TWI885691B - Electronic device - Google Patents

Abstract

An electronic device includes a metal back cover, a metal frame, a first radiator and a second radiator. The metal frame includes two connecting members and a disconnected member separated from the two connecting members. The two connecting members are connected to the metal back cover, and the disconnected member is separated from the metal back cover. The first radiator includes a feed end, a first section, a second section, a third section, a fourth section and a fifth section. The first section is connected to the feed end, and the second section is connected to the first section and the disconnected member. The third section is connected to the second section. The fifth section is connected to the fourth section, is partially parallel to the disconnection section and vertical to the fourth section. The second radiator is connected to the disconnected member and connected to the metal back cover through a ground terminal.

Description

Electronic devices

The present invention relates to an electronic device, and in particular to an electronic device using a metal frame as an antenna path.

Currently, it is quite common for electronic devices to have a better appearance by using a metal casing. How to make the metal casing provide functions other than protection and beauty, such as providing an antenna function, is the goal of research in this field.

The present invention provides an electronic device which can utilize a metal frame as a part of an antenna path.

An electronic device of the present invention includes a metal back cover, a metal frame, a first radiator and a second radiator. The metal frame includes two connecting parts and a disconnecting part located between the two connecting parts and separated from the two connecting parts, the two connecting parts are connected to the metal back cover, and the disconnecting part is separated from the metal back cover. The first radiator includes a feeding end, a first section, a second section, a third section, a fourth section and a fifth section, wherein the first section is connected to the feeding end, the second section is connected to the first section and the disconnecting part, the third section is connected to the second section, and the fifth section is connected to the fourth section, partially parallel to the disconnecting part and perpendicular to the fourth section. The second radiator is connected to the disconnecting part and is connected to the metal back cover through a first grounding end. The feed end, the first section, the second section, the break portion, the second radiator and the metal back cover form a first antenna loop, which excites a low frequency band, a first medium and high frequency sub-band and a first ultra-high frequency sub-band. The feed end, the first section and the third section form a second antenna loop, which excites a second ultra-high frequency sub-band and a third ultra-high frequency sub-band.

In one embodiment of the present invention, a first slot is formed between the fifth section and the break portion, and the fifth section and the break portion are associated with a second mid-high frequency sub-band.

In one embodiment of the present invention, a second slot is formed between the fourth segment and the fifth segment, and the fourth segment and the fifth segment are associated with a fourth ultra-high frequency sub-band.

In one embodiment of the present invention, the third section includes an end away from the second section, and a third groove is formed between the feeding end and the end.

In an embodiment of the present invention, the electronic device further includes a first switching circuit, and the third section is connected to a second ground terminal through the first switching circuit.

In an embodiment of the present invention, the electronic device further includes a second switching circuit, and the second radiator is connected to the first ground terminal through the second switching circuit.

In an embodiment of the present invention, the electronic device further includes a matching circuit connected to the feed end.

In an embodiment of the present invention, the length of the first antenna loop is 0.5 times the wavelength of the low frequency band, and the length of the second antenna loop is 0.5 times the wavelength of the second ultra-high frequency sub-band or the third ultra-high frequency sub-band.

In one embodiment of the present invention, the length of the above-mentioned breaking portion is 0.25 times the wavelength of the low frequency band.

In an embodiment of the present invention, the electronic device further comprises a metal baffle, the first radiator and the second radiator are located between the metal baffle and the break portion, and the distance between the break portion and the metal baffle is 0.05 times the wavelength of the low frequency band.

Based on the above, the disconnected portion of the metal frame of the electronic device of the present invention is separated from the two connecting parts and the metal back cover. The first section of the first radiator is connected to the feed end, the second section is connected to the first section and the disconnected portion, the third section is connected to the junction of the first section and the second section, the fourth section is connected to the feed end and extends in the opposite direction of the second section, and the fifth section is connected to the fourth section and is located between the disconnected portion and the fourth section. The second radiator is connected to the disconnected portion and is connected to the metal back cover through the first grounding terminal. The electronic device of the present invention is designed as above. The feed end, the first section, the second section, the break portion, the second radiator to the metal back cover form a first antenna loop. The first antenna loop excites a low frequency band, a first medium and high frequency sub-band, and a first ultra-high frequency sub-band. The feed end, the first section, and the third section form a second antenna loop. The second antenna loop excites a second ultra-high frequency sub-band and a third ultra-high frequency sub-band. Therefore, the electronic device of the present invention can use the metal frame as part of the antenna path and can provide the function of a multi-band antenna.

