TWI686010B - Dual-mode antenna array and electronic device having the same - Google Patents

Abstract

A dual-mode antenna array comprises a dual-mode antenna, a switch, a transmission line an antenna unit and an open circuit. The switch has a first end, a second end and a third end. The first end of the switch connects the dual-mode antenna. The switch is controlled by a control signal to select operation status connecting the first end with the third end or the second end. The impedance of the dual-mode antenna at the first frequency band and the second frequency band ranges from half to one times of the input impedance of the transmission line. The antenna unit connects the second end of the switch through the transmission line. A low-frequency band rejection filter unit of the open circuit connects to the third end of the switch, for rejecting a first RF signal from the third end, and for passing a second RF signal from the third end. A high-frequency open circuit adjusting unit of the open circuit connects between the low-frequency band rejection filter unit and a ground, for rejecting the second RF signal from the low-frequency band rejection filter unit to flow into the ground. Thus, by using design of simple feeding, radiation pattern control and reduction of the manufacturing cost can be achieved.

Description

Dual-mode antenna array and electronic device with dual-mode antenna array

The invention relates to an antenna, and in particular to a dual-mode antenna array and an electronic device with a dual-mode antenna array.

The radiation pattern of the antenna varies according to the basic working principle of the antenna. For example, a dipole antenna can generate an omnidirectional radiation pattern, and a patch antenna can generate a broadside Radiation field pattern. Various radiation field types have different applications. For example, the omnidirectional radiation field type is suitable for the terminal device, so that the terminal device can receive wireless signals in various directions. For another example, a base station antenna, such as an antenna of a wireless access point (wireless access point), may need to generate a radiation pattern in a specific direction to enable wireless communication with terminal devices located at various specific locations.

Generally speaking, although an array antenna can be used to control a specific radiation pattern, the control circuit of the array antenna (including switching, phase control, and feed-in network, etc.) introduces more transmission loss problems. Furthermore, the wireless transmission of current electronic devices usually requires the function of multi-band transmission, and manufacturers must manufacture wireless modules (including antennas) that operate at multiple frequencies. If you want to use a design with multiple antennas (arrays), you also need to have multi-band operation at the same time. For example, the operation requirements of the 2.4GHz band and 5GHz band that are commonly used in wireless LANs, choose the traditional array antenna design. Multiple switches, multiple feeds In addition to the consideration of the transmission loss in addition to the network, it is also necessary to consider the characteristics of the impedance impact on the different frequency bands when the multi-frequency (or dual-frequency) operation of the feeding network stubs, especially in the current electronic devices, the antenna requires light and short In the case of a feeder network that provides dual-frequency operation or higher, the circuit area is quite large (may be larger than the antenna array, which makes it difficult to reduce the overall size of the antenna array module), which traditionally requires a complicated feeder network. When the dual-frequency (or multi-frequency) operation is realized, the manufacturing cost of the antenna array product will increase significantly.

In order to solve the foregoing prior art problems, embodiments of the present invention provide a dual-mode antenna array, including a dual-mode antenna, a switch, a transmission line, an antenna unit, and an open circuit. The dual-mode antenna has a first feed-in end. The dual-mode antenna receives a first radio frequency signal from the first feed-in end to operate in a first frequency band, and receives a second radio frequency signal from the first feed-in end to operate in a second frequency band. The frequency of the second frequency band is higher than the frequency of the first frequency band. The switch has a first end, a second end and a third end. The first end of the switch is connected to the first feed end of the dual-mode antenna. The switch is controlled by the control signal to select the operating state in mode zero or mode one. Mode zero is Turn on the first end to the third end. Mode one is to turn on the first end to the second end. The second end of the switch is connected to the transmission line, wherein the input impedance of the dual-mode antenna in the first frequency band and the second frequency band is between half and double the impedance of the transmission line. The antenna unit has a second feed-in end, and the second feed-in end of the antenna unit is connected to the second end of the switch via a transmission line, wherein the input impedance of the antenna unit in the first frequency band and the second frequency band is the same as the impedance of the transmission line. The open circuit includes a low-band rejection filter unit and a high-frequency open-circuit adjustment unit. The low-band rejection filter unit is connected to the third end of the switch. The high-frequency open-circuit adjustment unit is connected between the low-band rejection filter unit and the ground. The filter unit is used to block the first RF signal from turning on The third terminal of the switch flows in, and is used to let the second radio frequency signal flow in from the third terminal of the switch, wherein the high-frequency open-circuit adjustment unit is used to block the second radio frequency signal from the low-band rejection filter unit from flowing to ground.

