CN111326858A - Antenna structure - Google Patents

Abstract

The present invention discloses an antenna structure, comprising: a metal structure, a grounding element, a feed radiation part, a coupling part, a dielectric substrate, and a switching circuit. The metal structure has a slot. The feed radiation part extends across the slot. A coupling gap is formed between the feed radiation part and the coupling part. The feed radiation part and the coupling part are both arranged on the dielectric substrate. The switching circuit comprises a first metal part, a second metal part, a reactance element, a capacitor, and a diode. The first metal part is coupled to the coupling part. The reactance element is embedded in the first metal part. The second metal part is coupled to the grounding element via the capacitor. The diode is coupled between the first metal part and the second metal part, wherein the diode is selectively turned on or off according to a control voltage.

Description

Antenna structure

technical field

The present invention relates to an antenna structure, in particular to a wideband antenna structure.

Background technique

With the development of mobile communication technology, mobile devices have become more and more common in recent years, such as portable computers, mobile phones, multimedia players and other portable electronic devices with mixed functions. In order to meet people's needs, mobile devices usually have the function of wireless communication. Some cover long-distance wireless communication range, such as: mobile phones use 2G, 3G, LTE (Long Term Evolution) systems and their use of 700MHz, 850MHz, 900MHz, 1800MHz, 1900MHz, 2100MHz, 2300MHz and 2500MHz frequency bands for communication, while Some cover the short-range wireless communication range, for example: Wi-Fi, Bluetooth systems use the 2.4GHz, 5.2GHz and 5.8GHz frequency bands for communication.

In pursuit of aesthetic appearance, nowadays designers often add elements of metal elements into mobile devices. However, the newly added metal element is likely to have a negative impact on the antenna supporting wireless communication in the mobile device, thereby reducing the overall communication quality of the mobile device. Therefore, it is necessary to propose a new mobile device and antenna structure to overcome the problems faced by the conventional technology.

SUMMARY OF THE INVENTION

In a preferred embodiment, the present invention provides an antenna structure, comprising: a metal mechanism member having a slot; a grounding element coupled to the metal mechanism member; a feeding and radiating portion coupled to a signal source , wherein the feeding and radiating part extends across the slot; a coupling part is adjacent to the feeding and radiating part, wherein a coupling gap is formed between the feeding and radiating part and the coupling part; a dielectric substrate, wherein the feeding The radiation part and the coupling part are both disposed on the dielectric substrate; and a switching circuit includes: a first metal part coupled to the coupling part; a reactance element embedded in the first metal part; a first metal part two metal parts; a capacitor, wherein the second metal part is coupled to the ground element through the capacitor; and a diode is coupled between the first metal part and the second metal part, wherein the diode is based on a control voltage to selectively turn on or off.

In some embodiments, the metal mechanism component is a metal back cover of a mobile device.

In some embodiments, the slot is a closed slot having a first closed end and a second closed end.

In some embodiments, the ground element is a ground copper foil, and extends from the metal structure to the dielectric substrate.

In some embodiments, the feeding and radiating portion presents a straight bar shape.

In some embodiments, the feeding and radiating portion has an unequal width structure.

In some embodiments, the feeding and radiating portion includes a narrower portion and a wider portion, the wider portion has a vertical projection on the metal mechanism member, and the vertical projection at least partially overlaps the slot hole.

In some embodiments, the feeding and radiating portion further includes a first protruding portion, the first protruding portion is coupled to a positive electrode of the signal source, the ground element further includes a second protruding portion, and the second protruding portion The part is coupled to a negative pole of the signal source.

In some embodiments, the first protruding portion of the feed-radiation portion is coupled to the narrower portion of the feed-radiation portion.

In some embodiments, the coupling portion has a serpentine structure.

In some embodiments, the diode has an anode and a cathode, the anode is coupled to the first metal portion, and the cathode is coupled to the second metal portion.

In some embodiments, each of the first metal portion and the second metal portion has a straight bar shape.

In some embodiments, the first metal portion and the second metal portion are used to receive the control voltage.

In some embodiments, when the control voltage becomes smaller, the diode is turned off and the antenna structure covers a first frequency range, and when the control voltage becomes larger, the diode is turned on and the antenna structure covers higher than the A second frequency interval of the first frequency interval.

