TWI497818B - Antenna and electronic device - Google Patents

Description

Antenna and electronic device

The invention relates to an antenna and an electronic device, in particular to an antenna and an electronic device with good integration.

Generally, an electronic device having a mobile communication function transmits or receives a mobile radio wave through an antenna to transmit or exchange a mobile electric signal, thereby accessing a mobile communication system. In order to make it easier for users to access the mobile communication system, the bandwidth of the ideal antenna should be increased as much as possible within the permissible range, and the size should be minimized to match the trend of miniaturization of electronic products. Therefore, with the trend of the size of the electronic device and the reduction of the antenna space, how to effectively utilize the spatial arrangement inside the electronic device and integrate the antenna into the electronic device has become one of the challenges in the industry.

Accordingly, it is a primary object of the present invention to provide an antenna and an electronic device that are well integrated.

The present invention discloses an antenna for an electronic device, the antenna includes a radiator, and a signal feeding end electrically connected to the radiator for feeding an RF signal to the radiator to transmit the radiator Transmitting the RF signal; a grounding portion for providing grounding to the antenna; a grounding end electrically connected to the grounding portion; a first connecting unit, Electrically connected to the signal feeding end; a second connecting unit electrically connected to the grounding end; and a transmission line electrically connected to the first connecting unit and the second connecting unit for transmitting the RF signal The RF signal is transmitted to the signal feed end through the first connection unit, and is electrically connected to the ground terminal through the second connection unit.

The present invention further discloses an electronic device including an RF signal processing unit for generating a first RF signal, and a first antenna coupled to the RF signal processing unit, the first antenna including a first radiation a first signal feed end electrically connected to the first radiator for feeding the first RF signal to the first radiator to transmit the first RF signal through the first radiator; a first grounding portion is provided to be grounded to the first antenna; a first grounding end is electrically connected to the first grounding portion; and a first connecting unit is electrically connected to the first signal feeding end a second connection unit electrically connected to the first ground end; and a transmission line electrically connected to the first connection unit and the second connection unit for transmitting the first RF signal and transmitting the first RF signal The connecting unit transmits the first RF signal to the first signal feeding end, and is electrically connected to the first ground end through the second connecting unit.

Please refer to FIG. 1 , which is a schematic diagram of an electronic device MS according to an embodiment of the present invention. The electronic device MS includes an antenna 11 , a casing 13 , a system circuit board 45 , and an RF signal processing unit 40 . The housing 13 can be used for any electronic device, such as a mobile phone, a tablet computer, a Global Positioning System (GPS) or a USB adapter (Dongle), and has an electronic device with wireless communication function. In addition to the electronic device MS, an antenna 11 is formed thereon for transmitting and receiving an RF signal RF_1 to achieve wireless communication. The antenna 11 can be formed on the casing 13 through a laser direct structuring (LDS) technology. Therefore, the combination of the casing 13 and the antenna 11 can also be regarded as an antenna module AMD. The RF signal processing unit 40 is disposed on the system circuit board 45 for generating the RF signal RF_1 and processing the RF signal RF_1 transmitted and received by the antenna 11. The system board 45 is preferably a printed circuit board (PCB) of a multi-layer structure, at least one of which may be a ground layer for reference to the ground portion GND_2 as one of the remaining electronic components on the system board 45.

In detail, the antenna 11 includes a radiator 110, a signal feeding end 112, a grounding end 113, a grounding portion GND, a branch 111, connecting units 41, 42 and a transmission line 44. The signal feeding end 112 is electrically connected to the radiator 110 for feeding the RF signal RF_1 to the radiator 110 to transmit the RF signal RF_1 to the air through the radiator 110. The grounding portion GND is electrically connected to the grounding end 113 for providing grounding to the antenna 11. The branch 111 is electrically connected between the radiator 110 and the ground GND. In other embodiments, the antenna designer may choose to add or not use according to actual application requirements. The connecting units 41 and 42 are electrically connected to the signal feeding end 112 and the grounding end 113, respectively. The transmission line 44 is electrically connected to the connection unit 41, 42 for transmitting the RF signal RF_1, and transmits the RF signal RF_1 to the signal feeding end 112 through the connection unit 41, and is electrically connected to the ground terminal 113 and the ground through the connection unit 42. Part GND. The connection units 41, 42 and the transmission line 44 are disposed above the system circuit board 45, wherein the connection units 41, 42 are preferably a pedestal (Pogo Pin). In addition, the system board 45 can be additionally set The matching circuit M1 is coupled thereto, and the matching circuit M1 is coupled between the connecting units 41 and 42 to be coupled between the grounding portion GND and the antenna 11 for matching the antenna 11. The matching circuit M1 may be composed of electronic components such as capacitors, inductors or resistors, wherein the matching circuit M1 is preferably disposed at a position close to the connection units 41, 42.

