TWI466378B - Flexible combo antenna - Google Patents

Description

Flexible composite antenna

The present invention relates to antennas, and more particularly to a flexible composite antenna.

In recent years, with the increasing maturity of wireless transmission technology, the application of wireless communication electronic devices has become more and more popular, such as wireless mouse, wireless keyboard or mobile phone. Therefore, it is necessary to configure an antenna in a wireless communication electronic device. To wirelessly transmit and receive data. Moreover, wireless communication electronic devices must be capable of supporting the transmission of more and more different wireless network signals, such as global satellite positioning signals, wireless local area network (WLAN) signals, Bluetooth signals or digital television signals, and the like. . These wireless signals use different frequency bands respectively. In order to receive the wireless signals of these different frequency bands, many antennas need to be established in the wireless communication electronic device. There are many types of antennas. For example, the antennas include both non-built-in and built-in types. The non-built-in antenna includes a monopole antenna, a dipole antenna, and a helix antenna, and the built-in antenna includes a Planar Inverted F Antenna (Planar Inverted F Antenna, PIFA) and microstrip antennas...etc.

Furthermore, since the appearance of the wireless communication electronic device requires a light, thin and short design, the built-in antenna must also be appropriately adjusted and designed with the electronic device to make it suitable for the appearance and size requirements of the electronic device. In general, the antenna can be set to hard On the printed circuit board (PCB), the antenna body is formed by using a microstrip line or a printed copper foil layout line, thereby reducing the space occupied by the antenna and the design cost thereof. Although the above method can reduce the space of the antenna, in order to maintain the transmission quality of the signal, the area on the printed circuit board needs to be kept clear to set the antenna. Due to the current slim size of the electronic device, the required clearance area of the antenna is also limited by the mechanism design of the electronic device and the shape of the printed circuit board assembly, which causes design difficulties and affects the transmission quality of the antenna.

Moreover, more and more wireless communication modules are arranged in the electronic device, and the GPS communication module and the WiFi communication module may be simultaneously configured in the electronic device, and the frequency bands used by each wireless communication module are different, and the frequency band is greatly increased. The probability of being disturbed, the traditional method of using hardware circuit design to prevent interference is no longer sufficient.

Taking a notebook computer as an example, the position of the antenna is usually placed in the casing around the screen, but the available space around the screen is limited, which often causes great trouble in the antenna setting. For a wireless network signal of 2.4G Hz or 5G Hz, just use a short length antenna. Taking a dipole antenna as an example, an antenna having a main frequency of 5 GHz is 3 cm in length, and an antenna having a main frequency of 2.4 GHz is about 6 cm in length. But for lower frequency signals (such as extremely high frequency signals (VHF, 45M Hz - 300M Hz) for digital TVs or UHF, 300MHz Hz - 900M Hz), the required antenna length will be quite For example, a dipole antenna having a main frequency of 150 Hz is about 100 cm in length, and a planar inverted-F antenna (PIFA) having a main frequency of 150 Hz is about 70 cm in length. In this case, the length is about 70 cm. It is quite difficult to place various antennas in a single hard board in a conventional manner.

Furthermore, based on the appearance and size requirements of the electronic device, for example: various frequencies The antenna must be placed at the curved shape position of the electronic device according to the product requirements. At this time, the conventional design of the antenna printed on the hard circuit board will not be able to use this method due to the inflexible physical properties of the hard circuit board. The antenna is disposed at a position where the arc is within the electronic device.

In view of the above problems of the prior art, it is an object of the present invention to provide a flexible composite antenna to solve the problem that the antenna cannot be placed at a position where the antenna is curved in the electronic device.

According to an object of the present invention, a flexible composite antenna is provided on a flexible substrate, which is provided with a plurality of antenna lines of different frequency bands, a plurality of feeding portions and a grounding surface, wherein the grounding surface is disposed on the flexible substrate One side, and each antenna line is disposed on the flexible substrate, one end of which is connected to the ground plane, and the other end is bent back and forth on the flexible substrate to form a desired length and antenna characteristics on the flexible substrate. Each of the feeding portions is disposed at a position where the flexible substrate is provided with a ground plane, and is respectively connected to one of the antenna lines by a transmission line, and the flexible substrate is provided with an isolation unit between the antennas for isolating the antennas. Interaction between each other to form a flexible composite antenna.

