CN202059560U - Microphone device - Google Patents
Microphone device Download PDFInfo
- Publication number
- CN202059560U CN202059560U CN2010206884130U CN201020688413U CN202059560U CN 202059560 U CN202059560 U CN 202059560U CN 2010206884130 U CN2010206884130 U CN 2010206884130U CN 201020688413 U CN201020688413 U CN 201020688413U CN 202059560 U CN202059560 U CN 202059560U
- Authority
- CN
- China
- Prior art keywords
- circuit
- resistance
- input
- electric capacity
- pass filter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Landscapes
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
A microphone device comprises an input circuit, a low pass filter connected with an output end of the input circuit, an echo elimination circuit connected with an output end of the low pass filter and an output circuit connected with an output end of the echo elimination circuit. Before processing echo elimination, the microphone device first carries out filtering processing on differentially inputted audio signals, and filters high frequency noises in the audio signals to improve noises in the audio signals used for echo elimination, thereby improving the integral timbre of the microphone device.
Description
Technical field
The utility model relates to the Audio Processing design field, particularly is used to improve the microphone apparatus of microphone tonequality.
Background technology
At present, in the use of microphone, find reflective generation through regular meeting.The generation of echo is owing to have the acoustics loop between loud speaker and the microphone.Specifically, from the voice signal of far-end, connect the arrival near-end, and emit by the loud speaker of near-end through communication.Behind voice signal process loud speaker and the acoustics loop between the microphone that loud speaker is emitted, collected by microphone.Then, the voice signal that is collected by microphone is passed far-end back again through the communication connection.At this moment, the speaker of far-end just can hear the echo of oneself, i.e. far-end echo.Described echo can have a strong impact on speech quality.
For solving above-mentioned echo problem, prior art has proposed the solution that multiple echo is eliminated, for example Chinese patent ZL200610144055.5 has just proposed a kind of microphone echo cancelling device and echo cancel method, comprise the frame length adjusting module in its device, be used to adjust data frame length, present frame and plurality of data are before united to form the Frame of length and adaptive frequency domain filter coefficient equal in length, to carry out adaptive-filtering.
Yet, though prior art is eliminated echo many solutions have been proposed, other new problems have also been found in the further raising of tonequality requirement when microphone is used.Existing supply power mode to microphone normally with shared one road power supply of other functional circuits, to cause outside power supply to disturb like this, thereby in the use of microphone, when for example using the hands-free phone conversation in car, bigger noise can be heard in the outer other end of car (conversation recipient).Described situation also will influence speech quality and for other voice applications of microphone.
The utility model content
The utility model provides a kind of microphone apparatus, and conversation receives the problem that can hear big noise when using to improve microphone.
For addressing the above problem, the utility model provides a kind of microphone apparatus, comprising: input circuit; Be connected in the low pass filter of input circuit output; Be connected in the echo cancel circuit of low pass filter output; Be connected in the output circuit of echo cancel circuit output.
Compared with prior art, the utility model microphone apparatus has the following advantages: by before to echo cancellation process, earlier the audio signal of difference input is carried out Filtering Processing, high-frequency noise in the described audio signal of filtering, improve the noise that audio signal comprised that is used to carry out the echo elimination, thereby improved the overall sound quality of microphone apparatus.
Description of drawings
Fig. 1 is a kind of execution mode block diagram of the utility model microphone apparatus;
Fig. 2 is a kind of embodiment circuit block diagram of the utility model microphone apparatus;
Fig. 3 is the another kind of embodiment circuit block diagram of the utility model microphone apparatus.
Embodiment
With reference to shown in Figure 1, a kind of execution mode of the utility model microphone apparatus comprises:
Echo cancel circuit 300 carries out echo cancellation process to the audio signal via filter filtering;
In the above-mentioned microphone apparatus, described input circuit 100, echo cancel circuit 300 and output circuit 400 all can adopt the design of known microphone apparatus corresponding function circuit.For example, described input circuit 100 can adopt the design of existing difference input voltage gain.The design form of corresponding difference input, described output circuit 400 can adopt the design of existing difference output equally.
In the above-mentioned microphone apparatus, prime at echo cancel circuit 300 has increased low pass filter 200, because the high-frequency signal of described low pass filter 200 in can the audio signal that filtering received, thereby realized filtering to the high-frequency noise in the audio signal that is received.The origin cause of formation of described high-frequency noise can be because the situation of previously described common source also can be that other equipment in the microphone apparatus environment for use cause.Hence one can see that, and the high-frequency noise in the audio signal that described echo cancel circuit 300 is received also will improve.Thereby, finish echo cancellation process at described echo cancel circuit 300, and via output circuit 400 during with audio signal output, the high-frequency noise in the audio signal of described output will improve also, thereby the overall sound quality of microphone apparatus has obtained raising.