As shown in FIG. 1, the antenna 11 can be regarded as a dipole antenna or a Planar Inverted-F Antenna (PIFA). Specifically, the radiator 110 and the ground portion GND form a structure of the dipole antenna, and the radiator 110 further includes a branch 111 electrically connected between the radiator 110 and the ground portion GND to form a structure of the planar inverted-F antenna. The grounding portion GND and the radiator 110 may have a meandering shape or at least one bend to extend the grounding portion GND and the length of the radiator 110 in a limited space of the casing 13. In addition, transmission line 44 can be used to equivalently increase the electrical length of radiator 110 to cause antenna 11 to resonate to the desired bandwidth of the low frequency band. Therefore, the antenna designer can appropriately adjust the length or the number of bends of the radiator 110 and the ground portion GND according to actual application requirements, or adjust the length of the transmission line 44 to obtain the optimum antenna performance.

It should be noted that the connecting unit 42 is electrically connected to the grounding end 113 and the grounding portion GND of the RF signal processing unit 40, so that the return current of the antenna 11 is returned from the grounding portion GND through the connecting unit 42 to the RF signal processing unit 40. Both ends of the transmission line 44 include an I-PEX connector 46 that is coupled through a U.FL connector 47 on the system board 45 to deliver an RF signal RF_1. Specifically, please refer to FIG. 2, which is a detailed structural diagram of the transmission line 44, the I-PEX connector 46, and the U.FL connector 47. As shown in FIG. 2, the transmission line 44 is preferably a transmission line having a specific impedance value, such as an impedance value. A 50 ohm coaxial cable or the like includes an outer conductor (woven shield) 441 and an inner conductor (internal core) 442. The outer conductor 441 is electrically connected to the grounding portion of the I-PEX connector 46 (ie, the metal iron member of the outer appearance), and the inner conductor 442 is electrically connected to the inner pin of the I-PEX connector 46 (inner pin, not shown in the figure). Medium), used to transmit RF signal RF_1. It should be noted that the outer conductor 441 of the transmission line 44, the grounding portion of the I-PEX connector 46, and the grounding portion 471 of the peripheral ring type of the U.FL connector 47 must be electrically connected to the ground portion GND (or the connecting unit 42). The transmission path of the RF signal RF_1 is made to refer to the continuous ground GND. For example, the ground portion of the I-PEX connector 46 and the ground portion 471 of the U.FL connector 47 can be routed through one of the layers of the multi-layer system circuit board 45 (Trace, not shown) and the ground GND ( Or the connection unit 42) is electrically connected, so the transmission path of the RF signal RF_1 can be referred to the continuous ground GND. In this way, when the I-PEX connector 46 is combined with the U.FL connector 47, the RF signal RF_1 can be made by the inner conductor 442 of the transmission line 44, the inner pin of the I-PEX connector 46, and the U.FL connector 47. The inner pin 472 or the connecting unit 42 is transmitted to the antenna 11, and the transmission path of the radio frequency signal RF_1 is referred to the same ground portion GND. In this architecture, when the antenna module AMD including the antenna 11 and the casing 13 is combined with the system circuit board 45, the antenna 11 can pass through the connection units 41 and 42 and the radio frequency signal processing unit 40 in the system circuit board 45. Connected to achieve the function of wireless communication.

Please refer to FIG. 3, which is a schematic diagram of another electronic device MS_3 according to an embodiment of the present invention. Compared with the electronic device MS, the electronic device MS_3 further includes an antenna 32, so the electronic device MS_3 can simultaneously transmit and receive mobile power by using more than two antennas. The wave is used to perform Multiple Input Multiple Output (MIMO) technology to improve the data throughput (Throughput) of the electronic device MS_3. The electronic device MS_3 includes an antenna 11, 32, a housing 13, a system circuit board 45, and an RF signal processing unit 40. The antennas 11, 32 and the housing 13 can also be regarded as an antenna module AMD_3. The antenna 32 is configured to transmit and receive an RF signal RF_2, wherein the antenna 32 can also be formed on the housing 13 by a laser direct forming technique. The RF signal processing unit 40 is configured to generate another RF signal RF_2 and process the RF signal RF_2 transmitted and received by the antenna 32.

