CN101499553B - Multi-frequency antenna - Google Patents

Abstract

A multi-frequency antenna is applied to GSM frequency band and comprises a base part, a high-frequency radiation part and a low-frequency radiation part. The base portion comprises a first end and a second end which are opposite, the first end is provided with a grounding point, and the second end is provided with a signal feed-in point. The high-frequency radiation part extends outwards from one side of the second end and is used for working at a high-frequency band. The low-frequency radiation part extends outwards from the other side of the second end and is used for working in a low-frequency band, and comprises a first radiation section connected with the second end and a second radiation section extending from one end of the first radiation section to the direction far away from the first end, and the first radiation section forms at least one slot hole for controlling the low-frequency band drop point. In addition, the invention adds a second grounding segment which can improve the defect of insufficient low-frequency bandwidth in the prior art.

Description

multi-frequency antenna

technical field

The invention relates to a multi-frequency antenna, in particular to a multi-frequency antenna applied to the GSM frequency band.

Background technique

Portable communication products are increasingly miniaturized, so there is not much space available for antenna design, so the limited mechanism space must be fully utilized. In addition, in order to avoid the decline in antenna performance caused by human body contact during actual use, Usually the antenna is arranged on the fuselage.

As shown in Figure 1, the traditional way is to set the multi-frequency antenna 11 on the casing 13 of the portable communication product 12, and connect it to the main circuit board (not shown in the figure) through a ground wire 14 and a signal feed-in wire 15. ), but the traditional antenna structure using a single feed point and a single ground point, although its high-frequency impedance bandwidth can be adjusted to the required bandwidth by adjusting the distance between the ground point and the feed point, such as 1710MHz ~ 1990MHz , but its low-frequency impedance bandwidth is too narrow. For example, it can only choose to operate in the GSM850 frequency band (bandwidth 824MHz~894MHz) or GSM900 frequency band (bandwidth 880~960MHz), which affects the performance of the antenna.

Contents of the invention

Therefore, the purpose of the present invention is to provide a multi-band antenna with a dual ground point design and sufficient low-frequency bandwidth.

Therefore, the multi-frequency antenna of the present invention includes a base, a high-frequency radiation part and a low-frequency radiation part.

The base includes a first end and a second end opposite to each other, the first end is provided with a grounding point, and the second end is provided with a signal feed-in point.

The high-frequency radiating part extends outward from one side of the second end, and is used for working in a high-frequency band.

The low-frequency radiation part is extended from the other side of the second end to work in a low-frequency band, and includes a first radiation section connected to the second end, and a first radiation section extending from one end of the first radiation section to The second radiating section extends in a direction away from the first end, and the first radiating section forms at least one slot for controlling the drop point of the low frequency section.

Description of drawings

FIG. 1 is a schematic diagram of the structure of a traditional multi-frequency antenna;

Fig. 2 shows the front view of the structure of the multi-frequency antenna of the preferred embodiment of the present invention;

Fig. 3 shows the schematic diagram of the structure of the multi-frequency antenna of the preferred embodiment of the present invention;

Fig. 4 shows the measurement result figure of the voltage standing wave ratio (VSWR) of the multi-frequency antenna of the preferred embodiment of the present invention;

Fig. 5 shows the radiation pattern (Radiation Pattern) figure when the multi-frequency antenna of the preferred embodiment of the present invention is in the GSM850 frequency band;

Fig. 6 shows the radiation field pattern figure when the multi-frequency antenna of the preferred embodiment of the present invention is in the GSM900 frequency band;

Fig. 7 shows the radiation pattern figure when the multi-frequency antenna of the preferred embodiment of the present invention is in DCS1800 (being GSM1800) frequency band;

Fig. 8 shows the radiation pattern figure when the multi-frequency antenna of the preferred embodiment of the present invention is in PCS1900 (being GSM1900) frequency band; And

FIG. 9 is a schematic diagram showing the structure of a multi-frequency antenna according to a preferred embodiment of the present invention.