In some embodiments, the antenna structure has an operating frequency band between 2400MHz and 2500MHz, or/and between 5150MHz and 5850MHz.

In some embodiments, the length of the slot is equal to 0.5 wavelengths of the lowest frequency of the operating band.

In some embodiments, the length of the feed radiator is equal to 0.25 wavelengths of the lowest frequency of the operating band.

In some embodiments, the length of the coupling portion is equal to 0.25 wavelengths of the lowest frequency of the operating band.

In another preferred embodiment, the present invention provides an antenna structure, comprising: a metal mechanism member having a slot; a grounding element coupled to the metal mechanism member; a feeding and radiating portion coupled to a a signal source, wherein the feeding and radiating part extends across the slot; a coupling part is adjacent to the feeding and radiating part, wherein a coupling gap is formed between the feeding and radiating part and the coupling part; a dielectric substrate, wherein the The feeding radiation part and the coupling part are both disposed on the dielectric substrate; and a switching circuit includes: a first metal part coupled to the coupling part; a first resistor embedded in the first metal part a second metal portion; a second resistor embedded in the second metal portion; and a bipolar junction transistor operating according to a control voltage, wherein the bipolar junction transistor has a an emitter, a base, and a collector, the emitter is coupled to the ground element, the base is coupled to the second metal part, and the collector is coupled to the first metal part.

In another preferred embodiment, the present invention provides a mobile device, comprising: a metal mechanism member having a slot; a grounding element coupled to the metal mechanism member; a feed-in radiation portion coupled to a a signal source, wherein the feeding and radiating part extends across the slot; a coupling part is adjacent to the feeding and radiating part, wherein a coupling gap is formed between the feeding and radiating part and the coupling part; a dielectric substrate, wherein the The feeding radiation part and the coupling part are both disposed on the dielectric substrate; and a switching circuit includes: a first metal part coupled to the coupling part; an inductor embedded in the first metal part; a second metal portion; a capacitor, wherein the second metal portion is coupled to the ground element via the capacitor; and a diode coupled between the first metal portion and the second metal portion, wherein the diode is coupled according to the A control voltage is selectively turned on or off; wherein the metal structure element, the ground element, the feeding and radiating portion, the coupling portion, the dielectric substrate, and the switching circuit together form an antenna structure.

Description of drawings

1A is a top view of an antenna structure according to an embodiment of the present invention;

1B is a cross-sectional view of an antenna structure according to an embodiment of the present invention;

2A is a voltage standing wave ratio diagram of an antenna structure according to an embodiment of the present invention;

2B is a voltage standing wave ratio diagram of the antenna structure according to another embodiment of the present invention;

FIG. 3 is a radiation efficiency diagram of an antenna structure according to an embodiment of the present invention;

4 is a top view of an antenna structure according to another embodiment of the present invention;

5 is a top view of an antenna structure according to another embodiment of the present invention;

6 is a top view of an antenna structure according to another embodiment of the present invention;

FIG. 7 is a schematic diagram of a mobile device according to an embodiment of the present invention.

Symbol Description

100, 400, 500, 600, 750 ~ antenna structure;

110～Metal parts;

120～Slotted hole;

121～the first closed end of the slot;

122～the second closed end of the slot;

130～grounding element;

135～the second protruding part of the grounding element;

140～feed into the radiation part;

141～feeding into the first end of the radiation part;

142～feeding into the second end of the radiating part;

143 ~ feed into the narrower part of the radiating part;

144 ~ feed into the wider part of the radiating part;

145～feeding into the first protruding part of the radiation part;

150, 450 ~ coupling part;

151, 451 to the first end of the coupling part;

152, 452～the second end of the coupling part;

160～dielectric substrate;

170, 570, 670 ~ switching circuit;

180, 580, 680 ~ the first metal part;

181, 681 to the first part of the first metal part;

182, 682 ~ the second part of the first metal part;

185～Reactive element;

190, 590, 690 to the second metal part;

650～Bipolar junction transistor;

691 ~ the first part of the second metal part;

692 ~ the second part of the second metal part;

199～signal source;

700～mobile device;

C ~ capacitor;

CC1～the first curve;

CC2～the second curve;

D ~ diode;

E1～the first surface of the dielectric substrate;

E2～the second surface of the dielectric substrate;

FP ~ feed point;

FV1 ~ the first frequency range;

FV2 ~ the second frequency range;

GC1 ~ coupling gap;

GP ~ ground point;

L～inductor;

L1, L2, L3, L4, L5 ~ length;

LC1～section line;

R1～the first resistor;

R2～the second resistor;

VD ~ control voltage;

W1, W2 ~ width.

