WO2013166885A1

WO2013166885A1 - Mobile communication terminal and circuit for reducing mutual interference between antenna and loudspeaker thereof

Info

Publication number: WO2013166885A1
Application number: PCT/CN2013/072831
Authority: WO
Inventors: 郑辉; 付从华; 武建军; 胡川; 郑业胜
Original assignee: 深圳凯虹移动通信有限公司
Priority date: 2012-05-09
Filing date: 2013-03-18
Publication date: 2013-11-14
Also published as: CN202617106U

Abstract

The present invention relates to the technical field of mobile communications, and more particularly to a mobile communication terminal and a circuit for reducing mutual interference between an antenna and a loudspeaker thereof. The circuit for reducing mutual interference between an antenna and a loudspeaker provided by the present invention is connected among two audio output ends of a baseband chip of a mobile communication terminal and a loudspeaker, and comprises a magnetic ball processing unit, a differential filtering unit, and a filtering protection unit. Mutual interface between an antenna and a loudspeaker is reduced through simple circuit elements, and absorption of a magnetic loudspeaker for high-frequency electromagnetic wave in antenna radiation can be preferentially reduced, or even prevented. Therefore, on one hand, a low-frequency audio signal is put under protection to avoid interference with a communication terminal baseband circuit, and on the other hand, the efficiency of the antenna can be improved, and the emission radiation power of the antenna and the reception sensitivity of the mobile terminal can be enhanced.

Description

Mobile communication terminal and circuit for reducing mutual interference between antenna and speaker

Technical field

The utility model belongs to the technical field of mobile communication, in particular to a mobile communication terminal and a circuit for reducing mutual interference between the antenna and the speaker.

Background technique

With the advancement and development of technology, the production technology of mobile communication terminal antennas has made great progress. Taking a mobile phone as an example, the antenna is moved from the mobile phone case to the mobile phone, from iron sheet and steel sheet hot melt technology to FPC flexible circuit technology and laser engraving technology. Since the antenna has become iron or steel and placed inside the mobile phone, the antenna needs a support structure to support it inside the mobile phone. At the same time, in order to realize the real-time efficiency and signal sensitivity of the antenna, the area of the antenna must be guaranteed. At present, the antennas of many mobile phones are attached to the speaker bracket or to the casing outside the speaker. As we all know, the radiation of the antenna is very large, which will affect the speaker. Especially for the PIFA antenna, the high-speed signal of the antenna affects the audio signal of the speaker, and there is also a requirement for the forced air environment around the antenna. On the other hand, due to the speaker It consists of metal magnets and coils and also affects the performance of the antenna. At present, this problem is mainly solved by keeping the antenna and the horn at a certain distance. However, with the development of mobile phone design and manufacturing level, mobile phones are getting thinner and thinner. Due to the mutual interference of antennas and speakers, it is bound to affect the design of mobile phone structure and thickness. In view of the above problems in the prior art, it is necessary to provide a low cost design for reducing the mutual interference of the antenna and the speaker of the mobile communication terminal.

technical problem

The purpose of the utility model is to provide a circuit for reducing the mutual interference between the antenna and the speaker of the mobile communication terminal, so as to solve the problem that the mutual interference problem of the antenna and the speaker in the existing mobile communication terminal affects the design of the main body of the mobile communication terminal.

Technical solution

In order to solve the above technical problems, the present invention is implemented as follows:

A circuit for reducing mutual interference between an antenna and a speaker is connected between two audio outputs of a baseband chip of a mobile communication terminal and a speaker, including:

a two-input terminal is respectively connected to the first output end and the second output end of the baseband chip, and a differential filtering unit that performs filtering processing on the signals output by the two audio output ends;

The two input ends are respectively connected to the two output ends of the differential filtering unit and the two output ends are connected with the input end of the speaker, filtering out the radio frequency interference signal and protecting the filter protection unit of the low frequency audio signal.

Further, the differential filtering unit includes a differential mode capacitor C1, a differential mode capacitor C2, a common mode capacitor C3, an electrostatic resistor T1, and an electrostatic resistor T2; a first end of the differential mode capacitor C1 and the electrostatic resistor The first end of the differential mode capacitor C1 is connected to the first end of the differential filter unit, and the second end of the electrostatic impedance device T1 is grounded. The first end of the differential mode capacitor C2 is coupled to the first end of the electrostatic resistor T2, and serves as a second input end and a second output end of the differential filter unit, and the differential mode capacitor C2 The two ends are grounded to the second end of the electrostatic impedance device T2, and two ends of the common mode capacitor C3 are respectively connected between the first input end and the second input end of the differential filtering unit.

Further, the filter protection unit includes an inductor L1 and an inductor L2; the first end and the second end of the inductor L1 are respectively a first input end and a first output end of the filter protection unit, and the inductor L2 The first end and the second end are respectively a second input end and a second output end of the filter protection unit.

