WO2015176398A1

WO2015176398A1 - Antenna system and terminal

Info

Publication number: WO2015176398A1
Application number: PCT/CN2014/084077
Authority: WO
Inventors: 吴鹏飞
Original assignee: 中兴通讯股份有限公司
Priority date: 2014-05-23
Filing date: 2014-08-11
Publication date: 2015-11-26
Also published as: CN105098322A

Abstract

An antenna system and terminal are provided in the embodiments of the present invention. The antenna system comprises: a main antenna for transmitting and receiving radio signals; a compensation antenna for compensating the bandwidth of the main antenna by transmitting and receiving radio signals; and a connection unit for connecting the main antenna and the compensation antenna respectively. The terminal comprises the antenna system.

Description

Antenna system and terminal

Technical field

The present invention relates to the field of communications technologies, and in particular, to an antenna system and a terminal. BACKGROUND OF THE INVENTION The development of communication technologies is becoming more and more mature, and the network has been widely covered in every corner of life. LTE (Long Term Evolution), a new generation of mobile broadband technology, has been rapidly deployed around the world. Currently, 163 operators worldwide have launched LTE services in 67 countries, and there are more than 100 million LTE users worldwide. The LTE service is moving from a single data service to a full service.

However, LTE technology is facing many challenges while it is developing rapidly. End products, especially smart terminal products, are emerging one after another, but few products can meet the network needs of multiple operators at the same time, because the antenna bandwidth design of the terminal cannot meet the demand. In addition, the LTE frequency band is often very wide. After being compatible with the 2G/3G (2 Generation, 2nd Generation, 3 Generation, 3rd Generation Mobile Communication Technical Specifications) band, the bandwidth of the terminal antenna is extremely high. Claim. If the antenna bandwidth is increased in a conventional manner, it is necessary to provide more space for the antenna inside the terminal to improve the performance of the antenna. However, this often runs counter to the slim design concept of the terminal, and after the antenna space is increased, the terminal volume is followed. Increase, will reduce the user experience. If the bandwidth of the terminal is increased while increasing the bandwidth of the antenna, the handheld performance of the terminal is lowered. SUMMARY OF THE INVENTION The technical problem to be solved by the embodiments of the present invention is to provide an antenna system and a terminal, which are used to solve the problem that the antenna bandwidth of the existing terminal cannot meet the demand.

An antenna system comprising: a primary antenna configured to transmit and receive radio frequency signals; a compensation antenna configured to compensate for bandwidth of the primary antenna by transmitting and receiving radio frequency signals; and a connection unit configured to respectively connect the primary antennas And the compensation antenna.

The main antenna includes: a main radiating unit configured to receive and transmit a radio frequency signal; and a main radio frequency excitation point configured to connect the main radiating unit and the connecting unit. The compensation antenna includes: a compensation radiation unit configured to compensate a bandwidth of the main antenna by receiving and transmitting a radio frequency signal; and a compensation RF excitation point, configured to connect the compensation radiation unit and the connection unit.

The connection unit is a power divider.

The power splitter includes a first port, a second port, and a third port; wherein the first port is connected to an antenna feed network; the second port is connected to the main antenna; and the third port is connected The compensation antenna.

Wherein, the power splitter comprises a radio frequency line and/or a microstrip line.

Wherein, when the power splitter is implemented by using a microstrip line, the method includes: the microstrip line uses a 50 ohm microstrip line, and the first port, the second port, and the third port of the power splitter Set the load separately.

The load of the first port is a PI type network; and the load of the second port and the third port is a T type network.

Wherein the main antenna and the compensation antenna are respectively disposed on a clearance area other than the printed circuit board or a bracket of the printed circuit board; a length of a main radiation unit in the main antenna, and the compensation antenna The length of the compensated radiating element is equal to the quarter plus/minus adjustment factor of its resonant wavelength, respectively.

A terminal comprising the antenna system described above; wherein the position of the compensation antenna is maintained at a predetermined distance from a hand-held position of the terminal.

