CN116191004A - Distributed antenna and terminal - Google Patents

Abstract

The application provides a distributed antenna, including signal source, first feed branch road, second feed branch road and antenna branch knot. The antenna branch comprises a first feeding point and a second feeding point which are arranged at intervals, the first feeding branch is connected between the signal source and the first feeding point, and the second feeding branch is connected between the signal source and the second feeding point. The antenna branch includes a first ground point located between the first and second feed points. The first tuning unit is connected in series with the first feed branch and is used for realizing frequency matching of the distributed antenna. The distributed antenna has the advantages that the distributed feed effect is formed, a plurality of modes can be excited on the same antenna branch, the radiation efficiency between the modes is continuous, and the bandwidth effect can be generated. The distributed feed multiplexing antenna branch can effectively utilize the antenna caliber and reduce the volume of the antenna. The application also relates to a terminal equipped with the distributed antenna.

Description

Distributed antenna and terminal

Technical Field

The present application relates to the field of antennas, and in particular, to a distributed antenna and a terminal.

Background

With the development of communication technology, the frequency band that the antenna of the terminal product needs to cover is gradually increased. Meanwhile, the current development trend of terminal products is concentrated in the directions of large screen occupation ratio, multiple camera modules and the like, the internal space of the terminal products is further extruded, and the clearance area required by the work of the antenna is greatly reduced.

The signal frequency band that traditional antenna structure can cover is limited, and the bandwidth is narrower, and the required antenna size of partial frequency band is great, needs a plurality of antennas collocation work, just can realize the coverage to the multiband.

Disclosure of Invention

The application provides a distributed antenna which can cover more frequency bands and has better signal quality. The application also provides a terminal comprising the distributed antenna. The application specifically comprises the following technical scheme:

in a first aspect, the present application provides a distributed antenna, including a signal source, a first feed leg, a second feed leg, and an antenna branch; the antenna branch comprises a first feeding point and a second feeding point which are arranged at intervals, the first feeding branch is connected with the first feeding point and the signal source, and the second feeding branch is connected with the second feeding point and the signal line; the antenna branch comprises a first grounding point, and the first grounding point is positioned between the first feeding point and the second feeding point; the first tuning unit is connected in series with the first feed branch and is used for realizing frequency matching of the distributed antenna.

The distributed antenna starts from the same signal source, and signals are transmitted to the same antenna branch by two paths (the first feeding branch and the second feeding branch), so that the distributed feeding effect is achieved. The distributed feed can excite multiple modes on the same antenna branch, and the radiation efficiency between the modes is continuous, so that the bandwidth effect can be generated. The distributed feed multiplexing antenna branch can effectively utilize the antenna caliber and reduce the volume of the antenna.

The first tuning unit can adjust resonance points corresponding to all modes by utilizing the characteristics of frequency selection characteristics, matching characteristics and the like, so that the distributed antenna covers a plurality of preset frequency bands in the working process.

In one possible implementation, the first tuning unit is a capacitor, or the first tuning unit is a first series circuit formed by a capacitor and an inductor, or the first tuning unit is a first parallel circuit formed by a capacitor and an inductor.

In the implementation manner, the effect of adjusting the resonance point of the distributed antenna can be achieved by utilizing the frequency selection characteristic and the matching characteristic of a series circuit or a parallel circuit formed by the capacitor, the capacitor and the inductor, and the distributed antenna can be covered to a plurality of preset frequency bands.

In one possible implementation, the first tuning unit is set to a capacitance, and the capacitance value is 0.75pf.

In one possible implementation, a second tuning unit is connected in series with the second feed branch, and the second tuning unit is configured to cooperate with the first tuning unit to implement frequency matching of the distributed antenna.

In the implementation mode, the second tuning unit is matched with the first tuning unit, so that frequency matching of the distributed antenna can be better realized, and the size of an antenna branch is shortened through matching adjustment of the electric length.

In one possible implementation, the second tuning unit is a capacitor, or the second tuning unit is a second series circuit formed by a capacitor and an inductor, or the second tuning unit is a second parallel circuit formed by a capacitor and an inductor.

In one possible implementation, when the first tuning unit is a capacitor, the second tuning unit is correspondingly set to be a capacitor, and the capacitance value is greater than or equal to 3.3pf.

In one possible implementation, when the first tuning unit is a capacitor, the second tuning unit is correspondingly set to be an inductor, and the inductance value is less than or equal to 33nH.

In one possible implementation manner, a first matching unit is further connected in parallel to the first feeding branch, and the first matching unit is a capacitor and/or an inductor and is used for realizing electrical length matching of the distributed antenna.

In one possible implementation, the first matching unit may be a capacitor or an inductor, or may be a series or a combination of a capacitor and an inductor.

In the implementation manner, the first matching unit is connected in parallel to the first feed branch, so that the electric length of the distributed antenna in a partial mode can be adjusted, and the effect of frequency matching adjustment is achieved.

In one possible implementation, the first matching unit is located between the signal source and the first tuning unit, or the first matching unit is located between the first feed point and the first tuning unit.

In one possible implementation, the number of first matching units is two, wherein one first matching unit is located between the signal source and the first tuning unit and the other first matching unit is located between the first feeding point and the first tuning unit.

In the implementation manner, the positions of the first matching unit and the first tuning unit can be correspondingly adjusted to the electric lengths of the distributed antenna in different modes, so that the effect of frequency matching is achieved.

In one possible implementation manner, a second matching unit is further connected in parallel to the second feeding branch, and the second matching unit is a capacitor and/or an inductor and is used for realizing electrical length matching of the distributed antenna.

In one possible implementation, the second matching unit may be a capacitor or an inductor, or may be a series or a combination of a capacitor and an inductor.

In the implementation mode, the second matching unit is connected in parallel to the second feed branch, so that the electric length of the distributed antenna in a partial mode can be adjusted, and the effect of frequency matching adjustment is achieved.

In one possible implementation, the second matching unit is located between the signal source and the second tuning unit, or the second matching unit is located between the second feeding point and the second tuning unit.

