TWI492453B - Communication device and broadband slot antenna element therein - Google Patents

Description

Communication device and its wide-band slot antenna element

The present invention relates to a communication device, and more particularly to a mobile communication device having a wideband slot antenna element.

With the rapid development of wireless communication technology, people's demand for wireless communication technology is also growing, and the antenna is an important key to master the quality of wireless communication transmission. The user's requirements for communication must not only support the operation of the wireless local area network (WLAN), but also increase the mobility of the communication device (for example, tablet device) by covering the operation of the wireless wide area network (WWAN). You can connect to the network anywhere. In addition, the appearance of the mobile communication device is targeted for thinning. Therefore, in the antenna design part, not only the user's use frequency band needs but also an antenna design suitable for the thinned mobile communication device.

In the prior art, for example, Taiwan Patent Publication No. I341053 "Multi-frequency single-pole slot antenna" discloses a WWAN antenna design formed by having multiple slots, which is suitable for thin-shaped mobile communication devices, in order to synthesize broadband Operation, which is used in a multi-slot manner to generate multi-mode characteristics to synthesize the required bandwidth, although it can also achieve multi-frequency operation requirements, but in order to generate multi-mode, additional slots are added, Therefore, the size of the antenna is increased.

Therefore, it is necessary to provide a small-sized mobile communication device antenna design, which can achieve at least WWAN five-frequency operation, which has two broadband operating bands, covering at least about 824~960MHz and 1710~2170MHz frequencies. The belt has the characteristics that the antenna element has a planar structure and a small size.

It is an object of the present invention to provide a communication device having an antenna element that achieves wide frequency operation using a single slot.

To achieve the above object, a communication device of the present invention comprises a grounding element and an antenna element on the dielectric substrate, the antenna element comprising an open slot on a metal surface of the dielectric substrate and a metal surface electrical Connected to the grounding element, the open slot is excited by the feeding microstrip line on the other side of the dielectric substrate, the open slot generates at least one resonant mode in the operating band of the antenna element; and a slot, which is located in the metal On the surface, the slot creates a parallel resonance near the center frequency of the operating band of the antenna element, thereby adjusting the impedance matching of the operating band and increasing the bandwidth of the operating band.

In one embodiment of the invention, an open slot is used as a radiating element to provide a resonant mode, and a slot is added to the same metal surface as the open slot as a resonant element to provide a parallel connection. Resonance helps improve the impedance matching of the antenna elements, thereby increasing the operating bandwidth of the antenna elements. Since the resonant mode is not required to be added to other conventional closed slots or open slots, the area occupied by the antenna element of the present invention can be greatly reduced, and the overall antenna size is basically determined by only one open slot. Therefore, the antenna size can be greatly reduced.

The antenna bandwidth increasing technique of the present invention mainly generates an additional imaginary impedance zero point near the resonant mode of the antenna by the parallel resonance provided by the slot itself, thereby adding an additional resonant mode, and With the original The resonant mode is combined to increase the operating bandwidth of the antenna. In addition, the present invention can be directly formed on a dielectric substrate by using printing or etching techniques, which not only makes the manufacturing process simple, but also reduces the production cost.

In an embodiment of the present invention, the antenna is a planar structure, and the size is only about 10×45 mm ² , which can cover at least the WWAN five-frequency (824~960/1710~2170 MHz) operation, achieving small size, flat printing and The advantages of broadband operation.

The above described objects, features and advantages of the present invention will become more apparent from the description of the appended claims.

Please refer to FIG. 1. FIG. 1 is a structural diagram of a first embodiment of a communication device 1 and an antenna element 11 thereof according to the present invention. In this embodiment, the communication device 1 includes a grounding component 10 and an antenna component 11 on a dielectric substrate 12. The dielectric substrate 12 has a metal surface 13 on which the antenna element 11 is located and includes a spiral slot 14 and an open slot 15. The spiral slot 14 has a first end (open end) 141 and a second end (closed end) 142; the open slot 15 has a first end (open end) 151 and a second end (closed end) 152. The open slot 15 has two bends such that the closed end extends toward the open end. On the other side of the metal surface, there is a feeding microstrip line 16, and the microwave signal is input via the antenna feeding point 161, and fed into the microstrip line 16 (the feeding microstrip line 16 and the opening slot 15 and the slot 14 are located on different surfaces. Projection on the metal surface 13 and including an opening slot 15 and a portion of the slot 14.

