CN202475405U - Audio receiver, portable equipment with same, and audio communication system - Google Patents
Audio receiver, portable equipment with same, and audio communication system Download PDFInfo
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- CN202475405U CN202475405U CN2012200604332U CN201220060433U CN202475405U CN 202475405 U CN202475405 U CN 202475405U CN 2012200604332 U CN2012200604332 U CN 2012200604332U CN 201220060433 U CN201220060433 U CN 201220060433U CN 202475405 U CN202475405 U CN 202475405U
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Abstract
The utility model relates to an audio receiver, portable equipment with the same, and an audio communication system. The audio receiver is applied to a wireless microphone system, and comprises a local oscillator, a mixer, an analogue-to-digital converter, a frequency selecting filter, a demodulator, a channel allocation logic module, a correcting value estimation module, a logic processing circuit and an Epsilon-Delta modulator, wherein the local oscillator comprises a crystal oscillator, a phase discriminator, a loop filter, a voltage-controlled oscillator and a multi-frequency dividing ratio frequency divider. The accuracy of receiving frequency of the audio receiver can be improved, and production cost and requirements for the frequency accuracy of the crystal oscillator can be lowered.
Description
Technical field
The utility model relates to microelectronic, relates in particular to a kind of voice receiver, has portable equipment, the audio communication system of voice receiver.
Background technology
When people carried out exchange activity in bigger spaces such as meeting room, stages, the acoustic energy of sending because of natural sound source (like speech, instrument playing and performance etc.) was limited, and its sound pressure level is decay rapidly along with the increase of propagation distance; Add influence of environmental noise; Make the propagation distance of sound shorter, therefore need to use public address system to amplify, with the signal amplification of sound source; Improve the sound pressure level in the sound field scope effectively, increase the propagation distance of sound.Common wireless microphone system mainly is made up of equipment such as wireless microphone, audio transmitter, voice receiver, power amplifier and loud speakers.Wireless microphone will be converted into audio signal from the voice signal of source of sound; Audio transmitter carries out the FM modulation to this audio signal; Obtain after the radiofrequency signal this radiofrequency signal with form of electromagnetic wave from launching in the air, voice receiver receives electromagnetic wave, then radiofrequency signal is amplified, is obtained audio signal after the demodulation; This audio signal is delivered to power amplifier, finally delivers to loud speaker through the amplification of power amplifier and is converted into sound.
As shown in Figure 1; Structural representation for prior art sound intermediate frequency receiver; Frequency mixer 11 carries out the radiofrequency signal of different frequency and the local oscillated signal of local oscillator 10 generations to obtain the intermediate frequency FM signal in the certain frequency scope after the mixing; This intermediate frequency FM signal is sent into demodulator 13 after frequency-selecting filter 12 filtering, demodulator 13 demodulates audio signal.When transferring platform, the frequency of the local oscillated signal that local oscillator 10 generates can change, and the radiofrequency signal of different channel will be converted to the intermediate frequency FM signal in the certain frequency scope like this.Shown in Fig. 2 A; Structural representation for a kind of local oscillator in the prior art; PVC electric capacity 211 forms parallelly connected LC loop with inductance 212; Cooperate oscillating circuit 213, form a LC oscillator, the frequency of oscillation of LC oscillator is:
visible; Capacitance has directly determined frequency of oscillation; And the PVC capacitance is 30～50PPM/ ℃ with variation of temperature, and receiver is difficult to accurately to be operated on the target channel like this, always and certain deviation arranged.In traditional broadcast; The tranmitting frequency of supposing transmitter is accurate, and operation of receiver is in the frequency range of 100MHz, if 2 ℃ of environmental changes in the course of work; Then receiving and dispatching frequency difference is: (30～50) 2 ℃ of * 100MHz=of PPM/ ℃ of * (6～10) kHz; And in traditional broadcast, the bandwidth range of intermediate frequency FM signal is 50kHz～100kHz, exists under the situation of 6～10kHz transmitting-receiving frequency difference; Most of intermediate frequency FM signal can get into demodulator 13 through frequency-selecting filter 12, and demodulator 13 carries out demodulation to intermediate frequency FM signal again and obtains audio signal.The structure applications of conventional audio receiver when the wireless public address system of 900MHz frequency range, is supposed 2 ℃ of variation of ambient temperature equally, and had only the PVC capacitance of local oscillator unstable in the hypothesis receiver; Its capacitance is 30～50PPM/ ℃ with variation of temperature; Then the transmitting-receiving frequency difference of wireless public address system is: (30～50) 2 ℃ of * 900MHz=of PPM/ ℃ of * (54～90) kHz, and the bandwidth of the intermediate frequency FM signal of wireless public address system is 50kHz, the bandwidth of the transmitting-receiving frequency difference of (54～90) kHz and intermediate frequency FM signal is suitable; And in side circuit; The PVC capacitance is bigger with variation of temperature, causes maximum transmitting-receiving frequency difference to reach the several times of intermediate frequency FM signal bandwidth, and useful signal at all can't be through the frequency-selecting filter 12 in the receiver; Signal after 13 pairs of filtrations of demodulator is separated timing, also can't obtain correct audio signal.