FIG. 1 is a partial three-dimensional schematic diagram of an electronic device according to an embodiment of the present invention. It should be noted that in FIG. 1 , the plastic bracket 162 is represented by a dotted line. Referring to FIG. 1 , the electronic device 100 of this embodiment includes a metal back cover 110, a metal frame 120, a first radiator 130, a second radiator 140, a coaxial transmission line 172 and an antenna board 170. The electronic device 100 of this embodiment is, for example, a tablet computer or a mobile phone, but is not limited thereto, and can be a device with a narrow frame. The coaxial transmission line 172 is welded under the antenna board 170, and is 1.6 mm away from the metal back cover 110.

The first radiator 130 and the second radiator 140 are disposed in the frame area of the electronic device 100. The first radiator 130 and the second radiator 140 are printed on the plastic bracket 162 by LDS, for example. The width of the plastic bracket 162 corresponding to the first radiator 130 is, for example, 3 mm.

The electronic device 100 of this embodiment can provide multi-band requirements by using the metal frame 120 as a part of the antenna path, and by combining the special design of the first radiator 130 and the second radiator 140. This will be described below.

In this embodiment, the metal frame 120 includes two connecting portions 122 and a disconnecting portion 124 located between and separated from the two connecting portions 122. The two connecting portions 122 are connected to the metal back cover 110, and the disconnecting portion 124 is separated from the metal back cover 110. The length of the disconnecting portion 124 is the sum of the lengths L1 and L2. The length L1 is, for example, 78 mm, and the length L2 is, for example, 14 mm, but not limited thereto. The distance L3 between the connecting portion 122 and the disconnecting portion 124 is 2 mm.

The first radiator 130 includes a feeding end F, a first section 131 (positions A1-A3), a second section 132 (positions A3 and A4), a third section 133 (positions A3 and B1-B3), a fourth section 134 (positions A1 and C3), and a fifth section 135 (positions C1 and C2).

The first section 131 (position A1-A3) is connected to the feeding end F. The second section 132 (position A3, A4) is connected to the first section 131 (position A1-A3) and the disconnecting portion 124. The third section 133 (position A3, B1-B3) is connected to the second section 132 (position A3, A4). Specifically, the third section 133 (position A3, B1-B3) is connected to the junction of the first section 131 (position A1-A3) and the second section 132 (position A3, A4).

In addition, the fourth section 134 (position A1, C3) of the first radiator 130 is connected to the feeding end F and extends in the opposite direction of the first section 131 (position A2, A3). The fifth section 135 (position C1, C2) is connected to the fourth section 134 (position A1) and is partially parallel to the break portion 124. The fifth section 135 (position C1, C2) and the fourth section 134 (position A1, C3) are located in different planes perpendicular to each other.

The signal end of the coaxial transmission line 172 is conducted to the top surface through the through hole on the bottom surface of the antenna board 170, and is connected to the feed-in terminal F through a matching circuit M3 on the antenna board 170 in series, so as to be electrically connected to the signal end of the motherboard module card (not shown).

The second radiator 140 (position A8-A9) is connected to the disconnection portion 124 and is connected to the metal back cover 110 through a first ground terminal G1 to be electrically connected to the ground terminal (system ground terminal) of the motherboard module card. In this embodiment, the distance L4 between the first ground terminal G1 and the feed terminal F is about 50 mm.

In this embodiment, the feed end F, the first section 131 (positions A1-A3), the second section 132 (positions A3, A4), the break portion 124, the second radiator 140 and the metal back cover 110 form a first antenna loop. The first antenna loop excites a low frequency band, a first mid-high frequency sub-band and a first ultra-high frequency sub-band.

Specifically, in this embodiment, the low frequency band is between 617MHz and 960MHz, the first mid-high frequency sub-band is between 2100MHz and 2200MHz, and the first ultra-high frequency sub-band is between 4100MHz and 4200MHz.

In addition, the feed end F, the first section 131 (position A1-A3), and the third section 133 (position A3, B1-B3) form a second antenna loop, which excites a second ultra-high frequency sub-band and a third ultra-high frequency sub-band. The second ultra-high frequency sub-band is between 3200MHz and 3300MHz, and the third ultra-high frequency sub-band is between 4800MHz and 5100MHz.

