TWI513109B - Diversity antenna - Google Patents

Description

Diversity antenna

The present invention relates to an antenna, and more particularly to a microwave waveguide structure design for the absorption isolation of a diversity antenna.

In the booming environment of communication technology, the evolution of wireless access technology is driving the wave of mobile data applications. With the rapid growth of wireless data traffic, the prospects for commercial applications of wireless networks are even more promising. However, in multi-antenna system applications, multiple antennas are considered to be a useful technique that can reduce multipath interference fading. The two ends of the multi-antenna system may be referred to as a Multiple-Input Multiple-Output System (MIMO System).

In the operating frequency bands of various wireless communication standards, it typically operates with the resonant frequency of the antenna. However, the diversity antenna radiator used is near the 900/1800/2100 MHz band, for example: (1) GPRS (GSM 900/DCS1800/PCS1900 MHz); (2) UMTS/HSPA (2.1 GHz WCDMA Band I).

Although there are many designs or practical studies of diversity antennas in mobile communication environments today, the terminal design part of MIMO systems is still a problem with improved space and challenges. With the evolution of the trend and the demand for use, in the mobile terminal equipment, in order to reduce the cost, reduce the size, and improve the reception and transmission efficiency, the diversity antennas in the mobile terminal equipment must strictly require extremely low correlation. Correlation coefficient and higher isolation (Isolation).

However, there are two main factors affecting the isolation characteristics: (1) the energy exchange of the electromagnetic mutual coupling caused by the antenna radiated to the electromagnetic field in space; (2) the signal transmission in the circuit board Energy exchange of electromagnetic mutual coupling caused by the transfer path. In general, the orthogonal nature of antenna polarization is often applied to eliminate electromagnetic mutual coupling caused by spatial radiation. The improvement of the electromagnetic mutual coupling phenomenon of the signal transmission path in the circuit board usually requires the signal feeding transmission line between the diversity antennas to maintain an appropriate distance and the proper layout of the microwave waveguide structure.

Therefore, under the trend of wireless communication terminals pursuing light, thin, short and small, there is often not enough space to maintain proper distance between the diversity antennas, and the antennas will generate space radiation and printed circuit boards (PCB, The Printed Circuit Board has an effect on the mutual coupling problem caused by the ,, so even with the orthogonal characteristics of the antenna polarization, it is impossible to suppress the isolation better than 20 dB.

Embodiments of the present invention provide a diversity antenna having a substrate including a first metal surface and at least one feed impedance unit. The first metal surface is disposed on an upper surface of the substrate and has a groove line. The first metal surface includes a first diversity portion and a second diversity portion, and the feed impedance unit has a first side and a second side. The opening of the slot line is located on the first side of the first metal face. The first diversity part is used to set the first antenna, and the second diversity part is used to set the second antenna, and the slot line separates the first diversity part and the second diversity part on the first metal surface. The first side of the feed impedance unit is electrically connected to the first diversity part, and the second side is electrically connected to the second diversity part, and the feed impedance unit straddles the slot line.

In summary, the present invention also needs to have a good overall performance of the correlation coefficient in order to solve the size limitation of the development device. Therefore, the diversity antenna proposed by the present invention is combined with the circuit design of the FR4 substrate circuit and coupled with the grounding noise of the resistor integrated component, corresponding to the miniaturized antenna for the handheld device, improving the isolation and the configuration between the radiators. Space constraints to provide a superior, low cost and high efficiency design.

In order to further understand the features and technical aspects of the present invention, reference should be made to the detailed description of the invention and the accompanying drawings. The invention is not to be construed as limiting the scope of the invention.

1, 2‧‧‧ diversity antenna

11, 21‧‧‧ substrate

12, 22‧‧‧ first metal surface

123, 223‧‧‧ first side

124, 224‧‧‧ second side

121, 221‧‧‧ First Division

1211‧‧‧ first through hole

122, 222‧‧‧Second Division

1221‧‧‧Second through hole

13, 23‧‧‧ first antenna

131, 231‧‧‧ first feed point

14, 24‧‧‧ second antenna

141, 241‧‧‧ second feed point

15, 25‧‧‧ slot line

17‧‧‧Second metal surface

16, 26‧‧‧Feed in impedance unit

161, 261‧‧‧ first conductive contact pads

162, 262‧‧‧Second conductive contact pads

163, 263‧‧‧ impedance components

1601, 2601‧‧‧ first side

1602, 2602‧‧‧ second side

1 is a front elevational view of an embodiment of a diversity antenna of the present invention.