In the embodiment of the present invention, by adding a compensation antenna, the compensation antenna compensates for the shortage of the bandwidth of the main antenna, and the bandwidth of the antenna is improved. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a structural diagram of an antenna system according to an embodiment of the present invention;

2 is a structural diagram of a power splitter of an antenna system according to an embodiment of the present invention;

3 is a schematic diagram of a matching network according to an embodiment of the invention;

4 is a schematic diagram of a matching network according to an embodiment of the invention; FIG. 5 is a schematic diagram showing a transmission coefficient and a reflection coefficient curve of each port of a power splitter according to an embodiment of the invention; FIG.

6 is a schematic diagram of a return loss curve of an antenna feed network port before and after adding a compensation antenna according to an embodiment of the invention. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other.

In order to solve the problem that the antenna bandwidth of the existing terminal cannot meet the demand. Embodiments of the present invention provide an antenna system and a terminal. In the embodiment of the present invention, by adding a compensation antenna to the existing antenna system, the compensation antenna compensates for the shortage of the main antenna bandwidth, and the bandwidth of the antenna is improved. Further, by arranging the main antenna and the compensation antenna on both ends of the PCB (Printed Circuit Board) board, the influence of the human body on the antenna is reduced, and the handheld performance of the terminal is increased.

The antenna system includes a main antenna, a compensation antenna, and a connection unit.

The main antenna is set to transmit and receive RF signals. The radio frequency signal includes a high frequency signal and a low frequency signal.

The compensation antenna is set to compensate for the bandwidth of the main antenna by transmitting and receiving RF signals. The radio frequency signal includes a high frequency signal and/or a low frequency signal. The main antenna and the compensation antenna may be: an inverted F-shaped antenna, a monopole antenna, a loop antenna, a coupled antenna, or the like.

The main antenna and the compensation antenna are respectively disposed at both ends of the PCB. Preferably, the main antenna and the compensation antenna may be respectively disposed on a clearance area other than the PCB board or a bracket of the PCB board.

The connection unit is configured to connect the main antenna and the compensation antenna respectively. Further, in order to feed the main antenna and the compensation antenna, the connection unit is also connected to the antenna feed network. Further, the connection unit is disposed on the PCB.

As shown in Fig. 1, Fig. 1 is a structural diagram of an antenna system according to an embodiment of the present invention.

When setting up the main antenna and the compensation antenna, the main antenna and the compensation antenna require a certain amount of open space support. In this embodiment, the main antenna is disposed in a clearance area below the PCB board, and the compensation antenna is disposed in a clearance area above the PCB board. The length of the clearance area is equal to the width of the PCB board, and the clearance area The width is a predetermined distance, which is related to the size of the terminal.

The main antenna comprises a main radiating element 1, a main RF excitation point 6. The primary antenna may also include a primary RF grounding point depending on the type of antenna selected for the primary antenna. In this embodiment, the main antenna uses an inverted F-shaped antenna, so the main antenna further includes a main RF grounding point 7.

The main radiating element 1 is arranged to transmit and receive high frequency and low frequency radio frequency signals. The length of the main radiating element 1 is related to the resonant wavelength, such as: the length L of the main radiating element 1 is equal to the quarter plus/minus adjustment coefficient λ θ of the resonant wavelength λ, that is, L = 1/4 A ± λ θ, The coefficient λ θ is an empirical value or a value calculated according to a predetermined formula, and usually, λ 0=0.

The primary RF excitation point 6, as a connection point, is set to connect the primary radiating element 1 and the connecting unit 3.

The main RF grounding point 7, set to connect the ground of the PCB board, ground the main antenna.

The compensation antenna includes: a compensation radiation unit 2 and a compensation RF excitation point 8. Depending on the type of antenna selected by the compensation antenna, the compensation antenna may also include a compensation RF grounding point, a compensation RF grounding point, and a ground for connecting the PCB to ground the compensation antenna. In this embodiment, the compensation antenna uses a monopole antenna, so the compensation antenna does not include the compensation RF grounding point.