The flexible substrate is a flexible printed circuit (FPC).

Wherein, the metal coated on one side of the flexible substrate forms a ground plane.

The antenna lines of the plurality of different frequency bands are a first frequency band antenna line and a second frequency band antenna line.

The frequency range received by the first frequency band antenna line is 1.575 MHz, 1.71 GHz to 2.17 GHz, or 2.3 GHz to 2.5 GHz.

The first frequency band antenna line is a GPS (Global Positioning System) antenna, a WIFI antenna, a Bluetooth antenna, a GSM1800/2100 antenna or a WiMax antenna.

The frequency range received by the second frequency band antenna line is between 824 MHz and 960 MHz and between 1.71 GHz and 2.17 GHz.

The second frequency band antenna line is a GSM antenna.

The first frequency band antenna line and the second frequency band antenna line are printed metal lines which are bent back by one edge of one surface of the grounding surface by the flexible substrate.

Wherein, the plurality of feeding portions comprise a feeding point and a separation area, wherein the separation area is a blank space in the grounding surface where no metal is disposed, and each feeding point is a gap between the central portion of the blank and the grounding surface. Metal.

The isolation unit is a metal extending between the first frequency band antenna line and the second frequency band antenna line by a ground plane.

The transmission line is disposed on the other side of the flexible substrate and penetrates between the first frequency band antenna line and the second frequency band antenna line and the matched feeding point.

Among them, the impedance matching value of the transmission line is 50 ohms (Ω).

Wherein, one surface of the flexible substrate is provided with a protective layer covering the ground plane, each antenna line and the isolation unit, and each feeding point is exposed.

Wherein, the protective layer is respectively provided with a grounding end at a position of the adjacent plurality of feeding portions, and each of the grounding ends provides a woven metal mesh connection of the coaxial cable.

In view of the above, a flexible composite antenna according to the present invention may have one or more of the following advantages:

(1) Set antenna lines of different frequency bands on the same flexible substrate. In order to save space for the electronic device to install the antenna line.

(2) The grounding surface and the feeding point position can be elastically set on the flexible substrate.

(3) The flexible composite antenna can be directly connected to the hard circuit board of the electronic device with a flexible substrate, or connected to the hard circuit board of the electronic device through a coaxial cable.

(4) The antennas of the flexible composite antenna are separated by isolation units, resulting in a fairly good isolation effect, so that the antennas do not affect each other.

(5) The flexible characteristics of the flexible composite antenna can be adjusted according to the structure of the mounted electronic device so that it can be placed at a position where the electronic device is curved.

(6) The grounding surface of the flexible composite antenna can separately form the required grounding effect, and can be further connected to the grounding surface of the electronic device or other grounding surface for better grounding effect.

(7) The flexible composite antenna can be provided with antenna lines of a plurality of different frequency bands on the flexible substrate as required.

10‧‧‧Flexible substrate

11‧‧‧Protective layer

12‧‧‧Antenna line

120‧‧‧1st band antenna line

122‧‧‧second band antenna line

13‧‧‧ Grounding terminal

14‧‧‧Feeding Department

140‧‧‧Feeding point

142‧‧‧Separation area

15‧‧‧ coaxial cable

150‧‧‧woven metal mesh

16‧‧‧ transmission line

18‧‧‧Isolation unit

19‧‧‧ Ground plane

Figure 1A is a front elevational view of the flexible composite antenna of the present invention.

FIG. 1B is a schematic diagram of the flexible composite antenna connecting coaxial cable and protective layer of the present invention.

Figure 2 is a schematic rear view of the flexible composite antenna of the present invention.

Fig. 3 is a graph showing the return loss corresponding to the operating frequency of the flexible composite antenna of the present invention.

Figure 4 is a schematic diagram of a first aligned flexible composite antenna.

