CN101527387B - multi-frequency antenna - Google Patents

Abstract

A multi-frequency antenna includes a loop radiating portion, a first radiating arm and a second radiating arm. The loop radiating portion includes a turning point, a feeding end and a grounding end that are away from the turning point and adjacent to each other. The first radiating arm extends outward from the feeding end. The second radiating arm extends outward from the turning point and is located on the same side of the loop radiating portion as the first radiating arm. The present invention has many advantages such as small size, wide frequency, simple design structure and easy control of its frequency.

Description

multi-frequency antenna

technical field

The present invention relates to a multi-frequency antenna, in particular to a multi-frequency antenna applied to a wireless personal area network (WPAN).

Background technique

Bluetooth (Bluetooth) communication technology was developed by the Swedish telecommunications company Sony Ericsson (Sony Ericsson) in 1998. 』(Harald Bluetooth), he is famous for unifying Denmark. One thousand years later, Sony Ericsson's marketers think that they are unifying consumer electronics products, and their contribution to the world is comparable to that of King Harald Bluetooth. This wireless transmission technology is named Bluetooth.

However, in Luo Guanzhong's Romance of the Three Kingdoms, he said at the beginning that "the general trend of the world, the long-term division must be united, and the long-term union must be divided." Sony Ericsson wants to use Bluetooth technology to unify consumer electronics products, but various communication technologies are constantly introducing new ones. For example, Ultra-Wideband (UWB) technology has been approved by the US Federal Communications Commission (FCC) in 2002 to be used in consumer electronics.

The built-in antennas of notebook computers used in the above two communication technologies {that is, personal wireless area network WPAN [2.402～2.480GHz (Bluetooth) and 3.168～4.752GHz (UWB Band I)]} are currently based on inverted F flat panel antennas ( PIFA (Planar Inverted-F Antennas) type antenna architecture, some designs will add parasitic or coupling elements, which will overlap in space to generate strong coupling to achieve dual-band or broadband effects. Here, the present invention also proposes a multi-band antenna for WPAN to benefit the consumer market.

Contents of the invention

Therefore, the object of the present invention is to provide a multi-frequency antenna with small size, wide frequency, simple structure and easy frequency control.

Therefore, the multi-frequency antenna of the present invention includes a loop radiating part, a first radiating arm and a second radiating arm.

The loop radiation part includes a turning point, a feeding end and a grounding end which are far away from the turning point and adjacent to each other.

The first radiation arm extends outward from the feeding end.

The second radiating arm extends outward from the turning point, and is located in the same example as the first radiating arm at the loop radiating portion.

Description of drawings

Fig. 1 is a perspective view illustrating the structure of a preferred embodiment of the multi-frequency antenna of the present invention;

Fig. 2 is a schematic diagram illustrating the position where the preferred embodiment is arranged on a notebook computer;

Fig. 3 is a plan view (reverse side), illustrates the structure of this preferred embodiment;

Fig. 4 is a plan view (front), illustrating the structure of this preferred embodiment;

Figure 5 is a plan view illustrating the dimensions of the preferred embodiment;

Figure 6 is a graph of the measurement results of the voltage standing wave ratio (VSWR) of the preferred embodiment, the (a) curve is the result measured when only the loop radiation part exists, and the (b) curve is the combination of the loop radiation part and the first radiation arm The result measured afterward, the curve (c) is the result measured after the loop radiation part, the first radiating arm and the second radiating arm of the multi-frequency antenna of this embodiment are combined.

Fig. 7 is the measurement result figure of the voltage standing wave ratio (VSWR) that this preferred embodiment is arranged on notebook computer;

Fig. 8 is the radiation pattern (Radiation Pattern) figure of this preferred embodiment at 2440MHz;

Fig. 9 is the radiation pattern (Radiation Pattern) figure of this preferred embodiment when 3168MHz;

Fig. 10 is the radiation pattern (Radiation Pattern) figure of this preferred embodiment when 3960MHz; And

Fig. 11 is the radiation pattern (Radiation Pattern) figure of the preferred embodiment at 4752MHz.

Description of main component symbols

1 multi-frequency antenna

2 loop radiation part

21 The first radiation segment

22 The second radiation section

23 The third radiation segment

24 turning point

25 Feed end

26 ground terminal

3 The first radiating arm

31 first paragraph

32 Second paragraph

4 second radiating arm

43 third paragraph

44 Fourth paragraph

45 clearance

8 coaxial transmission line

81 positive end

82 negative terminal

9 laptops

91 positions

92 positions

Detailed ways

The foregoing and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the accompanying drawings.

Referring to Fig. 1 and Fig. 2, the preferred embodiment of multi-frequency antenna 1 of the present invention is arranged in notebook computer 9, and the position of setting can be position 91 or position 92, and its main structure comprises a loop radiation part 2, a first radiation arm 3 and a second radiating arm 4 .

In order to be conveniently accommodated in a specific space in the notebook computer 9, the multi-frequency antenna 1 is designed as a three-dimensional type and arranged in the notebook computer 9. However, it can also exist in a planar form. Here, for the convenience of explaining its structure, it is first described as The plane type (referring to Fig. 3 and Fig. 4, Fig. 4 is a front view, Fig. 3 is a reverse view) will be described.

