CN203660057U - broadband antenna - Google Patents

Abstract

A broadband antenna. The wideband antenna is for a wireless communication device, the wideband antenna comprising: a grounding assembly for providing grounding; a first radiator; the second radiator is electrically connected to the grounding component; a signal feed-in component, which is used for transmitting a radio frequency signal to the first radiator so as to transmit the radio frequency signal through the first radiator; and a passive component, including an inductance element, electrically connected between the first radiator and the second radiator or between a metal piece connected with the first radiator and the second radiator, for forming a loop antenna effect with the first radiator, the second radiator and the ground component. The utility model discloses can produce the broadband effect, still can provide low band mode resonance route, and then adjust impedance match and resonant frequency's bandwidth and displacement, make the antenna have high bandwidth, high efficiency and small-size advantage concurrently.

Description

broadband antenna

technical field

The utility model relates to a broadband antenna, in particular to a broadband antenna combined with an inductance element to increase the bandwidth of the antenna, adjust impedance matching, and effectively reduce the size of the antenna.

Background technique

Electronic products with wireless communication functions, such as notebook computers, tablet computers, personal digital assistants (Personal Digital Assistant), wireless base stations, mobile phones, smart meters (Smart Meter), USB wireless network cards (USB dongle), etc., through the antenna To transmit or receive radio waves, to pass or exchange radio signals, and to access wireless networks. With the rise of Long Term Evolution (LTE), the demand for antenna bandwidth has increased significantly to increase the transmission rate of wireless communication products. On the other hand, the appearance and size of wireless communication products are pursued to be light, thin and short, and the size of the antenna should be reduced as much as possible to meet the trend of shrinking product volume.

Broadband planar antenna architectures commonly used in the LTE frequency band are planar inverted-F antennas, coupled antennas, and the like. Among them, the planar inverted F antenna has conductive pins to assist in impedance matching, but requires a large extension space to achieve wider bandwidth and better antenna radiation performance, while the coupled antenna is usually small in size, but is easily affected by the environment , and it is not easy to carry out impedance matching.

In addition, the design of the antenna also needs to consider the safety specification SAR (Specific Absorption Rate, Specific Absorption Rate) certification, so the antenna design in mobile communication devices such as tablet computers, notebook computers, and mobile phones usually avoids the use of antennas in three-dimensional space , which increases the difficulty of antenna design. As is well known in the art, reducing the external interference (i.e. SAR value) of wireless communication devices usually affects the performance of the antenna. Therefore, at the same time, it is more important to design a good radiation performance of the antenna and to comply with the safety standard SAR certification in the safety standard test. Not easy.

Therefore, how to increase the antenna bandwidth, comply with the safety standard SAR certification, and effectively reduce the size of the antenna has become one of the goals of the industry.

Therefore, it is necessary to provide a broadband antenna to meet the above requirements.

Utility model content

The utility model mainly provides a broadband antenna, which combines a coupling antenna and an inductance element to increase the bandwidth of the antenna, adjust impedance matching, and effectively reduce the size of the antenna.

The utility model discloses a broadband antenna, which is used for a wireless communication device. The broadband antenna includes: a grounding component, which is used to provide grounding; a first radiator; a second radiator, the first Two radiators are electrically connected to the ground component; a signal feed component is used to transmit a radio frequency signal to the first radiator so as to emit the radio frequency signal through the first radiator; and a signal feed component is used to transmit a radio frequency signal to the first radiator; A passive component, the passive component includes an inductance element, the passive component is electrically connected between the first radiator and the second radiator or connects a metal piece of the first radiator to the second radiator used to form a loop antenna effect with the first radiator, the second radiator and the ground component.

The utility model utilizes high-frequency and low-frequency radiators to couple each other to reduce the low-frequency resonance frequency, and resonate multiple modes in the high-frequency band to produce a broadband effect. In addition, the utility model will include a passive component with an inductance element It is connected between the high and low frequency radiators to provide a low frequency band modal resonance path, and then adjust the impedance matching and the bandwidth and displacement of the resonance frequency, so that the antenna can have the advantages of high bandwidth, high efficiency and small size.

Description of drawings

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

FIG. 2A is a schematic diagram of current flow in the broadband antenna of FIG. 1 without an inductive element.

FIG. 2B is a schematic diagram of the current flow of the broadband antenna in FIG. 1 .

FIG. 3A is a schematic diagram of VSWR of the broadband antenna in FIG. 1 .

FIG. 3B is a schematic diagram of the radiation efficiency of the broadband antenna in FIG. 1 .

FIG. 4 is a schematic diagram of a broadband antenna according to an embodiment of the present invention.

FIG. 5A is a schematic diagram of VSWR of the broadband antenna shown in FIG. 4 .