Figure 5 is a graphical representation of the return loss corresponding to the operating frequency of the first aligned flexible composite antenna.

Figure 6 is a schematic diagram of a second aligned flexible composite antenna.

Figure 7 is a graphical representation of the return loss corresponding to the operating frequency of the second aligned flexible composite antenna.

Figure 8 is a schematic diagram of a third aligned flexible composite antenna.

Figure 9 is a graphical representation of the return loss corresponding to the operating frequency of the third aligned flexible composite antenna.

Figure 10 is a schematic diagram of a fourth aligned flexible composite antenna.

Figure 11 is a graphical representation of the return loss corresponding to the operating frequency of the fourth aligned flexible composite antenna.

Please refer to FIGS. 1A, 1B and 2, which are respectively a front view of the flexible composite antenna of the present invention, a schematic diagram of the flexible composite antenna connecting the coaxial cable and the protective layer, and a schematic view of the back of the flexible composite antenna. The figure includes a flexible substrate 10, a plurality of antenna lines 12, a plurality of feeding portions 14, a plurality of transmission lines 16, at least one isolation unit 18, and a ground plane 19. The grounding surface 19 is disposed on one surface of the flexible substrate 10 and extends from one end edge of the flexible substrate 10 to the other end edge. Each antenna line 12 is disposed between the other end of one surface of the flexible substrate 10 to the ground plane 19, and each antenna line One end of the 12 is connected to the ground plane 19, and the other end is bent back and forth on the flexible substrate 10, thereby forming a desired length and antenna characteristics in the flexible substrate 10. Each of the feeding portions 14 is provided at a position where the flexible substrate 10 is provided with the ground plane 19. Each transmission line 16 is disposed on the other side of the flexible substrate 10 and connected between each of the antenna lines 12 matched by the feeding portion 14 (as shown in FIG. 2), and the impedance matching value of the transmission line 16 is 50 ohms ( Ω). Each of the isolation units 18 is disposed between each of the antenna lines 12 and connected to the ground plane 19 for isolating the interaction between the antenna lines 12 to form a flexible composite antenna.

In an embodiment of the invention, the flexible substrate 10 is a flexible printed circuit (FPC). A metal (for example, a conductive metal such as copper foil, silver foil, or gold foil) coated on one side of the flexible substrate 10 forms a ground plane. The plurality of antenna lines 12 of different frequency bands include a first frequency band antenna line 120 and a second frequency band antenna line 122. The first frequency band antenna line 120 receives a frequency range of 1.575 GHz, 2.3 GHz to 2.5 GHz, and 1.71 GHz to 2.17 GHz, and further is a GPS (Global Positioning System) antenna, a WIFI antenna, a Bluetooth antenna, and a GSM1800/2100 antenna. Or WiMax antenna. The second frequency band antenna line 122 receives a frequency range of 824 MHz to 960 MHz and 1.71 GHz to 2170 GHz, and further is a GSM antenna. Therefore, the flexible composite antenna of the present invention can be applied to GPS (1.575GHz), GSM (880~960MHz), DCS (1710~1880MHz), PCS (1850~1990MHz) and UMTS (1920~2170MHz), WIFI and Bluetooth. Wireless communication system (2.45GHz).

Referring to FIG. 1B , in the embodiment, the first frequency band antenna line 120 and the second frequency band antenna line 122 are formed by the flexible substrate 10 with one edge of the ground plane 19 and a curved printed metal. (such as: copper foil, silver foil or gold foil... etc. Metal) line. Each of the feeding portions 14 includes a feeding point 140 and a partitioning area 142. The partitioning area 142 is a blank space in the grounding surface 19 where no metal (such as copper foil, silver foil or gold foil, etc.) is disposed. The entry point 140 is a metal (for example, a conductive metal such as copper foil, silver foil, or gold foil) that is not electrically conductive between the center and the ground plane 19 at the center of the blank. The isolation unit 18 is a metal (such as a conductive metal such as copper foil, silver foil or gold foil) that is disposed between the first frequency band antenna line 120 and the second frequency band antenna line 122 by the ground plane 19. The transmission line 16 is disposed on the other side of the flexible substrate 10 and penetrates between the first band antenna line 120 and the second band antenna line 122 and its matched feed point.