Detailed ways

In order to make the objects, features and advantages of the present invention more clearly understood, the following specific embodiments of the present invention are given and described in detail in conjunction with the accompanying drawings.

Certain terms are used in the specification and claims to refer to particular elements. It should be understood by those skilled in the art that hardware manufacturers may refer to the same element by different nouns. The description and claims do not use the difference in name as a way to distinguish elements, but use the difference in function of the elements as a criterion for distinguishing. The words "including" and "including" mentioned throughout the specification and claims are open-ended terms and should be interpreted as "including but not limited to". The word "substantially" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and achieve the basic technical effect. Furthermore, the word "coupled" in this specification includes any direct and indirect means of electrical connection. Therefore, if a first device is described as being coupled to a second device, it means that the first device can be directly electrically connected to the second device, or indirectly electrically connected to the second device through other devices or connecting means .

FIG. 1A shows a top view of an antenna structure 100 according to an embodiment of the present invention. FIG. 1B shows a cross-sectional view (along a section line LC1 of FIG. 1A ) of the antenna structure 100 according to an embodiment of the present invention. Please refer to FIG. 1A and FIG. 1B together. The antenna structure 100 can be applied to a mobile device, such as a smart phone, a tablet computer, or a notebook computer. In the embodiment shown in FIGS. 1A and 1B , the antenna structure 100 at least includes: a Metal Mechanism Element 110 , a Ground Element 130 , a Feeding Radiation Element 140 , and a Feeding Radiation Element 140 . A coupling element 150, a dielectric substrate 160, and a switchable circuit 170, wherein the ground element 130, the feeding and radiating portion 140, and the coupling portion 150 can all be made of metal materials, such as : Copper, silver, aluminum, iron, or their alloys.

The metal mechanism component 110 may be a metal housing of the mobile device. In some embodiments, the metal mechanism 110 is a metal upper cover of a notebook computer, or a metal back cover of a tablet computer, but not limited thereto. The metal mechanism member 110 has a slot hole 120 , wherein the slot hole 120 of the metal mechanism member 110 can be roughly in the shape of a straight bar. Specifically, the slot 120 belongs to a closed slot, which has a first closed end 121 and a second closed end 122 that are far away from each other. The antenna structure 100 may further include a non-conductive material filled in the slot 120 of the metal structure member 110 .

The dielectric substrate 160 may be an FR4 (Flame Retardant 4) substrate, a Printed Circuit Board (PCB), or a Flexible Circuit Board (FCB). The dielectric substrate 160 has a first surface E1 and a second surface E2 opposite to each other, wherein the feeding and radiating part 140 and the coupling part 150 are both disposed on the first surface E1 of the dielectric substrate 160 , and the second surface E2 of the dielectric substrate 160 The slot 120 is adjacent to the metal frame member 110 . It must be noted that the term "adjacent" or "adjacent" in this specification may mean that the distance between the corresponding two elements is less than a predetermined distance (for example: 5mm or shorter), and may also include two corresponding elements in direct contact with each other. case (ie, the aforementioned pitch is shortened to 0). In some embodiments, the second surface E2 of the dielectric substrate 160 and the metal mechanism member 110 are attached to each other, wherein the dielectric substrate 160 extends across the slot 120 of the metal mechanism member 110 . The ground plane 130 can be a ground copper foil (Ground Copper Foil), which can have a stepped shape (as shown in FIG. 1B ). For example, the ground plane 130 may be coupled to the metal mechanism component 110 and then extend from the metal mechanism component 110 to the first surface E1 of the dielectric substrate 160 .

