TWI581508B - Lte antenna sturcture - Google Patents

Description

LTE antenna structure

The present invention relates to an LTE antenna, and more particularly to an LTE antenna that can be used to operate an antenna at 700 MHz to 2600 MHz.

In order to meet the improvement of communication performance and quality requirements, the new generation of mobile wireless broadband technology, which is attracting attention in the market, has gradually emerged as a long-term evolution (LTE) technology, and its performance is better than that of 3G wireless network. With better communication transmission, LTE has been officially listed as a new wireless standard specification by the Third Generation Partnership Project (3GPP).

The LTE frequency bands are widely divided. The frequency bands supported by different countries and different carriers may also be different. For example, the frequency bands used in North America are 700/800MHz and 1700/1900MHz; the frequency bands used in Europe are 800MHz, 1800MHz, 2600MHz; Japan 800MHz, 1500MHz, 1800MHz. 2100MHz; Taiwan uses 700/900/1800MHz. Due to the faster transmission speed and larger transmission bandwidth of LTE technology, the antenna design must also meet the bandwidth requirements.

The invention provides a novel antenna design concept, which can effectively improve the bandwidth of the LTE antenna structure in a low frequency band in a limited antenna configuration space.

The LTE antenna structure of the present invention includes a low frequency radiation member, a short circuit member, a high frequency radiation member, a feed end, an impedance matching unit, a first connection portion, and a second connection portion. The shorting member is connected to the ground terminal. The low frequency radiating element provides a first resonant path, wherein the low frequency radiating element operates in a low frequency band. The first connecting section has a first end and a second end. The first end of the first connecting section is connected to the feeding end, and the second end of the first connecting section is connected to the short-circuiting member. The second connecting section has a first end and a second end, the first end of the second connecting section is connected to the second end of the first connecting section, and the second end of the second connecting section is connected to the low frequency radiating element, the first The connecting section and the second connecting section provide a first resonant path. The high frequency radiating element is coupled to the first end of the feed end, and the high frequency radiating element provides a second resonant path, wherein the high frequency radiating element corresponds to the second frequency band. The impedance matching unit has a first end and a second end. The first end is connected to the low frequency radiating element, the second end is connected to the feeding end, the impedance matching unit adjusts the inductance, and the bandwidth of the low frequency band is adjusted to offset the series connection of the feeding end. Inductive, wherein the ground end is located at the second end of the short-circuiting member, and the feeding end, the short-circuiting member and the first connecting portion form a current loop.

In an embodiment of the invention, the LTE antenna structure further includes an inductor unit connected in series with the short-circuiting member between the low-frequency radiating member and the ground to increase the relative bandwidth of the low-frequency radiating member.

In an embodiment of the invention, the operating bandwidth of the low frequency radiating element after the bandwidth is increased is between 700 MHz and 960 MHz.

In an embodiment of the invention, the length of the first resonant path is large The length of the second resonant path.

In an embodiment of the invention, the LTE antenna structure is a planar inverted-F antenna.

In an embodiment of the invention, the high frequency radiation device has an operating bandwidth of between 1710 MHz and 2170 MHz.

In an embodiment of the invention, the low frequency radiating element and the high frequency radiating element are disposed in parallel with each other.

In an embodiment of the invention, the first connecting section and the second connecting section are L-shaped.

Based on the above, the embodiment of the present invention changes the inductivity of the feed end by connecting an impedance matching unit between the feed end and the low frequency radiating element to effectively improve the LTE antenna structure in the low frequency band in a limited antenna configuration space. Bandwidth, which contributes to the development of miniaturization of electronic devices using LTE antenna structures.

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

100, 200, 300‧‧‧ LTE antenna structure

101, 301‧‧‧ low frequency radiation parts

102, 302‧‧‧ Short-circuit parts

104, 304‧‧‧ feed end

114, 314‧‧‧ impedance matching unit

108, 308‧‧‧ high frequency radiation parts

110, 310‧‧‧ first connection section

112, 312‧‧‧Second connection section

106, 306‧‧‧ feed signal

202, 316‧‧‧Inductance unit

402, 404, 406‧‧‧ characteristic curve

FP1‧‧‧Feeding point

GP1‧‧‧ grounding terminal

FIG. 1 is a schematic diagram showing the structure of an LTE antenna according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing the structure of an LTE antenna according to another embodiment of the present invention.