Please refer to FIG. 2, which is a structural diagram of a communication device according to a second embodiment of the present invention. The antenna element 21 does not have a spiral slot 14, and the rest is the same as the antenna element 11 of the first embodiment. The first embodiment selects the grounding element 10 to have a length of about 150 mm and a width of about 200 mm; the dielectric substrate 12 has a length of about 45 mm, a width of about 10 mm, and a thickness of about 0.8 mm; the length of the open slot 15 is about 64 mm, and the spiral groove The slit 14 has a length of about 58 mm and an area of only about 6 x 6 mm ² .

Please refer to FIG. 3, which is a measurement return loss diagram of the first embodiment of the communication device of the present invention, wherein the first operating band 31 is covered by the resonant modes 311, 312; and the second operating band 32 is It is covered by the resonant modes 321, 322. Under the definition of 6dB return loss (general mobile communication antenna design specification), the first operating band of the first embodiment may cover at least two-frequency operation of GSM850/900 (about 824-960 MHz); the second operation of the first embodiment The frequency band can cover at least the tri-band operation of the GSM1800/1900/UMTS (about 1710~2170MHz). Therefore, the first operating band and the second operating band of the communication electronic device and the antenna element thereof can cover at least one mobile communication band. And can meet at least WWAN five-frequency operation needs.

Please refer to FIG. 4, which is a comparison diagram of the simulated return loss of the first embodiment of the communication device of the present invention and the reference embodiment. In the reference embodiment, the open slot 15 produces a resonant mode forming a first operational frequency band 43 of the antenna element and produces a frequency doubling resonant mode to form a second operational frequency band 44. In the first embodiment, the open slots 15 respectively generate a resonant mode in the first operating band 41 and a frequency doubling resonant mode in the second operating band 42. When in The metal surface 13 is joined to a slot 14, wherein the slot 14 produces a parallel resonant mode near the center frequency of the operating band of the antenna element 11 (the length of the slot 14 is close to a quarter wavelength of the center frequency of the parallel resonance) And additionally generating an imaginary impedance zero point, and synthesizing a wider first operational frequency band 41 with the resonant mode produced by the open slot 15 and synthesizing a wider second operational frequency band 42 with the frequency doubling resonant mode. As can be seen from the comparison diagram, the bandwidths of the first operating band 41 and the second operating band 42 are respectively greater than the first operating band 43 and the second operating band 44, that is, the slot 14 simultaneously increases the first and second operating bands. bandwidth.

Please refer to FIG. 5, which is an input real part impedance diagram of different slot lengths of the communication device of the present invention. The slot 14 can generate a parallel resonance near the center frequency of the operating band, and then increase the bandwidth by additionally generating an imaginary impedance zero. In the first embodiment, if the length of the slit 14 is changed, the real impedance variation curves 51, 52, 53 of the different slit length changes of the first embodiment can be observed, and the original opening slot 15 is hardly affected. The generated mode, so that this technology can accurately control the frequency position of the resonance and does not affect the effective excitation of the original slot mode.

Please refer to FIG. 6. FIG. 6 is a structural diagram of a second embodiment of the communication device 6 and its antenna element 61 of the present invention. The structure of the communication device 6 of the second embodiment is basically the same as that of the communication device 1 of the first embodiment, except that the slot 64 of the metal surface 63 has a shape of a shape having a first end (open end) 641. With a second end (closed end) 642. As such, the second embodiment can also achieve similar effects as the first embodiment.

Please refer to FIG. 7, which is a communication device 7 and its day of the present invention. A block diagram of a third embodiment of the line member 71. The structure of the communication device 7 of the third embodiment is basically the same as that of the communication device 1 of the first embodiment, except that the slot 74 of the metal surface 73 has a shape of a composite turn and a spiral, and has a first end (opening) The end 741 and the second end (closed end) 742, and in order to match the position of the first end (open end) 741 of the slot, the position of the feed microstrip line 76 and the antenna feed point may also vary. Thus, the third embodiment can also achieve similar effects as the first embodiment.