In detail, the antenna 32 includes a radiator 320, a signal feeding end 322, and a connecting unit 43. The grounding portion GND_2 of the system circuit board 45 can be used as a grounding portion of the antenna 32. The signal feeding end 322 is electrically connected to the radiator 320 for feeding the RF signal RF_2 to the radiator 320 to transmit the RF signal RF_2 to the air through the radiator 320. The connecting unit 43 is disposed on the system circuit board 45 for electrically connecting the signal feeding end 322 to transmit the RF signal RF_2 to the signal feeding end 322. The connecting unit 43 is preferably a thimble. In addition, the system circuit board 45 can be further provided with a matching circuit M2, wherein the matching circuit M2 is coupled between the grounding portion GND_2 and the connecting unit 43 for matching the antenna 32. The matching circuit M2 may be composed of electronic components such as a capacitor, an inductor or a resistor, and the matching circuit M2 is preferably disposed at a position close to the connecting unit 43.

As shown in FIG. 3, the radiator 320 of the antenna 32 and the ground portion GND_2 form a structure of a dipole antenna. The radiator 320 may have a meandering shape or at least one bend to In the limited space of the housing 13, the length of the radiator 320 is extended to adjust the radiation frequency of the antenna 32. Therefore, the antenna designer can appropriately adjust the length of the radiator 320 or the number of bends according to actual application requirements to obtain the best antenna performance.

Under this architecture, when the antenna module AMD_3 including the antennas 11, 32 and the casing 13 is combined with the system circuit board 45, the antennas 11, 32 can pass through the connection units 41, 42 and 43 and the system circuit board 45. The RF signal processing unit 40 is coupled to achieve the function of wireless communication. It is to be noted that the ground portion GND of the antenna 11 and the ground portion GND_2 of the antenna 32 are insulated from each other, so that the antennas 11, 32 can have better isolation. For example, in a small electronic device, the distance between the antenna and the antenna is often very close. If the antennas 11 and 32 share the same grounding portion, such as the grounding portion GND_2 of the system board, the mirror currents of the antennas 11 and 32 (Image) Current) or the return current flows to the same ground portion GND_2, resulting in poor isolation between the antennas 11, 32. The poor isolation means that most of the energy of the RF signal RF_1 radiated by the antenna 11 is received by the antenna 32; vice versa, most of the energy of the RF signal RF_2 radiated by the antenna 32 is received by the antenna 11. Therefore, even if the antennas 11, 32 have a good match, the poor isolation is equivalent to weakening the emission performance of the antennas 11, 32.

Please refer to FIG. 4, which shows the voltage standing wave ratio and isolation of the antennas 11, 32. The voltage standing wave ratio of the antenna 11 is indicated by a broken line, the voltage standing wave ratio of the antenna 32 is indicated by a solid line, and the isolation is represented by a dotted line. Since the ground portions GND and GND_2 of the antennas 11, 32 are insulated from each other, the antennas 11, 32 have better isolation. As shown in Figure 4 As shown, the antennas 11, 32 have a voltage standing wave ratio of about 1.4 at a frequency of 867 MHz, but the isolation between them is only -8.34 dB. When the RF signal RF_1 is fed into the antenna 11 to radiate into the air, the RF signal RF_1 has only -8.34dB (or 14%) of the energy received by the antenna 32; conversely, when the RF signal RF_2 is fed into the antenna 32 to radiate into the air. At the time, only 14% of the energy of the RF signal RF_2 is received by the antenna 11. The antennas 11, 32 that do not share the ground portion can maintain good matching and have better isolation so that the transmission performance of the antennas 11, 32 is not greatly affected in a limited space.

In summary, with the trend of the volume of the electronic device and the shrinking of the antenna space, the present invention effectively utilizes the spatial configuration inside the electronic device to form the radiator and the ground portion of the antenna on the housing, and on the system circuit board. The transmission line is added to resonate the radiated frequency band of the antenna at a low frequency, and the antenna is integrated into the electronic device. In addition, the present invention also integrates multiple antennas and a casing into an antenna module, increases the utilization of the internal space of the electronic device, and uses the design of the antenna not sharing the grounding portion, so that the return currents of the antennas are respectively circulated in the phase. Different grounding parts improve the isolation between the antenna and the antenna, so that the transmitting performance of the antenna is not greatly affected in a limited space.

The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

MS, MS_3‧‧‧ electronic device

AMD, AMD_3‧‧‧ antenna module

11, 32‧‧‧ antenna

13‧‧‧Shell

110, 320‧‧‧ radiator

112, 322‧‧‧ signal feed end

RF_1, RF_2‧‧‧ RF signals

GND, GND_2, 471‧‧‧ Grounding

111‧‧‧ branch

113‧‧‧ Grounding terminal

40‧‧‧RF signal processing unit

41, 42, 43‧‧‧ Connection unit

44‧‧‧ transmission line

45‧‧‧System Board

46‧‧‧I-PEX connector

47‧‧‧U.FL connector

441‧‧‧Outer conductor

442‧‧‧ inner conductor

472‧‧‧insert

M1, M2‧‧‧ matching circuit

FIG. 1 is a schematic diagram of an electronic device according to an embodiment of the present invention.