An embodiment of the present invention also provides an electronic device having a dual-mode antenna array, including the aforementioned dual-mode antenna array, an application unit, and a control unit, wherein the first feed end of the dual-mode antenna of the dual-mode antenna array and the first One end is connected to the wireless chip of the electronic device. The application unit is connected to the wireless chip, and the wireless chip receives the received signal strength indication or the received data rate of the dual-mode antenna array. The control unit connects the application unit and the switch to determine whether to switch the first end of the switch to the second end to control the radiation pattern of the dual-mode antenna array.

In summary, the embodiments of the present invention provide a dual-mode antenna array and an electronic device with a dual-mode antenna array. The dual-mode antenna has an input impedance that can be matched with the characteristics of the single-antenna operating mode and the dual-antenna operating mode to make the dual-mode antenna The array does not need to use a complex dual-frequency feed network under the requirement of dual-frequency operation, and only needs to use a switch and an open circuit, so that the purpose of radiation field control and the reduction of manufacturing costs can be achieved at the same time, and the control The circuit is easy to realize and has high industrial application value.

In order to further understand the features and technical content of the present invention, please refer to the following detailed description and drawings of the present invention, but these descriptions and the drawings are only used to illustrate the present invention, not the rights of the present invention Any restrictions on the scope.

1‧‧‧ dual-mode antenna array

11‧‧‧Dual mode antenna

12‧‧‧switch

13‧‧‧ Transmission line

14‧‧‧ Antenna unit

119‧‧‧First feed end

121‧‧‧The first end

122‧‧‧The second end

149‧‧‧Second feed end

123‧‧‧The third end

111‧‧‧The first part

112‧‧‧Second part

141‧‧‧The third part

142‧‧‧The fourth part

9‧‧‧Earth edge

100‧‧‧ substrate

X, Y, Z‧‧‧ axis

15‧‧‧Open circuit

151‧‧‧Low band rejection filter unit

152‧‧‧High frequency open circuit adjustment unit

9a‧‧‧Projection

G‧‧‧Ground

2‧‧‧Application unit

3‧‧‧Control unit

4‧‧‧Wireless chip

FIG. 1 is a perspective view of the structure of a dual-mode antenna array provided by an embodiment of the present invention Figure.

2 is a schematic diagram of a circuit form of a dual-mode antenna array provided by an embodiment of the present invention.

3 is a schematic diagram of the structure of a dual-mode antenna array provided by another embodiment of the present invention.

4 is a block diagram of an electronic device with a dual-mode antenna array provided by an embodiment of the present invention.