The loop radiating part 2 is generally a rectangular open circuit, including a first radiating section 21, a second radiating section 22, a third radiating section 23, a turning point 24, a feeder that is far away from the turning point 24 and adjacent to each other. An input terminal 25 and a ground terminal 26. One end (open end) of the first radiating section 21 is the grounding terminal 26, and the other end thereof is connected to one end of the second radiating section 22, and the first and second radiating sections 21, 22 are almost vertical. The other end of the second radiating section 22 is connected to one end of the third radiating section 23, and both the second and third radiating sections 22, 23 are approximately vertical, and the other end of the third radiating section 23 is the feeding end 25. In addition, the turning point 24 is an end where the third radiating section 23 is connected to the second radiating section 22 . It is worth mentioning that the positive end 81 of a coaxial transmission line 8 can be connected to the feed-in end 25 , and the negative end 82 of the coaxial transmission line 8 can be connected to the ground end 26 to complete signal feed-in.

The first radiating arm 3 extends outwards from the feed-in end 25, and includes a first section 31 with one end connected to the feed-in end 25 of the loop radiation part 2, and one end connected to the other end of the first section 31 and connected to the first section 31. The segment 31 is substantially vertical to a second segment 32 , and the first segment 31 is substantially perpendicular to the third radiating segment 23 .

The second radiating arm 4 extends outward from the turning point 24, and is located on the same side of the loop radiating part 2 as the first radiating arm 3, and includes a third section 43 whose end is connected to the turning point 24 of the loop radiating part 2, And a fourth section 44 whose one end is connected to the other end of the third section 43 and is almost perpendicular to the third section 43 , and the third section 43 is almost perpendicular to the third radiating section 23 . In addition, the fourth segment 44 and the second segment 32 face each other with a gap 45 therebetween.

Referring to Fig. 4 and Fig. 5, Fig. 5 is the dimension mark diagram of the multi-frequency antenna 1 of this preferred embodiment, as can be seen from the figure, the gap 45 that the fourth section 44 is separated from the second section 32 is 1.5mm, and The gap between the first radiating section 21 and the third radiating section 23 is 1 mm, and this 1 mm is the width of the second radiating section 22 , and the lengths of each section are shown in Table 1 below.

When the multi-frequency antenna 1 is bent from the planar form of FIG. 4 to the three-dimensional form of FIG. 1, the first radiating section 21 is located in a first plane (not shown); the second radiating section 22, the third radiating section 23, The first section 31 and the third section 43 are located on a second plane (not shown) which is approximately perpendicular to the first plane; the second section 32 and the fourth section 44 are located on a third plane which is approximately perpendicular to the second plane (not shown). By bending into a three-dimensional way, the volume of the antenna can be reduced and the industrial utilization rate can be increased.

Length (mm) Width (mm) The first radiation segment 30 5 The second radiation section 7 1 The third radiation segment 30 3 first paragraph 5 4 second paragraph 14 5 third paragraph 5 5 Fourth paragraph 14.5 5

Table 1

And this multi-frequency antenna 1 is mainly used in (but not limited to) ultra-wideband frequency band (UWBBand I, 3168MHz～4752MHz) and bluetooth frequency band (Bluetooth, 2402MHz～2480MHz) in the present embodiment, and its design concept is to utilize loop radiation part 2 Working in a first frequency band (approximately an ultra-wide frequency band), and then combining the second radiating arm 4 with the loop radiation part 2, the multi-frequency antenna 1 can work in a third frequency band (i.e. Bluetooth frequency band, 2402MHz～2480MHz); and if you want the multi-frequency antenna 1 to work in the above two frequency bands, you can adjust the length or width of each section of the loop radiation part 2 and the second radiation arm 4 (as shown in Table 1 size) to adjust to the desired frequency band. However, referring to Fig. 6, the curve (a) of Fig. 6 is the voltage standing wave ratio (VSWR) measured when only the loop radiation part 2 exists in the antenna. Among them, the impedance matching effect is poor and the bandwidth is narrow. For example, the voltage standing wave ratio (VSWR) of a small frequency band is greater than 2.5; in view of this, the present invention adds the design of the first radiating arm 3. A radiation arm 3 is combined with the loop radiation part 2 so that the multi-frequency antenna 1 can work in a second frequency band (approximately an ultra-wide frequency band), and the combination of the first frequency band and the second frequency band enables the multi-frequency antenna 1 to operate at a voltage Under the requirement of standing wave ratio (VSWR), work in the desired ultra-wide frequency band, as shown in the (b) curve of Figure 6, it is the measured voltage standing of the antenna combined with the loop radiation part 2 and the first radiation arm 3 Wave ratio (VSWR), as can be seen from the figure, in the ultra-wide frequency band of 3168MHz to 4752MHz, its voltage standing wave ratio (VSWR) is less than 2.5, and less than the value of curve (a), so the working bandwidth can include The entire ultra-wide frequency band solves the problem of insufficient bandwidth. In addition, the (c) curve of FIG. 6 is the voltage standing wave ratio measured by the multi-frequency antenna 1 combined with the loop radiation part 2, the first radiating arm 3 and the second radiating arm 4. Compare the (c) curve with ( It can be seen from the curve b) that the curve (c) can work in the frequency band of 2402MHz-2480MHz due to the addition of the second radiation arm 4, and its voltage standing wave ratio (VSWR) can be less than 2.5.