Further, the circuit further includes: connecting two audio output ends of the baseband chip and two input ends of the differential filtering unit to perform noise cancellation on signals output by the two audio output ends a magnetic bead processing unit; the magnetic bead processing unit includes a magnetic bead B1 and a magnetic bead B2; the first end of the magnetic bead B1 and the first end of the magnetic bead B2 are respectively connected to two audios of the baseband chip The output end, the second end of the magnetic bead B1 and the second end of the magnetic bead B2 are respectively connected to two input ends of the differential filtering unit.

Another object of the present invention is to provide a mobile communication terminal including the above-described antenna and speaker interfering circuit, including but not limited to a mobile phone and a palmtop computer PAD.

Beneficial effect

The mobile communication terminal provided by the utility model and the circuit for reducing the mutual interference between the antenna and the speaker realize the mutual interference between the antenna and the speaker by using simple circuit components, and can preferentially reduce or even prevent the high frequency of the radiation radiated by the magnetic horn to the antenna. The absorption of electromagnetic waves, on the one hand, protects the low-frequency audio signal, avoids interference with the baseband circuit of the communication terminal, and on the other hand improves the efficiency of the antenna, increases the radiated radiated power of the antenna and the receiving sensitivity of the mobile terminal.

DRAWINGS

1 is a structural block diagram of a circuit for reducing antenna and speaker mutual interference provided by an embodiment of the present invention;

2 is a diagram showing an example component of a circuit for reducing antenna and speaker mutual interference provided by an embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

In order to make the objects, technical solutions and advantages of the present invention more comprehensible, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The mobile communication terminal provided by the utility model and the circuit for reducing mutual interference between the antenna and the speaker reduce the mutual interference between the antenna and the speaker by simple circuit components, and protect the low frequency audio signal on the one hand to avoid interference. The baseband circuit of the communication terminal can improve the efficiency of the antenna and increase the radiated power of the antenna and the receiving sensitivity of the mobile terminal.

1 is a structural block diagram of a circuit for reducing antenna and speaker interfering provided by an embodiment of the present invention. For convenience of description, only parts related to the embodiment of the present invention are shown.

As shown in the figure, as a preferred embodiment of the present invention, the circuit for reducing antenna and speaker mutual interference is connected between two audio output terminals SPKP0, SPKN0 and speaker SPK of the baseband chip of the mobile communication terminal, including magnetic bead processing. Unit 100, differential filtering unit 200 and filter protection unit 300;

The magnetic bead processing unit 100 has two input ends respectively connected to the two audio output ends SPKP0 and SPKN0 of the baseband chip of the mobile communication terminal, and performs noise cancellation on the signals output by the two audio output terminals;

The differential filtering unit 200 also has two input ends respectively connected to the two output ends of the magnetic bead processing unit 100, and continues to filter the signals output by the two audio output terminals;

The filter protection unit 300 also has two input terminals respectively connected to the two output ends of the differential filter unit 200, and two output terminals are connected to the input end of the speaker SPK for filtering the radio frequency interference signal and protecting. Low frequency audio signal.

2 is an example component diagram of a circuit for reducing antenna and speaker interfering provided by an embodiment of the present invention. Similarly, for convenience of explanation, only parts related to the embodiment of the present invention are shown.

As a preferred embodiment of the present invention, the magnetic bead processing unit 100 includes a magnetic bead B1 and a magnetic bead B2; the first end of the magnetic bead B1 is connected to the audio output end SPKP0 of the baseband chip, and the second end of the magnetic bead B1 is a magnetic bead. The first output end of the processing unit 100 is connected to the first input end of the differential filtering unit 200. The first end of the magnetic bead B2 is connected to the audio output end SPKN0 of the baseband chip, and the second end of the magnetic bead B1 is the magnetic bead processing unit 100. The second output end is connected to the second input end of the differential filtering unit 200.

The differential filtering unit 200 includes a differential mode capacitor C1, a differential mode capacitor C2, a common mode capacitor C3, an electrostatic resistor T1, and an electrostatic resistor T2; the first end of the differential mode capacitor C1 is coupled to the first end of the electrostatic resistor T1, At the same time, as the first input end and the first output end of the differential filter unit 200, the second end of the differential mode capacitor C1 and the second end of the electrostatic resistor T1 are grounded, and the first end of the differential mode capacitor C2 and the electrostatic resistor T2 The first end of the differential filter unit C2 is connected to the second end of the differential filter unit 200, and the second end of the differential mode capacitor C2 is grounded, and the common mode capacitor C3 is The terminals are respectively connected between the first input end and the second input end of the differential filtering unit 200. The electrostatic resistor T1 and the electrostatic resistor T2 in the differential filtering unit 200 improve the electrostatic performance of the entire circuit.