Please refer to FIG. 1, which is a perspective view of the structure of a dual-mode antenna array provided by an embodiment of the present invention. The dual-mode antenna array 1 includes a dual-mode antenna 11, a switch 12, a transmission line 13, an antenna unit 14, and an open circuit 15. The dual-mode antenna 11 and the antenna unit 14 of the embodiment of FIG. 1 are both implemented using double-sided printed circuit board technology, and are fabricated on the substrate 100. The dual-mode antenna 11 has a first feeding end 119. The dual-mode antenna 11 receives a first radio frequency signal from the first feeding end 119 to operate in a first frequency band, and receives a second radio frequency signal from the first feeding end 119 to operate In the second frequency band, the frequency of the second frequency band is higher than the frequency of the first frequency band. The switch 12 has a first end 121, a second end 122, and a third end 123. The first end 121 of the switch 12 is connected to the first feed end 119 of the dual-mode antenna 11. The switch 12 is controlled by a control signal to select an operating state at Mode zero (Mode 0) or mode one (Mode 1), mode zero is to conduct the first end 121 to the third end 123, and mode one is to conduct the first end 121 to the second end 122. The second end 122 of the switch 12 is connected to the transmission line 13. The switch 12 is implemented by, for example, an adhesive element disposed on the surface of the substrate 100. The input impedance of the dual mode antenna 11 in the first frequency band and the second frequency band is between one-half and one times the impedance of the transmission line 13, for example, the impedance of the transmission line 13 is 100 ohms, then the dual mode antenna 11 The input impedance between the first frequency band and the second frequency band is between 50 ohms and 100 ohms. The above-mentioned first frequency band is, for example, the 2.4 GHz band, and the second frequency band is, for example, the 5 GHz band (for example, WiFi band). The antenna unit 14 has a second feeding end 149, and the second feeding end 149 of the antenna unit 14 is connected to the second end 122 of the switch 12 through the transmission line 13, wherein the input impedance of the antenna unit 14 in the first frequency band and the second frequency band is the same as The impedance of the transmission line 13 is, for example, 100 ohms. The open circuit 15 includes a low-band rejection filter unit 151 and a high-frequency open-circuit adjustment unit 152. The low-band rejection filter unit 151 is connected to the third end 123 of the switch 12, and the high-frequency open-circuit adjustment unit 152 is connected to the low-band rejection filter unit 151 and Between the ground G, the low-band rejection filter unit 151 is used to prevent the first RF signal from flowing into the third terminal 123 of the switch 12 and to allow the second RF signal to flow from the third terminal 123 of the switch 12, wherein the high The open frequency adjustment unit 152 is used to block the second radio frequency signal from the low-band rejection filter unit 151 from flowing into the ground G.

The low-band rejection filter unit 151 and the high-frequency open circuit adjustment unit 152 are implemented by, for example, adhesive elements provided on the surface of the substrate 100. Please refer to FIG. 1 and FIG. 2 together, in order to realize the function of the low-band rejection filter unit 151, when the first frequency band is the 2.4GHz band, a 2.4GHz band rejection filter needs to be implemented, for example, it is necessary to include the first parallel The inductor L1 and the first capacitor C1. In other words, the low-band rejection filter unit 151 uses an open circuit for the first frequency band (eg, 2.4 GHz band) and a short circuit for the second frequency band (eg, 5 GHz band), such as the setting of the first inductor L1 and the first capacitor C1 The value must be such that the impedance value of the first inductance L1 and the first capacitor C1 in parallel when the frequency is around 2.4 GHz is closer to an open circuit, and the impedance of the first inductance L1 and the first capacitor C1 in parallel when the frequency is around 5 GHz The closer the value is to the short circuit. Next, in order to realize the function of the high-frequency open-circuit adjustment unit 152, when the second frequency band is the 5GHz band, the high-frequency open-circuit adjustment unit 152 needs to realize an open circuit of 5GHz (impedance value is close to infinity), for example, to include The second inductance L2, and the parallel connection of the first inductance L1 and the first capacitor C1 in series with the second inductance L2 is connected to the ground G, such a circuit effect is to open the first frequency band (for example, 2.4GHz band) and The second frequency band (for example, the 5GHz frequency band) is also an open circuit, and the low-band rejection filter unit 151 and the high-frequency open circuit adjustment unit 152 are each independently responsible for the open circuit control of the first frequency band and the second frequency band. This design makes the open circuit characteristics easier to control. The complexity of adjustment is reduced, in particular, it is convenient to eliminate the influence and error caused by the characteristics of the components of the switch 12 on the overall circuit impedance. In an exemplary embodiment, when the first frequency band is the 2.4 GHz band and the second frequency band is the 5 GHz band, the inductance value of the first inductor L1 is preferably 3.9 nH, and the capacitance value of the first capacitor C1 is preferably 1pF, the inductance value of the second inductor L2 is preferably 1.2 nH, but the invention is not limited thereto.