The feeding and radiating part 140 may be roughly in the shape of a straight bar. The feeding radiation part 140 has a feeding point (Feeding Point) FP, which can be coupled to a signal source (Signal Source) 199 . For example, the signal source 199 may be a radio frequency (RF) module, and the feeding and radiating portion 140 may extend across the slot 120 of the metal structure member 110 to excite the antenna structure 100 . The feeding and radiating portion 140 has a first end 141 and a second end 142 that are distant from each other, wherein the first end 141 and the second end 142 of the feeding portion 140 are two open ends. In some embodiments, the feeding and radiating portion 140 has an unequal width structure. For example, the feeding and radiating portion 140 may include a narrower portion 143 and a wider portion 144, wherein the narrowing portion 143 is adjacent to the first end 141 of the feeding and radiating portion 140, and the wider portion 144 is adjacent to the feeding and radiating portion Second end 142 of 140 . Specifically, the wider portion 144 of the feeding radiation portion 140 has a vertical projection on the metal structure member 110 , wherein the vertical projection at least partially overlaps the slot hole 120 . In addition, the narrower portion 143 of the feeding radiating portion 140 has a vertical projection on the metal mechanism member 110 , wherein the vertical projection may partially overlap with the slot hole 120 , or may not overlap the slot hole 120 at all. In some embodiments, the feeding and radiating portion 140 further includes a first protruding portion 145 coupled to the narrower portion 143, and the grounding element 130 further includes a second protruding portion 135, wherein the first protruding portion 145 and the second protruding portion 145 The protruding portions 135 may extend generally toward each other. Each of the first protruding portion 145 and the second protruding portion 135 may approximately represent a rectangle or a square. In some embodiments, the feeding point FP is located on the first protruding portion 145 of the feeding radiation portion 140 and is coupled to a positive electrode of the signal source 199, and a grounding point GP is located on the ground element The second protruding portion 135 of the 130 is coupled to a negative electrode (Negative Electrode) of the signal source 199 . It must be noted that the aforementioned first protruding portion 145 and second protruding portion 135 are optional elements, which can also be removed in other embodiments.

The coupling portion 150 may have a meandering structure. For example, the coupling portion 150 may be approximately in a W-shape, but not limited to this. The coupling part 150 is adjacent to the feeding and radiating part 140 , wherein a coupling gap (Coupling Gap) GC1 may be formed between the wider part 144 of the feeding and radiating part 140 and the coupling part 150 . In detail, the coupling portion 150 has a first end 151 and a second end 152, wherein the first end 151 of the coupling portion 150 is coupled to the switching circuit 170, and the second end 152 of the coupling portion 150 is an open end, It may extend between the feeding radiation part 140 and the grounding element 130 . In some embodiments, the coupling portion 150 has a vertical projection on the metal structure member 110 , wherein the vertical projection at least partially overlaps the first closed end 121 of the slot 120 , so as to fine-tune the impedance matching of the antenna structure 100 . .

The switching circuit 170 includes a first metal element 180 , a second metal element 190 , a reactance element 185 , a capacitor C, and a diode D. The first metal part 180 may be substantially in the shape of a straight bar. The first metal part 180 includes a first part 181 and a second part 182 , wherein the first part 181 of the first metal part 180 is coupled to the first end 151 of the coupling part 150 . The reactance element 185 is embedded in the first metal part 180 , wherein the reactance element 185 is coupled in series between the first part 181 and the second part 182 of the first metal part 180 . For example, the reactance element 185 may include an inductor (Inductor) L, which may be a fixed inductor (Fixed Inductor) or a variable inductor (Variable Inductor), but not limited thereto. The second metal portion 190 may also be substantially in a straight shape, wherein the second metal portion 190 and the first metal portion 180 may be substantially parallel to each other. A middle portion of the second metal portion 190 may be coupled to the ground element 130 via the capacitor C. As shown in FIG. In some embodiments, the antenna structure 100 further includes a voltage generator (not shown), which can generate and adjust a control voltage (Control Voltage Difference) VD according to a processor instruction. The first metal part 180 and the second metal part 190 may be used to receive the aforementioned control voltage VD. The diode D is coupled between the first metal portion 180 and the second metal portion 190 , wherein the diode D is selectively turned on (Turned On) or turned off (Turned Off) according to the control voltage VD. In detail, the diode D has an anode (Anode) and a cathode (Cathode), wherein the anode of the diode D is coupled to the first metal part 180 , and the cathode of the diode D is coupled to the second metal part 190 . However, the present invention is not limited to this. In other embodiments, the anode of the diode D can also be changed to be coupled to the second metal part 190 and the cathode of the diode D to be coupled to the first metal part 180 , and the polarity of the control voltage VD can be changed accordingly.

