TW201724646A - Electronic device - Google Patents

Abstract

An electronic device including a housing structure, a ground plane and a dual-band antenna is provided. The housing structure includes a first housing for forming a side wall of the electronic device. The dual-band antenna includes a radiation element and a parasitic element. The radiation element includes a feeding point and a resonant path from the feeding point to the ground plane, and the dual-band antenna operates in a first band through the radiation element. The parasitic element is connected to the ground plane and includes a first parasitic portion and a second parasitic portion. The second parasitic portion is located between the first housing and the radiation element and is spaced apart a coupling distance from the radiation element. The dual-band antenna operates in a second band through the parasitic element, and a center frequency of the second band is lower than a center frequency of the first band.

Description

Electronic device

The present invention relates to an electronic device, and more particularly to an electronic device including a dual frequency antenna.

In recent years, dual-band antennas that can operate at 2.4 GHz and 5 GHz have been widely used in various electronic devices, such as tablet computers and notebook computers, so that electronic devices can support communication functions under the WiFi standard through dual-frequency antennas. In general, traditional dual-band antennas are mostly architectures using a planar inverted-F antenna (PIFA). In addition, when a conventional dual-band antenna with a PIFA architecture is applied to an electronic device, the specific absorption ratio (SAR) measured by the electronic device in the safety test often has an excessive problem.

Therefore, when a conventional dual-band antenna having a PIFA architecture is applied to an electronic device, the electronic device often has to reduce the transmission power of the conventional dual-frequency antenna to conform to the specification of the SAR value. However, as the transmission power of the conventional dual-frequency antenna is reduced, the communication quality of the electronic device is also affected. Therefore, how to balance the specification of SAR values and the communication quality of electronic devices has become an important issue in the design of electronic devices.

The present invention provides an electronic device in which a second parasitic portion in a parasitic element is disposed between a radiating element and a first housing, and a resonant path of the radiating element and the parasitic element is independent of each other. Thereby, the electronic device will still maintain good communication quality under the SAR compliance specification.

The electronic device of the present invention comprises a housing structure, a ground plane and a dual frequency antenna. The housing structure includes a first housing to form a sidewall of the electronic device. The ground plane and the dual frequency antenna are disposed within the housing structure. The dual frequency antenna includes a radiating element and a parasitic element. The radiating element includes a feed point and a resonant path extending from the feed point to the ground plane, and the dual frequency antenna is operated in the first frequency band by the radiating element. The parasitic element includes a first parasitic portion and a second parasitic portion. The first parasitic portion is electrically connected between the ground plane and the second parasitic portion. The second parasitic portion is between the first housing and the radiating element and is spaced apart from the radiating element by a coupling pitch. The dual frequency antenna operates in the second frequency band through the parasitic element, and the center frequency of the second frequency band is smaller than the center frequency of the first frequency band.

In an embodiment of the invention, the radiating element includes a first radiating portion, a second radiating portion, and a third radiating portion. The first radiating portion has a feeding point and faces the first parasitic portion. The second radiating portion is electrically connected to the first radiating portion and spaced apart from the second parasitic portion by the coupling pitch. The second parasitic portion is between the first housing and the second radiating portion. The third radiating portion is electrically connected to the second radiating portion and the ground plane. The first radiation portion is between the first parasitic portion and the third radiation portion.

Based on the above, the dual-frequency antenna in the electronic device of the present invention includes a radiating element and a parasitic element, and the radiating element includes a resonant path extending from the feeding point to the ground plane. Furthermore, the second parasitic portion disposed between the first housing and the radiating element will cause the radiating element to be relatively far from the first housing of the electronic device. Thereby, the electronic device can conform to the specification of the SAR value without lowering the transmission power of the dual-frequency antenna. In other words, the electronic device can still maintain good communication quality under the SAR compliance specification.

The above described features and advantages of the invention will be apparent from the following description.

1 is a schematic diagram of an electronic device in accordance with an embodiment of the present invention. As shown in FIG. 1 , the electronic device 100 includes a housing structure 110 , a ground plane 120 , and a dual frequency antenna 130 . The housing structure 110 includes a first housing 111, a second housing 112, and a third housing 113. The dual frequency antenna 130 includes a radiating element 131 and a parasitic element 132. Further, the radiating element 131 includes a first radiating portion 141, a second radiating portion 142, and a third radiating portion 143. The parasitic element 132 includes a first parasitic portion 151 and a second parasitic portion 152.