Below by two specific embodiments the utility model microphone apparatus is further illustrated.
With reference to shown in Figure 2, among a kind of embodiment of the utility model microphone apparatus, input circuit 110 is the difference input circuit, and it has differential input end, comprises input anode MIC+ and input negative terminal MIC-.Correspondingly, output circuit 410 is a differential output circuit, and it has difference output end, comprises output plus terminal MIC_P and output negative terminal MIC_N.In the present embodiment, corresponding to 310 concrete chip ports that adopt of echo cancel circuit, the output port of low pass filter should be corresponding with described chip port.
In the present embodiment, described echo cancel circuit 310 can adopt for example FM2010 model chip of Fortemedia company.Continuation is with reference to figure 3, and described low pass filter comprises: the first input resistance R11, the second input resistance R12, first capacitor C 1 and second capacitor C 2.Wherein, first end of the first input resistance R11 is connected in an output of described difference input circuit; First end of first capacitor C 1 is connected in second end of the first input resistance R11, and second end of first capacitor C 1 is connected in an input of echo cancel circuit 310; First end of the second input resistance R12 is connected in another output of described difference input circuit; First end of second capacitor C 2 is connected in second end of the second input resistance R12, and second end of second capacitor C 2 is connected in another input of echo cancel circuit 310.
Herein, described low pass filter essence has comprised two low pass filters, is respectively first low pass filter that is made of the first input resistance R11 and first capacitor C 1, and second low pass filter that is made of the second input resistance R12 and second capacitor C 2.
Be to realize low-pass filtering, can carry out corresponding consideration and configuration based on factors such as the frequency range of the audio signal of want filtering and offset error, costs for the first input resistance R11, the second input resistance R12, first capacitor C 1 and second capacitor C 2 resistance value and capacitance separately.
For example, for the first input resistance R11, the second input resistance R12, first capacitor C 1 and second capacitor C 2 separately resistance value and the configuration of capacitance make described first low pass filter and second low pass filter all can filtering 50kHz with the audio signal of upper frequency.Suppose, the microphone audio signal that causes importing described difference input circuit 110 owing to the reason of aforesaid common source has comprised the noise of 50kHz with upper frequency, then when through described first low pass filter and second low pass filter filtering after, to no longer comprise the signal of 50kHz from the audio signal of first low pass filter and second low pass filter output, the noise of 50kHz that be filtering also with upper frequency with upper frequency.
In the described low pass filter, the actual value of the first input resistance R11 and the second input resistance R12 is generally 1M Ω or less than 1M Ω.The selection of resistance value is that between offset error and capacitance is compromise.The first input resistance R11 and the second input resistance R12 are big more, because the input offset voltage that input offset current causes is big more.The offset voltage drift also can increase.And when the first input resistance R11 and the second input resistance R12 selected lower resistance value for use, first capacitor C 1 must use higher input capacitance value to provide identical-3dB turnover, corresponding frequencies F with second capacitor C 2
-3dB=1/ (2 π R1C1), R11=R12 and C1=C2 here.
In addition, in the selection for capacitor,, otherwise should use nonpolar capacitor unless big dc voltage appears in the input of AC coupling capacitor.Therefore, in order to keep size of devices as far as possible little, the value of capacitor C 1 and C2 should be 0.1 μ F or littler.Usually, capacitance is the smaller the better, because such cost can reduce and size can reduce.The rated operational voltage of input coupling capacitor needs enough high puncture to avoid causing because of any contingent high input transient voltage.
Therefore, described in conjunction with preamble, the audio signal of noise that described echo cancel circuit 410 also will obtain filtering, thereby after described echo cancel circuit 410 carries out echo cancellation process, the audio signal of exporting via described differential output circuit 410 also will no longer comprise the noise of 50kHz with upper frequency.
Need to prove, more than for the explanation of filtering only for for example, be not frequency range and follow-up corresponding circuit arrangement in order to restriction filtering.
One of reason of considering initiation microphone apparatus noise in the prior art is that the power supply that common source brings disturbs, thereby, if can when using microphone apparatus, avoid described power supply to disturb, should produce bigger help to the tonequality that improves microphone apparatus.
With reference to shown in Figure 3, among the another kind of embodiment of the utility model microphone apparatus, state difference input circuit, low pass filter, echo cancel circuit and the differential output circuit of mentioning except embodiment illustrated in fig. 2, also comprise: power circuit, described power circuit is connected in the input of described input circuit.In the present embodiment, described power circuit is connected in the input anode of described difference input circuit.