FIG. 2A shows a voltage standing wave ratio (VSWR) diagram of the antenna structure 100 according to an embodiment of the present invention. In the embodiment of FIG. 2A , when the control voltage VD becomes smaller (eg, the control voltage VD may be equal to 0V), the diode D is non-conductive and the antenna structure 100 may cover a first frequency interval (FrequencyInterval) FV1 . FIG. 2B shows a voltage standing wave ratio diagram of the antenna structure 100 according to another embodiment of the present invention. In the embodiment of FIG. 2B , when the control voltage VD increases (for example, the control voltage VD may be greater than 1.5V), the diode D is turned on and the antenna structure 100 may cover a second frequency interval higher than the first frequency interval FV1 FV2. For example, the first frequency interval FV1 may be between 2400MHz and 2470MHz, and the second frequency interval FV2 may be between 2430MHz and 2500MHz. According to the measurement results of FIGS. 2A and 2B , the antenna structure 100 as a whole can cover an operating frequency band, which can be between 2400MHz and 2500MHz, or (and) can be between 5150MHz and 5850MHz. Therefore, the antenna structure 100 can support WLAN (Wireless Local Area Networks) broadband operation of 2.4GHz/5GHz, wherein the switching circuit 170 is mainly used to increase the low frequency operation bandwidth of the antenna structure 100 .

In some embodiments, the principle of operation of the antenna structure 100 may be as follows. The metal mechanism component 110 and its slot 120 are excited by the feed radiator 140 to form the aforementioned operating frequency band. A mutual coupling effect will be generated between the coupling portion 150 and the feeding and radiating portion 140 , so the aforementioned operating frequency range can be fine-tuned. According to the actual measurement results, when the diode D is not conducting, the coupling portion 150 is in a floating state and provides a short coupling length, so that the first frequency range FV1 moves toward a relatively low frequency; and when the diode D is conducting At the time, the coupling part 150 is in a grounded state and provides a longer coupling length, so that the second frequency interval FV2 moves toward a relatively high frequency direction. For the antenna structure 100, the capacitor C can be regarded as a short-circuited path (Short-Circuited Path), which can be used to block low-frequency ground noise; and the inductor L can be regarded as an open-circuit path (Open-Circuited Path), which can be used for Block high frequency resonance currents. On the other hand, the first protruding portion 145 of the feeding radiating portion 140 and the second protruding portion 135 of the grounding element 130 help to reduce the difficulty of manufacturing and welding of the antenna structure 100 . If the first protruding part 145 and the second protruding part 135 are omitted, the feeding point FP and the grounding point GP can be moved to any edge of the feeding radiating part 140 and any edge of the grounding element 130, respectively, but not affect the effect of the present invention.

3 shows a radiation efficiency diagram of the antenna structure 100 according to an embodiment of the present invention, wherein a first curve CC1 represents the radiation efficiency of the antenna structure 100 when the diode D is not conducting, and a second curve CC2 represents the radiation efficiency of the antenna structure 100 The radiation efficiency of the antenna structure 100 when the diode D is turned on. According to the measurement results shown in FIG. 3 , within the aforementioned operating frequency bands (for example, from 2400MHz to 2500MHz, and then from 5150MHz to 5850MHz), the radiation efficiency of the antenna structure 100 can reach 30% or higher, which can meet the requirements of general mobile communication The actual application requirements of the device.