FIG. 5B is a schematic diagram of the radiation efficiency of the broadband antenna in FIG. 4 .

FIG. 6 is a schematic diagram of a broadband antenna according to an embodiment of the present invention.

FIG. 7 is a schematic diagram of a broadband antenna according to an embodiment of the present invention.

FIG. 8 is a schematic diagram of a broadband antenna according to an embodiment of the present invention.

Description of main component symbols:

Detailed ways

Please refer to FIG. 1 , which is a schematic diagram of a broadband antenna 10 according to an embodiment of the present invention. The wideband antenna 10 can be used in a wireless communication device to send and receive wideband or multi-band wireless signals, such as signals of LTE wireless communication system (the frequency bands are generally between 704MHz-960MHz and 1710MHz-2700MHz). The broadband antenna 10 includes a signal feeding component 100 , a grounding component 102 , a first radiator 104 , a second radiator 106 and an inductance element 112 . The first radiator 104 can be connected to a metal part, and the metal part can include a third radiator 108 and a fourth radiator 110 . The grounding component 102 is used to provide grounding. One grounding end of the signal feed-in component 100 can be connected to a system grounding piece of a wireless communication device or a ground wire of a coaxial cable, and the other end is used to transmit a radio frequency signal to the first radiator 104 , to transmit radio frequency signals through the first radiator 104 , the third radiator 108 and the fourth radiator 110 . In addition, the radio frequency signal is also fed into the second radiator 106 electrically connected to the ground component 102 from the first radiator 104 in a coupling manner, and the inductance element 112 is electrically connected between the first radiator 104 and the second radiator 106 The metal parts of the first radiator 104 and the second radiator 106 are occasionally connected to form a loop antenna effect with the first radiator 104 , the second radiator 106 and the grounding component 102 . The broadband antenna 10 can be regarded as a combination of a monopole antenna and a parasitic component. The first radiator 104, the third radiator 108, and the fourth radiator 110 are high-frequency radiators, representing the part of the monopole antenna; the second radiator Body 106 is a low frequency radiator representing part of the parasitic component. The mutual coupling of high and low frequency radiators can effectively utilize the antenna space, and the coupling effect can lower the resonance frequency, and resonate multiple modes in the high frequency band, resulting in broadband effect, and combined with the inductance element 112 connected in series Between the radiators 104 , 108 , 110 and the radiator 106 , a low-frequency modal resonance path is provided, and means for adjusting matching, bandwidth, and resonance frequency shift is added to achieve a micro-sized broadband antenna with high bandwidth and high efficiency.

In detail, the lengths of the first radiator 104 , the second radiator 106 , the third radiator 108 , and the fourth radiator 110 are all approximately a quarter wavelength of the resonance frequency. The second radiator 106 is used to provide a path for low-frequency modes, mainly generating modes in the low-frequency range of 704 MHz to 960 MHz. The area of the second radiator 106 can increase the bandwidth and have some high-frequency mode resonance. Before the inductance element 112 is added, the broadband antenna 10 can still work normally, and the current flow on the first radiator 104 and the second radiator 106 is shown in FIG. 2A . It is worth noting that the current flow direction D1 on the first radiator 104 is opposite to the current flow direction D2 on the second radiator 106, and the opposite current flow direction can resonate the mode of 900-1100MHz in the low frequency band, which becomes a high frequency mode in the low frequency band. important factor in bandwidth. The first radiator 104, the third radiator 108, the fourth radiator 110 and the second radiator 106 have at least coupling intervals h1, h2, and h3 respectively. By adjusting the size of the coupling intervals h1, h2, h3 and the coupling interval The lengths of h1, h2, and h3 can adjust the matching of the two low-frequency modes to achieve optimal impedance matching. Since the first radiator 104, the third radiator 108, the fourth radiator 110 and the second radiator 106 are mutually coupled, the lengths of the second radiator 106 and the third radiator 108 can be greatly shortened, thereby reducing the size of the antenna. purpose of size.

On the other hand, the first radiator 104, the third radiator 108, and the fourth radiator 110 are used to provide paths for high-frequency modes, mainly generating modes in the high-frequency range of 1710 MHz to 2700 MHz, wherein the third radiator 108 can generate high-frequency modes. For the lower frequency (1710-2170MHz) part of the frequency band, the first radiator 104 and the fourth radiator 110 can generate the middle and high-frequency part (2170-2700MHz), and adjust the first radiator 104 and the second radiator The coupling distance h1 between 106 can produce a resonance effect, and can also contribute part of the lower frequency bandwidth, thereby adjusting the bandwidth of 1710MHz-2700MHz and the energy required by each frequency band.