Particularly, described power circuit comprises: second resistance R 2, the 3rd resistance R 3, the 4th resistance R 4, the 3rd capacitor C 3, the 4th capacitor C 4, the 5th capacitor C 5, the 6th capacitor C 6 and NPN pipe Q1.Wherein, first power end (5V power end) and second source end (MIC_VCCS power end, voltage are 5V, are provided by corresponding power management chip usually) are provided respectively for collector electrode, the emitter of NPN pipe Q1, and base stage links to each other with second end of second resistance R 2; First end of second resistance R 2 links to each other with the 5V power end, and second end links to each other with first end of the 3rd capacitor C 3, the 4th capacitor C 4; The 3rd capacitor C 3,4 parallel connections of the 4th capacitor C, the equal ground connection of second end; First end of the 5th capacitor C 5 links to each other the second end ground connection with the emitter of NPN pipe Q1; First end of the 3rd resistance R 3 links to each other with the MIC_VCCS power end, and second end links to each other with first end of the 4th resistance R 4; Second end of the 4th resistance R 4 links to each other with the input anode MIC+ of difference input circuit 110; First end of the 6th capacitor C 6 links to each other with first end of the 4th resistance R 4, the second end ground connection.
In the above-mentioned power circuit, the 4th capacitor C 4 and the 6th capacitor C 6 are the electrochemical capacitor of band polarity, and the 4th resistance R 4 is as the pull-up resistor of the input anode MIC+ of difference input circuit 110.
Below the course of work of described power circuit further is analyzed as follows:
Because the base stage of NPN pipe Q1 is connected to collector electrode by second resistance R 2, and collector electrode is connected to the 5V power end, therefore, the voltage that the base stage of NPN pipe Q1 has greater than Vbe makes the triode conducting, thereby at the emitter voltage MIC_VCCS of triode is 5V, at this moment, described power circuit draws power supply by the 3rd resistance R 3, the 4th resistance R 4 on the input anode MIC+ of difference input circuit 110.Each electric capacity in the described power circuit then can carry out filtering to the power supply signal that described power circuit produces, and disturbs to avoid that described input anode MIC+ is produced power supply.
Based on above-mentioned analysis as can be known, above-mentioned power circuit is connected between the power pins (input anode MIC+) and ground of microphone apparatus, has realized the power decoupling function.Thereby, even power end has signal to disturb, its influence to the power pins of microphone apparatus is also less, power pins from described microphone apparatus, the power supply that just can avoid the prior art common source and cause disturbs, thereby, improved the noise situations at microphone apparatus power pins place.Therefore, present embodiment is better with respect to the overall sound quality of the microphone apparatus of a last embodiment.
In sum, the utility model microphone apparatus is by before to echo cancellation process, earlier the audio signal of difference input is carried out Filtering Processing, high-frequency noise in the described audio signal of filtering, improve the noise that audio signal comprised that is used to carry out the echo elimination, thereby improved the overall sound quality of microphone apparatus.
Further, the utility model microphone apparatus also is provided with the power circuit of independent power supply except described Filtering Processing, thereby has further improved the overall sound quality of microphone apparatus.
More than disclose many aspects of the present utility model and execution mode, it will be understood by those skilled in the art that others of the present utility model and execution mode.Disclosed many aspects and execution mode just are used to illustrate in the utility model, are not to be to qualification of the present utility model, and real protection range of the present utility model and spirit should be as the criterion with claims.
Claims (8)
1. microphone apparatus, comprise: input circuit, echo cancel circuit and output circuit, described output circuit is connected in the output of echo cancel circuit, it is characterized in that, also comprise: low pass filter, described low pass filter is connected in the output of described input circuit; Described echo cancel circuit is connected in the output of described low pass filter.
2. microphone apparatus as claimed in claim 1 is characterized in that, described input circuit is the difference input circuit; Described output circuit is a differential output circuit; Described low pass filter comprises first low pass filter and second low pass filter, and described first low pass filter and second low pass filter are connected in the output of described input circuit jointly.
3. microphone apparatus as claimed in claim 2 is characterized in that, described first low pass filter comprises first input resistance and first electric capacity of series connection; Described second low pass filter comprises second input resistance and second electric capacity of series connection.
4. microphone apparatus as claimed in claim 3 is characterized in that, described first input resistance is identical with the resistance of second input resistance; Described first electric capacity is identical with the capacitance of second electric capacity.
5. microphone apparatus as claimed in claim 1 is characterized in that, described microphone apparatus also comprises: power circuit, described power circuit is connected in the input of described input circuit.
