CN1479409A - Dual-frequency dipole antenna - Google Patents

Abstract

A dual-band dual dipole antenna is suitable for being arranged on a dielectric substrate, comprising two substantially rectangular radiating metal sheets and a coaxial transmission line. The substantially rectangular radiating metal sheets are arranged symmetrically on both sides of the dielectric substrate relative to the center line of the dielectric substrate, wherein each radiating metal sheet also has a feeding point and a U-shaped slot. One feeding point is arranged relative to another feeding point, and the opening of the U-shaped slot faces the direction of the feeding point to divide the substantially rectangular radiating metal sheet into a larger sub-metal sheet and a smaller metal sheet, wherein the former is used to generate a first (low frequency) operating mode of the dual-band dual dipole antenna, and the latter is used to generate a second (high frequency) operating mode of the dual-band dual dipole antenna. The coaxial transmission line has a central conductor and an outer grounding conductor, which are respectively connected to the feeding points.

Description

Dual frequency dual dipole antenna

technical field

The present invention relates to an antenna, and more particularly to a dual-band dual-dipole antenna for a wireless local area network (WLAN) system.

Background technique

The vigorous development of wireless transmission brings various products and technologies for multi-frequency transmission, so that many new products have the performance for wireless transmission in order to meet the needs of consumers. For example, the inconvenience caused by the frequent data transmission of the notebook computer can be simplified by the wireless transmission device. Therefore, the design of the antenna is very important to achieve the purpose of wireless transmission. Furthermore, if a notebook computer with wireless transmission function is to be widely accepted and affirmed in the market, its appearance, size, and performance are quite critical. Therefore, it is relatively more important for a notebook computer to have a well-designed antenna.

Common antennas suitable for wireless transmission products such as notebook computers are generally divided into two types, one is an inverted F-shaped panel antenna (PIFA), and the other is a dual-band dual-dipole antenna. Both of these types are capable of operating in a 1/4 wavelength resonance mode. For example, U.S. Patent No. 5,926,139 issued to Korisch on July 20, 1999 discloses a panel antenna for a wireless transceiver device having first and second surfaces, a first layer, and a On, a unitary second layer, located on the second surface, has two radiating parts as an inverted F-shaped panel antenna (PIFA) and a connection part combining the radiating parts, a grounding pin, and a feeder into the needle. However, the ground pin must extend through the substrate and structurally interconnect the connecting portion of the first layer and the second layer, and thus the manufacture of the antenna can be found to be rather difficult and complicated. In addition, such inverted-F patch antennas typically have a narrow bandwidth, so that their use is disadvantageously limited. Although the dual dipole antenna has a relatively large bandwidth, it requires a relatively wide ground plane to achieve the desired radiation efficiency. Since the space provided for disposing an antenna in a notebook computer is relatively narrow, the dual dipole antenna is also limited in use.

Furthermore, common antennas can only operate in a single frequency band at most, such as U.S. Patent No. 6,008,774 titled "Printed antenna structure for wireless data communication" issued to Wu on December 28, 1999 datacommunications)", which discloses a printed antenna, including a printed circuit board, a hook-shaped radiating metal wire, printed on the upper surface of the printed circuit board, a feed-in point, connected to the hook-shaped radiating metal wire, and a ground plane printed on the lower surface of the printed circuit board. However, this antenna can only be used in the 2.4GHz band for WLAN operation. Therefore, it can be expected that as the market grows, the performance and market competitiveness of an antenna that can only operate in a single frequency band will be insufficient. Therefore, the development of antennas suitable for dual frequency bands will be a mainstream trend of related electronic products.

Contents of the invention

Therefore, it is necessary to provide a dual-band dual-dipole antenna capable of operating in dual frequency bands (such as 2.4 and 5.2 GHz bands) and having a slim profile, which is suitable for communication products such as notebook computers in order to achieve concealment of the antenna With the purpose of maintaining the appearance of the product.

The main object of the present invention is to provide a dual-band dual-dipole antenna that can be used in dual-band for WLAN operation.

A secondary object of the present invention is to provide a dual-band dual-dipole antenna with a slim profile especially suitable for communication products such as notebook computers.