Unstable in order to overcome the PVC capacitance, and in uhf band and the shortcoming that enlarges of high band operation frequency influence more, the local oscillator of prior art adopts crystal oscillator and fractional-n phase-locked loop (Phase-Locked Loop; Be called for short: PLL) structure combining realizes; Shown in Fig. 2 B, be the structural representation of another kind of local oscillator in the prior art, this local oscillator comprises crystal oscillator 101,1/M frequency divider 22 and phase-locked loop (Phase-Locked Loop; Be called for short: PLL) 23; PLL 23 comprises phase discriminator 103, loop filter 104, voltage controlled oscillator 105 and 1/N frequency divider 234, and wherein, M and N are the divide ratio frequency dividing ratio.The output frequency Fvco of voltage controlled oscillator 105 is exactly the receive frequency of receiver; Therefore should be according to the free oscillation frequency and the receiving channels value of crystal oscillator 101; Set the value of M and N, make the output frequency Fvco of voltage controlled oscillator 105 try one's best near the receiving channels value.The free oscillation frequency of supposing crystal oscillator 101 is Fxtal; The output frequency Fvco=Fxtal/M*N of voltage controlled oscillator 105 so; And the output frequency Fvco of voltage controlled oscillator 105 is exactly the receive frequency of receiver; Therefore, behind selected divide ratio frequency dividing ratio M and the N, the receive frequency of voice receiver has just been confirmed.
For the voice receiver that adopts local oscillator shown in Fig. 2 B; The accuracy of the receive frequency of voice receiver receives the limitations affect of following two factors: one is the minimum channel stepped intervals Fstep of voice receiver; Fstep=Fxtal/M; Fstep is big more, and when there were deviation in receive frequency and tranmitting frequency, the adjustable precision of receive frequency accuracy of receiver was just low more; Another is the accurate stability of frequency of crystal oscillator, and generally speaking, the frequency accuracy of crystal oscillator is all below 0.5ppm/ ℃, guaranteed operation of receiver after, variation of ambient temperature can not make a big impact to receive frequency.But the crystal of producing in batches, its frequency accuracy has the fabrication error of 20ppm～50ppm, if directly be used for high frequency wireless microphone system such as UHF, the error of receive frequency is unacceptable equally.Frequency accuracy in the prior art; Generally speaking; The minimum channel stepped intervals Fstep of voice receiver is not less than 25kHz, and the too low meeting of Fstep makes the design of PLL loop become very difficult, though can adopt the automatic frequency correction technology to make receiver can adjust the frequency of local oscillated signal according to the tranmitting frequency of transmitter; But correction error is suitable with minimum channel stepped intervals Fstep, makes that finally the accuracy of receive frequency of receiver is lower.In order further to improve the accuracy of the receive frequency of voice receiver; Usually adopt the way of the frequency accuracy that improves crystal oscillator; At this moment just can only adopt the frequency accuracy of calibrating crystal oscillator manually; Or select the higher crystal oscillator of frequency accuracy, therefore can't reduce requirement, and increase production cost the frequency accuracy of crystal oscillator.
The utility model content
The utility model provides a kind of voice receiver, has the portable equipment of voice receiver, audio communication system; In order to the accuracy of the receive frequency that realize to improve voice receiver, reduce production costs simultaneously and to the requirement of the frequency accuracy of crystal oscillator.