In addition, the broadband antenna 10 is connected in parallel with the inductance element 112 between the low frequency radiator and the high frequency radiator to form a loop antenna effect with the first radiator 104 , the second radiator 106 and the ground component 102 . As shown in Figure 2B, within a certain range of inductance, the low-frequency current path of the antenna is lengthened, the high-frequency current is suppressed by the inductance, and does not affect the resonance characteristics of the high-frequency band, so it can be used to adjust the low-frequency matching of the antenna. When the inductance of the inductance element 112 is smaller, more high-frequency current can flow, the low-frequency loop effect is reduced, and the low-frequency bandwidth is narrower, but the matching is better and the energy is more concentrated. On the contrary, when the inductance of the inductance element 112 is larger, the high-frequency current that can flow is less, the low-frequency loop effect is increased, and the low-frequency bandwidth is wider, but the matching will be worse and the energy will be dispersed. The effect produced by the inductance element 112 can be confirmed by the measurement results of the antenna shown in FIGS. 3A to 3B . FIG. 3A is a schematic diagram of the voltage standing wave ratio (Voltage Standing WaveRatio, VSWR) of the broadband antenna 10 , and FIG. 3B is a schematic diagram of the radiation efficiency of the broadband antenna 10 . Wherein, the dotted line represents the antenna characteristic when the inductance element 112 is not added to the broadband antenna 10, the thin line represents the antenna characteristic of the broadband antenna 10 when the inductance element 112 has an inductance value of about 22nH, and the thick line represents the antenna characteristic when the inductance element 112 has an inductance value Antenna characteristics of broadband antenna 10 at about 56 nH. As shown in FIG. 3B , using an inductance element 112 (thick line) with an appropriate inductance value can make the antenna have higher bandwidth and better antenna radiation efficiency. When lower inductance values are used, the specification for higher antenna efficiency required for specific LTE bands can be enforced at low frequencies without retuning the antenna architecture.

It should be noted that in the present invention, a passive component including an inductance element is disposed between the monopole antenna and the parasitic component to increase antenna bandwidth, adjust impedance matching, and reduce antenna size. The broadband antenna 10 in FIG. 1 is an embodiment of the present invention, and those skilled in the art can make various modifications accordingly, without being limited thereto. For example, in the embodiment of FIG. 1, the metal piece connected to the first radiator 104 includes the third radiator 108 and the fourth radiator 110, but not limited thereto, the metal piece connected to the first radiator 104 also includes More radiators may be included, or only one radiator or a simple metal connection piece, as long as the electrical connection characteristics of the metal parts can make the inductance element 112 and the first radiator 104, the second radiator 106 and the grounding component 102 It is enough to form a loop antenna effect. The position of the inductance element 112 is not limited to that shown in FIG. 1, as long as it is electrically connected between the first radiator 104 and the second radiator 106 or a metal piece connected to the first radiator 104 (such as the third radiator 108, the fourth There are similar effects between the radiator 110 ) and the second radiator 106 . As shown in FIG. 4 , the inductance element may be the inductance element 112 , or the inductance element 114 , the inductance element 116 , or the inductance element 118 . Changing the position of the inductance element can change the current path of the low-frequency radiator of the broadband antenna 10, thereby changing the low-frequency resonance point. FIG. 5A is a schematic diagram of voltage standing wave ratio when inductive elements are arranged at different positions in the broadband antenna 10 , and FIG. 5B is a schematic diagram of radiation efficiency when inductive elements are arranged in different locations in the broadband antenna 10 . Wherein, the thick line represents the antenna characteristics when the broadband antenna 10 uses the inductance element 112 , the thin line represents the antenna characteristics when the broadband antenna 10 uses the inductance element 114 , and the dotted line represents the antenna characteristics when the broadband antenna 10 uses the inductance element 116 . It can be seen from FIG. 5A and FIG. 5B that the position of the inductance element can determine the frequency of the antenna. Therefore, by properly selecting the inductance value and position of the inductance element, resonance modes covering all LTE low frequency bands (704-960MHz) can be generated.