In one possible implementation, the number of second matching units is two, wherein one second matching unit is located between the signal source and the second tuning unit and the other second matching unit is located between the second feeding point and the second tuning unit.

In the implementation manner, the positions of the second matching unit and the second tuning unit can be correspondingly adjusted to the electric lengths of the distributed antenna in different modes, so that the effect of frequency matching is achieved.

In one possible implementation, the first tuning unit is set to a capacitance, and the capacitance value is 1pf; the number of the first matching units is two, the two first matching units are respectively arranged at two sides of the first tuning unit, the first matching unit between the first tuning unit and the signal source is set to be 5.6nH of inductance, and the other first matching unit is set to be 0.7pf of capacitance; the second matching unit is set to a capacitance of 0.75 pf.

In one possible implementation, the first and second feeding points are arranged in parallel, and the second feeding point is arranged in parallel to the first feeding point.

In this implementation, the parasitic branches are introduced, so that a parasitic mode can be added in the distributed antenna, and the coverage frequency range is increased.

In one possible implementation, the length of the parasitic stub is 1/4 of the corresponding wavelength of the N41 band.

In one possible implementation, the antenna further includes a first slot and a second ground point, the first slot is located on a side of the first feeding point away from the second feeding point, and the second ground point is located on a side of the first slot away from the second feeding point.

In the implementation mode, a first gap is formed at one side of the first feeding point far away from the second feeding point, so that the antenna branch is broken into two sections, one section forms distributed feeding with the first feeding point and the second feeding point respectively, the other section forms signal radiation through coupling, the excited mode of the distributed antenna is changed, and the effect of multi-frequency-band coverage can be achieved.

In one possible implementation, the signal source, the first feed leg and the second feed leg are all disposed on a printed circuit board.

In this implementation mode, signal source, first feed branch road and second feed branch road all set up on printed circuit board, and its relative position and electrical property are all relatively stable, are favorable to guaranteeing the uniformity of antenna.

In one possible implementation, the signal source, the first feeding leg and the second feeding leg may also be disposed on a liquid crystalline polymer (Liquid Crystal Polymer, LCP).

In one possible implementation, the frequency bands covered by the distributed antenna include MHB, NR, LB, wifi 6E, 5G, UWB, or millimeter wave frequency bands.

In a second aspect, the present application provides a terminal, including a housing, and the distributed antenna provided in the first aspect of the present application, wherein an antenna branch of the distributed antenna is located on the housing, and a signal source, a first feeding branch and a second feeding branch of the distributed antenna are accommodated inside the housing.

In one possible implementation, the terminal includes a metal frame and a middle frame, and the frame and the middle frame are relatively fixed in position. The antenna branch is arranged at the frame position, and the first grounding point of the antenna branch is conducted to the middle frame.

Drawings

Fig. 1 is an external schematic view of a terminal according to an embodiment of the present application;

Fig. 2 is a schematic plan view of a terminal according to an embodiment of the present application;

fig. 3 is a schematic structural diagram of a distributed antenna according to an embodiment of the present application;

fig. 4a is a schematic structural diagram of a parallel circuit formed by a capacitor and an inductor in a distributed antenna according to an embodiment of the present application;

fig. 4b is a schematic structural diagram of a series circuit formed by a capacitor and an inductor in a distributed antenna according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of a feeding network of a distributed antenna according to an embodiment of the present application;

fig. 6 is a schematic diagram of a matching combination of a feed network of a distributed antenna according to an embodiment of the present application;

fig. 7a is a schematic diagram of a first current radiation mode of a distributed antenna according to an embodiment of the present application;

fig. 7b is a schematic diagram of a second current radiation mode of a distributed antenna according to an embodiment of the present application;

fig. 7c is a schematic diagram of a third current radiation mode of a distributed antenna according to an embodiment of the present application;

fig. 7d is a schematic diagram of a fourth current radiation mode of a distributed antenna according to an embodiment of the present application;

fig. 7e is a schematic diagram of a fifth current radiation mode of the distributed antenna according to an embodiment of the present application;

Fig. 8 is a schematic diagram of antenna efficiency of a distributed antenna according to an embodiment of the present application;

fig. 9 is a schematic diagram of antenna efficiency of another distributed antenna according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of a side frame antenna provided in the prior art;

FIG. 11a is a schematic diagram of a first current radiation pattern of a side frame antenna according to the prior art;

FIG. 11b is a schematic diagram of a second current radiation pattern of a side frame antenna according to the prior art;

FIG. 11c is a schematic diagram of a third current radiation pattern of a side frame antenna according to the prior art;

fig. 12 is a schematic diagram of antenna efficiency of a side frame antenna according to the prior art;

fig. 13 is a schematic diagram of the antenna efficiency of another side frame antenna provided by the prior art;

fig. 14 is a schematic structural diagram of another distributed antenna according to an embodiment of the present application;

fig. 15a is a schematic view of a first current radiation pattern of another distributed antenna according to an embodiment of the present application;

fig. 15b is a schematic diagram of a second current radiation pattern of another distributed antenna according to an embodiment of the present application;

fig. 15c is a schematic diagram of a third current radiation pattern of another distributed antenna according to an embodiment of the present application;

Fig. 15d is a schematic diagram of a fourth current radiation pattern of another distributed antenna according to an embodiment of the present application;

fig. 15e is a schematic diagram of a fifth current radiation pattern of another distributed antenna according to an embodiment of the present application;

fig. 15f is a schematic diagram of a sixth current radiation pattern of another distributed antenna according to an embodiment of the present application;

fig. 16 is a schematic diagram of antenna efficiency of another distributed antenna according to an embodiment of the present application;

fig. 17 is a schematic structural diagram of still another distributed antenna according to an embodiment of the present application;

fig. 18 is a schematic diagram of a matching combination of a feed network of another distributed antenna according to an embodiment of the present application;

fig. 19a is a schematic view of a first current radiation pattern of another distributed antenna according to an embodiment of the present application;

fig. 19b is a schematic view of a second current radiation pattern of another distributed antenna according to an embodiment of the present application;

fig. 19c is a schematic view of a third current radiation pattern of a further distributed antenna according to an embodiment of the present application;

fig. 19d is a schematic view of a fourth current radiation pattern of another distributed antenna according to an embodiment of the present application;

fig. 19e is a schematic view of a fifth current radiation pattern of another distributed antenna according to an embodiment of the present application;

Fig. 20 is a schematic diagram of antenna efficiency of yet another distributed antenna according to an embodiment of the present application.