In this embodiment, the length of the disconnection portion 124 (the sum of the lengths L1 and L2) is 0.25 times the wavelength of the low frequency band. For example, the length of the disconnection portion 124 (the sum of the lengths L1 and L2) is 92 mm, which is about 0.25 times the wavelength of 800 MHz. The length of the first antenna loop is 0.5 times the wavelength of the low frequency band, and the length of the second antenna loop is 0.5 times the wavelength of the second ultra-high frequency sub-band or the third ultra-high frequency sub-band. Such a design allows the electronic device 100 to well excite the above-mentioned frequency bands.

The electronic device 100 further includes a metal baffle 150. The first radiator 130 and the second radiator 140 are located between the metal baffle 150 and the break portion 124. The distance L5 between the break portion 124 and the metal baffle 150 is 0.05 times the wavelength of the low frequency band. For example, the distance L5 is about 15 mm to 16 mm, which is about 0.042 times the wavelength of 800 MHz.

In addition, a first slot S1 is formed between the fifth section 135 (positions C1 and C2) and the break portion 124. The fifth section 135 (positions C1 and C2) and the break portion 124 are related to a second mid-high frequency sub-band. The second mid-high frequency sub-band is between 1620 MHz and 1700 MHz. By adjusting the spacing of the first slot S1 and the length and width of the fifth section 135 (positions C1 and C2), the center frequency position of the second mid-high frequency sub-band and the impedance matching of the third ultra-high frequency sub-band can be adjusted.

A second slot S2 is formed between the fourth section 134 (position A1, C3) and the fifth section 135 (position C1, C2). A fourth ultra-high frequency sub-band is between 5500MHz and 5700MHz. Adjusting the spacing of the second slot S2 and the length and width of the fourth section 134 (position A1, C3) can be used to adjust the center frequency position of the fourth ultra-high frequency sub-band and the impedance matching of the third ultra-high frequency sub-band and the fourth ultra-high frequency sub-band.

In addition, in this embodiment, the third section 133 (positions A3, B1-B3) of the first radiator 130 includes an end (position B3) far away from the second section 132 (positions A3, A4), and a third slot S3 is formed between the feeding end F and the end (position B3).

The second antenna loop is connected to a second ground terminal G2 at position B2. The path length and width at positions B2 and B3 can be adjusted to adjust the third slot S3 so as to adjust the resonance frequency point position at the junction of the two frequency bands of 2600MHz~2700MHz and 3300MHz~5000MHz.

The electronic device 100 further includes a first switching circuit M1 and a second switching circuit M2. The third section 133 (positions A3, B1-B3) is connected to the second ground terminal G2 through the first switching circuit M1. The first switching circuit M1 switches between an open circuit, a capacitor, or an inductor to increase the impedance matching of the low frequency band. The second radiator 140 is connected to the first ground terminal G1 through the second switching circuit M2. In the embodiment of the present invention, M2 is a resistor of 0 ohm, and different capacitance values can be used when necessary to achieve switching frequency bands or increase impedance matching.

The first switching circuit M1 will be described in detail below. In this embodiment, the first switching circuit M1 can be implemented by a single-pole 5-throw switch of the RF switch SP5T or a single-pole n-throw switch of the SPnT in combination with a passive element. When there is no passive element between position B2 and position G2 (i.e., open circuit), the low-frequency band range is 698~862MHz (bandwidth is about 164MHz); when the switching circuit M1 is selected to be connected to a capacitance value of 0.2~0.8pF, the low-frequency band can be switched to a frequency band range of 617~777MHz; when the switching circuit M1 is selected to be connected to an inductance value of 18~33nH, the low-frequency band can be switched to a frequency band range of 814~960MHz. The first switching circuit M1 can switch between five low frequency ranges. When the first switching circuit M1 switches the low frequency (LB), the performance of the medium and high frequency (MHB) and the ultra high frequency (UHB) is not affected.

Specifically, for the low frequency band (LB, 617MHz~960MHz), the first switching circuit M1 is connected to a capacitor of 0.8pF, the low frequency band range is 617MHz~725.5MHz, and the bandwidth is about 108.5MHz. The first switching circuit M1 is connected to a capacitor of 0.2pF, the low frequency band range is 663MHz~777MHz, and the bandwidth is about 114MHz. The first switching circuit M1 is open, the low frequency band range is 698MHz~862MHz, and the bandwidth is about 164MHz. The first switching circuit M1 is connected to an inductor of 33nH, the low frequency band range is 814MHz~925MHz, and the bandwidth is about 111MHz. The first switching circuit M1 is connected to an inductor of 18nH, with a low frequency band range of 836.5MHz~960MHz and a bandwidth of about 123.5MHz.