2 is a schematic diagram of a slot line of an embodiment of a diversity antenna of the present invention.

3 is a schematic rear view of an embodiment of a diversity antenna of the present invention.

4 is a schematic view of a through hole of an embodiment of the diversity antenna of the present invention.

FIG. 5A is a schematic diagram of an embodiment of a feed impedance unit according to an embodiment of the present invention.

FIG. 5B is a schematic diagram of an embodiment of a feed impedance unit according to an embodiment of the present invention.

FIG. 5C is a schematic diagram of an embodiment of a feed impedance unit according to an embodiment of the present invention.

Figure 6 is a front elevational view of another embodiment of the diversity antenna of the present invention.

Fig. 7A is a diagram showing the mutual coupling suppression measurement of the diversity antenna of the present invention.

Fig. 7B is a diagram showing the mutual coupling suppression measurement of the diversity antenna of the present invention.

Various illustrative embodiments are described more fully hereinafter with reference to the accompanying drawings. However, the inventive concept may be embodied in many different forms and should not be construed as being limited to the illustrative embodiments set forth herein. Rather, these exemplary embodiments are provided so that this invention will be in the In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity. Similar numbers always indicate similar components.

It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, such elements are not limited by the terms. These terms are used to distinguish one element from another. Thus, a first element discussed below could be termed a second element without departing from the teachings of the inventive concept. As used herein, the term "and/or" includes any of the associated listed items and all combinations of one or more.

[Embodiment of Diversity Antenna]

Referring to FIG. 1 and FIG. 3, the present invention provides a diversity antenna 1. The diversity antenna 1 has a substrate 11, and the diversity antenna 1 includes a first metal surface 12, a second metal surface 17, a first antenna 13, a second antenna 14, and at least one feed impedance unit 16. The first metal face 12 has a slot line 15 and the first metal face 12 includes a first diversity portion 121 and a second diversity portion 122. The feed impedance unit 16 has a first side 1601 and a second side 1602 and includes a first conductive contact pad 161, a second conductive contact pad 162, and an impedance element 163.

The first metal surface 12 is disposed on the upper surface of the substrate 11 , the second metal surface 17 is disposed on the lower surface of the substrate 11 , and the first metal surface 12 is electrically connected to the second metal surface 17 . The first antenna 13 is disposed on the first diversity portion 121, and the second antenna 14 is disposed on the second diversity portion 122. The first side 1601 of the feed impedance unit 16 is electrically connected to the first diversity unit 121 , and the second side 1602 is electrically connected to the second diversity unit 122 .

Referring to FIGS. 1 and 3, the substrate 11 has an upper surface and a lower surface, and a first metal surface 12 and a second metal surface 17 are respectively disposed. The substrate 11 is made of RF4 material and is a high dielectric constant handheld printed circuit board (PCB). The substrate should be understood that other materials, such as a flexible printed circuit (FPC), can be used to provide the first metal surface 12, the second metal surface 17, the first antenna 13, and the second antenna. 14. The slot line 15 and the integrated circuit are integrated and arranged.

The first metal face 12 is disposed on the upper surface of the substrate 11, and the groove line 15 is formed in the first metal face 12 in a hollowed manner. In addition, the first metal surface 12 has a first diversity portion 121 and a second diversity portion 122 for respectively providing the first antenna 13 and the second antenna 14. The first diversity portion 121 and the second diversity portion 122 have a first through hole 1211 and a second through hole 1221, respectively.