Detailed Description

The following embodiments of the present application are described below with reference to the drawings in the embodiments of the present application.

Fig. 1 illustrates an external structure of a terminal 200 according to an embodiment of the present application. Fig. 2 illustrates a planar structure of a terminal 200 provided in an embodiment of the present application.

The terminal 200 provided in the embodiment of the present application includes a housing 210, where the housing 210 has a frame 211, and the frame 211 surrounds an outer edge of the housing 210 and can be used to form a sidewall of the housing 210. The frame 211 is provided with a plurality of gaps, and the plurality of gaps divide the frame 211 into mutually insulated multi-section structures, wherein at least one frame section 211a has conductivity (such as metal) and is used for forming a radiator of the distributed antenna 100. In the illustrations of fig. 1 and 2, the housing 210 is generally rectangular in shape, with the rim section 211a as a radiator being located on the long side of the rim 211. In other embodiments, the rim section 211a as a radiator may also be located on a short side of the rim 211.

The terminal 200 provided in the embodiment of the present application may include, but is not limited to, mobile or fixed terminals with communication functions, such as a mobile phone, a tablet computer, a notebook computer, an Ultra-Mobile Personal Computer (UMPC), a handheld computer, an interphone, a netbook, a POS machine, a personal digital assistant (Personal Digital Assistant, PDA), a vehicle recorder, a security device, and the like. Wherein the distributed antenna 100 is used to implement the function of transceiving its wireless signals. The frequency Band of the distributed antenna 100 may cover a Middle High Band (MHB), a Low Band (LB), a Wi-Fi6E Band, a 5G Band, an Ultra Wide Band (UWB), or a millimeter wave Band, etc., for implementing a wireless communication function of the terminal 200 on the corresponding frequency Band. The distributed antenna 100 includes a feed network in addition to the radiators described above. The feed network is used for feeding signals to the radiator to emit outwards or is used for receiving wireless signals received by the radiator.

For convenience of description, the terminal 200 is illustrated by taking a mobile phone as an example in this embodiment.

With continued reference to fig. 2, in the terminal 200 provided in the embodiment of the present application, the housing 210 further accommodates a middle frame 220 and a circuit board 230. The middle frame 220 is fixedly connected with the frame 211, and is used for supporting components inside the terminal 200. In some embodiments, the middle frame 220 may also be constructed as a unitary structure with the rim 211. The circuit board 230 is fixed to the middle frame 220 and serves to carry the internal components of the terminal 200 to implement various functions of the terminal 200. In the present embodiment, the feeding network of the distributed antenna 100 is disposed on the circuit board 230.

Please refer to fig. 3 in conjunction with a block diagram of one embodiment of a distributed antenna 100 of the present application.

The distributed antenna 100 of the present application includes a signal source 30, a first feed leg 10, a second feed leg 20, and an antenna stub 40. The signal source 30, the first feeding branch 10, and the second feeding branch 20 are configured as the feeding network of the distributed antenna 100, and the signal source 30, the first feeding branch 10, and the second feeding branch 20 are disposed on the circuit board 230. The circuit board 230 may take the form of a printed circuit board (printed circuit board, PCB), a flexible circuit board (Flexible Printed Circuit, FPC), or a liquid crystal polymer (Liquid Crystal Polymer, LCP).

The antenna branch 40 is implemented as a radiator of the distributed antenna 100 using a conductive (metal) frame section 211 a. In other embodiments, the antenna branches 40 of the distributed antenna 100 may also be implemented in the form of a planar antenna, a body antenna, a two-dimensional antenna, or a three-dimensional antenna.

In the distributed antenna 100 provided in the embodiment of the present application, the antenna branch 40 includes a first feeding point 11 and a second feeding point 21 that are disposed at intervals, the first feeding branch 10 is connected between the first feeding point 11 and the signal source 30, and the second feeding branch 20 is connected between the second feeding point 21 and the signal source 30. That is, the first feeding branch 10 is connected between the signal source 30 and the antenna branch 40, and a connection point between the first feeding branch 10 and the antenna branch 40 forms the first feeding point 11; the second feed leg 20 is also connected between the signal source 30 and the antenna branch 40, the connection point between the second feed leg 20 and the antenna branch 40 forming the second feed point 21. The first feeding point 11 and the second feeding point 21 are disposed at intervals along the length direction of the antenna branch 40 (in the present embodiment, the length direction of the antenna branch 40 is defined as the first direction 001).

The antenna stub 40 includes opposite first and second ends 41, 42 along its length (first direction 001), and includes a first ground point 43. The first end 41 is located at a side of the first feeding point 11 remote from the second feeding point 21, and the second end 42 is located at a side of the second feeding point 21 remote from the first feeding point 11. The first ground point 43 is located between the first end 41 and the second end 42 in the first direction 001, and further located between the first feeding point 11 and the second feeding point 21. The first end 41 and the second end 42 of the antenna branch 40 are open ends, and the first grounding point 43 is used for realizing the grounding function of the antenna branch 40.

In one embodiment, the first ground point 43 is connected to the middle frame 220, where the middle frame 220 is electrically conductive and may be used as the overall ground for the terminal 200. In other embodiments, the first ground point 43 may also be electrically connected to other devices or structures within the terminal 200 to perform the grounding function of the antenna stub 40.