In some embodiments, the element dimensions of the antenna structure 100 may be as follows. The length L1 of the slot 120 (the length L1 from the first closed end 121 to the second closed end 122 ) may be approximately equal to 0.5 times the wavelength (λ/2) of the lowest frequency (eg, 2400MHz) of the operating frequency band of the antenna structure 100 . The length L2 of the feed radiating portion 140 (the length L2 from the first end 141 to the second end 142 ) may be approximately equal to 0.25 wavelengths (λ/4) of the lowest frequency of the operating frequency band of the antenna structure 100 . In the feeding and radiating portion 140 , the width W2 of the wider portion 144 may be 1 to 2 times (eg, 1.5 times) the width W1 of the narrower portion 143 . The length L3 of the coupling portion 150 (the length L3 from the first end 151 to the second end 152 ) may be approximately equal to 0.25 wavelengths (λ/4) of the lowest frequency of the operating frequency band of the antenna structure 100 . The width of the coupling gap GC1 may be between 0 mm and 3 mm (eg, 1 mm). In addition, starting from the first portion 181 of the first metal portion 180, through the diode D, the second metal portion 190, and the capacitor C, and then to the grounding element 130, a switchable grounding path (Switchable Grounding Path) is formed, and the length L4 can also be is approximately equal to 0.25 wavelengths (λ/4) of the lowest frequency of the operating frequency band of the antenna structure 100 . Therefore, when the diode D1 is turned on, the total coupling length of the coupling portion 150 can be regarded as the sum of the aforementioned lengths L3 and L4, that is, 0.5 times the wavelength (λ/2) of the lowest frequency of the operating frequency band of the antenna structure 100 . The inductance of the inductor L may be between 100 nH and 200 nH (eg, 120 nH). The capacitance value of the capacitor C may be between 2pF and 3pF (eg, 2.7pF). The cut-in voltage (Cut-In Voltage Difference) of diode D may be about 0.7V. The parameter ranges of the above components are calculated according to multiple experimental results, which help to optimize the operation bandwidth (Operation Bandwidth) and impedance matching of the antenna structure 100 .

FIG. 4 shows a top view of an antenna structure 400 according to another embodiment of the present invention. Figure 4 is similar to Figure 1A. In the embodiment of FIG. 4 , a coupling portion 450 of the antenna structure 400 is approximately in a relatively simple L-shape. The coupling portion 450 has a first end 451 and a second end 452, wherein the first end 451 of the coupling portion 450 is coupled to the first metal portion 180 of the switching circuit 170, and the second end 452 of the coupling portion 450 is an open circuit The end, which may extend between the feeding radiating part 140 and the grounding element 130 . The length L5 of the coupling portion 450 may be approximately equal to 0.25 wavelengths (λ/4) of the lowest frequency of the operating frequency band of the antenna structure 400 . According to the actual measurement results, even if the coupling part 450 does not have a complicated meandering structure, the antenna structure 400 can still support the aforementioned broadband operation. The remaining features of the antenna structure 400 of FIG. 4 are similar to those of the antenna structure 100 of FIGS. 1A and 1B , so the two embodiments can achieve similar operation effects.

FIG. 5 shows a top view of an antenna structure 500 according to another embodiment of the present invention. Figure 5 is similar to Figure 1A. In the embodiment of FIG. 5 , a switching circuit 570 of the antenna structure 500 includes a first metal portion 580 , a second metal portion 590 , an inductor L, a capacitor C, and a diode D. The connection methods and the diagrams The switching circuit 170 of 1A is similar. The main difference from the embodiment of FIG. 1A is that the switching circuit 570 is adjacent to the narrower portion 143 of the feed radiating portion 140 rather than the wider portion 144 of the feed radiating portion 140 . Under this design, the operating frequency band between 5150 MHz and 5850 MHz can also be adjusted by switching the diode D, so that the high frequency operating bandwidth of the antenna structure 500 can be increased. The remaining features of the antenna structure 500 of FIG. 5 are similar to those of the antenna structure 100 of FIGS. 1A and 1B , so the two embodiments can achieve similar operation effects.