Figure 2 shows the details of the transmission line, I-PEX connector and U.FL connector of Figure 1. Structure diagram.

FIG. 3 is a schematic diagram of another electronic device according to an embodiment of the present invention.

Figure 4 is a schematic diagram of the voltage standing wave ratio of the antenna of Figure 3 and its isolation.

MS‧‧‧Electronic device

AMD‧‧‧Antenna Module

11‧‧‧Antenna

13‧‧‧Shell

40‧‧‧RF signal processing unit

41, 42‧‧‧ Connection unit

44‧‧‧ transmission line

45‧‧‧System Board

46‧‧‧I-PEX connector

47‧‧‧U.FL connector

110‧‧‧ radiator

111‧‧‧ branch

112‧‧‧ Signal Feeder

113‧‧‧ Grounding terminal

RF_1‧‧‧RF signal

GND, GND_2‧‧‧ Grounding

M1‧‧‧ matching circuit

Claims (18)

An antenna for an electronic device, the antenna comprising: a radiator; a signal feed end electrically connected to the radiator for feeding an RF signal to the radiator for transmitting through the radiator The RF signal; a grounding portion for providing grounding to the antenna; a grounding end electrically connected to the grounding portion; a first connecting unit electrically connected to the signal feeding end; and a second connecting unit Electrically connected to the grounding end; and a transmission line electrically connected to the first connecting unit and the second connecting unit for transmitting the RF signal and for equivalently increasing the electrical length of the radiator The first connecting unit transmits the radio frequency signal to the signal feeding end, and is electrically connected to the ground end through the second connecting unit. The antenna of claim 1, wherein the transmission line is a coaxial cable. The antenna of claim 1, further comprising a branch electrically connected between the radiator and the ground. The antenna of claim 3, the electronic device further comprising a housing, the radiator, the branch and the ground portion of the antenna are formed on the housing. The antenna of claim 1, wherein the connecting unit is the first connecting unit and The second connecting unit is a thimble. The antenna of claim 1, wherein the radiator and the ground portion have a meandering shape or at least one bend. The antenna of claim 1, wherein the electronic device further comprises a system circuit board, the transmission line, the first connection unit and the second connection unit are disposed on the system circuit board. The antenna of claim 7, wherein the system circuit board is provided with a matching circuit coupled between the first connecting unit and the second connecting unit for matching the antenna. An electronic device includes: an RF signal processing unit for generating a first RF signal; and a first antenna coupled to the RF signal processing unit, the first antenna includes: a first radiation a first signal feed end electrically connected to the first radiator for feeding the first RF signal to the first radiator to transmit the first RF signal through the first radiator; a first grounding portion is provided to be grounded to the first antenna; a first grounding end is electrically connected to the first grounding portion; and a first connecting unit is electrically connected to the first signal feeding end ; a second connection unit electrically connected to the first ground end; and a transmission line electrically connected to the first connection unit and the second connection unit for transmitting the first RF signal and for increasing the equivalent The first RF signal is transmitted to the first signal feed end through the first connection unit, and is electrically connected to the first ground terminal through the second connection unit. The electronic device of claim 9, wherein the transmission line is a coaxial cable. The electronic device of claim 9, wherein the first antenna further comprises a branch electrically connected between the first radiator and the first ground. The electronic device of claim 11, further comprising a housing, the first radiator, the branch and the first ground portion of the first antenna being formed on the housing. The electronic device of claim 12, further comprising a second antenna, the second antenna comprising: a second radiator; a second signal feeding end electrically connected to the second radiator The second RF signal is generated by the RF signal processing unit to generate a second RF signal to the second radiator to transmit the second RF signal through the second radiator; and a third connection unit is electrically connected to the first a second signal feed end for transmitting the second RF signal to the second signal feed end; Wherein the second radiator is formed on the casing. The electronic device of claim 13, wherein the first connecting unit, the second connecting unit, and the third connecting unit are a thimble. The electronic device of claim 13, wherein the first radiator, the second radiator, and the first ground portion of the first antenna have a meandering shape or at least one bend. The electronic device of claim 13, further comprising a second ground portion for providing grounding to the second antenna, wherein the second ground portion is insulated from the first ground portion of the first antenna. The electronic device of claim 13, further comprising a system circuit board, the transmission line, the first connection unit, the second connection unit and the third connection unit are disposed on the system circuit board. The electronic device of claim 17, wherein the system circuit board further comprises: a first matching circuit coupled between the first connecting unit and the second connecting unit for matching the first antenna And a second matching circuit coupled between the second ground portion of the electronic device and the third connecting unit for matching the second antenna; wherein the first matching circuit and the second matching circuit insulation.