Fig. 7 is a voltage standing wave ratio (VSWR) diagram of multi-frequency antenna 1 applied to notebook computer 9 (see Fig. 2). It can be seen from the figure that the frequencies from 2402MHz to 2480MHz and 3168MHz to 4752MHz are all less than 2.5. Table 2 on the next page is a table of the total radiation power (Total Radiation Power) and efficiency (Efficiency) of the multi-frequency antenna 1 in the application frequency band. It can be seen from the table that the total radiation power is >-5.5dB, and the efficiency is >30%. . Finally, Figs. 5 to 8 are the radiation patterns measured at 2440MHz, 3168MHz, 3960MHz and 4752MHz respectively in this preferred embodiment. As can be seen from the figures, the radiation pattern has good omnidirectionality.

Frequency (MHz) Total radiated energy (dB) efficiency(%) 2402 -5.2 30.2

2440 -4.2 37.6 2480 -4.4 36.4 3168 -3.2 48.1 3432 -3.2 48.2 3696 -3.1 48.5 3960 -2.8 52.6 4224 -3.3 47.3 4488 -4.0 39.7 4752 -4.4 36.0

Table 2

To sum up, the multi-frequency antenna 1 of this embodiment is small in size, and the problem of insufficient bandwidth is solved by the design of the second radiating arm 4 to achieve broadband characteristics, and its design structure is simple, and it is easy to control the frequency, so Really can realize the purpose of the present invention.

The above are only preferred embodiments of the present invention, and should not limit the scope of the present invention, that is, all simple equivalent changes and modifications made according to the content of the present invention are still covered by the present invention. within range.

Claims (12)

1. A multi-frequency antenna, comprising: A loop radiating part, including a turning point, a feed-in end and a grounding end that are far away from the turning point and adjacent to each other, wherein the loop radiating part includes a first radiating section whose one end is the grounding end, and one end is connected to the second a second radiating section whose other end is approximately perpendicular to the first radiating section, and a third radiating section whose one end is connected to the other end of the second radiating section and which is approximately perpendicular to the second radiating section, The other end of the third radiating section is the feed-in end, and the end where the third radiating section is connected to the second radiating section is the turning point; a first radiating arm extending outward from the feed-in end, the first radiating arm includes a first segment with one end connected to the feed-in end of the loop radiation part, and one end connected to the other end of the first segment and a second segment approximately perpendicular to the first segment, the first segment approximately perpendicular to the third radial segment; and A second radiating arm extending outward from the turning point and located on the same side of the loop radiating portion as the first radiating arm, the second radiating arm includes a third radiating arm with one end connected to the turning point of the loop radiating portion segment, and a fourth segment connected at one end to the other end of the third segment and approximately perpendicular to the third segment, the third segment being approximately perpendicular to the third radial segment; The first radiating section is located on a first plane, the second radiating section, the third radiating section, the first section and the third section are located on a second plane approximately perpendicular to the first plane, and the second segment and the fourth segment lie on a third plane approximately perpendicular to the second plane. 2. The multi-frequency antenna according to claim 1, wherein the loop radiating portion is substantially a rectangular open loop. 3. The multi-frequency antenna according to claim 2, wherein the second segment and the fourth segment face each other with a gap therebetween. 4. The multi-frequency antenna according to any one of claims 1-3, wherein the loop radiating part works in a first frequency band, and the first radiating arm is combined with the loop radiating part to work in a second frequency band, And the first frequency band and the second frequency band can be synthesized into an ultra-wideband frequency band. 5. The multi-frequency antenna according to claim 4, wherein the second radiating arm is combined with the loop radiating part to work in a third frequency band whose frequency range is lower than the ultra-wide band. 6. The multi-frequency antenna according to claim 5, wherein the ultra-wide frequency band is 3168MHz-4752MHz. 7. The multi-frequency antenna according to claim 6, wherein the third frequency band is 2402MHz˜2480MHz. 8. The multi-frequency antenna according to claim 3, wherein the gap is substantially 1.5mm. 9. The multi-frequency antenna according to claim 7, wherein the length of the first segment is substantially 5 mm, and the width is substantially 4 mm; the length of the second segment is substantially 14 mm, and the width is substantially 5 mm. 10. The multi-frequency antenna according to claim 9, wherein the length of the third segment is substantially 5 mm, and the width is substantially 5 mm; the length of the fourth segment is substantially 14.5 mm, and the width is substantially 5 mm. 11. The multi-frequency antenna according to claim 10, wherein the length of the first radiating section is substantially 30 mm, and the width is substantially 5 mm; the length of the second radiating section is substantially 7 mm, and the width is substantially 1 mm ; The length of the third radiating section is substantially 30 mm, and the width is substantially 3 mm. 12. The multi-frequency antenna according to claim 11, which is set on a notebook computer.

Images