TWI446626B - Wideband antenna for mobile communication - Google Patents

Description

Broadband mobile communication antenna

The invention relates to a mobile communication antenna, in particular to a mobile communication antenna capable of operating at a wide frequency, and is suitable for use in a mobile communication product.

Mobile communication technology is changing with each passing day. In just a few decades, it has evolved from traditional analog mobile phones to the current variety of mobile communication products. The application of mobile communication devices can be seen everywhere. The requirements of traditional communication systems are from the early first generation mobile communication systems (First Generation System) has developed into the current third generation of the Third Generation System (Third Generation System), and the future application of wireless communication will move toward the high-speed information transmission field of the fourth-generation Forth Generation System. Currently, the communication band required for the third-generation mobile communication system should have the operating bandwidth of the GSM/UMTS five-band system (824~960MHz and 1710~2170MHz), and the recently developed Long Term Evolution (LTE) technology will Becoming the main application of the fourth-generation mobile communication system, the application frequency band is not only compatible with the operating band of the third-generation mobile communication, but also integrates the application frequency band of the fourth-generation mobile communication system, so that the overall has more than five frequency Operating bandwidth (698~960MHz and 1710~2690MHz), whose application frequency band is defined by the European Telecommunication Standards Institute (ETSI) and 3GPP (3rd Generation Partnership Project), the low frequency operating band of the operating band has about 30% The bandwidth is wide, and the high-frequency operating band has a bandwidth of about 45%, which makes the antenna design design greatly difficult. Generally, the prior art cannot easily achieve its bandwidth requirement.

Taiwan Patent Publication No. I276248 "A Built-in Broadband Mobile Communication Antenna" discloses an antenna design for third-generation mobile communication, which utilizes an inverted F-shaped antenna design of a widened metal sheet to make the antenna current section uniform to achieve broadband operation. The antenna design can only achieve the bandwidth requirement of the basic five-frequency; Japanese Patent Application Publication No. 2006-33798A "Antenna Device and Portable Radio Terminal" discloses a dual-frequency antenna designed by using a parasitic element, which utilizes the resonance of the monopole antenna itself. The modal synthesis of another resonant mode generated on the parasitic element covers multi-frequency operation, however, such an antenna design cannot design an operating band for achieving a fourth-generation mobile communication system in a limited space.

In order to solve the above problems, the present invention provides a mobile communication antenna, in particular, an innovative design of a mobile communication antenna capable of operating at a wide frequency, and effectively utilizes multiple coupling feed characteristics of the antenna to generate multiple resonances in the low frequency operation frequency band and the high frequency operation frequency band, respectively. Modal, to achieve double broadband operation, the antenna can not only cover the five-band communication band of the third-generation mobile communication system, but also meet the operating bandwidth requirements of the fourth-generation mobile communication system.

The object of the present invention is to propose an innovative design of a broadband mobile communication antenna, achieving a double broadband frequency bandwidth in an effective design space, a low frequency bandwidth covering 698 to 960 MHz, and a high frequency bandwidth covering 1710 to 2690 MHz to cover the fourth generation. The need for mobile communication bandwidth operation.

The present invention is a wideband mobile communication antenna, comprising: a grounding portion having a grounding point and a shorting point; a first radiating portion located on one side of the grounding portion, comprising: a first sub-radiation portion, the first The sub-radiation portion has a first connection point, and generates a first resonance frequency band near a first specific frequency; and a second sub-radiation portion located on one side of the first sub-radiation portion, and the ground portion and the The first sub-radiation portion has no substantial connection, and has a first specific spacing from the first sub-radiation portion, and has a feed point and a second connection point, and generates a second resonance near a second specific frequency. a second radiation portion, located on one side of the grounding portion, comprising: a third sub-radiation portion, one end of the third sub-radiation portion being connected to the first connection point of the first sub-radiation portion, and the other end a short circuit point connected to the ground portion; and a fourth sub-radiation portion between the second sub-radiation portion and the third sub-radiation portion, and having no substantial connection with the ground portion and the third sub-radiation portion And having a second specific spacing, and the fourth sub-radiation One end is connected to the second connection point of the second sub-radiation part, and the other end is an open end; and a feeding device is configured to transmit a signal, which is respectively connected to the grounding point of the grounding part and the second sub-radiation part Feed point.