In addition, the broadband antenna of the present invention can also be used with capacitors, for example, one or more inductors and/or capacitors are connected in series between one end of the inductance element 112 and the radiator, or one or more inductors and/or capacitors are connected to the inductance element 112 in parallel to form a filter loop. In this way, the current in a specific frequency band will be conducted to form a loop antenna effect in a specific frequency band, thereby adjusting the desired frequency response. Alternatively, a variable inductance or a variable capacitor can also be used to control the change in inductance or capacitance by the system, and then switch the usable frequency band of the low frequency band to meet the antenna performance required by different specifications. As shown in FIG. 6 , the inductance element 612 of the broadband antenna 60 is an adjustable inductance element, which is coupled to a radio module controller (Sensor Hub, sensor hub) 620 in the wireless communication device. The radio module controller 620 can be used to switch an inductance value of the inductance element 612, thereby changing the resonant frequency and matching of the broadband antenna 60, so that the broadband antenna 60 can meet antenna performance required by different specifications. As shown in FIG. 7 , the broadband antenna 70 has an adjustable inductive element 712 and a passive component 714 connected in series. The passive component 714 can be an adjustable capacitive element. The adjustable inductive element 712 can be connected in series with the passive component 714 to produce a bandpass filter. Band-pass Filter (Band-pass Filter) effect makes the signal flow in a specific frequency band and forms a loop antenna effect to adjust the antenna matching. As shown in Figure 8, the broadband antenna 80 has a parallel adjustable inductive element 812 and a passive component 814, the passive component 814 may be an adjustable capacitive element, and the adjustable inductive element 812 is connected in parallel with the passive component 814 to generate a band-stop filter Band-stop Filter (Band-stop Filter) effect allows specific frequency band signals to flow, and forms a loop antenna effect to adjust antenna matching. The above-mentioned means for adjusting antenna matching can be used together to meet different communication applications.

In addition, as is well known in the industry, the radiation frequency, bandwidth, and efficiency of the antenna are related to the shape and material of the antenna. Therefore, the designer should be able to adjust the wideband antenna 10 , 60 , 70 , 80 appropriately to meet the needs of the system. It should be noted that the above-mentioned various changes of the broadband antenna of the present utility model are intended to illustrate that the utility model uses passive components such as capacitors and inductors to be arranged between the mutually coupled high-frequency and low-frequency radiators to improve the bandwidth and the bandwidth of the antenna. Matching, other things such as material, manufacturing method, shape and position of each component can be appropriately changed according to different needs, but are not limited thereto.

To sum up, the utility model utilizes high-frequency and low-frequency radiators to couple with each other to reduce the low-frequency resonance frequency and resonate multiple modes in the high-frequency band to produce a broadband effect. In addition, the utility model electrically connects a passive component including an inductance element between the high-frequency radiator and the low-frequency radiator to provide a low-frequency mode resonance path, and then adjusts impedance matching and resonance frequency bandwidth and displacement, so that the antenna can It combines the advantages of high bandwidth, high efficiency and small size.

The above descriptions are only preferred embodiments of the present utility model, and all equivalent changes and modifications made according to the scope of the claims of the present utility model shall fall within the scope of the present utility model.

Claims (10)

1. A broadband antenna, which is used for a wireless communication device, the broadband antenna comprising: a grounding assembly for providing grounding; a first radiator; a second radiator electrically connected to the ground component; and a signal feeding component, the signal feeding component is used to transmit a radio frequency signal to the first radiator, so as to transmit the radio frequency signal through the first radiator; It is characterized in that the broadband antenna further includes a passive component, the passive component includes an inductance element, and the passive component is electrically connected between the first radiator and the second radiator or connected to the first radiator Between a metal part and the second radiator, it is used to form a loop antenna effect with the first radiator, the second radiator and the grounding component. 2. The wideband antenna according to claim 1, wherein there is a first coupling distance between the first radiator and the second radiator, so that the radio frequency signal is coupled by the first radiator feed into the second radiator. 3. The broadband antenna as claimed in claim 1, wherein the direction of the current generated by the radio frequency signal on the first radiator and the second radiator is opposite. 4. The wideband antenna according to claim 1, wherein the metal piece comprises a third radiator, the third radiator is electrically connected to the first radiator, and the third radiator is connected to the first radiator There is a second coupling distance between the two radiators, so that the radio frequency signal is fed into the second radiator from the third radiator in a coupled manner. 5. The broadband antenna according to claim 4, wherein the metal part further comprises a fourth radiator, the fourth radiator is electrically connected to the third radiator, and is connected to the first radiator The direction of extension is the same. 6. The wideband antenna as claimed in claim 4, wherein the direction of the current generated by the radio frequency signal on the third radiator and the second radiator is the same. 7. The broadband antenna as claimed in claim 1, wherein the passive component further comprises one or more inductors or capacitors, and the one or more inductors or capacitors are connected in series or parallel to the inductive element. 8. The broadband antenna as claimed in claim 1, wherein the inductance element is an adjustable inductor. 9. The broadband antenna according to claim 1, wherein the inductance element is coupled to a radio module controller of the wireless communication device, and is used to switch an inductance value of the one or more inductance elements to change the A resonant frequency and matching of radio frequency signals. 10. The broadband antenna as claimed in claim 7, wherein the one or more capacitors are adjustable capacitors.

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