2 is a cross-sectional view of an electronic device in accordance with an embodiment of the present invention, wherein FIG. 2 is a broken line showing the set position of the dual band antenna 130 of FIG. As shown in FIGS. 1 and 2, the first housing 111 in the housing structure 110 can be used to form a side wall of the electronic device 100. That is, the first housing 111 can be used to form a short edge or a long edge near the upper half of the electronic device 100. Further, the dual frequency antenna 130 is disposed in the upper half of the electronic device 100 and adjacent to the first housing 111.

Specifically, the ground plane 120 and the dual frequency antenna 130 are disposed within the housing structure 110. The radiating element 131 in the dual frequency antenna 130 has a feed point FP1. Further, the radiating element 131 has a loop antenna structure. For example, the first radiating portion 141, the second radiating portion 142, and the third radiating portion 143 are connected in series with each other. Further, the first radiating portion 141 has a feeding point FP1, and the third radiating portion 143 is electrically connected to the ground plane 120. Thereby, the radiating element 131 will form a resonant path that extends from the feed point FP1 to the ground plane 120.

On the other hand, the parasitic element 132 extends from the ground plane 120 to form another resonant path. The first parasitic portion 151 is electrically connected between the ground plane 120 and the second parasitic portion 152 . The second parasitic portion 152 is located between the first housing 111 and the radiating element 131, and the second parasitic portion 152 is spaced apart from the radiating element 131 by a coupling pitch. From another perspective, the orthographic projection of the second parasitic portion 152 at the first housing 111 overlaps the orthographic projection portion of the radiating element 131 at the first housing 111. Furthermore, the coupling pitch can be, for example, between 0.2 mm and 3 mm.

In operation, a transceiver (not shown) in the electronic device 100 can transmit a feed signal to the feed point FP1 of the dual frequency antenna 130. Under excitation of the feed signal, the radiating element 131 can generate a first resonant mode, thereby causing the dual frequency antenna 130 to operate in the first frequency band through the radiating element 131. Furthermore, the feed signal can be coupled from the radiating element 131 to the parasitic element 132 through the coupling pitch. Thereby, the parasitic element 132 will be able to generate a second resonant mode, which in turn causes the dual frequency antenna 130 to operate in the second frequency band through the parasitic element 132. In addition, the center frequency of the second frequency band is smaller than the center frequency of the first frequency band. That is, the first frequency band can be, for example, a high frequency band, and the second frequency band can be, for example, a low frequency band.

For example, FIG. 3 is a graph of return loss of a dual band antenna according to an embodiment of the invention. As shown in FIG. 3, the dual band antenna 130 can operate in the first frequency band 310 through the radiating element 131, and the first frequency band 310 can be, for example, a 5 GHz band. Moreover, dual frequency antenna 130 can operate in second frequency band 320 through parasitic element 132, and second frequency band 320 can be, for example, a 2.4 GHz frequency band. In other words, in an embodiment, the center frequency of the first frequency band 310 can be, for example, 5 GHz, and the center frequency of the second frequency band 320 can be, for example, 2.4 GHz.

It is worth mentioning that, as shown in FIG. 2, in the measurement of the SAR value, the test device (not shown) is set up at the highest point of the side wall of the electronic device 100 (that is, the first casing 111). A reference line 230 is used to measure the SAR value based on the reference line 230. In addition, in the case of a conventional dual-band antenna having a PIFA architecture, when the electronic device does not lower the transmission power of the conventional dual-band antenna, and operates directly in the high-frequency band (for example, the 5 GHz band) through the conventional dual-band antenna, the reference line The SAR value measured by 230 for the benchmark is often too high to meet the test specifications.

On the other hand, with the dual-band antenna 130 of FIG. 1, the radiating element 131 operable to operate in the high frequency band (ie, the first frequency band) faces the side wall of the electronic device 100 via the second parasitic portion 152 ( That is, the first housing 111). In other words, the second parasitic portion 152 disposed between the first housing 111 and the radiating element 131 will cause the radiating element 131 to be further away from the sidewall of the electronic device 100. That is, the arrangement of the parasitic element 132 will cause the radiating element 131 to be further away from the reference line 230 of the electronic device 100 on the test.