The opening of the slot line 15 is located on the first side 123 of the first metal face 12, and the other end of the slot line 15 extends into the interior of the first metal face 12. The slot line 15 is disposed between the first diversity unit 121 and the second diversity unit 122 to partition the first diversity unit 121 and the second diversity unit 122. In other words, the arrangement of the slot lines 15 will be the first metal face 12 The first diversity part 121 and the second diversity part 122 are separated. The first diversity part 121 is located on the left side of the groove line 15, and the second diversity part 122 is located on the right side of the groove line 15. Please refer to FIG. 2. FIG. 2 is a schematic diagram of a slot line of an embodiment of the diversity antenna of the present invention. As can be clearly seen from FIG. 1 and FIG. 2, the groove line 15 of the embodiment of the present invention may be L-shaped except that it may be linear. However, the embodiment of the slot line 15 is not limited to the above-described shape, and may be irregular, different lengths, and different widths. The present invention is merely illustrative and not limited thereto.

Referring to FIG. 1 , the first antenna 13 is disposed on the first diversity portion 121 and adjacent to the first side 123 of the first metal surface 12 . The second antenna 14 is disposed on the second diversity portion 122 and adjacent to the second side 124 of the first metal surface 12 . In general, the first antenna 13 is disposed adjacent to the first side 123 of the first metal surface 12 and the second antenna 14 is disposed adjacent to the second side 124. The first feeding point 131 of the first antenna 13 can be arbitrarily disposed on the first diversity portion 121, and the second feeding point 141 of the second antenna 14 can be arbitrarily disposed on the second diversity portion 122. The first feed point 131 and the second feed point 141 are used to feed at least one transmit signal to the first antenna 13 and the second antenna 14. The first antenna 13 is a meandering antenna, and the second antenna 14 is an inverted F-type panel antenna. It is to be noted that, in the embodiment of the present invention, only the meandering antenna and the inverted F-type panel antenna are used as the first antenna 13 and the second antenna 14, and those skilled in the art may also use other types of antennas. The implementation of the invention is not limited by the implementation of other different antenna types, such as unipolar and dipole antennas.

Referring to Figure 3, Figure 3 is a schematic rear view of an embodiment of the diversity antenna of the present invention. In the embodiment of the present invention, the second metal surface 17 is disposed on the lower surface of the substrate 11, and is hollowed out at the position where the second metal surface 17 corresponds to the groove line 15 of the first metal surface 12. In other words, as shown in FIG. 3, the portion of the second metal face 17 that is hollowed out exposes the lower surface of the portion of the substrate 11. Two feed impedance units 16 are provided at positions where the lower surface of the substrate 11 is exposed. Each of the feed impedance units 16 has a first side 1601 and a second side 1602. The first side 1601 of the feed impedance unit 16 is electrically connected to the first diversity portion 121 through the first through hole 1211, and the second side 1602 Electrically connected to the second through the second through hole 1221. The second diversity unit 122. That is, the feed impedance unit 16 is a portion that is not directly connected or touched to the second metal surface 17.

Next, please refer to FIG. 4. FIG. 4 is a schematic diagram of a through hole of an embodiment of the diversity antenna of the present invention. It can be clearly seen from FIG. 4 that the first conductive vias 1211 respectively communicate with the first conductive portion 121 and the first conductive contact pads 161 of the feed impedance unit 16, and the two ends of the second through holes 1221 respectively communicate with the second diversity portion 122. And a second conductive contact pad 162 that is fed into the impedance unit 16. That is, the feed impedance unit 16 forms a path with the first metal hole 12 through the first through hole 1211 and the second through hole 1221, so that the first diversity portion 121 and the second diversity portion 122 are in electrical communication. It is worth mentioning that the feed impedance unit 16 spans the left and right sides of the slot line 15. For example, referring back to FIG. 1 or FIG. 2, from the top of the first metal surface 12 on the front side of the diversity antenna 1, the projection of the impedance unit 16 is fed across the slot line 15 (only the portion of the impedance element 163 is seen). . The through hole of FIG. 3 is shown as an embodiment of the two feed impedance units 16 as shown in FIG. 1 , and the single feed impedance unit 16 is a single first through hole 1211 and a single second through hole 1221 . The invention is not limited thereto.