FIG. 3 is a schematic diagram showing the structure of an LTE antenna according to another embodiment of the present invention.

FIG. 4 is a schematic diagram showing the characteristics of an LTE antenna structure according to an embodiment of the present invention.

FIG. 1 is a schematic diagram showing the structure of an LTE antenna according to an embodiment of the present invention. Please refer to FIG. 1. The LTE antenna structure 100 is a Planar Inverted F Antenna (PIFA). The LTE antenna structure 100 may include a high frequency radiating element 108, a low frequency radiating element 101, a short circuiting member 102, a feeding end 104, and an impedance matching unit 114. The first connection section 110 and the second connection section 112.

In the present embodiment, the low frequency radiation member 101 and the high frequency radiation member 108 are disposed in parallel with each other. The first end of the short-circuiting member 102 is connected to the low-frequency radiating element 101, the second end of the short-circuiting member 102 is connected to a grounding end GP1, the first end of the feeding end 104 is connected to the high-frequency radiating element 108, and the second end of the feeding end 104 has The feed point FP1, the short-circuiting member 102 is connected to a ground through the grounding end GP1, and the feeding end 104 receives a feeding signal 106 through the feeding point FP1.

Further, in this embodiment, the first connecting section 110 and the second connecting section 112 are in an L shape. The first connecting section 110 has a first end and a second end. The first end of the first connecting section 110 is connected to the first end of the feeding end 104, and the second end of the first connecting section 110 is connected to the shorting part 102. First end. The second connecting section 112 has a first end and a second end, the first end of the second connecting section 112 is connected to the second end of the first connecting section 110, and the second end of the second connecting section 112 is connected to the low frequency radiation. Item 101.

The low frequency radiating element 101 can provide a resonant path, and in the resonant mode, correspondingly operate in a low frequency band, and in addition, the interconnected first connecting sections 110 and The second connecting section 112 can also form a resonant path. By the excitation of the feed signal 106, the feed terminal 104, the first connection segment 110 and the short circuit member 102 can form a current loop, and the LTE antenna structure 100 can generate a resonance mode through the resonance path, thereby covering the low frequency band. In addition, the high frequency radiating element 108 is connected to the first end of the feeding end 104, and the high frequency radiating element 108 can provide another resonant path. The high frequency radiating element 108 correspondingly operates in a second frequency band in the resonant mode, wherein the low frequency radiation The length of the resonant path of the member 101 is greater than the length of the resonant path of the high frequency radiating element 108, and the frequency of the low frequency radiating element 101 in the low frequency band is lower than the frequency of the second frequency band.

In addition, the impedance matching unit 114 is connected between the first end of the feeding end 104 and the low frequency radiating element 101, which can adjust the inductance of the feeding end 104, thereby increasing the bandwidth of the LTE antenna structure 100 in the low frequency band. . Further, the inductivity of the feed end 104 is related to the manner in which the antenna is fed, for example, by a coaxial cable or a spring contact to feed the signal, by being connected to the first end of the feed end 104. The impedance matching unit 114 between the end and the low frequency radiating element 101 can cancel the series inductance of the feeding end 104, reduce the quality factor, and increase the bandwidth of the low frequency band. In the present embodiment, the impedance matching unit 114 is implemented by a connecting section connected between the first end of the feeding end 104 and the low frequency radiating element 101, wherein the connecting section can be, for example, copper foil or Other electrical conductors. It should be noted that the implementation of the impedance matching unit 114 is not limited to the embodiment, and the impedance matching unit may be implemented by other components that can cancel the series inductance of the feeding terminal 104. For example, in some embodiments, the impedance matching unit 114 can also be connected, for example, between the first end of the feed end 104 and the low frequency radiating element 101. The inductor is implemented.