For the mid-high frequency band (MHB, 1710MHz~2690MHz) including the first mid-high frequency sub-band and the second mid-high frequency sub-band, the use of the switching circuit M1 allows the antenna efficiency to have a better performance. For example, for the Japanese B11/B12 band (1427.9MHz~1510.9MHz), the switching circuit M1 allows the antenna efficiency to reach -3.9dBi~-7.4dBi. For example, for the GPS band (1565MHz~1610MHz), the switching circuit M1 allows the antenna efficiency to still maintain a good performance of -1.9dBi~-5.4dBi. For example, for the band 1710MHz~2690MHz, the switching circuit M1 allows the antenna efficiency to still maintain a good performance of -1.3dBi~-6.4dBi.

For the ultra-high frequency band (UHB, 3300MHz~5000MHz) including the first ultra-high frequency sub-band, the second ultra-high frequency sub-band, the third ultra-high frequency sub-band, and the fourth ultra-high frequency sub-band, the switching circuit M1 is used to make the antenna efficiency have a better performance. For example, for the frequency band 3300MHz~5000MHz, the switching circuit M1 makes the antenna efficiency reach -2.6dBi~-7.3dBi. For example, for the frequency band 5150MHz~5925MHz, the switching circuit M1 makes the antenna efficiency reach -3.7dBi~-7.9dBi.

Therefore, by adding the first switching circuit M1, the bandwidth of the low frequency band is about 110MHz. For the low frequency band with a center frequency of 617MHz, the use of the switching circuit M1 makes the antenna efficiency reach -6.7dBi; for the low frequency band with a center frequency of 960MHz, the use of the switching circuit M1 makes the antenna efficiency reach -5.8dBi, thus having good performance.

FIG2 is a frequency-VSWR relationship diagram of the electronic device of FIG1 in the low frequency band. Referring to FIG2, by switching the first switching circuit M1, the frequency band of the electronic device can cover 617MHz~960MHz, and the VSWR can be below 5, which has a good performance. The electronic device 100 of this embodiment can effectively expand the low frequency bandwidth by switching the low frequency through the first switching circuit M1.

FIG3 is a frequency-VSWR relationship diagram of the electronic device of FIG1 in the mid-high frequency band and the ultra-high frequency band. Referring to FIG3, the electronic device 100 can cover the mid-high frequency band of 1710MHz~2690MHz and the ultra-high frequency band of 3300MHz~5000MHz of n77~n79, and the VSWR performance can be below 4.5, which has the functions of broadband and multi-band.

FIG4 is a diagram showing the relationship between frequency and antenna efficiency in the low frequency band of the electronic device in FIG1. Referring to FIG4, the antenna efficiency of the electronic device in the low frequency band 617MHz~960MHz is -2.8~-6.7dBi, and the antenna efficiency in the GPS band 1565MHz~1610MHz is -1.9~-5.4dBi, which shows good performance.

FIG5 is a diagram showing the relationship between frequency and antenna efficiency in the mid-high frequency band and the high frequency band of the electronic device in FIG1. Referring to FIG5, the antenna efficiency of the mid-high frequency band 1710MHz~2690MHz is -1.3dBi~-6.4dBi, the antenna efficiency of the ultra-high frequency band 3300MHz~5000MHz is -2.6dBi~-7.3dBi, and the antenna efficiency of the LAA band 5150MHz~5925MHz is -3.7dBi~-7.9dBi, which has a good performance.

Therefore, the electronic device 100 of this embodiment can have the characteristics of a full-band antenna, and has broadband and multi-band functions.

In summary, the disconnected portion of the metal frame of the electronic device of the present invention is separated from the two connecting parts and the metal back cover. The first section of the first radiator is connected to the feed end, the second section is connected to the first section and the disconnected portion, the third section is connected to the second section, the fourth section is connected to the feed end, and the fifth section is connected to the fourth section and is perpendicular to the fourth section. The second radiator is connected to the disconnected portion and is connected to the metal back cover through the first grounding end. Through the above design, the electronic device of the present invention forms a first antenna loop from the feed end, the first section, the second section, the disconnected portion, the second radiator to the metal back cover, and the first antenna loop excites a low frequency band, a first mid-high frequency sub-band, and a first ultra-high frequency sub-band. The feed end, the first section, and the third section form a second antenna loop, and the second antenna loop excites the second ultra-high frequency sub-band and the third ultra-high frequency sub-band. Therefore, the electronic device of the present invention can use the metal frame as part of the antenna path and can provide the function of a multi-band antenna.