In particular, the feed impedance unit 16 further includes a first conductive contact pad 161, a second conductive contact pad 162, and an impedance element 163. The first conductive contact pad 161 is electrically connected to the first diversity portion 121 through the first through hole 1211 , and the second conductive contact pad 162 is electrically connected to the second diversity portion 122 through the second through hole 1221. The impedance element 163 has a first end and a second end, and the first end and the second end are electrically connected to the first conductive contact pad 161 and the second conductive contact pad 162, respectively. The impedance element 163 is capable of absorbing the energy difference between the first antenna 13 and the second antenna 14 when the signal is transmitted. The impedance element 163 of the present embodiment is implemented with a resistance of 0603. However, the impedance element 163 may also be other components having impedance values, and the invention is not limited thereto.

Please refer to FIGS. 7A and 7B. FIGS. 7A and 7B are cross-coupling suppression measurement diagrams of the diversity antenna of FIG. 1. The measurement is in the UMTS Band-I 2100MHz environment, and the impedance component has an impedance value of 196 Ω. As shown in the figure, the diversity antenna provided by the embodiment of the present invention enables the antenna to be located on the printed circuit board to suppress the signal. The electromagnetic coupling between the number transmission paths improves the isolation between the first antenna and the second antenna.

Referring to FIGS. 5A, 5B, and 5C, FIGS. 5A, 5B, and 5C are schematic views of different embodiments of the feed impedance unit according to an embodiment of the present invention. Briefly, the diversity antennas of FIGS. 5A, 5B, and 5C have the same structure as that of the front and back embodiments of the diversity antenna 1 shown in FIGS. 1 and 3, except that they are fed into the impedance unit. The implementation is different and will be explained in detail later.

The feed impedance unit 16 shown in FIG. 5A includes a first conductive contact pad 161, a second conductive contact pad 162, and an impedance element 163. Referring to FIG. 2, the difference between the two is that the feed impedance unit 16 of FIG. 5A can also be implemented by feeding the impedance unit 16 in a single manner.

And the feed impedance unit 16 shown in FIG. 5B includes a first conductive contact pad 161, a second conductive contact pad 162, and two impedance elements 163. It should be noted that the two impedance elements 163 in FIG. 5B are respectively used for the first conductive contact pad 161 and the second conductive contact pad 162 respectively.

Next, please refer to FIG. 3 and FIG. 5C at the same time. FIG. 5C has a plurality of feed impedance units 16, and each feed impedance unit 16 is set in the embodiment of the impedance unit 16 fed in FIG. 5B. 5A, 5B, and 5C, it can be clearly seen that the feed impedance unit of the embodiment of the present invention has various implementations, and is not limited thereto.

As illustrated by the above embodiments, the present invention enables the shortest path transmission of the first feed point 131 and the second feed point 141 of the first antenna 13 and the second antenna 14 by the arrangement of the slot lines 15. The signal is blocked. Therefore, the signal transmission paths of the first feeding point 131 and the second feeding point 141 provided by the first antenna 13 and the second antenna 14 must bypass the slot line 15 to make the signal transmission path become long. Further, by the setting of the impedance component 163, the original signal needs to be transmitted through the elongated signal transmission path, so that the first antenna 13 and the second antenna 14 have the first feeding point 131 and the second feeding point respectively. 141 obtains a closer path of conduction, and the conduction path is transmitted through the impedance Element 163 is to transmit the coupling. However, since the energy difference between the signals transmitted by the first antenna 13 and the second antenna 14 is selected by the impedance element 163 by selecting a closer signal transmission path, it can be eliminated by the impedance element 163. The energy difference between the antenna 13 and the second antenna 14 is transmitted and coupled, and the mutual coupling effect between the first antenna 13 and the second antenna 14 is suppressed.

[Another embodiment of a diversity antenna]

The embodiment of the invention provides a diversity antenna 2 . The diversity antenna 2 has a substrate 21, and the diversity antenna 2 includes a first metal surface 22, a second metal surface (same as the second metal surface 17 of the previous embodiment), a first antenna 23, and a second antenna 24 And at least one feed impedance unit 26. The first metal surface 22 has a groove line 25, and the first metal surface 22 includes a first diversity portion 221 and a second diversity portion 222. The feed impedance unit 26 has a first side 2601 and a second side 2602 including a first conductive contact pad 261, a second conductive contact pad 262, and an impedance element 263.