Moreover, as shown in FIG. 1B, one surface of the flexible substrate 10 is further provided with a protective layer 11 covering the ground plane 19, the antenna lines 12 and the isolation unit 18, and the feed point 140 is exposed. The protective layer 11 is provided with a grounding end 13 adjacent to the plurality of feeding portions 14, and each of the grounding ends 13 is connected to the woven metal mesh 150 of the coaxial cable 15 (as shown in FIG. 1B).

Please refer to FIG. 3, which is a schematic diagram of the return loss corresponding to the operating frequency of the flexible composite antenna of the present invention. In the figure, the first frequency band antenna line 120 has a return loss (return loss (S11)) in the frequency range of the wireless frequency of 1.57 GHz, and the return loss (S11) is less than -10 dB, which is in compliance with the requirements, so the receiving frequency range obviously conforms to the wireless of the GPS antenna. Frequency Range. The second frequency band antenna line 122 has a return loss (return loss (S22)) in the frequency range of 824 MHz to 960 MHz and 1.71 GHz to 2.17 GHz, and the return loss (S22) is less than -6 dB, which meets the requirements, so the receiving frequency range is obviously Meets the wireless frequency range of the GSM 5-band antenna.

In order to better understand the function and effectiveness of the isolation unit for each antenna line, a number of comparison flexible antennas are described below.

Please refer to FIG. 4 and FIG. 5, FIG. 4 is a schematic diagram of a first comparative flexible composite antenna, and FIG. 5 is a schematic diagram of a return loss corresponding to a working frequency of a first comparative flexible composite antenna. . In the figure, there is no isolation unit 81 between the first frequency band antenna line 120 and the second frequency band antenna line 122, wherein the return loss (return loss (S11)) of the first frequency band antenna line 120 is less than -10 dB. The wireless frequency range to the WiFi antenna. The return loss (return loss (S22)) of the second band antenna line 122 is higher than the frequency point of -6 dB, and the bandwidth is widened.

Please refer to FIG. 6 and FIG. 7 , FIG. 6 is a schematic diagram of a second comparative flexible composite antenna, and FIG. 7 is a schematic diagram of a return loss corresponding to a working frequency of a second comparative flexible composite antenna. . In the figure, the flexible composite antenna has an isolation unit 18 biased toward the second frequency band antenna line 122, wherein the return loss (return loss (S11)) of the first frequency band antenna line 120 is less than -10 dB, and the radio frequency point is high, and the frequency is high. Wide and wide. The return loss (return loss (S22)) of the second band antenna line 122 is lower than the frequency point of -6 dB, and the bandwidth is narrowed.

Please refer to FIG. 8 and FIG. 9 , FIG. 8 is a schematic diagram of a third comparative flexible composite antenna, and FIG. 9 is a schematic diagram of a return loss corresponding to a working frequency of a third comparative flexible composite antenna. . In the figure, the flexible composite antenna has an isolation unit 18 biased toward the first frequency band antenna line 120, wherein the return loss (S11) of the first frequency band antenna line 120 is less than -10 dB, and the wireless frequency point is high, and the frequency is high. Wide and narrow. The return loss (return loss (S22)) of the second band antenna line 122 is lower than the frequency point of -6 dB, and the bandwidth is narrowed.

Please refer to FIG. 10 and FIG. 11 , FIG. 10 is a schematic diagram of a fourth comparative flexible composite antenna, and FIG. 11 is a schematic diagram of a return loss corresponding to a working frequency of a fourth comparative flexible composite antenna. . In the figure, the flexible composite antenna has a bias to the first frequency band. The isolation unit 18 of the antenna line 120, and the length of the isolation unit 18 is shorter than that of the isolation unit 18 of FIG. 8, wherein the return loss (S11) of the first frequency band antenna line 120 is less than -10 dB. Move to the wireless frequency range of the WiFi antenna and the bandwidth is narrowed. The return loss (return loss (S22)) of the second band antenna line 122 is higher than the frequency point of -6 dB, and the bandwidth is widened.