FIG. 6 shows a top view of an antenna structure 600 according to another embodiment of the present invention. Figure 6 is similar to Figure 1A. In the embodiment of FIG. 6, a switching circuit 670 of the antenna structure 600 includes a first metal part 680, a second metal part 690, a first resistor (Resistor) R1, a second resistor R2, and a pair of Polar Junction Transistor (Bipolar Junction Transistor, BJT) 650 . The first metal part 680 may be substantially in the shape of a straight bar. The first metal part 680 includes a first part 681 and a second part 682 , wherein the first part 681 of the first metal part 680 is coupled to the first end 151 of the coupling part 150 . The first resistor R1 is embedded in the first metal part 680 , wherein the first resistor R1 is coupled in series between the first part 681 and the second part 682 of the first metal part 680 . The second metal portion 690 can also be roughly in the shape of a straight bar. The second resistor R2 is embedded in the second metal part 690 , wherein the second resistor R2 is coupled in series between the first part 691 and the second part 692 of the second metal part 690 . The first metal part 680 and the second metal part 690 may be used to receive the aforementioned control voltage VD. The bipolar junction transistor 650 may be an NPN type, which may operate according to the control voltage VD. In detail, the bipolar junction transistor 650 has an emitter, a base, and a collector, wherein the emitter of the bipolar junction transistor 650 is coupled to the ground element 130 , the base of the bipolar junction transistor 650 is coupled to the first portion 691 of the second metal portion 690 , and the collector of the bipolar junction transistor 650 is coupled to the first portion 681 of the first metal portion 680 . However, the present invention is not limited to this. In other embodiments, the bipolar junction transistor 650 can also be changed to a PNP type, wherein the polarity of the control voltage VD can be changed accordingly. The resistance of the first resistor R1 may be between 0Ω and 1000kΩ, for example, 100kΩ. The resistance value of the second resistor R2 may be between 0Ω and 1000kΩ, eg, 1kΩ. In this design, the bipolar junction transistor 650 can selectively couple the first metal part 680 to the second metal part 690 according to the control voltage VD, and the first resistor R1 and the second resistor R2 can be used to suppress Low frequency ground noise and high frequency resonant currents. The remaining features of the antenna structure 600 of FIG. 6 are similar to those of the antenna structure 100 of FIGS. 1A and 1B , so the two embodiments can achieve similar operation effects.

FIG. 7 shows a schematic diagram of a mobile device 700 according to an embodiment of the present invention. In the embodiment of FIG. 7 , the mobile device 700 includes an antenna structure 750 , which may be the antenna structure described in any of the embodiments of FIGS. 1A to 6 . For example, the mobile device can be a smart phone, a tablet computer, or a notebook computer integrated with the aforementioned antenna structure, but it is not limited thereto.

The present invention proposes a novel antenna structure that can cover wide-band operation with only a single slot and switching circuit. When the antenna structure is applied to a mobile device integrating a metal mechanism, since the metal mechanism can be regarded as an extension of the antenna structure, it can effectively prevent the metal mechanism from negatively affecting the communication quality of the mobile device. It should also be noted that the present invention can further improve the appearance design of the mobile device without excavating any antenna window (Antenna Window) on the metal structure. All in all, the present invention can have the advantages of small size, wide frequency band, and beautify the appearance of the device, so it is very suitable for mobile communication devices with various narrow borders.

It should be noted that the above-mentioned component size, component shape, component parameters, and frequency range are not limitations of the present invention. Antenna designers can adjust these settings according to different needs. The antenna structure and the mobile device of the present invention are not limited to the states illustrated in FIGS. 1A to 7 . The present invention may include only any one or more features of any one or more of the embodiments of FIGS. 1A-7 . In other words, not all of the illustrated features need to be implemented in both the antenna structure and the mobile device of the present invention.

The ordinal numbers in this specification and the claims, such as "first", "second", "third", etc., do not have a sequential relationship with each other, and are only used to identify two people with the same name. different components.

Although the present invention has been disclosed in conjunction with the above preferred embodiments, it is not intended to limit the scope of the present invention. Anyone skilled in the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, The scope of protection of the present invention should be defined by the appended claims.

Claims (20)

1. An antenna structure, comprising:

a metal machine component having a slot;

a grounding element coupled to the metal machine component;

a feed-in radiation part coupled to the signal source, wherein the feed-in radiation part extends across the slot;

a coupling part adjacent to the feed-in radiation part, wherein a coupling gap is formed between the feed-in radiation part and the coupling part;

a dielectric substrate, wherein the feed-in radiation part and the coupling part are both arranged on the dielectric substrate; and

a switching circuit, comprising:

a first metal part coupled to the coupling part;

a reactance element embedded in the first metal part;

a second metal portion;

a capacitor, wherein the second metal portion is coupled to the ground element via the capacitor; and

and a diode coupled between the first metal part and the second metal part, wherein the diode is selectively conducted or not conducted according to a control voltage.