Description of main component symbols

2 multi-frequency antenna

3 electronic devices

31 shell wall

32 circuit board

33 Institutional space

4 base

41 first end

411 Grounding point

42 second end

421 Signal feed point

5 High Frequency Radiation Department

51 extension

52 Prominent paragraph

6 Low frequency radiation department

61 The first radiation section

611 Slots

612 slots

613 slots

62 The second radiation segment

621 slots

7 Second ground segment

8 The first ground segment

9 Signal feed-in section

91 vertical segment

92 horizontal sections

93 meeting place

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. 2 and Fig. 3, be the preferred embodiment of multi-frequency antenna of the present invention, multi-frequency antenna 2 is to be located on the housing wall 31 of portable mobile communication electronic device 3 such as PDA (Personal Digital Assistant) or Smart Phone, and Located at the upper left corner of the shell wall 31, it mainly works in the low frequency band of 824MHz~960MHz and the high frequency band of 1710MHz~1990MHz. Its main structure includes a base 4, a high frequency radiation part 5 and a low frequency radiation part 6.

The base 4 is generally rectangular and includes a first end 41 and a second end 42 opposite to each other. The first end 41 is provided with a grounding point 411, and the second end 42 is provided with a signal feed-in point 421. The grounding point The design of 411 away from the signal feeding point 421 can contribute to the impedance bandwidth of the high frequency band.

The high-frequency radiation part 5 is used to work in the aforementioned high-frequency band, and includes an extension section 51 that extends outward and downward from one side of the second end 42 and whose width tapers, and an extension section 51 that is not connected to the base. 4 is connected to a protruding section 52 extending outward and leftward at one end. The protruding section 52 is connected to the extending section 51 approximately perpendicularly and approximately parallel to the base 4 .

The low-frequency radiation part 6 is used to work in the aforementioned low-frequency band, including a first radiation section 61 extending outward and upward from the other side of the second end 42 of the base 4, and extending from one end of the first radiation section 61 to The second radiating section 62 extending in a direction away from the first end 41 of the base 4 . The first radiating section 61 is generally rectangular, and three long and narrow slots 611, 612, 613 are hollowed out on it; the second radiating section 62 is similar to the shape of an axe, and is slightly inclined to the lower left, and is also hollowed out. A slot 621 is formed. These slots 611 , 612 , 613 , 621 are used to change the path length of the current, so that the designer can adjust (reduce or increase) the low-frequency resonant frequency of the antenna through the slots to meet the requirements of the working frequency.

Although the drop point of the low-frequency resonance frequency can be changed by adjusting the size of the slots 611 , 612 , 613 , 621 , the low-frequency impedance bandwidth of the antenna is still too narrow to meet the requirements. As shown in Figure 4, the voltage standing wave ratio (VSWR) of (a) graph is lower than 3 in the bandwidth of 824MHz～894MHz (GSM850 frequency band), which can meet the requirements, but in the bandwidth of 880～960MHz (GSM 900 frequency band) During this time, the voltage standing wave ratio is out of specification. Therefore, this embodiment also adds a design of a second ground segment 7 to improve this problem.

Before introducing the second grounding section 7 , the structures of the first grounding section 8 and the signal feed-in section 9 should be described first. The first ground segment 8 is connected between the ground point 411 and a circuit board 32 of the electronic device 3 (the circuit board 32 is spaced from the shell wall 31); the signal feed-in segment 9 is used to connect the signal feed-in point 421 and The circuit board 32 comprises a vertical section 91 between the signal feed-in point 421 and the circuit board 32 and a horizontal section 92 connected with the vertical section 91 and arranged on the circuit board 32, and the second grounding section 7 is formed At the intersection 93 of the horizontal segment 92 and the vertical segment 91 , and extending to the right from the intersection 93 , it becomes an L-shaped wire. The second grounding segment 7 can control the concentration of the low-frequency band impedance, and achieve the purpose of impedance matching of 50 ohms under the requirement that the VSWR of the bandwidth of 824 MHz to 960 MHz is lower than 3, as shown in (b) graph of Fig. 4 As shown, compared with the graph (a), the design of the graph (b) can cover 824MHz-960MHz (GSM850 and GSM900 frequency bands) due to the design of the second ground section 7 added.