The switch 12 is controlled by the control signal to select the operating state in mode zero or mode one. In both FIGS. 1 and 2, the control line for transmitting the control signal to the switch 12 is omitted. The mode zero is to conduct the first end 121 to the third end 123 so that the antenna unit 14 does not receive the feed signal. The impedance value of the RF line at the source end of the feed signal is usually 50 ohms. After proper design, the input impedance value of the dual-mode antenna 11 can be close to the matching state of 50 ohms, but it must also meet the operating impedance of mode 1. Therefore, the dual-mode antenna 11 The input impedance in the first frequency band and the second frequency band is preferably between 50 ohms and 100 ohms. When the operating state of the switch 12 is mode zero, the first end 121, the third end 123 of the switch 12 and the open circuit 15 are turned on to become a stub of the switch circuit (with a specific impedance value), and the dual mode antenna 11 and the switch circuit are The input impedance of the parallel sections is half of the impedance of the transmission line 13, which is 50 ohms, to achieve impedance matching.

On the other hand, mode one is to connect the first end 121 to the second end 122, so that the antenna unit 14 receives the feed signal using the second feed end 149, and the antenna The unit 14 and the dual-mode antenna 11 constitute the operation of the antenna array. The input impedance value of the antenna unit 14 in the first frequency band and the second frequency band is equal to or close to 100 ohms of the transmission line 13, at this time the dual-mode antenna 11 and the antenna unit 14 form a parallel line to achieve a parallel input impedance close to 50 ohms . In other words, preferably, when the operating state of the switch 12 is mode one, the input impedance of the dual-mode antenna 11 and the antenna unit 14 in parallel with the switch 12 is half of the impedance of the transmission line 13.

Please refer to FIG. 1 again, in order to achieve dual-band operation, the dual-mode antenna 11 and the antenna unit 14 of FIG. 1 are an exemplary embodiment. The dual-mode antenna 11 has a first member 111 and a second member 112. The first member 111 is on the upper surface of the substrate 100 and the second member 112 is on the lower surface of the substrate 100. The first component 111 is connected to the first feeding end 119. The first component 111 is used to generate an operating mode of a second frequency band (for example, 5 GHz frequency band), and the second component 112 is coupled to the first component 111 to generate a first frequency band (for example, 2.4GHz band) operating mode. The first component 111 is a monopole antenna, and the second component 112 is connected to the ground edge 9, but the invention is not limited thereto. The antenna unit 14 has a third member 141 and a fourth member 142, the third member 141 is on the upper surface of the substrate 100, and the fourth member 142 is on the lower surface of the substrate 100. The third component 141 is connected to the second feeding end 149, the third component 141 is used to generate an operating mode of the second frequency band (for example, 5GHz band), and the fourth component 142 is coupled to the third component 141 to generate the first frequency band (for example, 2.4GHz band) operating mode. The third component 141 is a monopole antenna, and the fourth component 142 is connected to the ground edge 9, but the present invention is not limited thereto. In addition, the phase difference caused by the spatial distance between the dual-mode antenna 11 and the antenna unit 14 and the length of the transmission line 13 can make the radiation patterns of mode zero and mode one or two modes significantly different.

Please refer to FIG. 3. FIG. 3 is a schematic diagram of a dual-mode antenna array according to another embodiment of the present invention. The solid line represents the line on the upper surface of the substrate 100. The dashed line represents the line on the lower surface of the substrate 100. Based on the difference of the grounding edge 9, the grounding edge 9 has a protrusion 9a between the dual-mode antenna 11 and the antenna unit 14, the first member 111, the second member 112, the third member 141 and the fourth member 142 The installation position and structure are different from the structure of the embodiment of FIG. 1, and the transmission line 13 is also appropriately bent to reduce the occupied line area. In another embodiment, the dual-mode antenna 11 may also be changed to a planar inverted-F antenna (PIFA), or the antenna unit 141 is a planar inverted-F antenna (PIFA), and both the dual-mode antenna 11 and the antenna unit 14 The structure need not be the same.

