TWI514667B - Antenna device - Google Patents

Description

Antenna device

The present invention relates to an antenna device, and more particularly to an antenna device having a wide bandwidth.

With the development of digital TVs, such as mobile phones and personal digital assistants (PDAs), the development of short, small, light and thin, the antennas for receiving digital TV signals need to be miniaturized. .

From the perspective of the antenna, when the antenna is miniaturized, the possibility that the antenna works normally in the low frequency band is small, that is, the bandwidth of the low frequency band is small. However, since the frequency band in which the antenna receives digital television signals is generally 470 MHz to 800 MHz, the frequency is low and the bandwidth is wide. Therefore, how to reduce the size of the antenna and make it better to receive digital TV signals has become the biggest challenge for various antenna manufacturers.

In view of this, the present invention provides an antenna device that is small in size and wide in bandwidth.

An antenna device includes a substrate, an antenna, and a coupling body. The antenna and the coupling body are respectively disposed on opposite surfaces of the substrate, and the antenna is connected to the substrate. The antenna includes a feeding body, two first radiators, and The second radiating body is symmetrically disposed on two sides of the feeding body, and the second radiating body is symmetrically disposed on two sides of the extending line of the feeding body, and the coupling body and the antenna are coupled to each other.

Compared with the prior art, the antenna device uses the first radiator in the antenna and The second radiators are respectively arranged symmetrically about the feeding body and the extension line thereof, and a coupling body is coupled with the antenna to widen the bandwidth range from the DVB (Digital Video Broadcasting) frequency band to the same time. Covering the DVB band and the GSM (Global System for Mobile Communications) band significantly broadens the working bandwidth of the antenna device. In addition, the antenna device can be bent, so that the size of the antenna device can be further reduced.

100‧‧‧Antenna device

20‧‧‧Antenna

12‧‧‧Feeding end

22‧‧‧Feeding body

26‧‧‧Second radiator

34‧‧‧Second coupling

102‧‧‧ ground plane

244‧‧‧second radiation arm

2424‧‧‧First long side

2444‧‧‧Second long side

268‧‧‧ Short side

10‧‧‧Substrate

30‧‧‧ Coupled body

14‧‧‧ Grounding terminal

24‧‧‧First radiator

32‧‧‧First Coupling

101‧‧‧Antenna surface

242‧‧‧First Radiation Arm

2422‧‧‧First short side

2442‧‧‧second short side

262, 264, 266‧‧‧ three long sides

1 is a perspective view of an antenna device according to a preferred embodiment of the present invention; FIG. 2 is a perspective view of another antenna device of FIG. 1; FIG. 3 is an optimized return loss diagram of the antenna device of FIG. It is a plan view of the antenna device shown in Fig. 1.

Referring to FIG. 1 , an antenna device 100 according to a preferred embodiment of the present invention is disposed in a portable wireless communication device (not shown) such as a mobile phone, for transmitting and receiving radio waves to transmit and exchange radio data signals. For example, a mobile phone is taken as an example.

Referring to FIG. 4 , the antenna device 100 includes a substrate 10 , an antenna 20 , and a coupling body 30 . The antenna 20 and the coupling body 30 are respectively disposed on opposite surfaces of the substrate 10, and the antenna 20 is connected to the substrate 10. The coupling body 30 and the antenna 20 are coupled to each other.

Referring to FIG. 1 and FIG. 2 together, the substrate 10 has a substantially rectangular panel-like structure, which may be a printed circuit board substrate or a part of a printed circuit board. The substrate 10 is made of a bendable material to facilitate bending the antenna device 100 to reduce the size of the antenna device 100. The substrate 10 includes an antenna surface 101 and a ground plane 102. One side of the substrate 10 A feed end 12 is provided on the edge, and the feed end 12 is used for feeding signals to and receiving signals from the antenna 20.

The antenna 20 is disposed on the antenna surface 101 and includes a feed body 22, two first radiators 24, and two second radiators 26. The feed body 22 is disposed in the middle of the antenna surface 101 and has a substantially rectangular strip shape. The feed body 22 has one end connected to the feed end 12 and the other end connected to the two first radiators 24.