The first metal surface 22 is disposed on the upper surface of the substrate 21, the second metal surface (not shown) is disposed on the lower surface of the substrate 21, and the first metal surface 22 is electrically connected to the second metal surface. The first antenna 23 is disposed on the first diversity unit 221, and the second antenna 24 is disposed on the second diversity unit 222. The first side 2601 of the feed impedance unit 26 is electrically connected to the first diversity part 221 , and the second side 2602 is electrically connected to the second diversity part 222 .

Please refer to FIG. 6. FIG. 6 is a front elevational view showing another embodiment of the diversity antenna of the present invention. The substrate 21 has an upper surface and a lower surface, and a first metal surface 22 and a second metal surface (not shown, which are the same as the second metal surface 17 of the previous embodiment) are respectively disposed. The substrate 21 is made of RF4 material and is a high dielectric constant handheld printed circuit board (PCB). The substrate should be understood to be able to use other materials, such as a flexible printed circuit board (FPC), to provide the first metal surface 22, the second metal surface (not shown), the first antenna 23, and the second. The antenna 24, the slot line 25 and the integrated circuit are integrally connected.

The first metal face 22 is disposed on the upper surface of the substrate 21, and the groove line 25 is formed in the first metal face 22 by hollowing out. In addition, the first metal surface 22 has a first diversity The portion 221 and the second diversity portion 222 are respectively configured to set the first antenna 23 and the second antenna 24.

The opening of the slot line 25 is located on the first side 223 of the first metal face 22, and the other end of the slot line 25 extends into the interior of the first metal face 22. The slot line 25 is disposed between the first diversity unit 221 and the second diversity unit 222 to partition the first diversity unit 221 and the second diversity unit 222. In other words, the arrangement of the groove lines 25 separates the first metal portion 22 from the first diversity portion 221 and the second diversity portion 222. The first diversity portion 221 is located on the left side of the groove line 25, and the second diversity portion 222 is located on the right side of the groove line 25. Referring to FIG. 2, FIG. 2 is a schematic diagram of a slot line of an embodiment of the diversity antenna of the present invention. It can be clearly seen from FIG. 2 and FIG. 6 that the slot line 25 of the embodiment of the present invention may be L-shaped in addition to being linear. However, the embodiment of the slot line 25 is not limited to the above-described shape, and may be irregular, different lengths, and different widths. The present invention is only described by way of limitation and not by way of limitation.

The first antenna 23 is disposed on the first diversity portion 221 and adjacent to the first side 223 of the first metal surface 22 . The second antenna 24 is disposed on the second diversity portion 222 and adjacent to the second side 224 of the first metal surface 22 . Generally, the first antenna 23 is disposed on the first side 223 of the first metal surface 22, and the second antenna 24 is disposed on the second side 224. The first feeding point 231 of the first antenna 23 can be arbitrarily disposed on the first diversity portion 221, and the second feeding point 241 of the second antenna 24 can be arbitrarily disposed on the second diversity portion 222 for At least one transmit signal is fed to the first antenna 23 and the second antenna 24. The first antenna 23 is a meandering antenna, and the second antenna 24 is an inverted F-type panel antenna. It is to be noted that the embodiment of the present invention only uses a meandering antenna and an inverted F-type panel antenna as the first antenna 23 and the second antenna 24, and those skilled in the art may also use other types of antennas. The invention is implemented as a monopole or a dipole antenna, and the invention is not limited thereto.

Different from the previous embodiment, the feed impedance unit 26 of the embodiment of the present invention is provided with a feed impedance unit 26 above the first metal surface 22. Each feed impedance unit 26 has a first side 2601 and a second side 2602 fed into the first side of the impedance unit 26 2601 is electrically connected to the first diversity part 221, and the second side 2602 is electrically connected to the second diversity part 222.

In particular, the feed impedance unit 26 further includes a first conductive contact pad 261, a second conductive contact pad 262, and an impedance element 263. The first conductive contact pad 261 is electrically connected to the first diversity portion 221 , and the second conductive contact pad 262 is electrically connected to the second diversity portion 222 . The first conductive contact pads 261 and the second conductive contact pads are respectively disposed on the first diversity portion 121 and the second diversity portion 122. The impedance element 163 has a first end and a second end, and the first end and the second end are electrically connected to the first conductive contact pad 261 and the second conductive contact pad 262, respectively.