The filter protection unit 300 includes two equivalent inductors L1 and an inductor L2. The first end and the second end of the inductor L1 are respectively a first input end and a first output end of the filter protection unit 300, and the first end of the inductor L2 is The second ends are respectively a second input end and a second output end of the filter protection unit 300. The second ends of the two equivalent inductors are connected to the two inputs of the horn SPK. The two equivalent inductors can attenuate the RF signal, isolate the RF interference signal, prevent the RF electromagnetic wave absorbed by the speaker circuit, and avoid interference with the baseband circuit of the communication terminal; on the other hand, the two equivalent inductors can also be filtered out. Other high frequency clutter in the horn voice signal to protect the low frequency audio signal.

The embodiment of the present invention further provides a mobile communication terminal, including but not limited to a mobile phone, a handheld computer PAD, etc., such mobile communication terminal should have a speaker and an antenna, and the common feature is that it also includes any of the above implementations. The circuit for reducing mutual interference between the antenna and the speaker as described in the example.

The mobile communication terminal provided by the embodiment of the present invention and the circuit for reducing mutual interference between the antenna and the speaker mainly reduce the RF signal by adding two equivalent inductors as the filter protection unit 300 after the differential filtering unit 200. The RF interference signal is isolated, and other high-frequency clutter in the speaker voice signal can be filtered out to avoid interference with the baseband circuit of the communication terminal, and protect the low-frequency audio signal; on the other hand, the magnetic speaker pair can be prevented. The high-frequency electromagnetic wave radiated by the antenna absorbs, thereby improving the efficiency of the antenna, increasing the radiated radiated power of the antenna and the receiving sensitivity of the mobile terminal, thereby reducing the mutual interference between the antenna and the speaker.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, it is still possible for those skilled in the art to The technical solutions described in the foregoing embodiments are modified, or some of the technical features are equivalently replaced. Any modifications, equivalent substitutions and improvements made within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

A circuit for reducing mutual interference between an antenna and a speaker is connected between two audio output ends of a baseband chip of a mobile communication terminal and a horn, wherein the circuit comprises:

a two-input terminal is respectively connected to the first output end and the second output end of the baseband chip, and a differential filtering unit that performs filtering processing on the signals output by the two audio output ends;

The two input ends are respectively connected to the two output ends of the differential filtering unit and the two output ends are connected with the input end of the speaker, filtering out the radio frequency interference signal and protecting the filter protection unit of the low frequency audio signal.
The circuit for reducing mutual interference between an antenna and a speaker according to claim 1, wherein the differential filtering unit comprises a differential mode capacitor C1, a differential mode capacitor C2, a common mode capacitor C3, an electrostatic resistor T1, and an electrostatic resistor T2. ;

The first end of the differential mode capacitor C1 is coupled to the first end of the electrostatic resistor T1, and serves as a first input end and a first output end of the differential filtering unit, and the differential mode capacitor C1 The second end is grounded to the second end of the electrostatic resistor T1, and the first end of the differential mode capacitor C2 is coupled to the first end of the electrostatic resistor T2 and serves as the second of the differential filtering unit. An input end and a second output end, the second end of the differential mode capacitor C2 and the second end of the electrostatic resistor T2 are both grounded, and two ends of the common mode capacitor C3 are respectively connected to the differential filtering unit Between the first input and the second input.
The circuit for reducing mutual interference between an antenna and a speaker according to claim 1, wherein the filter protection unit comprises an equivalent inductor L1 and an inductor L2;

The first end and the second end of the inductor L1 are respectively a first input end and a first output end of the filter protection unit, and the first end and the second end of the inductor L2 are respectively the filter protection unit a second input and a second output.
The circuit for reducing mutual interference between an antenna and a speaker according to any one of claims 1 to 3, wherein the circuit further comprises:

A bead processing unit connected between the two audio output ends of the baseband chip and the two input ends of the differential filtering unit for noise cancellation of signals output by the two audio output terminals.
The circuit for reducing mutual interference between an antenna and a speaker according to claim 4, wherein the magnetic bead processing unit comprises a magnetic bead B1 and a magnetic bead B2;

The first end of the magnetic bead B1 and the first end of the magnetic bead B2 are respectively connected to two audio output ends of the baseband chip, the second end of the magnetic bead B1 and the second end of the magnetic bead B2 The terminals are respectively connected to the two input ends of the differential filtering unit.
A mobile communication terminal having a horn and an antenna, characterized in that the mobile communication terminal further comprises a circuit for reducing antenna and horn mutual interference according to any one of claims 1-5.
The mobile communication terminal according to claim 6, wherein said mobile communication terminal comprises, but is not limited to, a mobile phone, a palmtop computer PAD.