The two first radiators 24 are symmetrically disposed on both sides of the feeding body 22 . Each of the first radiators 24 includes a first radiating arm 242 and a second radiating arm 244. The first radiating arm 242 includes a first short side 2422 and a first long side 2424. The first short side 2422 extends perpendicularly to one end of the feed body 22 away from the feed end 12 . The first long side 2424 extends perpendicularly to the first short side 2422 away from one end of the feed end 12 and parallel to the feed body 22 . The length of the first long side 2424 is greater than the length of the first short side 2422.

The second radiating arm 244 includes a second short side 2442 and a second long side 2444. The second short side 2442 is formed by extending one end of the first long side 2424 away from the first short side 2422 in a direction away from the feeding body 22 . The second long side 2444 extends perpendicularly to the second short side 2442 away from one end of the feed body 22 . The second short side 2442 and the first short side 2422 are parallel to each other, and the length of the second short side 2442 is smaller than the length of the first short side 2422. The second long side 2444 and the feed body 22 are parallel to each other, and the length of the second long side 2444 is greater than the length of the first long side 2424. The center frequency of the antenna 20 is adjusted by adjusting the lengths of the first radiating arm 242 and the second radiating arm 244 of the first radiator 24.

The two second radiators 26 are respectively disposed at one end of the second long side 2444 of the two first radiators 24 away from the second short side 2442, and are symmetric about the extension line of the feeding body 22. Each of the second radiators 26 includes three long sides 262, 264, 266 and a short side 268. The short side 268 is disposed on the second long side 2444 away from one end of the second short side 2442, and is the second long Side 2444 is vertical. The three long sides 262, 264, and 266 are all the same in shape and size, and are all rectangular strip-shaped bodies. The long side 262 and the long side 266 are vertically disposed at opposite ends of the short side 268, respectively. The long side 264 is disposed between the long side 262 and the long side 266, and the three long sides 262, 264, and 266 are disposed in parallel. The separation distance between the three long sides 262, 264, and 266 can be adjusted as needed. In this embodiment, the distance between the long side 262 and the long side 264 is greater than the distance between the long side 264 and the long side 266. The symmetric structure of the second radiator 26 has the function of adjusting impedance matching and adjusting the bandwidth, so that the length of the three long sides 262, 264, 266 and the three long sides 262, 264, 266 are adjusted in a limited area. The mutual distance between them can enhance the coupling between each other, thereby adjusting the impedance matching and adjusting the bandwidth.

The first radiator 24 is in the same plane as the second radiator 26, and is connected to each other by perpendicularly intersecting the short side 268 with the second long side 2444 of the second radiating arm 244. The feed body 22 and the first radiator 24 are both located on one side of the second radiator 26 .

Referring to FIG. 2 , the grounding surface 102 defines a grounding end 14 adjacent to one end of the feeding end 12 . The grounding end 14 has a substantially rectangular panel-like structure and provides grounding for the substrate 10 . The coupling body 30 is disposed on the ground plane 102 on the substrate 10. The coupling body 30 is a bent structure having a substantially inverted "L" shape, and includes a first coupling portion 32 and a second coupling portion 34. The first coupling portion 32 extends perpendicularly from the edge of the grounding end 14 away from the feeding end 12 , and the second coupling portion 34 extends perpendicularly from the first coupling portion 32 away from one end of the feeding end 12 . When the antenna 20 is in operation, the coupling body 30 is coupled to the antenna 20 to enhance the radiation effect of the antenna 20.

Please refer to FIG. 3 , which is a schematic diagram of a preferred return loss (RL) obtained by the antenna device 100 of the preferred embodiment under the analog software detection. As can be seen from FIG. 3, during the test, the antenna device 100 has a return loss of -6 dB. There are two operating frequency points 32a and 32b, and the frequency values are 400MHz and 1100MHz, respectively. Therefore, when the return loss value is less than -6dB, the working bandwidth of the antenna device 100 can reach 700MHz (400MHz~1100MHz). Therefore, the bandwidth of the antenna device 100 can cover the DVB band (470MHz~800MHz) and the GSM 850/900MHz band.