To achieve the above object, the present invention provides a dual-frequency dual-dipole antenna, which is suitable for being disposed on a dielectric substrate, and includes two substantially rectangular radiating metal sheets and a coaxial transmission line, and the substantially rectangular radiating metal sheets The slices are symmetrically arranged on two sides of a dielectric substrate with respect to the center line of the dielectric substrate, wherein each radiation metal line has a feed-in point and a U-shaped slot hole. One feeding point is arranged opposite to the other feeding point, and the opening of the U-shaped slot faces the feeding point. The coaxial transmission line has a central conductor and an outer ground conductor, which are respectively connected to the feeding points.

According to another feature of the invention, each U-shaped slot is used to divide the corresponding substantially rectangular radiating metal sheet into a larger sub-metal sheet and a smaller metal sheet, wherein the former is used to generate the double A first (low frequency) mode of operation of the dual frequency dual dipole antenna, and the latter is used to generate a second (high frequency) mode of operation of the dual frequency dual dipole antenna.

According to yet another feature of the invention, the length of the larger sub-metal sheet may be selected to be approximately 1/4 wavelength of the center frequency of the first mode of operation, and the length of the smaller sub-metal sheet may be selected to be approximately 1/4 wavelength of the center frequency of the second mode of operation.

According to still another feature of the invention, the center frequency of the first mode of operation is about 2.4 GHz.

According to yet another feature of the invention, the center frequency of the first mode of operation is approximately 5.2 GHz.

Description of drawings

Other objects, advantages, and novel features of the present invention will become more apparent from the following detailed description, together with the associated drawings.

FIG. 1 is a top view showing a dual-band dual-dipole antenna according to a preferred embodiment of the present invention.

FIG. 2 is a top view of a dual-frequency dual-dipole antenna disposed on a dielectric substrate.

FIG. 3 is the measurement result of the return loss of the antenna in FIG. 2 .

4a and 4b are top views of other embodiments of the radiating metal sheet of the present invention. Label description

1: Dual frequency dual dipole antenna 5: Dielectric substrate

12: First (low frequency) operation mode 14: Second (high frequency) operation mode

20: Rectangular radiating metal sheet 22: Feed-in point

24: U-shaped slot 30: Rectangular radiating metal sheet

32: Feed-in point 34: U-shaped slot

40: Coaxial transmission line 42: Center wire

44: Outer layer grounding conductor 60: Radiating metal sheet

64: U-shaped slot 70: Radiation metal sheet

74: U-shaped slot 80: Radiation metal sheet

84: U-shaped slot 90: Radiation metal sheet

94: U-shaped slot 242: Larger sub-metal sheet

244: Smaller sub-metal sheet 245: First slit

247: The second slit 249: The third slit

342: Larger sub-metal sheet 344: Smaller sub-metal sheet

345: The first slit 347: The second slit

349: Third slit 642: Larger sub-metal sheet

644: Smaller sub-metal sheet 649: Third slit

742: Larger sub-metal sheet 744: Smaller sub-metal sheet

749: Third slit 842: Larger sub-metal sheet

844: Smaller sub-metal sheet 849: Third slit

942: Larger sub-metal sheet 944: Smaller sub-metal sheet

949: The Third Slit

Detailed ways

Although the present invention can be embodied in different forms, the embodiments shown in the drawings and described below are the preferred embodiments. Please understand that this disclosure is considered an example of the invention and is not intended to limit the invention to the particular embodiments shown.

Referring to FIG. 1 , it shows a top view of a dual-band dual-dipole antenna 1 according to a preferred embodiment of the present invention. The dual-band dual-dipole antenna 1 includes two substantially rectangular radiating metal pieces 20 , 30 and a coaxial transmission line 40 . The rectangular radiating metal sheets 20, 30 have corresponding feeding points 22, 32 thereon and U-shaped slots 24, 34 thereon. The coaxial transmission line 40 has a central conductor 42 and an outer ground conductor 44 . The U-shaped slots 24 , 34 further include corresponding first slits 245 , 345 , second slits 247 , 347 , and third slits 249 , 349 .