Next, please refer to FIG. 4, this embodiment provides an electronic device with a dual-mode antenna array, including the dual-mode antenna array 1, the application unit 2 and the control unit 3 as provided in the foregoing embodiment, wherein the dual-mode antenna array 1 The first feeding end 111 of the dual-mode antenna 11 and the first end 121 of the switch 12 are connected to the wireless chip 4 of the electronic device. The application unit 2 is connected to the wireless chip 4, and the wireless chip 4 receives the received signal strength indicator (RSSI) or the received data rate of the dual-mode antenna array 1. The control unit 3 connects the application unit 2 and the switch 12 to determine whether to switch the first end 121 of the switch 12 to the second end 122 to control the radiation pattern of the dual-mode antenna array 1. The application unit 2 may include a software program at the application layer of the operating system of the electronic device. The application unit 2 includes an algorithm to control the radiation pattern (based on the received signal strength indication or received data rate of the dual-mode antenna array 1) to control the control Unit 3. The algorithm operation of the application unit 2 can be separated from the operation of the wireless chip 4, so that the wireless chip 4 does not need to be responsible for controlling the dual-mode antenna array 1, and the antenna control is independent of the wireless chip 4, so the design of the wireless chip 4 can be reduced cost. Therefore, in the application at the product level, the wireless chip 4 can use a general-purpose chip. When changing the design of the dual-mode antenna array 1, only the application unit 2 needs to be modified (or, including the modification of the control unit 3, when the switch 12 Also together When modified). The electronic device is, for example, a notebook computer, a laptop computer, a tablet computer, an all-in-one computer, a smart TV, a small base station, or a wireless router, but the invention is not so limited.

In summary, the dual-mode antenna array and the electronic device with the dual-mode antenna array provided by the embodiments of the present invention utilize the dual-mode antenna whose input impedance can be matched with the characteristics of the single antenna operating mode and the dual antenna operating mode The mode antenna array does not need to use a complex dual-frequency feed network under the requirement of dual-frequency operation, and only needs to use a switch and an open circuit, so that the purpose of radiation field control and the reduction of manufacturing costs can be achieved at the same time. And the control circuit is easy to realize and has high industrial application value.

The above is only an embodiment of the present invention, and it is not intended to limit the patent scope of the present invention.

1‧‧‧ dual-mode antenna array

11‧‧‧Dual mode antenna

12‧‧‧switch

13‧‧‧ Transmission line

14‧‧‧ Antenna unit

119‧‧‧First feed end

149‧‧‧Second feed end

121‧‧‧The first end

122‧‧‧The second end

123‧‧‧The third end

111‧‧‧The first part

112‧‧‧Second part

141‧‧‧The third part

142‧‧‧The fourth part

9‧‧‧Earth edge

100‧‧‧ substrate

X, Y, Z‧‧‧ axis

15‧‧‧Open circuit

151‧‧‧Low band rejection filter unit

152‧‧‧High frequency open circuit adjustment unit

G‧‧‧Ground

Claims (8)