Further, the radiating element 131 having the loop antenna structure has a small specific absorption rate. The resonant path of the parasitic element 132 is independent of the resonant path of the radiating element 131, thereby reducing the mutual influence between the two. Therefore, when the electronic device 100 operates in the high frequency band (ie, the first frequency band) through the dual frequency antenna 130, the electronic device 100 does not need to reduce the transmission power of the dual frequency antenna 130, and the measured SAR value can conform to the test. specification. Thereby, the electronic device 100 can still maintain good communication quality under the SAR compliance specification.

For example, FIG. 4 is an antenna efficiency diagram in accordance with an embodiment of the present invention, wherein curve 410 is used to represent the antenna efficiency of dual-band antenna 130, and curve 420 is used to represent the antenna efficiency of a conventional dual-band antenna having a PIFA architecture. As shown in FIG. 4, in the 5 GHz band (ie, the first band), the antenna efficiency of the dual band antenna 130 is similar to that of the conventional dual band antenna. In addition, for the traditional dual-band antenna, if the electronic device does not reduce the transmission power of the conventional dual-frequency antenna, the measured SAR values are 1.11 W/kg (1 g) at 5180 MHz, 5500 MHz, and 5805 MHz, respectively. 1.18 W/kg (1 g) and 0.971 W/kg (1 g).

On the other hand, for the dual-frequency antenna 130, the measured SAR values are 0.267 W/kg at 5180 MHz, 5500 MHz, and 5805 MHz, respectively, without reducing the transmission power of the dual-frequency antenna 130. g), 0.334 W/kg (1 g) and 0.177 W/kg (1 g). In other words, compared with the conventional dual-band antenna with the PIFA architecture, the electronic device 100 does not need to reduce the transmission power of the dual-frequency antenna 130, and the measured SAR value can meet the test specifications.

Please continue to refer to Figure 1. In the case of the dual-frequency antenna 130, the first radiating portion 141 faces the first parasitic portion 151. The second radiating portion 142 is electrically connected to the first radiating portion 141 and spaced apart from the second parasitic portion 152 by the coupling pitch. The third radiating portion 143 is electrically connected to the second radiating portion 142 and the ground plane 120. Further, the first radiating portion 141 is positioned between the first parasitic portion 151 and the third radiating portion 143, and the second parasitic portion 152 is positioned between the first housing 111 and the second radiating portion 142.

In an embodiment, the second radiating portion 142 and the second parasitic portion 152 are parallel to each other. The first radiating portion 141, the third radiating portion 143, and the first parasitic portion 151 are parallel to each other. Further, the first parasitic portion 151 and the second parasitic portion 152 are perpendicular to each other. In other words, the shape of the parasitic element 132 can be, for example, an inverted L shape. Furthermore, the length of the radiating element 131, that is, the length of the resonant path formed by the radiating element 131, is 1/2 wavelength of the lowest frequency of the first frequency band. Further, the length of the parasitic element 132, that is, the length of the resonant path formed by the parasitic element 132, is 1/4 wavelength of the lowest frequency of the second frequency band.

Referring to FIG. 2 , the electronic device 100 further includes a display panel 210 , and the display panel 210 is fixed on the front surface 220 of the electronic device 100 . In addition, the second housing 112 is coupled to the first housing 111 and the third housing 113. The dual frequency antenna 130 is disposed in the first housing 111 and the second housing 112, and the ground plane 120 is disposed in the third housing 113. It should be noted that the first housing 111 and the second housing 112 are non-conductive materials to form a clearance area of the dual-frequency antenna 130. The third housing 113 can be, for example, a non-conductive material or a metal material. Moreover, in an embodiment, the ground plane 120 can be attached to the third housing 113 or the display panel 210, for example. In another embodiment, the ground plane 120 and the dual-band antenna 130 may also be disposed on a substrate (not shown) in the electronic device 100, for example.