The compensating radiating element 2 is arranged to compensate for the bandwidth of the main antenna by transmitting and receiving high frequency or low frequency radio frequency signals. In this embodiment, the compensation radiation unit 2 supports a low frequency band. The main antenna supports both low and high frequency bands. The compensation antenna supports the low frequency band. Thereby, the shortage of the low bandwidth of the main antenna is compensated by the compensation antenna. By properly winding, the space occupied by the compensation antenna is compressed, and further, the main antenna and the compensation antenna are less affected by the hand. The length of the compensating radiating element 2 is related to the resonant wavelength. For example: the length L of the compensation radiation unit 2 is equal to the quarter addition/subtraction coefficient λ 0 of the resonance wavelength λ ', that is, Ι/=1/4 λ '士λ 0, the coefficient λ θ is The empirical value is either a value calculated according to a predetermined formula, in general, λ 0, =0.

The compensation RF excitation point 8, as a connection point, is used to connect the compensation radiation unit 2 and the connection unit 3.

The connection unit 3 is connected to the main RF excitation point 6, the compensation RF excitation point 8, and the antenna feed network port 4, respectively. The connecting unit 3 is a power splitter, or other capable of connecting the main antenna, the compensating antenna and the antenna The structure of the feed network. The power divider can be used as the connection unit 3. The power splitter can be implemented using radio frequency lines and/or microstrip lines, ie, the power splitter includes radio frequency lines and/or microstrip lines. The connection line can be set on the PCB or the jumper for the external connection line can be set to form a successful splitter. The connecting lines are microstrip lines and RF lines. The main antenna, the compensation antenna, and the antenna feed network are connected through a microstrip line and a radio frequency line in the power splitter.

The power splitter includes a first port, a second port, and a third port. The first port is connected to the antenna feed network; the second port is connected to the main antenna; and the third port is connected to the compensation antenna.

As shown in FIG. 2, FIG. 2 is a structural diagram of a power splitter of an antenna system according to an embodiment of the present invention. The splitter in Figure 2 consists of a microstrip line.

The power splitter includes a first port Portl, a second port Port2 connected to the main antenna, and a third port Port3 connected to the compensation antenna.

The 50 ohm microstrip line is used in the main branch of the microstrip power splitter (the branch where the first port Port1 is located) and the branch road (the branch where the second port Port2 is located and the branch where the third port Port3 is located) . In order to make the output impedance of each branch microstrip line greater than 50 ohms, a load may be respectively set at the first port Portl, the second port Port2, and the third port Port3 of the power splitter, as shown in FIG. 2, at the first The port Port1 sets the load Z1, the load Z2 is set at the second port Port2 connected to the main antenna, and the load Z3 is set at the third port Port3 connected to the compensation antenna. Load Zl, load Z2, load Z3 can use different matching networks. The load Z1 uses a PI-type matching network, such as the PI-type matching network shown in Figure 3, that is, the inductor and capacitor are connected in parallel between the power supplies. The load Z2 and the load Z3 use a T-type matching network. For example, the T-type matching network shown in Figure 4 is used, that is, two inductors are connected in series between the positive poles of the power supply, one end of the capacitor is connected between the two inductors, and the other end is connected. At the negative electrode.

The power splitter can also be composed of a microstrip line and a radio frequency line. Replace the longer microstrip line in Figure 2 with the microstrip line where the third port Port3 is located. The RF line is a 50 ohm RF line. The two ends of the RF line are RF terminals. By setting a jumper point at both ends of the microstrip line, the RF line is connected across the ends of the microstrip line, so that the RF line replaces the microstrip line in the A area. When the PCB has a long microstrip line (such as the A area in Figure 2), it often affects the layout of other devices. This microstrip line is replaced by a 50 ohm RF line, which saves the design area of the PCB. If the main branch of the power splitter and the microstrip lines of both branches are long, the three microstrip lines can be replaced by RF lines.

FIG. 5 is a diagram showing transmission coefficients and reflection coefficient curves of respective ports of a power splitter according to an embodiment of the present invention. Line diagram. Figure 5 is derived by measuring the antenna system of the power splitter shown in Figure 2, the compensation antenna in the antenna system supporting low frequency signals. In Fig. 5, the abscissa is the frequency, and the ordinate is the coefficient value. S11 is the reflection coefficient of the first port Port1; S22 is the reflection coefficient of the second port Port2; S33 is the reflection coefficient of the third port Port3; S21 is the transmission coefficient of the first port Port1 to the second port Port2; S31 is the first port The transmission coefficient of Portl to the third port Port3. As can be seen from Figure 5, the frequency range is from 0.6 GHz to 3.0 GHz.