FIG. 2 discloses a top view of the dual-band dual-dipole antenna 1 on a dielectric substrate 5 . More specifically, the radiating metal sheets 20 , 30 are respectively and symmetrically disposed on two opposite sides of the dielectric substrate 5 , thereby forming two arms of the antenna 1 , and are disposed thereon by printing or etching techniques. According to the present invention, the dielectric substrate 5 is a printed circuit board made of BT (bismaleimide-triazine) resin or FR4 (glass fiber reinforced epoxy resin; fiberglass reinforced epoxy resin), and can also be made of polyimide (polyimide) Flexible film substrate.

The feeding points 22, 32 are respectively configured on the radiating metal sheets 20, 30 for transmitting signals. The U-shaped slots 24, 34 are respectively configured with their openings facing the feeding points 22, 32, so that the radiating metal sheets 20, 30 are respectively divided into larger sub-metal sheets 242, 342 therein. With smaller sub-metal sheets 244,344. The larger sub-metal sheet 242, 342 is used to generate a first (low frequency) mode of operation of the antenna 1, and the smaller sub-metal sheet 244, 344 is used to generate a second (high frequency) mode of operation of the antenna 1 frequency) mode of operation, wherein the length of the larger sub-metal sheet 242, 342 is selected to be approximately the wavelength of the center frequency of the first (low frequency) mode of operation, and the length of the smaller sub-metal sheet 244, 344 A wavelength may be selected to be approximately the center frequency of the second (high frequency) mode of operation. The center wire 42 and the outer ground conductor 44 are respectively connected to the feeding points 22 , 32 .

FIG. 3 discloses the return loss measurement results of the antenna 1 in FIG. 2 . The measurement results are obtained under these conditions: the dielectric substrate 5 is a glass fiber substrate with a length of 50 mm, a width of 5 mm, and a thickness of 0.4 mm; the two radiating metal sheets 20, 30 have a length of about 23 mm and a width of about 4mm, and printed on the glass fiber substrate 5; the U-shaped slot 24, 34 width is about 0.5mm; and from the opening of the U-shaped slot 24, 34 to the corresponding feed-in point 22, 32 The distance, which is marked with the symbol "A", is about 5mm. Thus, the center frequency of the first (low frequency) mode of operation 12 is about 2.45 GHz, and the center frequency of the second (high frequency) mode of operation 14 is about 5.25 GHz. Furthermore, under the definition of voltage standing wave ratio (VSWR) less than 2, the bandwidth of the first (low frequency) operation mode 12 and the second (high frequency) operation mode 14 can cover 2.4 for WLAN operation. GHz (2.4-2.484GHz) and 5.2GHz (5.15-5.35GHz) frequency bands. In addition, the antenna 1 of this embodiment is only 5 mm wide, and thus very suitable for notebook computers that only have a long and thin space for accommodating an antenna.

4a and 4b show top views of other embodiments of the radiating metal sheets 60, 70, 80, 90 of the present invention. These radiating metal sheets 60 , 70 , 80 , 90 are similar to the radiating metal sheets 20 , 30 shown in FIG. 2 , and similar or corresponding components are marked with the same reference numerals. The U-shaped slots 64, 74, 84, 94 respectively divide the radiating metal sheet 60, 70, 80, 90 into larger sub-metal sheets 642, 742, 842, 942 and smaller sub-metal sheets 644, 744 , 844, 944, wherein the former is used to generate a first (low frequency) mode of operation of the antenna 1, and the latter is used to generate a second (high frequency) mode of operation of the antenna 1. As shown in FIG. 4 a , the third slit 649 , 749 has a bend of a circular arc, and this configuration will produce substantially the same effect as that of FIG. 2 . Furthermore, the width of the third slit 849, 949 in FIG. 4b can be selectively adjusted so that the desired center of the first (low frequency) and second (high frequency) modes of operation can be obtained for various applications. frequency. For example, the width of the third slit 849, 949 can be increased towards the direction of the feeding point 22, 32 to reduce the length of the smaller sub-metal sheet 844, 944, so as to reduce the second (height frequency) the center frequency of the operating mode. Similarly, the positions of the U-shaped slots 24, 34 shown in FIG. 2 can be moved longitudinally relative to the radiating metal sheets 20, 30 so as to simultaneously change the first (low frequency) and second (high frequency) operating modes. Two center frequencies. Furthermore, the length of the radiating metal strips 20, 30 can extend outward relative to the U-shaped slots 24, 34, so as to reduce the central frequency of the first (low frequency) operating mode.