A dual-mode antenna array includes: a dual-mode antenna with a first feed-in end, the dual-mode antenna receives a first radio frequency signal from the first feed-in end to operate in a first frequency band, and A feed-in terminal receives a second radio frequency signal to operate in a second frequency band, wherein the frequency of the second frequency band is higher than the frequency of the first frequency band, wherein the dual-mode antenna has a first component and a second component, The first component is connected to the first feed-in terminal, the first component is used to generate the operating mode of the second frequency band, the second component is coupled to the first component to generate the operating mode of the first frequency band; a switch , With a first end, a second end and a third end, the first end of the switch is connected to the first feed end of the dual-mode antenna, the switch is controlled by a control signal to select the operating state A mode zero or a mode one, the mode zero is to conduct the first end to the third end, the mode one is to conduct the first end to the second end; a transmission line, the second end of the switch The transmission line is connected with an impedance of 100 ohms, wherein the input impedance of the dual-mode antenna in the first frequency band and the second frequency band is between 50 ohms and 100 ohms; an antenna unit has a second feed-in end , The second feeding end of the antenna unit is connected to the second end of the switch through the transmission line, wherein the input impedance of the antenna unit in the first frequency band and the second frequency band is 100 ohms, wherein the antenna unit has a A third component and a fourth component, the third component is connected to the second feeding end, the third component is used to generate the operation mode of the second frequency band, the fourth component is coupled to the third component to generate the first An operation mode of a frequency band; and an open circuit including a low-band rejection filter unit and a high-frequency open-circuit adjustment unit, the low-band rejection filter unit is connected to the third end of the switch, the high-frequency open circuit The adjustment unit is connected between the low-band rejection filter unit and a ground, wherein the low-band rejection filter unit is used to prevent the first RF signal from flowing in from the third end of the switch, and used to allow the second RF The signal flows in from the third end of the switch, wherein the high-frequency open-circuit adjustment unit is used to block the second RF signal from the low-band rejection filter unit from flowing to the ground; wherein, when the switch is in the operating mode When zero, the first end, the third end of the switch and the open circuit are turned into a switch line stub, which is used to make the input impedance of the dual-mode antenna in parallel with the switch line stub is 50 ohms; When the operating state of the switch is mode one, the input impedance of the dual-mode antenna and the antenna unit in parallel using the switch is close to 50 ohms. The dual-mode antenna array according to claim 1, wherein the low-band rejection filter unit includes a first inductor and a first capacitor connected in parallel with each other. The dual-mode antenna array according to claim 2, wherein the high-frequency open-circuit adjusting unit includes a second inductor, and the first inductor connected in parallel with the first capacitor is connected in series with the second inductor to the ground. The dual-mode antenna array according to claim 1, wherein the first frequency band is the 2.4 GHz frequency band, the second frequency band is the 5 GHz frequency band, the inductance value of the first inductor is 3.9 nH, and the capacitance value of the first capacitor Is 1pF, the inductance of the second inductor is 1.2nH. An electronic device with a dual-mode antenna array, comprising: the dual-mode antenna array according to claim 1, wherein the first feed-in end of the dual-mode antenna of the dual-mode antenna array and the first A wireless chip connected to the electronic device at one end; an application unit connected to the wireless chip, and the wireless chip receives the received signal strength indication or the received data rate of the dual-mode antenna array; and A control unit, connected to the application unit and the switch, to decide whether to turn on the first end of the switch to the second end to control the radiation pattern of the dual-mode antenna array; wherein when the operating state of the switch is When the mode is zero, the first end, the third end of the switch and the open circuit are turned into a switch line stub, and the input impedance of the dual mode antenna and the switch line stub in parallel is 50 ohms; when the switch When the operating state is mode one, the input impedance of the dual-mode antenna and the antenna unit in parallel using the switch is close to 50 ohms. The electronic device with a dual-mode antenna array according to claim 5, wherein the low-band rejection filter unit includes a first inductor and a first capacitor connected in parallel with each other. The electronic device with a dual-mode antenna array according to claim 6, wherein the high-frequency open-circuit adjustment unit includes a second inductor, and the first inductor connected in parallel with the first capacitor is connected in series with the second inductor The ground. The electronic device with a dual-mode antenna array according to claim 5, wherein the first frequency band is a 2.4 GHz frequency band, the second frequency band is a 5 GHz frequency band, the inductance value of the first inductor is 3.9 nH, and the first The capacitance value of the capacitor is 1 pF, and the inductance value of the second inductor is 1.2 nH.

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