Before and after the compensation antenna is added, the return loss of the frequency range of 0.6 GHz to 3.0 GHz is measured at the antenna feed network port at normal temperature and pressure. 6 is a schematic diagram of a return loss curve of an antenna feed network port before and after adding a compensation antenna according to an embodiment of the invention. The comparison shows that the compensation antenna reduces the return loss of the low-frequency bandwidth of the main antenna by about two times.

The embodiment of the invention further provides a terminal, which comprises the antenna system described above.

The terminal can be a mobile phone, a tablet, a laptop, or the like.

When the antenna system described above is applied to the terminal, the position of the compensation antenna is maintained at a predetermined distance from the hand-held position of the terminal, and the predetermined distance can be calculated by a preset formula. The hand-held position refers to the part of the terminal that the user holds when holding the terminal, that is, the part of the PCB that is held. In this way, the position of the compensation antenna is set away from the hand position. It can reduce the impact of the human body on the compensation antenna, increase the handheld performance of the terminal, and reduce the impact of the compensation antenna on other antennas in the terminal.

The embodiment of the present invention improves the bandwidth and hand-held performance of the main antenna by designing a compensation antenna in a region where the terminal has less influence on the handheld; according to the device layout requirements on the PCB, the microstrip line structure in the power splitter can use the RF line or Other structures are replaced. The embodiment of the invention is low in cost, and the space requirement of the compensation antenna is small, and the antenna form is not limited, and has no influence on other antenna systems, and is easy to implement on the current terminal.

While the preferred embodiments of the present invention have been disclosed for purposes of illustration, those skilled in the art will recognize that various modifications, additions and substitutions are possible, and the scope of the invention should not be limited to the embodiments described above. Industrial applicability

The solution of the embodiment of the invention is low in cost, and the space requirement of the compensation antenna is small, and the antenna form is not limited, and has no influence on other antenna systems, and is easy to implement on the current terminal.

Claims

Claim

1. An antenna system comprising:

a primary antenna, configured to transmit and receive radio frequency signals;

a compensation antenna configured to compensate for bandwidth of the primary antenna by transmitting and receiving radio frequency signals;

And a connecting unit, configured to respectively connect the main antenna and the compensation antenna.

2. The system of claim 1, wherein the primary antenna comprises:

a primary radiating element configured to receive and transmit radio frequency signals;

A primary RF excitation point is provided to connect the primary radiating element and the connecting unit.

3. The system of claim 2, wherein the compensation antenna comprises:

a compensation radiating unit configured to compensate for a bandwidth of the main antenna by receiving and transmitting a radio frequency signal;

A compensation RF excitation point is provided to connect the compensation radiation unit and the connection unit.

4. The system of claim 1, wherein the connecting unit is a power splitter.

5. The system of claim 4, wherein:

The power splitter includes a first port, a second port, and a third port;

The first port is connected to an antenna feed network;

The second port is connected to the main antenna;

The third port is connected to the compensation antenna.

6. The system of claim 4 or 5, wherein the power splitter comprises a radio frequency line and / or a microstrip line.

7. The system of claim 6 wherein, when said power splitter is implemented using a microstrip line, said microstrip line uses a 50 ohm microstrip line and is first in said power splitter The port, the second port, and the third port respectively set the load.

8. The system according to claim 7, wherein the load of the first port is a PI type network; and the load of the second port and the third port is a T type network.

9. The system of claim 3, wherein:

The main antenna and the compensation antenna are respectively disposed on a clearance area other than the printed circuit board or a bracket of the printed circuit board;

The length of the primary radiating element in the primary antenna and the length of the compensating radiating element in the compensating antenna are respectively equal to a quarter plus/minus adjustment coefficient of its resonant wavelength.

A terminal, comprising the system of any one of claims 1-9; wherein the position of the compensation antenna is maintained at a predetermined distance from the hand-held position of the terminal.