2. The antenna structure of claim 1 wherein the metal machine component is a metal back cover of a mobile device.

3. The antenna structure of claim 1 wherein the slot is a closed slot and has a first closed end and a second closed end.

4. The antenna structure of claim 1 wherein the grounding element is a grounding copper foil and extends from the metal frame member to the dielectric substrate.

5. The antenna structure according to claim 1, wherein the feeding radiating portion has a straight strip shape.

6. The antenna structure of claim 1, wherein the feeding radiating portion has a non-uniform width structure.

7. The antenna structure of claim 6, wherein the feed radiating element comprises a narrower portion and a wider portion, the wider portion having a vertical projection on the metal frame member, the vertical projection at least partially overlapping the slot.

8. The antenna structure of claim 7, wherein the feed radiating element further comprises a first protruding portion coupled to the positive pole of the signal source, the ground element further comprises a second protruding portion coupled to a negative pole of the signal source.

9. The antenna structure of claim 8, wherein the first protruding portion of the feed radiating portion is coupled to the narrower portion of the feed radiating portion.

10. The antenna structure of claim 1, wherein the coupling portion has a meandering structure.

11. The antenna structure of claim 1, wherein the diode has an anode and a cathode, the anode being coupled to the first metal portion and the cathode being coupled to the second metal portion.

12. The antenna structure of claim 1, wherein the first metal portion and the second metal portion each present a straight strip shape.

13. The antenna structure of claim 1, wherein the first metal portion and the second metal portion are for receiving the control voltage.

14. The antenna structure of claim 1, wherein when the control voltage is decreased, the diode is not turned on and the antenna structure covers a first frequency interval, and when the control voltage is increased, the diode is turned on and the antenna structure covers a second frequency interval higher than the first frequency interval.

15. The antenna structure of claim 1, wherein the antenna structure has an operating frequency band between 2400MHz and 2500MHz, or (and) between 5150MHz and 5850 MHz.

16. The antenna structure of claim 15 wherein the length of the slot is equal to 0.5 wavelengths of the lowest frequency of the operating band.

17. The antenna structure according to claim 15, wherein the length of the feeding radiating portion is equal to 0.25 times the wavelength of the lowest frequency of the operating band.

18. The antenna structure of claim 15, wherein the length of the coupling portion is equal to 0.25 wavelengths of the lowest frequency of the operating band.

19. An antenna structure, comprising:

a metal machine component having a slot;

a grounding element coupled to the metal machine component;

a feed-in radiation part coupled to the signal source, wherein the feed-in radiation part extends across the slot;

a coupling part adjacent to the feed-in radiation part, wherein a coupling gap is formed between the feed-in radiation part and the coupling part;

a dielectric substrate, wherein the feed-in radiation part and the coupling part are both arranged on the dielectric substrate; and

a switching circuit, comprising:

a first metal part coupled to the coupling part;

a first resistor embedded in the first metal part;

a second metal portion;

a second resistor embedded in the second metal portion; and

a BJT operating according to a control voltage, wherein the BJT has an emitter coupled to the ground element, a base coupled to the second metal portion, and a collector coupled to the first metal portion.

20. A mobile device, comprising:

a metal machine component having a slot;

a grounding element coupled to the metal machine component;

a feed-in radiation part coupled to the signal source, wherein the feed-in radiation part extends across the slot;

a coupling part adjacent to the feed-in radiation part, wherein a coupling gap is formed between the feed-in radiation part and the coupling part;

a dielectric substrate, wherein the feed-in radiation part and the coupling part are both arranged on the dielectric substrate; and

a switching circuit, comprising:

a first metal part coupled to the coupling part;

an inductor embedded in the first metal part;

a second metal portion;

a capacitor, wherein the second metal portion is coupled to the ground element via the capacitor; and

a diode coupled between the first metal part and the second metal part, wherein the diode is selectively conducted or not conducted according to a control voltage;

wherein the metal machine component, the grounding element, the feed-in radiation part, the coupling part, the dielectric substrate and the switching circuit together form an antenna structure.

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