In summary, the electronic device of the present invention includes a dual frequency antenna. Furthermore, the radiating element in the dual band antenna has a small specific absorption rate, and the arrangement of the parasitic element will cause the radiating element to move away from the first housing of the electronic device. Furthermore, the resonant paths of the radiating elements and the parasitic elements are independent of one another. Thereby, the electronic device does not need to reduce the transmission power of the dual-frequency antenna, and the measured SAR value can meet the test specification. In other words, the electronic device can still maintain good communication quality under the SAR compliance specification.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

100‧‧‧Electronic devices
110‧‧‧Shell structure
120‧‧‧ ground plane
130‧‧‧Double frequency antenna
111‧‧‧First housing
112‧‧‧Second housing
113‧‧‧ third housing
131‧‧‧radiation components
132‧‧‧ Parasitic components
141‧‧‧First Radiation Department
142‧‧‧Second Radiation Department
143‧‧ Third Radiation Department
151‧‧‧The first parasitic part
152‧‧‧Second parasitic
FP1‧‧‧Feeding point
210‧‧‧ display panel
220‧‧‧ positive
230‧‧‧ baseline
310‧‧‧First frequency band
320‧‧‧second frequency band
410, 420‧‧‧ curve

1 is a schematic diagram of an electronic device in accordance with an embodiment of the present invention. 2 is a cross-sectional view of an electronic device in accordance with an embodiment of the present invention. 3 is a graph showing a return loss of a dual band antenna according to an embodiment of the invention. 4 is a diagram showing an antenna efficiency diagram in accordance with an embodiment of the present invention.

100‧‧‧Electronic devices

110‧‧‧Shell structure

120‧‧‧ ground plane

130‧‧‧Double frequency antenna

111‧‧‧First housing

112‧‧‧Second housing

113‧‧‧ third housing

131‧‧‧radiation components

132‧‧‧ Parasitic components

141‧‧‧First Radiation Department

142‧‧‧Second Radiation Department

143‧‧ Third Radiation Department

151‧‧‧The first parasitic part

152‧‧‧Second parasitic

FP1‧‧‧Feeding point

Claims (10)

An electronic device comprising: a housing structure including a first housing to form a sidewall of the electronic device; a ground plane disposed within the housing structure; and a dual frequency antenna disposed in the housing Within the structure, and comprising: a radiating element comprising a feed point and a resonant path extending from the feed point to the ground plane, and the dual frequency antenna is operated in the first frequency band through the radiating element; and a parasitic The component includes a first parasitic portion and a second parasitic portion, wherein the first parasitic portion is electrically connected between the ground surface and the second parasitic portion, and the second parasitic portion is in the first housing and the A radiating element is spaced apart from the radiating element by a coupling pitch. The dual-frequency antenna operates in a second frequency band through the parasitic element, and a center frequency of the second frequency band is smaller than a center frequency of the first frequency band. The electronic device of claim 1, wherein the radiating element has a loop antenna structure. The electronic device of claim 2, wherein the length of the parasitic element is 1/4 wavelength of the lowest frequency of the second frequency band. The electronic device of claim 3, wherein the parasitic element has an inverted L shape. The electronic device of claim 1, wherein the radiating element comprises: a first radiating portion having the feeding point facing the first parasitic portion; and a second radiating portion electrically connected to the a first radiating portion separated from the second parasitic portion by the coupling pitch, and the second parasitic portion is between the first housing and the second radiating portion; and a third radiating portion electrically connected to the first portion a second radiating portion and the grounding surface, and the first radiating portion is between the first parasitic portion and the third radiating portion. The electronic device of claim 5, wherein the second radiating portion and the second parasitic portion are parallel to each other, and the first radiating portion, the third radiating portion and the first parasitic portion are parallel to each other. The electronic device of claim 6, wherein the first parasitic portion and the second parasitic portion are perpendicular to each other. The electronic device of claim 1, wherein the housing structure further comprises a second housing and a third housing, the second housing being coupled to the first housing and the third housing The dual frequency antenna is disposed in the first housing and the second housing, and the first housing and the second housing are non-conductive materials. The electronic device of claim 8, wherein the third housing is made of a non-conductive material or a metal material, and the grounding surface is disposed in the third housing. The electronic device of claim 1, wherein the first frequency band has a center frequency of 5 GHz and the second frequency band has a center frequency of 2.4 GHz.