The antenna of the present invention is designed by a dual coupling feeding mode, and the first radiating portion retains the characteristics of the conventional coupled antenna design, so that the transmitting antenna has a lower real impedance in the first resonant frequency band, and by adjusting the first The first specific spacing between a sub-radiation portion and the second sub-radiation portion is effective to increase the capacitance of the antenna to compensate for the inductivity of the first resonance frequency band; by appropriately adjusting the size of the first sub-radiation portion The first resonant frequency of the first resonant frequency band may be adjusted, the first resonant frequency being about a quarter of a wavelength of the total length of the first sub-radiation portion and the third sub-radiation portion; appropriately adjusting the second sub-radiation The size of the portion can adjust the second resonant frequency of the second resonant frequency band, and the second resonant frequency is about a quarter of the length of the second sub-radiation portion, so that the communication band of the basic five-frequency can be covered. In addition, in order to further extend the design to the application band of the fourth generation mobile communication system, the second radiating portion is designed to slow down the real part of the impedance of the first resonant band edge which is decremented too fast, by appropriate Designing the second specific spacing between the third sub-radiation portion and the fourth sub-radiation portion to compensate for the capacitance of the edge of the first resonant frequency band being too low, thereby increasing the impedance bandwidth of the first resonant frequency band; By adjusting the size of the third sub-radiation portion, the impedance bandwidth of the second resonance frequency band can be increased; by adjusting the size of the fourth sub-radiation portion, the impedance bandwidth of the second resonance frequency band can be further increased. Combined with the above design features, the present invention can synthesize a dual wideband impedance bandwidth covering the fourth generation mobile communication system.

1 is a structural diagram of an embodiment of an antenna according to the present invention, comprising: a grounding portion 10 having a grounding point 101 and a shorting point 102; a first radiating portion 11 on one side of the grounding portion 10, comprising: a first sub-radiation portion 12 having a first connection point 121 and generating a first resonance frequency band 21 near a first specific frequency; and a second sub-radiation portion 13 located at the first sub-radiation portion 12 One side of the first sub-radiation portion 12 has no substantial connection with the ground portion 10 and the first sub-radiation portion 12, and has a first specific spacing 131 from the first sub-radiation portion 12 and has a feeding point 132 and a second connection point 133, and a second resonance frequency band 22 is generated in the vicinity of a second specific frequency; a second radiation portion 14 is located on one side of the ground portion 10, and includes: a third sub-radiation portion 15 One end of the third sub-radiation portion 15 is connected to the first connection point 121 of the first sub-radiation portion 12, the other end of which is connected to the short-circuit point 102 of the ground portion 10, and a fourth sub-radiation portion 16 Between the second sub-radiation portion 13 and the third sub-radiation portion 15, and the ground portion 10 and the third sub-radiation 15 has no substantial connection and has a second specific spacing 161, and one end of the fourth sub-radiation portion 16 is connected to the second connection point 133 of the second sub-radiation portion 13, and the other end is an open end; and a feed The device 17 is configured to transmit signals to the grounding point 101 of the grounding portion 10 and the feeding point 132 of the second sub-radiation portion 13, respectively. The configuration of the present invention enables the antenna of the present invention to generate a wideband impedance bandwidth in the first resonant frequency band 21 and the second resonant frequency band 22 under a limited design space, thereby covering the application frequency band of the fourth generation mobile communication system. .

Fig. 2 is a measurement result of voltage standing wave ratio (VSWR) of an embodiment of the antenna of the present invention. In the first embodiment, the following dimensions were selected to carry out the experiment: the ground portion 10 has a length of 260 mm and a width of 200 mm; the first sub-radiation portion has a length of about 40 mm and a width of about 4 mm; and the second sub-radiation portion has a length of about 22 mm and a width of about 3mm; the third sub-radiation portion has a length of about 45 mm and a width of about 2 mm; the fourth sub-radiation portion has a length of about 55 mm and a width of about 2 mm; the first specific spacing is about 3 mm; and the second specific spacing is about 2 mm; The feed device 17 is a coaxial transmission line. According to the obtained experimental results, the present invention has a good voltage standing wave ratio and wide frequency impedance bandwidth, and the first resonance frequency band 21 covers 698 to 960 MHz, and the second resonance frequency band 22 covers 1710 to 2690 MHz, which easily covers the original third generation. The operating band of the mobile communication system GSM/UMTS and further covers the operating band of the fourth generation mobile communication system.

3 is a measurement result of an antenna radiation field type in an xy plane (horizontal plane; assuming that the ground is parallel to the xy plane), an xz plane, and a yz plane (vertical plane) at 850 MHz according to an embodiment of the antenna of the present invention; FIG. 4 is the present invention. An antenna antenna field measurement result at 2200 MHz in an xy plane (horizontal plane; assuming the ground is parallel to the xy plane), an xz plane, and a yz plane (vertical plane). It is known from the measurement results that the main polarization direction of the antenna of the present invention in the xy plane (horizontal plane) is vertical polarization, and is substantially an omnidirectional radiation field type, so that the antenna has a good receiving effect near the horizontal plane, which is in line with reality. The application needs are suitable for mobile communication applications.

Fig. 5 is a structural view showing the first other embodiment of the antenna of the present invention. The greatest difference between the fifth embodiment and the first embodiment is that the grounding portion 50, the first radiating portion 51, and the second radiating portion 54 have one or more bends, and form a three-dimensional structure. The volume occupied by the antenna can be reduced, and the operation principle is the same as that of the first embodiment 1, which meets the requirements of practical applications and is suitable for use as a mobile communication application.