A1~A9, B1~B3, C1~C3: Position F: Feed terminal G1: First ground terminal G2: Second ground terminal L1, L2: Length L3, L4, L5: Distance M1: First switching circuit M2: Second switching circuit M3: Matching circuit S1: First slot S2: Second slot S3: Third slot 100: Electronic device 110: Metal back cover 120: Metal frame 122: Connecting part 124: Disconnecting part 130: First radiator 131: First section 132: Second section 133: Third section 134: Fourth section 135: Fifth section 140: Second radiator 150: Metal retaining wall 162: Plastic bracket 170: Antenna board 172: Coaxial transmission line

FIG1 is a partial three-dimensional schematic diagram of an electronic device according to an embodiment of the present invention. FIG2 is a frequency-VSWR relationship diagram of the electronic device of FIG1 in a low frequency band. FIG3 is a frequency-VSWR relationship diagram of the electronic device of FIG1 in a medium-high frequency band and a high frequency band. FIG4 is a frequency-antenna efficiency relationship diagram of the electronic device of FIG1 in a low frequency band. FIG5 is a frequency-antenna efficiency relationship diagram of the electronic device of FIG1 in a medium-high frequency band and a high frequency band.

A1~A9, B1~B3, C1~C3: Location

F: Feeding end

G1: First ground terminal

G2: Second ground terminal

L1, L2: length

L3, L4, L5: distance

M1: First switching circuit

M2: Second switching circuit

M3: Matching circuit

S1: First groove seam

S2: Second groove seam

S3: The third groove

100: Electronic devices

110:Metal back cover

120:Metal frame

122: Connection part

124: Disconnection section

130: The First Radiant

131: First paragraph

132: Second paragraph

133: The third paragraph

134: The fourth paragraph

135: Fifth paragraph

140: Second Radiant

150:Metal retaining wall

162: Plastic bracket

170: Antenna board

172: Coaxial transmission line

Claims (10)

An electronic device, comprising: a metal back cover; a metal frame, comprising two connecting parts and a disconnecting part located between the two connecting parts and separated from the two connecting parts, the two connecting parts are connected to the metal back cover, and the disconnecting part is separated from the metal back cover; a first radiator, comprising a feeding end, a first section, a second section, a third section, a fourth section and a fifth section, wherein the first section is connected to the feeding end, the second section is connected to the first section and the disconnecting part, the third section is connected to the second section, the fifth section is connected to the fourth section, partially parallel to the disconnecting part and perpendicular to the fourth section; and a second radiator, connected to the disconnecting part and connected to the metal back cover through a first grounding end, wherein The feed end, the first section, the second section, the disconnection portion, the second radiator to the metal back cover form a first antenna loop, the first antenna loop excites a low frequency band, a first mid-high frequency sub-band and a first ultra-high frequency sub-band. The feed end, the first section and the third section form a second antenna loop, the second antenna loop excites a second ultra-high frequency sub-band and a third ultra-high frequency sub-band. An electronic device as described in claim 1, wherein a first slot is formed between the fifth section and the break portion, and the fifth section and the break portion are associated with a second mid-high frequency sub-band. An electronic device as described in claim 1, wherein a second slot is formed between the fourth segment and the fifth segment, and the fourth segment and the fifth segment are associated with a fourth ultra-high frequency sub-band. An electronic device as described in claim 1, wherein the third section includes an end away from the second section, and a third slot is formed between the feed end and the end. The electronic device as described in claim 1 further includes a first switching circuit, and the third section is connected to a second ground terminal through the first switching circuit. The electronic device as described in claim 1 further includes a second switching circuit, and the second radiator is connected to the first ground terminal through the second switching circuit. The electronic device as described in claim 1 further includes a matching circuit connected to the feed end. An electronic device as described in claim 1, wherein the length of the first antenna loop is 0.5 times the wavelength of the low frequency band, and the length of the second antenna loop is 0.5 times the wavelength of the second ultra-high frequency sub-band or the third ultra-high frequency sub-band. An electronic device as described in claim 1, wherein the length of the break portion is 0.25 times the wavelength of the low frequency band. The electronic device as described in claim 1 further includes a metal baffle, the first radiator and the second radiator are located between the metal baffle and the break portion, and the distance between the break portion and the metal baffle is 0.05 times the wavelength of the low frequency band.

Images