The signal source 30 is electrically connected to the first feeding branch 10 and the second feeding branch 20, respectively, and a signal inputted from the signal source 30 may be fed into the antenna branch 40 through the first feeding point 11 of the first feeding branch 10 and the second feeding point 21 of the second feeding branch 20, respectively. The ground loop formed by the first ground point 43 is then mated to form a composite distributed feed antenna structure. By utilizing the antenna structure, various radiation modes can be formed, so that the distributed antenna 100 can cover a plurality of different frequency bands, various radiation modes multiplex the antenna branches 40, the antenna caliber is effectively utilized, and the volume of the antenna is reduced.

Further, the first feeding branch 10 is further provided with a first tuning unit 12, and the first tuning unit 12 is connected in series with the first feeding branch 10 and is located between the first feeding point 11 and the signal source 30. The first tuning unit 12 may be used to achieve frequency matching of the distributed antenna 100. The first tuning unit 12 may take the form of a capacitor. Alternatively, the first tuning unit 12 may also take the form of a first parallel circuit formed by a capacitor and an inductor (as shown in fig. 4 a), a first series circuit formed by a capacitor and an inductor (as shown in fig. 4 b), or the like. Thus, the first tuning unit 12 may have a frequency selecting characteristic and a matching characteristic, and in a plurality of radiation modes formed by the distributed antenna 100, the resonance points of the distributed antenna 100 in the mode are respectively adjusted by different characteristics, so that the resonance points of the distributed antenna 100 are within expected preset frequency bands, and the effect that different resonance points of the distributed antenna 100 are respectively located in different preset frequency bands is formed. It should be noted that in the schematic diagrams of fig. 4a and 4b, C represents capacitance and L represents inductance. The number of capacitances and inductances in the series or parallel branches is shown as one, and in some embodiments, multiple capacitances and/or inductances may be connected in series or parallel to form the parallel or series circuit described above. The remarks herein apply equally to the definitions of parallel and series circuits that follow in this specification.

Based on the above-described configuration, the distributed antenna 100 of the present application may form a plurality of different current radiation modes during operation. The resonant points formed by each current radiating mode are different, and the distributed antenna 100 can cover a plurality of different radiating frequency bands. Among other things, the characteristics of the distributed antenna 100 for achieving frequency matching by the first tuning unit 12 are different in different current radiation modes. For example, in a current radiation mode of the distributed antenna 100, when the signal input from the signal source 30 through the first feeding branch 10 toward the first feeding point 11 passes through the first tuning unit 12, a frequency selection phenomenon that a part of the signal (such as a low-frequency signal) is blocked and another part of the signal (such as a high-frequency signal) can pass through is formed under the frequency selection characteristic of the first tuning unit 12, so that the signal fed into the antenna branch 40 from the first feeding point 11 only includes the signal (high-frequency signal) passing through the first tuning unit 12, that is, the first tuning unit 12 plays a filtering role when corresponding to the current radiation mode of the distributed antenna 100, and then the radiation frequency of the distributed antenna 100 in the current radiation mode, that is, the resonance point of the distributed antenna 100 corresponding to the current radiation mode can be adjusted.

In another current radiation mode of the distributed antenna 100, when the signal input from the signal source 30 through the first feeding branch 10 toward the first feeding point 11 passes through the first tuning unit 12, the electrical length of the first feeding branch 10 is changed under the matching characteristic of the first tuning unit 12, so as to adjust the radiation frequency of the distributed antenna 100 in the current radiation mode, so that the radiation frequency of the distributed antenna 100 is matched with a preset frequency band, that is, the radiation frequency is adjusted to the resonance point of the distributed antenna 100 corresponding to the current radiation mode. Generally, when the matching characteristic of the first tuning unit 12 is utilized, the first tuning unit 12 is used to increase the electrical length of the first feeding branch 10, thereby achieving the effect of reducing the total length of the antenna branch 40 and reducing the antenna caliber.

It should be noted that, in the embodiment of the distributed antenna 100 of the present application, the first feeding branch 10 and the second feeding branch 20 are merely relative concepts, that is, the distributed antenna 100 provided in the embodiment of the present application does not strictly define the position of the first feeding branch 10 or the second feeding branch 20. In the embodiment shown in fig. 3, the first feeding branch 10 is a relatively lower one, and the corresponding first tuning unit 12 is also connected in series within the first feeding branch 10. In other embodiments, the first tuning element 12 may be connected in series to a relatively upper feed branch, where the relatively upper feed branch is formed as the first feed branch 10 and the relatively lower feed branch is formed as the second feed branch 20.

Please refer to the schematic diagram of the feeding network in an embodiment illustrated in fig. 5.

In the illustration of fig. 5, a second tuning unit 22 may be arranged on the second feeding leg 20, the second tuning unit 22 being likewise connected in series to the second feeding leg 20 and being located between the second feeding point 21 and the signal source 30. The second tuning unit 22 may take the form of a capacitor or an inductor. Alternatively, the second tuning unit 22 may also take the form of a second parallel circuit or a second series circuit formed by a capacitor and an inductor, so that the second tuning unit 22 also has a frequency selecting characteristic and a matching characteristic. The second tuning unit 22 can cooperate with the first tuning unit 12 to achieve frequency matching of the distributed antenna 100.

In the present embodiment, the cooperation of the second tuning unit 22 with the first tuning unit 12 may utilize the frequency selection characteristics to the second tuning unit 22 and the first tuning unit 12, or the matching characteristics to the second tuning unit 22 and the first tuning unit 12. For example, in a current radiation mode of the distributed antenna 100, the frequency selection characteristic of the first tuning unit 12 may be used to control the signal fed to the antenna branch 40 at the first feeding point 11 to be a low-frequency signal, and the frequency selection characteristic of the second tuning unit 22 may be used to control the signal fed to the antenna branch 40 at the second feeding point 21 to be a high-frequency signal, where the two signals are fed into the antenna branch 40 from different positions, so as to form a resonance point within a preset frequency range, thereby meeting the working requirement of the distributed antenna 100.

