this gap of this ground plane and this feed-in connecting line; And this dielectric material is a glass fibre.

5, a kind of radio transmitting device is characterized in that, comprises wireless transmission/receive unit as claimed in claim 1.

6, a kind of wide frequency antenna is used for transmission one electromagnetic wave, it is characterized in that, comprises:

One radiation metal wires has one first end points and one second end points, comprises at least:

One first radiation metal line segment is connected to described first end points;

One second radiation metal line segment is connected to the described first radiation metal line segment via one first inflection point; And

One the 3rd radiation metal line segment is connected to the described second radiation metal line segment via one second inflection point, and is connected to described second end points, and wherein the length of the 3rd radiation metal line segment is greater than the length of the described first radiation metal line segment; And

One feed-in connecting line is connected to described first end points.

7, wide frequency antenna as claimed in claim 6 is characterized in that, described radiation metal wires has at least 2 times bending, make this radiation metal wires form the del of S shape bending and fall trapezoidal one of them.

8, wide frequency antenna as claimed in claim 6 is characterized in that,

The length of described the 3rd radiation metal line segment is 1/4 of described electromagnetic wavelength;

The length of described radiation metal wires is 1/2 of described electromagnetic wavelength; And/or

It is a distance of 5.08 centimetres that each described metal radiation line segment has a best.

9, a kind of method that increases antenna bandwidth comprises the following step,

One radiant element is provided, and this radiant element comprises at least one first edge and one second edge, and wherein the length at this first edge is greater than the length at this second edge; And

On this radiant element, form a plurality of cutting grooves, producing a plurality of and the parallel horizontal component of electric field of this cutting groove respectively, and a plurality of and the vertical vertical electric field of this cutting groove respectively, wherein respectively this horizontal component of electric field mutually offsets, and the respectively mutual addition of this vertical electric field.

10, method as claimed in claim 9 is characterized in that,

Described radiant element has a del and and falls trapezoidal one of them shape;

Each described cutting groove is formed by one of them method of machine cuts and etching; And/or

It is a width of 5.08 centimetres that each described cutting groove has a best.

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