Multifrequency antenna

[0012] Please refer to figure 1 with figure 2 , Which is a perspective view of a multi-band antenna according to a preferred embodiment of the present invention. The multi-frequency antenna 10 includes a first antenna 1 and a second antenna 2 for a wireless wide area network, and a third antenna 3 and a fourth antenna 4 for a wireless local area network. The multi-frequency antenna 10 is stamped and manufactured from a metal sheet, and combines a wireless wide area network antenna and a wireless local area network antenna.

[0013] The multi-frequency antenna 10 has a first mounting portion 61 and a second mounting portion 62 at both ends, and the first mounting portion 61 and the second mounting portion 62 form a mounting plane. The multi-frequency antenna 10 includes a ground portion 50 that is a ground portion shared by the first antenna 1, the second antenna 2, the third antenna 3 and the fourth antenna 4. The grounding portion 50 extends vertically upward to form a bending portion 14, the bending portion 14 is in a horizontal strip shape, and one end of the bending portion 14 is connected to the first mounting portion 61. The first antenna 1 and the second antenna 2 include a connecting portion 12 extending upward from the bending portion 14. The first antenna 1 includes a first radiating portion 11, and the radiating portion 11 and the ground portion 50 are connected to each other through the first connecting portion 12 and the bending portion 14. The first radiating portion 11 adopts a three-dimensional bending design and extends in a direction parallel to the longitudinal direction of the installation plane, thereby shortening the length of the installation plane perpendicular to the longitudinal direction in the transverse direction. If the plane where the first connecting portion 12 and the bending portion 14 are located is defined as the first plane, the plane where the radiation portion 11 of the first antenna 1 is located is defined as the second plane, and the plane where the ground portion 50 is located is defined as the third plane, then The first plane is perpendicular to the second plane and the third plane, and the first plane and the installation plane are on the same plane. The radiating portion 11 of the first antenna 1 extends toward the second mounting portion 62 in the second plane, and the open end 110 thereof is close to the second mounting portion 62. The center frequency at which the first antenna 1 works is about 900 MHz. The second antenna 2 includes a second radiating portion 21 extending from the first connecting portion 12 toward the first mounting portion 61, and its open end 210 is close to the first mounting portion 61. The center frequency at which the second antenna 2 works is about 1900 MHz. The first antenna 1 and the second antenna 2 share a feeding point 120, and the feeding point 120 is located on the first connecting portion 12. We can use a coaxial wire (not shown) feeding method to weld the inner core wire of the coaxial wire to the feeding point 120, and the metal braid to the grounding portion 50. The first antenna 1 and the second antenna 2 are both Planar Inverted-F Antenna (PIFA).

[0014] The third antenna 3 includes a third radiating part 31, and the fourth antenna 4 includes a fourth radiating part 41. The third antenna 3 and the fourth antenna 4 share a second connecting portion 34, and the second connecting portion 34 is connected to the other end of the bending portion 14. The third radiating portion 31 and the fourth radiating portion 41 are connected to the grounding portion 50 through the second connecting portion 34 and the bending portion 14. The third radiating portion 31 and the fourth radiating portion 41 are located in a straight line, and respectively extend from the ends of the second connecting portion 34 in opposite directions. The third radiating portion 31 extends in the direction of the first mounting portion 61, and the fourth radiating portion 41 extends in the direction of the second mounting portion 62. The second connecting portion 34 and the bending portion 14 connect the radiating portion 31 of the third antenna 3 and the radiating portion 41 of the fourth antenna 4 to the ground portion 50, respectively, forming two planar inverted F antennas. The third antenna 3 and the fourth antenna 4 share a feeding point 340, which is arranged on the second connecting portion 34, and the two antennas can also be fed by coaxial line feeding. The center frequency of the third antenna is 2.4 GHz, and the center frequency of the fourth antenna is 5.2 GHz.

[0015] The radiating part 11 of the first antenna 1 working in the low frequency band of the wireless wide area network and the radiating part 31 of the third antenna 3 working in the low frequency band of the wireless local area network are alternately placed so that the open ends 110 and 310 of the two are as far apart as possible , In order to reduce the first antenna and the third antenna signal reception and radiation interference. The distance between the center frequency of the second antenna 2 working in the high frequency band of the wireless wide area network and the center frequency of the third antenna 3 working in the low frequency band of the wireless local area network is the smallest, so interference between the two antennas is more likely to occur. However, in this embodiment, the two antennas are placed in space so that there is also a certain space interval between them, which can meet the requirements of the two antennas for normal operation. The radiating portion 21 of the second antenna 2, the radiating portion 31 of the third antenna 3, the radiating portion 41 of the fourth antenna 4, the first and second connecting portions 12, 34 and the bending portion 14 are all located on the same plane, that is, the first flat. The antenna of the present invention can be installed on the left and right sides of the upper side of the notebook computer display screen, and the double-feeding method is used so that the antenna can be used for different wireless network cards to combine various wireless applications.

[0016] image 3 It is the test chart of the voltage standing wave ratio of the wireless wide area network antenna. The vertical axis is the voltage standing wave ratio and the horizontal axis is the frequency value. Figure 4 It is the test chart of the voltage standing wave ratio of the wireless local area network antenna, the vertical axis is the voltage standing wave ratio value, and the horizontal axis is the frequency value. The ideal value of the voltage standing wave ratio is 1. In the actual test, it is generally considered that the voltage standing wave ratio is less than 2 that is within the acceptable range. image 3 It can be seen that the voltage standing wave ratio of the frequency bands around 900MHz and 1900MHz can meet the requirements. From Figure 4 It can be seen that the voltage standing wave ratio of the frequency band around 2.4GHz and 5.2GHz can also meet the requirements. Figure 5 It is the isolation test diagram of antenna 10, the vertical axis is the isolation value, and the horizontal axis is the frequency value. by Figure 5 It can be seen that in the wireless wide area network and wireless local area network frequency bands, the tested isolation values ​​are all lower than -15dB, which meets the requirements of practical applications.