Referring to FIG. 4, since the substrate 10 is made of a bendable material, the antenna device 100 can be bent as needed to reduce the size of the antenna device 100 to achieve the effect of miniaturizing the antenna device 100. In the present embodiment, the antenna device 100 can be bent according to the broken line L1 and the broken line L2 shown in the drawing, or the antenna device 100 can be bent according to the broken line L3 shown in the drawing.

Obviously, the antenna device 100 is disposed symmetrically with respect to the feed body 22 and its extension line by arranging the two first radiators 24 and the second radiators 26 of the antenna 20 respectively, and providing a coupling body 30 and the The antennas 20 are coupled to each other such that the bandwidth of the antenna device 100 is widened from the DVB band to cover both the DVB band and the GSM band, which significantly broadens the working bandwidth of the antenna device 100. Further, since the antenna device 100 can be bent, the size of the antenna device 100 can be further reduced.

In addition, various modifications, additions and substitutions in other forms and details may be made by those skilled in the art. It is a matter of course that various modifications, additions and substitutions made in accordance with the spirit of the invention are included in the scope of the invention as claimed.

100‧‧‧Antenna device

20‧‧‧Antenna

24‧‧‧First radiator

101‧‧‧Antenna surface

244‧‧‧second radiation arm

2424‧‧‧First long side

2444‧‧‧Second long side

268‧‧‧ Short side

12‧‧‧Feeding end

22‧‧‧Feeding body

26‧‧‧Second radiator

242‧‧‧First Radiation Arm

2422‧‧‧First short side

2442‧‧‧second short side

262, 264, 266‧‧‧ three long sides

Claims (8)

An antenna device includes a substrate, an antenna, and a coupling body, and the antenna is connected to the substrate, wherein the antenna and the coupling body are respectively disposed on opposite surfaces of the substrate, and the antenna is The first radiating body includes a first short radiating body and a first long radiating arm, and the first radiating arm includes a first short side and a first long length. The first short side extends perpendicularly to one end of the feeding body away from the feeding end, and the first long side extends perpendicularly to the first short side away from one end of the feeding end, The first long side and the feed body are parallel to each other, and the length thereof is greater than the length of the first short side, and the two first radiators are symmetrically disposed on two sides of the feed body, and the second radiation The body is symmetrically disposed on both sides of the feed line extension line, and the coupling body is coupled to the antenna. The antenna device of claim 1, wherein the substrate is made of a bent material, and includes an antenna surface and a ground plane, the antenna is disposed on the antenna surface, and the coupling body is located The ground plane. The antenna device of claim 1, wherein an edge of the substrate is provided with a feeding end, and the feeding end is configured to feed a signal to and receive a signal from the antenna. A grounding end is disposed on the grounding surface, and the grounding end provides a grounding function for the substrate. The antenna device according to claim 3, wherein the feeding body has a rectangular strip shape, one end of which is connected to the feeding end, and the other end of which is connected to the two first radiators. The antenna device of claim 1, wherein the two first radiators further comprise a second radiating arm, and the second radiating arm comprises a second short side and a second long side. The second short side is formed by extending the first long side away from the one end of the first short side in a direction away from the feeding body, and the second long side extends perpendicularly to the second short side Far from one end of the feed body, the second short side and the first short side are parallel to each other, and the length of the second short side is small The length of the first short side, the second long side and the feed body are parallel to each other, and the length of the second long side is greater than the length of the first long side. The antenna device of claim 5, wherein the two second radiators respectively comprise three long sides and one short side, and the impedance matching and the bandwidth of the antenna are adjusted by adjusting the length of the three long sides. And the mutual distance between the three long sides is adjusted. The antenna device of claim 6, wherein the short side is disposed on the second long side away from one end of the second short side, and perpendicular to the second long side, the three long The sides are the same in shape and size, and the three long sides are parallel to each other and perpendicular to the short sides. The antenna device of claim 3, wherein the coupling body includes a first coupling portion and a second coupling portion, the first coupling portion being separated from the feeding end by the grounding end The edge extends vertically, and the second coupling portion extends perpendicularly to the one end of the first coupling portion away from the feeding end.