In another current radiation mode of the distributed antenna 100, the matching characteristics of the first tuning unit 12 and the second tuning unit 22 can be utilized to respectively adjust the electrical lengths of the first feeding branch 10 or the second feeding branch 20, so that the antenna branch 40 forms a resonance point within a preset frequency range, and the working requirement of the distributed antenna 100 is met.

With continued reference to fig. 5, in one embodiment, a first matching unit (shown as 13a and 13b in fig. 5) may also be provided on the first feed leg 10. The first matching unit may be a capacitor or an inductor. Alternatively, the first matching unit may be a first parallel circuit formed by a capacitor and an inductor, or a first series circuit formed by a capacitor and an inductor. The first matching unit is connected in parallel to the first feeding branch 10 and is used for matching the electrical length of the first feeding branch 10.

The number of the first matching units may be one or two or more. In the illustration of fig. 5, the number of first matching units is two, wherein one first matching unit 13a is connected in parallel between the signal source 30 and the first tuning unit 12, and the other first matching unit 13b is connected in parallel between the first tuning unit 12 and the first feeding point 11. In other embodiments, the first matching unit may also include any of those shown in fig. 5 alone. Alternatively, in some embodiments, the number of the first matching units may be plural, that is, the number of the first matching units 13a between the signal source 30 and the first tuning unit 12 may be two or more, and the number of the first matching units 13b between the first tuning unit 12 and the first feeding point 11 may be two or more.

In one embodiment, a second matching unit (denoted 23a and 23b in fig. 5) may also be provided on the second feed leg 20. The second matching unit may be a capacitor or an inductor. Alternatively, the second matching unit may be a second parallel circuit formed by a capacitor and an inductor, or a second series circuit formed by a capacitor and an inductor. The second matching unit is connected in parallel to the second feeding branch 20 and is used for matching the electrical length of the second feeding branch 20.

The number of the second matching units may be one or two or more. In the illustration of fig. 5, the number of second matching units is two, wherein one second matching unit 23a is connected in parallel between the signal source 30 and the second tuning unit 22, and the other second matching unit 23b is connected in parallel between the second tuning unit 22 and the second feeding point 21. In other embodiments, the second matching unit may also include any of those shown in fig. 5 alone. Alternatively, in some embodiments, the number of the second matching units may be plural, that is, the number of the second matching units 23a between the signal source 30 and the second tuning unit 22 may be two or more, and the number of the second matching units 23b between the second tuning unit 22 and the second feeding point 21 may be two or more.

The embodiments of the second tuning unit 22, the first matching unit, and the second matching unit described above may all be matched with the first tuning unit 12 on the first feeding branch 10 to tune the feeding network of the distributed antenna 100 and form a preset frequency match in cooperation with the antenna branch 40.

Referring to fig. 6, fig. 6 provides a matched combination of the feed network of the distributed antenna 100. In the embodiment of fig. 6, the first tuning unit 12 is set to a capacitance, and the capacitance value is 1pf. The number of the first matching units is two, the two first matching units are respectively arranged on two sides of the first tuning unit 12, wherein the first matching unit 13a between the first tuning unit 12 and the signal source 30 is set as an inductor, and the inductance value is 5.6nH; the other first matching unit 13b is set as a capacitor, and the capacitance value is 0.7pf; in this embodiment, the second tuning unit 22 may not be provided, and a path may be formed between the signal source 30 and the second feeding point 21. That is, the second tuning unit 22 is set to a resistance of 0Ω; the number of the second matching units is one, the second matching unit is set as a capacitor, and the capacitance value is 0.75pf.

Since the second tuning unit 22 is not provided, the position of the one second matching unit may be regarded as the position of the second matching unit 23a as described in fig. 5, and also as the position of the second matching unit 23b, which is defined as the second matching unit 23b for convenience of description. And at the position of the second matching unit 23a, it can be equivalently regarded as an Open circuit (Open) state, that is, there is an infinite inductance or an infinitesimal capacitance connected in parallel.

In this matching combination form, the distributed antenna 100 of the present application forms five current radiation modes, and correspondingly obtains five different resonance points for respectively covering five different frequency bands. Referring to fig. 7a, a first current radiation mode is shown, in which the distributed antenna 100 operates as a 1/4 wavelength antenna, wherein a signal input from the signal source 30 is fed into the antenna branch 40 via the second feeding point 21, and flows from the second feeding point 21 toward the first end 41 of the antenna branch 40 (as indicated by the dashed arrow in fig. 7a, the following is the same). At this time, the current path length from the second feeding point 21 to the first end 41 is formed to be 1/4 of the frequency band wavelength corresponding to the current radiation mode; in the second current radiation mode shown in fig. 7b, the distributed antenna 100 also operates as a 1/4 wavelength antenna. The signal input by the signal source 30 is fed into the antenna branch 40 through the first feeding point 11, and flows from the first feeding point 11 towards the first end 41 of the antenna branch 40, and the current path length from the first feeding point 11 to the first end 41 is formed to be 1/4 of the frequency band wavelength corresponding to the current radiation mode; in a third antenna radiation pattern shown in fig. 7c, the distributed antenna 100 operates as a 1/2 wavelength antenna. Current flows from the second end 42 of the antenna branch 40 to the first end 41, i.e. the current path is the whole arm path of the antenna branch 40. At this time, the total length of the antenna branch 40 is 1/2 of the wavelength of the frequency band corresponding to the current radiation mode; in a fourth antenna radiation pattern shown in fig. 7d, the distributed antenna 100 operates as a 1/4 wavelength antenna. The signal input by the signal source 30 is fed into the antenna branch 40 through the second feeding point 21, and flows from the second feeding point 21 toward the second end 42 of the antenna branch 40, and at this time, the current path length (i.e., the short-arm path) from the second feeding point 21 to the second end 42 is formed to be 1/4 of the frequency band wavelength corresponding to the current radiation mode; in a fifth antenna radiation pattern shown in fig. 7e, the distributed antenna 100 operates as a 3/4 wavelength antenna. The signal input by the signal source 30 is fed into the antenna branch 40 through the first feeding point 11, and flows from the first feeding point 11 toward the first end 41 and the first grounding point 43 of the antenna branch 40, respectively, where the current path length from the first grounding point 43 to the first end 41 is formed to be 3/4 of the frequency band wavelength corresponding to the current radiation mode.