In summary, the length of the isolation unit 18 between the first frequency band antenna line 120 and the second frequency band antenna line 122 is preferably to completely separate the first frequency band antenna line 120 and the second frequency band antenna line 122, and the isolation unit. The interval between the first frequency band antenna line 120 and the second frequency band antenna line 122, and the interval from the isolation unit 18 side to the first frequency band antenna line 120 and the interval from the other side of the isolation unit 18 to the second frequency band antenna line 122. It is better to have the distance between the two. Thus, the present invention is used by the isolation unit 18 to isolate the interaction between the antenna lines. In addition, the flexible composite antenna can be adjusted according to the structure of the installed electronic device, and can be connected to the electronic device through a coaxial cable, or the ground plane can be directly connected to the ground plane of the electronic device to achieve better. Grounding effect.

The above is intended to be illustrative only and not limiting. Any equivalent modifications or alterations to the spirit and scope of the invention are intended to be included in the scope of the appended claims.

10‧‧‧Flexible substrate

11‧‧‧Protective layer

12‧‧‧Antenna line

120‧‧‧1st band antenna line

122‧‧‧second band antenna line

13‧‧‧ Grounding terminal

14‧‧‧Feeding Department

15‧‧‧ coaxial cable

150‧‧‧woven metal mesh

140‧‧‧Feeding point

142‧‧‧Separation area

18‧‧‧Isolation unit

19‧‧‧ Ground plane

Claims (10)

A flexible composite antenna includes: a flexible substrate; a ground plane disposed on one side of the flexible substrate and extending from one end edge of the flexible substrate to the other end edge; a plurality of antenna lines The plurality of antenna lines are disposed between the other end of one surface of the flexible substrate and the ground plane, one end of which is connected to the ground plane, and the other end of which is located at the other end of one surface of the flexible substrate The grounding surface is bent back and forth to form a desired length and antenna characteristics, and respectively receive wireless signals of different frequency bands; a plurality of feeding portions, the number of which is equivalent to the plurality of antenna lines, is disposed on the flexible substrate a position of the ground plane; a plurality of transmission lines having the same number as the plurality of antenna lines and the plurality of feed portions, disposed on the other side of the flexible substrate, and connecting each of the matching portions to the antenna And between the lines; and at least one isolation unit is disposed between the antenna lines and connected to the ground plane, and the separation distance between the isolation unit and each of the antenna lines is phase . The flexible composite antenna of claim 1, wherein the metal coated on one side of the flexible substrate forms the ground plane. The flexible composite antenna according to claim 2, wherein the plurality of antenna lines comprise a first frequency band antenna line and a second frequency band antenna line. The flexible composite antenna according to claim 3, wherein the first frequency band The frequency range received by the antenna line is 1.575 MHz, 2.3 GHz to 2.5 GHz, or 1.71 GHz to 2.17 GHz. The flexible composite antenna according to claim 3, wherein the second frequency band antenna receives a frequency range of 824 MHz to 960 MHz and 1.71 GHz to 2.17 GHz. The flexible composite antenna of claim 3, wherein the first frequency band antenna line and the second frequency band antenna line are disposed on the ground plane and the flexible substrate by the flexible substrate A printed metal line that bends back and forth between one end edge. The flexible composite antenna of claim 6, wherein the plurality of feeding portions respectively comprise a feeding point and a separation area, wherein the separation area is a blank space in the grounding surface where no metal is disposed. Each of the feeding portions is a metal that is not electrically connected to the ground surface at a center of the blank portion. The flexible composite antenna of claim 7, wherein the isolation unit extends from the ground plane to a metal disposed between the first frequency band antenna line and the second frequency band antenna line, and is connected to the ground Ground connection. The flexible composite antenna of claim 3, wherein the transmission line is disposed on the other side of the flexible substrate, and penetrates the first frequency band antenna line and the second frequency band antenna line, and Match between each of the feed points. The flexible composite antenna of claim 9, wherein the transmission line has an impedance matching value of 50 ohms.