It should be noted that the implementation of the feed impedance unit according to the embodiment of the present invention may also be the same as the embodiment of FIGS. 5A, 5B, and 5C. The only difference is that the feed impedance unit of the present embodiment is located above the first metal face 22. In other words, the embodiment of the present invention does not need to connect the feed impedance unit 26 and the first metal face 22 in a through hole manner.

[The possible effects of the invention]

The diversity antenna provided by the embodiment of the invention enables the antenna to be disposed on the portion of the printed circuit board to suppress electromagnetic mutual coupling caused by the signal transmission path and improve the isolation between the first antenna and the second antenna. Furthermore, the manner in which the groove lines are provided on the substrate enables the surface common mode noise coupling path between the metal surface regions provided by the antenna to be lengthened. In addition, by providing a coupling mode of feeding the impedance element, it is possible to make the surface common mode noise between the metal surface regions provided by the antenna absorb the energy difference between the antennas through the feeding impedance element, thereby achieving the elimination of the space radiation. The electromagnetic mutual coupling effect is caused. Therefore, the present invention can effectively reduce the electromagnetic coupling energy and improve the isolation, and can also maintain the operation frequency band of the antenna design while developing the device size limitation.

The above description is only the preferred embodiment of the present invention, but the features of the present invention are not limited thereto, and any one skilled in the art can easily change or modify it in the field of the present invention. Covered in the following patent scope of this case.

1‧‧‧Diversified antenna

11‧‧‧Substrate

12‧‧‧First metal surface

123‧‧‧First side

124‧‧‧Second side

121‧‧‧First Division

1211‧‧‧ first through hole

122‧‧‧Second Division

1221‧‧‧Second through hole

13‧‧‧First antenna

131‧‧‧First feed point

14‧‧‧second antenna

141‧‧‧second feed point

15‧‧‧ slot line

163‧‧‧ impedance components

Claims (8)

A diversity antenna having a substrate, comprising: a first metal surface disposed on an upper surface of the substrate and having a slot line, wherein one of the slot lines is located on a first side of the first metal surface The first metal surface includes: a first diversity portion for arranging a first antenna; and a second diversity portion for arranging a second antenna; wherein the slot line is on the first metal surface Separating the first diversity part and the second diversity part; at least one feeding impedance unit has a first side and a second side, the first side is electrically connected to the first diversity part, and the second side is electrically connected Connected to the second diversity portion, and the feed impedance unit spans the slot line; and wherein the feed impedance unit is disposed on a lower surface of the substrate, and the projection of the feed impedance unit spans the first metal The feed impedance unit includes: a first conductive contact pad disposed on the lower surface of the substrate, and electrically connected to the first diversity portion via one of the first through holes on the substrate; a second conductive contact pad disposed on a lower surface of the substrate and passing through the base The second through hole is electrically connected to the second diversity portion; and an impedance element having a first end and a second end, wherein the first end and the second end are electrically connected to the second end a first conductive contact pad and the second conductive contact pad. The diversity antenna of claim 1, wherein the feed impedance unit further comprises: a plurality of impedance elements, each of the impedance elements having a first end and a second end, the first end The second end is electrically connected to the first conductive contact pad and the second conductive contact pad, respectively, and the plurality of impedance elements are disposed in parallel. The diversity antenna according to claim 1, wherein the first antenna is configured The first antenna is disposed on the first side of the first metal surface, and the second antenna is disposed on a second side of the first metal surface. The diversity antenna of claim 1, wherein the first antenna is provided with a first feed point and the second antenna is provided with a second feed point. The second diversity portion is configured to feed at least one transmit signal to the first antenna and the second antenna. The diversity antenna of claim 1, wherein the first antenna is a meandering antenna and the second antenna is an inverted F-type panel antenna. The diversity antenna of claim 1, wherein the second antenna is an inverted F-type panel antenna. The diversity antenna of claim 1, wherein the first antenna is a meander antenna. The diversity antenna of claim 1, wherein the substrate further comprises a second metal surface disposed on a lower surface of the substrate.