Based on the above-mentioned five current radiation modes of the distributed antenna 100, after adjusting the total length of the antenna branch 40 and correspondingly adjusting the positions of the first feeding point 11 and the second feeding point 21 on the antenna branch 40, the positions of five different resonance points of the distributed antenna 100 in the embodiment of the present application can be controlled by matching with the frequency matching of the feeding network. Fig. 8 illustrates an S11 (return loss characteristic) efficiency map of the distributed antenna 100 in the present embodiment. Through the matching adjustment, the frequency points of the first antenna radiation mode to the fifth antenna radiation mode are respectively at 1.787GHz, 2.2GHz, 3.36GHz, 4.0GHz and 4.97 GHz. The distributed antenna 100 may cover 1.7GHz-2.2GHz,3.3GHz-5.1GHz, and five different resonance points cover five frequency bands of N3, N1, N77, N78, and N79, respectively.

The length of the antenna branch 40 is adjusted to adjust the frequency range of the distributed antenna 100. As shown in one embodiment provided in fig. 9, after adjusting the length of the antenna stub 40, the distributed antenna 100 may cover 1.9GHz-2.7GHz,3.3GHz-5.1GHz, and five different resonance points cover five frequency bands, N1, N41, N77, N78, and N79, respectively.

Fig. 10 illustrates a structure of a side frame antenna in the prior art. In the embodiment provided in fig. 10, the side frame antenna comprises a radiating section 1, a feed point 2, a ground point 3 and a parasitic section 4. Wherein the radiating section 1 and the parasitic section 4 are also formed by the frame structure of the terminal device. The feeding point 2 is located at the end point of the radiating section 1 close to the parasitic section 4, and the grounding point 3 is located at the end of the radiating section 1 away from the parasitic section 4. During operation of the prior art side frame antenna, it may form 3 resonance points in total, and correspond to the left-hand mode of the radiating section 1 (fig. 11 a), the parasitic mode of the parasitic section 4 (fig. 11 b), and the loop (loop) mode of the radiating section 1 (fig. 11 c), respectively. Fig. 12 illustrates an S11 efficiency diagram of a prior art side frame antenna, with three modes for covering three bands, N41, N78, and N79, respectively. By adjusting the lengths of the radiating section 1 and the parasitic section 4, in the efficiency diagram illustrated in fig. 13, three modes thereof are used to cover three frequency bands of N3, N41, and N78, respectively.

As can be seen from the schematic diagrams of fig. 12 and 13, in the scheme of the side frame antenna in the prior art, the overall bandwidth formed by the current radiation modes corresponding to the antenna is narrower, and the efficiency curve of the antenna has a pit (the 4 th point in fig. 13, where the antenna efficiency has been detected to be-12 dB), that is, the efficiency of the side frame antenna in the prior art is lower. In the illustration in fig. 13, the efficiency of the antenna in the third current radiation mode is lower than that of the first two current radiation modes, which is significantly lower than 3GHz, and the normal operation of the side frame antenna in the prior art in the frequency band cannot be satisfied. Further, in the prior art side frame antenna, the feeding point 2 is usually fixed by a screw, so as to form a coupling feeding mode. The tightness of the screw in the scene can greatly influence the coupling capacitance, so that the consistency of the side frame antenna in the prior art is poor.

The number of frequency bands of the distributed antenna 100 is 5, and is more than that of the prior art side frame antenna. In the antenna efficiency diagrams shown in fig. 8 and 9, the overall bandwidth covered by the antenna is wider (from N3 to N79 or from N1 to N79), the efficiency curve of the antenna has no pits, the peak efficiency reaches-1.7 dB, and the antenna efficiency of each frequency band can be ensured. Further, in the embodiment of the present application, the feeding network is further disposed on the circuit board 230, and the position accuracy and the connection reliability between the feeding network and the frame 211 are ensured by using the relative fixed relationship between the positions of the circuit board 230 and the frame 211, so that the consistency of the distributed antenna 100 is improved.

On the other hand, in the side frame antenna structure shown in fig. 10, the total length of the radiating section 1 and the parasitic section 4 reaches 36.5mm, but the length of the distributed antenna 100 provided in the embodiment of the present application can be controlled to be within 26mm, so that the utilization rate of the antenna caliber is improved by multiplexing the antenna branches 40, and meanwhile, the volume of the distributed antenna 100 is reduced.

Referring to fig. 14, in one embodiment, the distributed antenna 100 may further include a parasitic stub 50. The parasitic stub 50 is located in the extending direction from the second feeding point 21 to the first feeding point 11, i.e. the parasitic stub 50 is located on the side of the first end 41 of the antenna stub 40 along the first direction 001. The parasitic branch 50 is disposed at an interval with the first end 41, the antenna branch 40 is fed toward the parasitic branch 50 through coupling, and forms a resonance point of a parasitic mode through the parasitic branch 50.

The parasitic branch 50 further includes a parasitic grounding point 51, where the parasitic grounding point 51 is disposed on a side of the parasitic branch 50 away from the antenna branch 40, and the length of the parasitic branch 50 may be set corresponding to 1/4 of the wavelength corresponding to the preset frequency band to be covered, so that the distributed antenna 100 provided in this embodiment may work as a 1/4 wavelength antenna in the parasitic mode and correspondingly cover the preset frequency band.