The present invention is intended to be different from the prior art, and the various embodiments described above are merely illustrative for ease of explanation. The above is preferred and is not limited to the above embodiments.

1‧‧‧ First embodiment of the communication device of the present invention

2‧‧‧Reference embodiment of the communication device of the present invention

6‧‧‧Second embodiment of the communication device of the present invention

7.‧‧ A third embodiment of the communication device of the present invention

10‧‧‧ Grounding components

11,21,61,71‧‧‧Antenna components

12‧‧‧Media substrate

13,23,63,73‧‧‧Metal surface

14,64,74‧‧‧ slots

141,641,741‧‧‧The first end of the slot (open end)

142,642,742‧‧‧Second end of the slot (closed end)

15‧‧‧Slots

151‧‧‧ first end of the slot (open end)

152‧‧‧Second end of the slot (closed end)

16,76‧‧‧Feed into the microstrip line

161,761‧‧‧Antenna feed point

31‧‧‧First operating band of the first embodiment

32‧‧‧Second operating band of the first embodiment

311,312‧‧‧Resonance mode of the first (low frequency) operating band

321,322‧‧‧Resonance mode of the second (high frequency) operating band

41‧‧‧First operating band of the first embodiment (analog value)

42‧‧‧Second operating band of the first embodiment (analog value)

43‧‧‧First operational frequency band (analog value) of the reference embodiment

44‧‧‧The second operating band (analog value) of the reference embodiment

51, 52, 53‧‧‧ Real impedance curves of different slot length changes of the first embodiment

Figure 1 is a block diagram showing a first embodiment of a communication device of the present invention.

Figure 2 is a block diagram showing a reference embodiment of a communication device of the present invention.

Figure 3 is a graph showing the measured return loss of the first embodiment of the communication device of the present invention.

Figure 4 is a comparison diagram of the simulated return loss of the first embodiment of the communication device of the present invention and the reference embodiment.

Figure 5 is an input real part impedance diagram of different slot lengths of the communication device of the present invention.

Figure 6 is a block diagram showing a second embodiment of the communication device of the present invention.

Figure 7 is a block diagram showing a third embodiment of the communication device of the present invention.

1‧‧‧ First embodiment of the communication device of the present invention

10‧‧‧ Grounding components

11‧‧‧Antenna components

12‧‧‧Media substrate

13‧‧‧Metal surface

14‧‧‧Slots

141‧‧‧ first end of the slot (open end)

142‧‧‧Second end of the slot (closed end)

15‧‧‧Slots

151‧‧‧ first end of the slot (open end)

152‧‧‧Second end of the slot (closed end)

16‧‧‧Feed into the microstrip line

161‧‧‧ Antenna feed point

Claims (5)

A communication device comprising: a grounding element; and an antenna element on a dielectric substrate and comprising: an open slot on a metal surface of the dielectric substrate, the metal surface being electrically connected to The grounding element, the open slot generates at least one resonant mode in an operating frequency band of the antenna element; and a slot on the metal surface, the slot being substantially spiral or a shape Or a composite 蜿蜒 and a spiral, generating a parallel resonance near a center frequency of the operating band of the antenna element, thereby adjusting impedance matching of the operating band to increase a bandwidth of the operating band; the antenna element has a feed The microstrip line is located on the dielectric substrate, and the feeding microstrip line is on a different surface from the opening slot and the slot, and the projection of the feeding microstrip line on the metal surface comprises the opening slot and the slot One part. The communication device of claim 1, wherein the antenna element has a first operating frequency band and a second operating frequency band, and the first and second operating frequency bands each cover at least one mobile communication frequency band. The communication device of claim 1, wherein the open slots respectively generate a resonant mode in the first and second operating bands. The communication device as claimed in claim 1, the open slot It has at least 2 bends such that its closed end extends toward its open end. The communication device of claim 2, wherein the slot increases a bandwidth of the first and second operating bands.