As shown in Table 1 on the following page, for the total radiation performance (TRP, Total Radiated Power) table of each frequency band of the multi-frequency antenna 2 with the second ground segment 7 added, there are GSM850, GSM900, GSM1800 (1710MHz～1880MHz) and GSM1900 ( 1850MHz～1990MHz) four frequency bands, each frequency band is divided into low, medium and high three channels (Channel), for example, GSM850 frequency has three channels CH128, CH190, CH251. It can be seen from the table that the total radiation efficiency of each channel can reach more than 25dBm.

Fig. 5～Fig. 8 are the radiation pattern (Radiation Pattern) figure of this preferred embodiment in four frequency bands, as can be seen from the figure, the radiation pattern is omnidirectional in the horizontal plane.

In addition, as shown in FIG. 9, the multi-frequency antenna 2 is arranged at the upper left corner of the electronic device 3, and there is sufficient mechanism space 33 at the lower right of the multi-frequency antenna 2 for the designer to configure components such as flashlights, cameras, speakers, vibrators, etc. It should be further explained that the fixing method of the multi-frequency antenna 2 can be fixed by means of hot-melt positioning posts, which has good stability.

GSM850 CH128 CH190 CH251 Total Radiation Efficiency (dBm) 28.4 29.1 29.4

GSM900 CH975 CH37 CH124 Total Radiation Efficiency (dBm) 29.1 28.9 28.8

GSM1800 CH512 CH700 CH885 Total Radiation Efficiency (dBm) 26.7 27.1 26.8

GSM1900 CH512 CH661 CH810 Total Radiation Efficiency (dBm) 25.9 25.9 25.8

Table 1

To sum up, the multi-frequency antenna 2 of this embodiment is designed with double ground points (i.e. adding the second ground section 7), so that the bandwidth of the low-frequency band can cover 824 MHz to 960 MHz, which improves the traditional low-frequency bandwidth shortage. Shortcomings, moreover, the design of multiple slots 611, 612, 613, 621 allows the designer to easily adjust the antenna to the desired low-frequency resonance frequency. Finally, the multi-frequency antenna 2 of this embodiment is arranged on the electronic device 3 The housing wall 31 occupies a small space, allowing the designer of the electronic device 3 to have sufficient mechanism space 33 for use, so the object of the present invention can be achieved indeed.

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 description of the present invention still belong to the scope of the present invention Inside.

Claims (8)

1. multifrequency antenna comprises:

One base portion comprises one first opposite end and one second end, and this first end is provided with an earth point, and this second end is provided with a signal feed-in point;

One high-frequency radiation part is stretched by an epitaxial lateral overgrowth of this second end, in order to be operated in a high-frequency band; And

One low frequency radiation portion; Opposite side by this second end stretches out; In order to be operated in a low frequency frequency range; And comprise one first radiant section that links to each other with this second end, and by an end of this first radiant section toward one second radiant section that extends away from the direction of this first end, and this first radiant section forms at least one slotted eye of this low frequency frequency range drop point of control.

2. multifrequency antenna according to claim 1; It is arranged on the shell wall of an electronic installation; This electronic installation also has and this shell wall circuit board separately, and this multifrequency antenna also comprises the signal feed-in section that connects this signal feed-in point and this circuit board, is connected this earth point and one first ground connection section of this circuit board and the one second ground connection section of being located at this circuit board and being connected with this signal feed-in section.

3. multifrequency antenna according to claim 2, wherein, this base portion generally is rectangle.

4. multifrequency antenna according to claim 3, wherein, this high-frequency radiation part comprises by an epitaxial lateral overgrowth of this second end stretches and an extension of taper in width, and the outward extending nose section of an end that is not linked to each other with this base portion by this extension.

5. multifrequency antenna according to claim 4, wherein, this nose section generally is vertical with this extension, and generally is parallel with this base portion.

6. multifrequency antenna according to claim 3, wherein, this at least one slotted eye is long and narrow.

7. according to the wherein arbitrary described multifrequency antenna of claim 2-6, wherein, this high-frequency band is 1710MHz～1990MHz.

8. multifrequency antenna according to claim 7, wherein, this low frequency frequency range is 824MHz～960MHz.

Images