Please refer to the current radiation pattern illustrations shown in fig. 15a to 15f in sequence. In the structure shown in fig. 14, the distributed antenna 100 provided in this embodiment of the present application forms six current radiation modes, and correspondingly obtains six different resonance points, so as to cover six different frequency bands respectively. Referring to the first current radiation mode shown in fig. 15a, the distributed antenna 100 operates as a 1/4 wavelength antenna, wherein a signal input from the signal source 30 is fed into the antenna branch 40 via the second feeding point 21, and flows from the second feeding point 21 toward the first end 41 of the antenna branch 40. At this time, the current path length from the second feeding point 21 to the first end 41 is formed to be 1/4 of the frequency band wavelength corresponding to the current radiation mode; in the second current radiation mode shown in fig. 15b, the distributed antenna 100 also operates as a 1/4 wavelength antenna. The signal input by the signal source 30 is fed into the antenna branch 40 through the first feeding point 11, and flows from the first feeding point 11 towards the first end 41 of the antenna branch 40, and the current path length from the first feeding point 11 to the first end 41 is formed to be 1/4 of the frequency band wavelength corresponding to the current radiation mode; in a third antenna radiation mode, shown in fig. 15c, the distributed antenna 100 operates as a 1/4 wavelength antenna in a parasitic mode. Current is coupled from the antenna branch 40 to the parasitic branch 50. At this time, the total length of the parasitic branch 50 is formed to be 1/4 of the wavelength of the frequency band corresponding to the current radiation mode; in a fourth antenna radiation pattern shown in fig. 15d, the distributed antenna 100 operates as a 1/2 wavelength antenna. Current flows from the second end 42 of the antenna branch 40 to the first end 41, i.e. the current path is the whole arm path of the antenna branch 40. At this time, the total length of the antenna branch 40 is 1/2 of the wavelength of the frequency band corresponding to the current radiation mode; in a fifth antenna radiation pattern shown in fig. 15e, the distributed antenna 100 operates as a 1/4 wavelength antenna. The signal input by the signal source 30 is fed into the antenna branch 40 through the second feeding point 21, and flows from the second feeding point 21 toward the second end 42 of the antenna branch 40, and at this time, the current path length (i.e., the short-arm path) from the second feeding point 21 to the second end 42 is formed to be 1/4 of the frequency band wavelength corresponding to the current radiation mode; in a sixth antenna radiation pattern shown in fig. 15f, the distributed antenna 100 operates as a 3/4 wavelength antenna. The signal input by the signal source 30 is fed into the antenna branch 40 through the first feeding point 11, and flows from the first feeding point 11 toward the first end 41 and the first grounding point 43 of the antenna branch 40, respectively, where the current path length from the first grounding point 43 to the first end 41 is formed to be 3/4 of the frequency band wavelength corresponding to the current radiation mode.

It can be seen that the first, second, fourth, fifth and sixth antenna radiation patterns are the same as the fifth antenna radiation patterns in fig. 9. The difference is that the third antenna radiation pattern is a parasitic pattern formed by the parasitic branch 50 introduced. Based on the six current radiation modes of the distributed antenna 100, after adjusting the total length of the antenna branch 40 and correspondingly adjusting the positions of the first feeding point 11 and the second feeding point 21 on the antenna branch 40, the positions of six different resonance points of the distributed antenna 100 in the embodiment of the present application can be controlled by matching with the frequency matching of the feeding network. Fig. 16 illustrates an antenna efficiency diagram of the distributed antenna 100 in the present embodiment. Through the matching adjustment, the frequency points of the first antenna radiation mode to the sixth antenna radiation mode are respectively at 1.62GHz, 1.92GHz, 2.47GHz, 3.49GHz, 4.2GHz and 4.95 GHz. Six different resonance points formed by the distributed antenna 100 cover six frequency bands of N3, N1, N41, N77, N78, and N79, respectively. The length of the parasitic branch 50 is 1/4 of the wavelength corresponding to the N41 frequency band, so as to cover the signal of the N41 frequency band.

The distributed antenna 100 of the present application also provides an embodiment as shown in fig. 17. In the present embodiment, the antenna stub 40 includes a first slot 44 and a second ground point 45. The first slot 44 is located at a side of the first feeding point 11 away from the second feeding point 21, and the second grounding point 45 is disposed at the first end 41. That is, the first slot 44 separates the antenna branch 40 into two sections insulated from each other along the first direction 001, the second end 42, the second feeding point 21, the first grounding point 43 and the first feeding point 11 are located on one section (shown as a first section 40a in fig. 17), and the first end 41 and the second grounding point 45 are located on the other section (shown as a second section 40b in fig. 17). Since the signals of the first feeding point 11 and the second feeding point 21 can only be fed onto the first section 40a, the second section 40b needs to be fed by coupling through the first section 40a to achieve the radiating effect.

Please refer to the network matching combination of the corresponding feeds in the embodiment shown in fig. 18. In the embodiment of fig. 18, the first tuning unit 12 is set to a capacitance, and the capacitance value is 0.75pf; the second feeding branch 20 is then formed as a path, i.e. the second tuning unit 22 can be understood as a resistance of 0Ω, or as a large capacitance set to a capacitance value of 3.3pf or more, or as a small inductance set to an inductance value of 33nH or less. Further, in this embodiment, the first matching unit and the second matching unit are set to be in an open state.