FIG. 2 is a schematic diagram showing the structure of an LTE antenna according to another embodiment of the present invention. Please refer to FIG. 2 . The difference between the embodiment and the embodiment of FIG. 1 is that the LTE antenna structure 200 of the embodiment further includes an inductance unit 202. After the bandwidth of the low frequency band is increased by the impedance matching unit 114, if the frequency of the low frequency band corresponding to the low frequency radiating element 101 is to be further reduced, the inductive unit 202 and the short circuit member 102 may be connected in series to the low frequency radiating element 101 and the ground. In between, to reduce the center frequency of the low frequency band, the low frequency portion of the low frequency band can reach a lower frequency, thereby increasing the relative bandwidth of the low frequency radiating element 301.

FIG. 3 is a schematic diagram showing the structure of an LTE antenna according to another embodiment of the present invention. Please refer to FIG. 3. Similar to the embodiment of FIG. 2, the LTE antenna structure 300 of the present embodiment is also a planar inverted-F antenna, which includes a low frequency radiating element 301, a short circuiting member 302, a feeding end 304, a high frequency radiating element 308, and an impedance matching unit 314. And the inductive unit 316, the first connecting portion 310 and the second connecting portion 312, wherein the first end of the shorting member 302 is connected to the low frequency radiating member 301, and the second end of the shorting member 302 has the grounding end GP1, and the shorting member 302 is transmitted through Ground terminal GP1 is connected to ground. The first end of the feeding end 304 is connected to the high frequency radiating element 308, and the second end of the feeding end 304 has a feeding point FP1, and the feeding end 304 can receive the feeding signal 306 through the feeding point FP1. In addition, the connection manners of the first connection section 310 and the second connection section 312 are similar to the connection manner of the first connection section 110 and the second connection section 112 described above, and thus are not described herein again.

Similarly, in the present embodiment, the low frequency radiation member 301 can provide a resonance path. The path, while operating in a low frequency band in the resonant mode, and the first connecting section 310 and the second connecting section 312 connected to each other may also form a resonant path. By the excitation of the feed signal 306, the feed terminal 304, the first connection section 310 and the short circuit member 302 can form a current loop, and the LTE antenna structure 300 can generate a resonance mode through the resonance path, thereby covering the low frequency band. In addition, the high frequency radiating element 308 is connected to the first end of the feeding end 304, and the high frequency radiating element 308 can provide another resonant path. The high frequency radiating element 308 corresponds to a second frequency band (1710 MHz to 2170 MHz) in the resonant mode. The length of the resonant path of the low frequency radiating element 301 is greater than the length of the resonant path of the high frequency radiating element 308, and the frequency of the low frequency band is lower than the frequency of the second frequency band.

Similarly, the impedance matching unit 314 of the present invention can adjust the inductivity of the feed end 304, thereby increasing the bandwidth of the LTE antenna structure 300 in the low frequency band. As shown in the circuit diagram of the LTE antenna structure of FIG. 4, as shown in the circuit diagram of FIG. 3, in the present embodiment, the LTE antenna structure 300 is a communication applied to Long Term Evolution (LTE) technology, which is at a low frequency. The frequency band must cover 700MHz~960MHz. The characteristic curve 402 is a bandwidth range of the low frequency band of the LTE antenna structure 300 without the impedance matching unit 314 and the inductance unit 316. The center frequency of the LTE antenna structure 300 is covered to 700 MHz, and the bandwidth is still not in accordance with the communication requirements of the long term evolution technology. By connecting the impedance matching unit 314 (which is implemented by the connection section in this embodiment) between the first end of the feed end 304 and the low frequency radiating element 301, the series inductance of the feed end 304 can be cancelled, The quality factor is reduced to increase the bandwidth of the low frequency band of the LTE antenna structure 300 (as shown by characteristic curve 404). As shown in FIG. 4, the bandwidth of the LTE antenna structure 300 in its low frequency band is increased by the impedance matching unit 314. After that, although it is close to the communication requirement of the long-term evolution technology, while the bandwidth is increased, the low-frequency portion is also pulled up by the impedance matching unit 314 (the operating bandwidth of the low-frequency radiating element 301 is 777MHZ~960MHZ). Having the LTE antenna structure 300 less desirable in the low frequency portion of its low frequency band, in this case, by the inductive unit 316 of the present embodiment (which can be implemented, for example, as an inductor), the center frequency of the low frequency band can be pulled down, The low frequency portion of the low frequency band of the LTE antenna structure 300 can be reduced to 700 MHz to meet the communication requirements of the long term evolution technology (as shown by the characteristic curve 406), and the relative bandwidth of the low frequency radiating element 301 can be increased.