6. microphone apparatus as claimed in claim 2 is characterized in that, described microphone apparatus also comprises: power circuit, described power circuit are connected in the input anode of described difference input circuit.
7. microphone apparatus as claimed in claim 6 is characterized in that, described power circuit comprises: second resistance, the 3rd resistance, the 4th resistance, the 3rd electric capacity, the 4th electric capacity, the 5th electric capacity, the 6th electric capacity and NPN pipe, wherein,
The collector electrode of NPN pipe, emitter connect first power end and second source end respectively, and base stage links to each other with second end of second resistance;
First end of second resistance links to each other with first power end, and second end links to each other with first end of the 3rd electric capacity, the 4th electric capacity;
The 3rd electric capacity, the 4th electric capacity parallel connection, the equal ground connection of second end;
First end of the 5th electric capacity links to each other with the emitter of NPN pipe, the second end ground connection;
First end of the 3rd resistance links to each other with the second source end, and second end links to each other with first end of the 4th resistance;
Second end of the 4th resistance links to each other with the input anode of difference input circuit;
First end of the 6th electric capacity links to each other with first end of the 4th resistance, the second end ground connection.
8. microphone apparatus as claimed in claim 7 is characterized in that, described the 4th electric capacity and the 6th electric capacity are the electrochemical capacitor of band polarity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010206884130U CN202059560U (en) | 2010-12-29 | 2010-12-29 | Microphone device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010206884130U CN202059560U (en) | 2010-12-29 | 2010-12-29 | Microphone device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202059560U true CN202059560U (en) | 2011-11-30 |
Family
ID=45019522
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010206884130U Expired - Lifetime CN202059560U (en) | 2010-12-29 | 2010-12-29 | Microphone device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202059560U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102572644A (en) * | 2010-12-29 | 2012-07-11 | 上海博泰悦臻电子设备制造有限公司 | Microphone device |
| CN107864434A (en) * | 2017-09-30 | 2018-03-30 | 深圳市艾特智能科技有限公司 | Disappear talk-back circuit |
-
2010
- 2010-12-29 CN CN2010206884130U patent/CN202059560U/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102572644A (en) * | 2010-12-29 | 2012-07-11 | 上海博泰悦臻电子设备制造有限公司 | Microphone device |
| CN102572644B (en) * | 2010-12-29 | 2015-07-15 | 上海博泰悦臻电子设备制造有限公司 | Microphone device |
| CN107864434A (en) * | 2017-09-30 | 2018-03-30 | 深圳市艾特智能科技有限公司 | Disappear talk-back circuit |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107105366B (en) | Multi-channel echo cancellation circuit and method and intelligent device | |
| CN103634439A (en) | Noise reduction processing system | |
| CN102223428A (en) | Noise reducing method and mobile terminal | |
| CN102572644B (en) | Microphone device | |
| CN103297894A (en) | Earphone power amplifier, working method and mobile terminal equipment | |
| CN106790882A (en) | Communication Dolby circuit and noise-reduction method | |
| CN105322985A (en) | System and method for testing Bluetooth connection of vehicle-borne multimedia equipment | |
| US20120308041A1 (en) | Circuit assembly for processing an electrical signal of a microphone | |
| CN102543093B (en) | Microphone device | |
| CN102387429A (en) | Audio signal switching device and audio signal transmission system | |
| CN202059560U (en) | Microphone device | |
| CN103402038B (en) | Under Mobile phone hand-free state, eliminate method and the device of the echo of the other side's receiver | |
| CN201965907U (en) | Microphone device | |
| CN102932712B (en) | A kind of interface circuit design method, system and interface circuit | |
| CN105072241A (en) | Anti-sidetone circuit of intercom system isolation transformer | |
| CN204795237U (en) | Intercom system isolation transformer antisidetone circuit | |
| CN2694649Y (en) | Microphone input circuit capable removing noises | |
| CN203151729U (en) | Multifunctional earphone | |
| CN105451131A (en) | Monophone system and control-switchable monophone method | |
| CN112637438B (en) | Entrance guard double-end intercom method and system based on single-line transmission | |
| CN209962694U (en) | Echo cancellation circuit and electroacoustic equipment | |
| CN107172540A (en) | A kind of Dolby circuit, filter circuit and the equipment of earphone Mike signal | |
| CN2817244Y (en) | Mobile phone sharing sigle circuit for talking and ringing | |
| CN209358622U (en) | Echo suppression circuit and call class of electronic devices | |
| CN208285523U (en) | A kind of vehicle-mounted talkback unit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20111130 |