In this matching combination form, the distributed antenna 100 of the present application forms five current radiation modes, and correspondingly obtains five different resonance points for respectively covering five different frequency bands. Referring to fig. 19a, a first current radiation mode is shown, in which the distributed antenna 100 operates as a capacitor loop mode antenna, wherein a signal input from the signal source 30 is fed into the antenna branch 40 through the first tuning unit 12 and the first feeding point 11, and flows toward the first grounding point 43 of the antenna branch 40. The current path length from the signal source 30 to the first grounding point 43 is formed to be between 1/8 and 1/4 of the frequency band wavelength corresponding to the current radiation mode, and is adjusted based on the capacitance value of the first feeding point 11; in the second current radiation mode shown in fig. 19b, the distributed antenna 100 operates as a 1/4 wavelength antenna in the parasitic mode. The signal input by the signal source 30 is coupled from the first segment 40a to the second segment 40b, and the current path length of the second segment 40b is 1/4 of the wavelength of the frequency band corresponding to the current radiation mode; in a third antenna radiation pattern shown in fig. 19c, the distributed antenna 100 operates as a 1/2 wavelength antenna. Current flows from the second end 42 of the antenna branch 40 to the first end 41, i.e. the current path is the whole arm path of the antenna branch 40. At this time, the total length of the antenna branch 40 is 1/2 of the wavelength of the frequency band corresponding to the current radiation mode; in a fourth antenna radiation pattern shown in fig. 19d, the distributed antenna 100 operates as a 1/4 wavelength antenna. The signal input by the signal source 30 is fed into the antenna branch 40 through the second feeding point 21, and flows from the second feeding point 21 toward the second end 42 of the antenna branch 40, and at this time, the current path length (i.e., the short-arm path) from the second feeding point 21 to the second end 42 is formed to be 1/4 of the frequency band wavelength corresponding to the current radiation mode; in a fifth antenna radiation pattern shown in fig. 19e, the distributed antenna 100 operates as a 1/2 wavelength antenna. As in the first antenna radiation pattern shown in fig. 19a, the signal input by the signal source 30 is also fed into the antenna branch 40 via the first tuning unit 12 and the first feed point 11 and flows towards the first ground point 43 of the antenna branch 40. The difference is that, compared to the antenna of the first capacitive loop mode, the fifth antenna radiation mode provided in fig. 19e is also a capacitive loop mode and has the opposite characteristics to the first capacitive loop mode. The current path length from the signal source 30 to the first ground point 43 is thus formed to be between 1/8-1/4 of the wavelength of the frequency band to which the current radiation pattern corresponds and is likewise adjusted based on the capacitance value of the first feeding point 11.

It should be noted that, in the capacitive loop mode antenna shown in fig. 19a, since the frequency point is relatively close to the frequency point of the second current radiation mode, there is a current distribution of a part of the parasitic mode in fig. 19 a. That is, the distributed antenna 100 provided in this embodiment has the characteristics of both the capacitive loop mode antenna and the parasitic mode antenna in the current radiation mode shown in fig. 19 a.

Based on the above-mentioned five current radiation modes of the distributed antenna 100, after adjusting the total length of the antenna branch 40 and correspondingly adjusting the positions of the first feeding point 11 and the second feeding point 21 on the antenna branch 40, the positions of five different resonance points of the distributed antenna 100 in the embodiment of the present application can be controlled by matching with the frequency matching of the feeding network. Fig. 20 illustrates an antenna efficiency diagram of the distributed antenna 100 in the present embodiment. Through the matching adjustment, the frequency points of the first antenna radiation mode to the fifth antenna radiation mode are respectively at 2GHz, 2.46GHz, 3GHz, 4.28GHz and 4.99 GHz. The distributed antenna 100 may cover 1.7GHz-2.2GHz,3.3GHz-5.1GHz, and five different resonance points cover five frequency bands of N3, N1, N77, N78, and N79, respectively.

The above description is merely an embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions, such as reducing or adding structural components, changing the shape of structural components, etc., within the technical scope of the present application; embodiments of the present application and features of embodiments may be combined with each other without conflict. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (14)

1. The distributed antenna is characterized by comprising a signal source, a first feed branch, a second feed branch and an antenna branch;

the antenna branch comprises a first feeding point and a second feeding point which are arranged at intervals, the first feeding branch is connected with the signal source and the first feeding point, and the second feeding branch is connected with the signal source and the second feeding point;

the antenna branch comprises a first grounding point, wherein the first grounding point is positioned between the first feeding point and the second feeding point;

and the first tuning unit is connected in series with the first feed branch and is used for realizing frequency matching of the distributed antenna.

2. The distributed antenna of claim 1, wherein the first tuning element is a capacitor, or the first tuning element is a first series circuit formed by a capacitor and an inductor, or the first tuning element is a first parallel circuit formed by a capacitor and an inductor.

3. The distributed antenna of claim 2, wherein a second tuning unit is connected in series with the second feed branch, the second tuning unit configured to cooperate with the first tuning unit to achieve frequency matching of the distributed antenna.

4. A distributed antenna according to claim 3, wherein the second tuning element is a capacitor, or the second tuning element is a second series circuit formed by a capacitor and an inductor, or the second tuning element is a second parallel circuit formed by a capacitor and an inductor.

5. A distributed antenna according to any of claims 1-4, wherein a first matching unit is further connected in parallel to the first feed branch, the first matching unit being a capacitor and/or an inductor for achieving electrical length matching of the distributed antenna.

6. The distributed antenna of claim 5 wherein the first matching unit is located between the signal source and the first tuning unit or the first matching unit is located between the first feed point and the first tuning unit.

7. The distributed antenna of claim 5 wherein the number of first matching units is two, one of the first matching units being located between the signal source and the first tuning unit and the other of the first matching units being located between the first feed point and the first tuning unit.

8. A distributed antenna according to any of claims 1-7, wherein a second matching unit is further connected in parallel to the second feed branch, the second matching unit being a capacitor and/or an inductor for achieving electrical length matching of the distributed antenna.

9. The distributed antenna of claim 8, wherein the second matching unit is located between the signal source and the second tuning unit or the second matching unit is located between the second feed point and the second tuning unit.

10. The distributed antenna of claim 8 wherein the number of second matching units is two, one of the second matching units being located between the signal source and the second tuning unit and the other of the second matching units being located between the second feed point and the second tuning unit.

11. The distributed antenna of any of claims 1-10, further comprising a parasitic stub located in an extension direction of the second feed point to the first feed point, the parasitic stub further comprising a parasitic ground point.

12. The distributed antenna of any of claims 1-10, further comprising a first slot and a second ground point, the first slot being on a side of the first feed point remote from the second feed point, the second ground point being on a side of the first slot remote from the second feed point.

13. The distributed antenna of any of claims 1-12, wherein the signal source, the first feed leg, and the second feed leg are all disposed on a printed circuit board.

14. A terminal comprising a housing, and a distributed antenna according to any one of claims 1-13, wherein an antenna branch of the distributed antenna is located on the housing, and a signal source, a first feeding branch and a second feeding branch of the distributed antenna are housed inside the housing.

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