Figure 6 is a structural view showing a second embodiment of the antenna of the present invention. The difference between the sixth embodiment and the first embodiment is that the grounding portion 60, the first radiating portion 61 and the second radiating portion 64 are formed on a dielectric substrate 68 by printing or etching, and partially by metal. The stamping or cutting technology is used to form a composite antenna design, and the configuration of the configuration can also reduce the volume occupied by the antenna. The operation principle is the same as that of the first embodiment, and meets the requirements of practical applications. Suitable for mobile communication applications.

In summary, the present invention, regardless of its purpose, means, and function, exhibits features that are different from conventional techniques. It is to be noted that the above-described embodiments are merely illustrative of the principles of the invention and its advantages, and are not intended to limit the scope of the invention. Any person skilled in the art can make modifications or variations to the embodiments without departing from the spirit and scope of the invention. The scope of protection of the present invention should be as described in the scope of the patent application to be described later.

1. . . An embodiment of the broadband mobile communication antenna of the present invention

10,50,60. . . Grounding

101,501,601. . . Grounding point

102,502,602. . . Short circuit point

11,51,61. . . First radiation department

12,52,62. . . First sub-radiation department

121,521,621. . . First connection point

13,53,63. . . Second sub-radiation department

131,531,631. . . First specific spacing

132,532,632. . . Feeding point

133,533,633. . . Second connection point

14,54,64. . . Second radiation department

15,55,65. . . Third sub-radiation department

16,56,66. . . Fourth sub-radiation department

161,561,661. . . Second specific spacing

17. . . Feeding device

twenty one. . . First resonance band

twenty two. . . Second resonance band

68. . . Dielectric substrate

Fig. 1 is a structural view showing an embodiment of an antenna according to the present invention.

Fig. 2 is a measurement result of voltage standing wave ratio (VSWR) of an embodiment of the antenna of the present invention.

Figure 3 is a measurement result of the radiation field type of the operating antenna at an operating frequency of 850 MHz.

Fig. 4 is a measurement result of the radiation field type at an operating frequency of 2200 MHz in an embodiment of the present invention.

Fig. 5 is a structural view showing the first other embodiment of the antenna of the present invention.

Figure 6 is a structural view showing a second embodiment of the antenna of the present invention.

1. . . An embodiment of the broadband mobile communication antenna of the present invention

10. . . Grounding

101. . . Grounding point

102. . . Short circuit point

11. . . First radiation department

12. . . First sub-radiation department

121. . . First connection point

13. . . Second sub-radiation department

131. . . First specific spacing

132. . . Feeding point

133. . . Second connection point

14. . . Second radiation department

15. . . Third sub-radiation department

16. . . Fourth sub-radiation department

161. . . Second specific spacing

17. . . Feeding device

Claims (9)

A broadband mobile communication antenna includes: a grounding portion having a grounding point and a shorting point; a first radiating portion located on one side of the grounding portion, comprising: a first sub-radiation portion, the first sub-radiation portion Having a first connection point, and generating a first resonance frequency band near a first specific frequency; and a second sub-radiation portion located on one side of the first sub-radiation portion, the ground portion and the first sub-portion The radiation portion has no substantial connection, and has a first specific spacing from the first sub-radiation portion, and has a feed point and a second connection point, and generates a second resonance frequency band near a second specific frequency; The second radiating portion is located on one side of the grounding portion and includes: a third sub-radiation portion, one end of the third sub-radiation portion is connected to the first connection point of the first sub-radiation portion, and the other end is connected to the a short-circuit point of the grounding portion; and a fourth sub-radiation portion between the second sub-radiation portion and the third sub-radiation portion, having no substantial connection with the ground portion and the third sub-radiation portion, and having a a second specific spacing, and one end of the fourth sub-radiation Connected to the second connection point of the second sub-radiation portion, the other end is an open end; and a feeding device for transmitting signals, respectively connected to the grounding point of the grounding portion and the feeding of the second sub-radiation portion point. The broadband mobile communication antenna according to claim 1, wherein the grounding portion is a ground patch of an antenna element. The wideband mobile communication antenna according to claim 1, wherein the grounding portion is a system grounding surface of a wireless communication device. The wideband mobile communication antenna according to claim 1, wherein the grounding portion, the first radiating portion and the second radiating portion have one or more bends to form a three-dimensional structure. The wideband mobile communication antenna according to claim 1, wherein the first specific spacing and the second specific spacing are each less than 5 mm. The wideband mobile communication antenna according to claim 1, wherein the first resonant frequency band of the antenna is 698 to 960 MHz, and the second resonant frequency band of the antenna is 1710 to 2690 MHz. The wideband mobile communication antenna according to claim 1, wherein the grounding portion, the first radiating portion and the second radiating portion are fabricated by sheet metal stamping or cutting techniques. The broadband mobile communication antenna according to claim 1, wherein the grounding portion, the first radiating portion and the second radiating portion are formed on a dielectric substrate by printing or etching techniques. The wideband mobile communication antenna according to claim 1, wherein the grounding portion, the first radiating portion and the second radiating portion are formed on a dielectric substrate by printing or etching techniques, and partially formed of metal. Made by stamping or cutting technology.