It can be seen that the impedance matching unit 314 and the inductance unit 316 can effectively adjust the bandwidth characteristics of the LTE antenna structure 300 in the low frequency band. In addition, the impedance matching unit 314 and the inductive unit 316 can effectively improve the bandwidth of the LTE antenna structure in the low frequency band in a limited antenna configuration space, so as to meet the communication requirements of the long-term evolution technology, as shown in FIG. 3, the LTE antenna. The width L1 of the structure 300 is only 53.7 millimeters (mm), thus contributing to the development of miniaturization of electronic devices using the LTE antenna structure.

In summary, the present invention changes the series inductance of the feed end by connecting an impedance matching unit between the feed end and the low frequency radiating element to effectively improve the LTE antenna structure in the low frequency band in a limited antenna configuration space. Bandwidth, which contributes to the development of miniaturization of electronic devices using LTE antenna structures. In some embodiments, the center frequency of the low frequency band can be reduced by connecting the short circuit member to the inductive unit between the low frequency radiating element and the ground, so that the low frequency portion of the low frequency band can reach a lower frequency, thereby enabling LTE. The antenna structure is more in line with the needs of communication.

100‧‧‧LTE antenna structure

101‧‧‧Low frequency radiating parts

102‧‧‧Short-circuit parts

104‧‧‧Feeding end

106‧‧‧Feed in signal

108‧‧‧High frequency radiation parts

110‧‧‧First connection section

112‧‧‧Second connection section

114‧‧‧Impedance matching unit

FP1‧‧‧Feeding point

GP1‧‧‧ grounding terminal

Claims (8)

An LTE antenna structure includes: a short-circuiting member connected to a grounding end; a feeding end; a low-frequency radiating member providing a first resonant path, wherein the low-frequency radiating member corresponds to a low-frequency band; a first connecting region a first end and a second end, the first end of the first connecting section is connected to the feeding end, the second end of the first connecting section is connected to the short-circuiting member, and a second connecting section has a first end and a second end, the first end of the second connecting section is connected to the second end of the first connecting section, and the second end of the second connecting section is connected to the low frequency radiating element, the first connection Providing the first resonant path with the second connecting section; a high frequency radiating element connecting the first end of the feeding end, the high frequency radiating element providing a second resonant path, wherein the high frequency radiating element corresponds to a second frequency band; and an impedance matching unit having a first end and a second end, the first end is connected to the low frequency radiating element, the second end is connected to the feeding end, and the impedance matching unit adjusts the feeding Inductive, and adjust the bandwidth of the low frequency band to The series inductive pin feed end; wherein the ground terminal at a second end of the shorting member, the feeding end of the short-circuit member connected to the first section to form a current loop. For example, the LTE antenna structure described in claim 1 of the patent scope further includes: An inductive unit is connected in series with the short-circuiting member between the low-frequency radiating member and a ground to increase the relative bandwidth of the low-frequency radiating member. For example, in the LTE antenna structure described in claim 1, wherein the operating bandwidth of the low frequency radiating element after the bandwidth is increased is between 700 MHz and 960 MHz. The LTE antenna structure of claim 1, wherein the length of the first resonant path is greater than the length of the second resonant path. The LTE antenna structure according to claim 1, wherein the LTE antenna structure is a planar inverted-F antenna. The LTE antenna structure according to claim 1, wherein the high frequency radiating element has an operating bandwidth of between 1710 MHz and 2170 MHz. The LTE antenna structure of claim 1, wherein the low frequency radiating element and the high frequency radiating element are disposed in parallel with each other. The LTE antenna structure of claim 1, wherein the first connection section and the second connection section exhibit an L-shape.