Therefore, in order to obtain dual frequency operation with different ratios of the center frequency of the first (low frequency) mode of operation to the center frequency of the second (high frequency) mode of operation, the U-shaped slot 24 such as that shown in FIG. 2 can be modified. , 34 or the device of the radiating metal sheet 20, 30, whereby a dual-band dual-dipole antenna suitable for 2.4/5.2GHz dual-band WLAN operation can be designed. In addition, the two resonant frequencies (central frequencies of the first and second operating modes) can obtain good impedance matching without additional matching circuits installed on the antenna 1 .

Although the foregoing description and illustrations have disclosed preferred embodiments of the present invention, it must be understood that various additions, modifications and substitutions may be made to the preferred embodiments of the present invention without departing from the present invention as defined in the appended claims. The spirit and scope of the principles. One skilled in the art will appreciate that the present invention is possible in many forms, structures, arrangements, proportions, materials, devices and modifications of devices. Furthermore, the actual use of the present invention is particularly adapted to specific circumstances and operational requirements without departing from the essential principles of the invention. Therefore, the embodiments disclosed herein should be regarded as illustrating the present invention rather than limiting the present invention from all viewpoints. The scope of the invention should be defined by the claims, and their legal equivalents, not by the foregoing description.

Claims (10)

1. A dual-frequency dual-dipole antenna, suitable for being configured on a dielectric substrate, is characterized in that: comprising: Two substantially rectangular radiating metal sheets are symmetrically arranged on both sides of the dielectric substrate with respect to the center line of the dielectric substrate, thereby forming two arms of the dual-frequency dual-dipole antenna, wherein each substantially rectangular radiating metal sheet Also have a feed-in point, configured relative to another feed-in point for transmitting signals; a U-shaped slot opening facing the direction of the feed point for dividing the generally rectangular radiating metal sheet into a larger sub-metal sheet and a smaller sub-metal sheet, wherein the former is used to generate the a first (low frequency) mode of operation of the dual frequency dual dipole antenna, and the latter is used to generate a second (high frequency) mode of operation of the dual frequency dual dipole antenna; A coaxial transmission line has a central conductor and an outer layer ground conductor respectively connected to the feeding point. 2. The dual-frequency dual-dipole antenna according to claim 1, wherein the length of each larger sub-metal plate can be selected to be approximately 1/4 wavelength of a center frequency of the first operating mode, And the length of each smaller sub-metal sheet can be selected to be about 1/4 wavelength of a center frequency of the second operation mode. 3. The dual-band dual-dipole antenna as claimed in claim 1, wherein the central frequency of the first operation mode is about 2.4 GHz. 4. The dual-band dual-dipole antenna as claimed in claim 1, wherein the center frequency of the first operation mode is about 5.2 GHz. . 5. The dual-band dual-dipole antenna as claimed in claim 1, wherein the substantially rectangular radiating metal sheet is printed on the dielectric substrate. 6. The dual-band dual-dipole antenna as claimed in claim 1, wherein the substantially rectangular radiating metal sheet is etched on the dielectric substrate. 7. The dual-frequency dual-dipole antenna according to claim 1, wherein each U-shaped slot comprises: a first slit; a second slit maintained in a spaced apart relationship from the first slit; A third slit, one end of which is connected to one end of the first slit and the other end is connected to one end of the second slit, and the other ends of the first and second slits are placed between the third slit same side. 8. The dual-band dual-dipole antenna as claimed in claim 7, wherein each third slit is substantially perpendicular to the first and second slits. 9. The dual-frequency dual-dipole antenna as claimed in claim 7, wherein each third slit has a curved shape. 10. The dual-band dual-dipole antenna as claimed in claim 1, wherein the position of each U-shaped slot can move longitudinally relative to the substantially rectangular radiating metal sheet.

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