The utility model provides a kind of voice receiver, and said voice receiver is applied to wireless microphone system, and said voice receiver comprises:
Local oscillator; Comprise crystal oscillator, phase discriminator, loop filter, voltage controlled oscillator and many frequency dividing ratios frequency divider, said phase discriminator is connected with said crystal oscillator, and said loop filter is connected with said phase discriminator; Said voltage controlled oscillator is connected with said loop filter; Said many frequency dividing ratios frequency divider is connected between said voltage controlled oscillator and the said phase discriminator, and wherein, said many frequency dividing ratios frequency divider has two above frequency dividing ratios;
Frequency mixer is connected with said voltage controlled oscillator;
Analog to digital converter is connected with said frequency mixer;
Frequency-selecting filter is connected with said analog to digital converter;
Demodulator is connected with said frequency-selecting filter;
The channel allocation logic module; Be connected with said many frequency dividing ratios frequency divider, be used for free oscillation frequency Fxtal, generate integer frequency ratio N and fractional frequency division and compare P according to receiving channels value Fchan and said crystal oscillator; Said integer frequency ratio N is sent to said many frequency dividing ratios frequency divider; Wherein, integer frequency ratio N equals the integer part of Fchan/Fxtal, and fractional frequency division equals the fractional part of Fchan/Fxtal than P;
The correcting value estimation module is connected with said demodulator, is used for the signal according to said demodulator output, estimates the correcting value Fafc of said fractional frequency division than P;
Logic processing circuit is connected with said channel allocation logic module with said correcting value estimation module, and said logical circuit receives said fractional frequency division than P and said correcting value Fafc, carries out following logical process: P+Fafc/Fxtal;
Sigma-delta modulator is connected between said logic processing circuit and the said many frequency dividing ratios frequency divider;
Said many frequency dividing ratios frequency divider is used for according to said frequency dividing ratio N, generates said two above frequency dividing ratios, under the control of the output signal of said sigma-delta modulator, between said two above frequency dividing ratios, switches.
The utility model also provides a kind of portable equipment with voice receiver, comprising:
The channel option interface;
Voice receiver;
The audio signal output interface;
Wherein, said voice receiver comprises arbitrary module of aforementioned voice receiver.
The utility model also provides a kind of audio communication system, comprises audio transmitter and voice receiver, and said voice receiver comprises arbitrary module of aforementioned voice receiver.
In the utility model; The minimum channel stepped intervals of voice receiver is very little, through adopting the automatic frequency correction technology, can automatically the receive frequency of receiver be aimed at the tranmitting frequency of transmitter; Reduced requirement to the frequency accuracy of crystal oscillator; Needn't adopt the frequency accuracy of calibrating crystal oscillator manually, also needn't select the higher crystal oscillator of frequency accuracy, become to produce cost and to the requirement of the frequency accuracy of crystal oscillator thereby reduced.
Description of drawings
Fig. 1 is the structural representation of prior art sound intermediate frequency receiver;
Fig. 2 A is the structural representation of a kind of local oscillator in the prior art;
Fig. 2 B is the structural representation of another kind of local oscillator in the prior art;
Fig. 3 is the structural representation of the utility model voice receiver embodiment;
Fig. 4 is the structural representation that the utlity model has the portable equipment embodiment of voice receiver.
Embodiment
Below in conjunction with Figure of description and embodiment the utility model is done further to describe.
As shown in Figure 3; Structural representation for the utility model voice receiver embodiment; This voice receiver can be applied to wireless microphone system, and this voice receiver can comprise local oscillator 10, frequency mixer 11, analog to digital converter 303, frequency-selecting filter 12, demodulator 13, correcting value estimation module 307, channel allocation logic module 308, logic processing circuit 309, sigma-delta modulator 310.Wherein, local oscillator 10 comprises crystal oscillator 101, phase discriminator 103, loop filter 104, voltage controlled oscillator 105 and many frequency dividing ratios frequency divider 106.Be connected, phase discriminator 103 is connected with crystal oscillator 101, loop filter 104 is connected with phase discriminator 103, voltage controlled oscillator 105 is connected with loop filter 104, many frequency dividing ratios frequency divider 106 is connected between voltage controlled oscillator 105 and the phase discriminator 103.Frequency mixer 11 is connected with voltage controlled oscillator 105; Analog to digital converter 303 is connected with frequency mixer 11; Frequency-selecting filter 12 is connected with analog to digital converter 303; Demodulator 13 is connected with frequency-selecting filter 12; The correcting value estimation module is connected with demodulator 13; Channel allocation logic module 308 is connected with many frequency dividing ratios frequency divider 106; Logic processing circuit 309 is connected with channel allocation logic module 308 with the correcting value estimation module; Sigma-delta modulator 310 is connected between logic processing circuit 309 and the many frequency dividing ratios frequency divider 106.
Many frequency dividing ratios frequency divider 106 has two above frequency dividing ratios in the present embodiment.
Channel allocation logic module 308 is used for the free oscillation frequency Fxtal according to receiving channels value Fchan, crystal oscillator 101; Generate integer frequency ratio N and fractional frequency division and compare P; Integer frequency ratio N is sent to many frequency dividing ratios frequency divider 106, fractional frequency division is sent to logic processing circuit 309 than P.Correcting value estimation module 307 is used for the signal according to demodulator 13 outputs; Estimation is to the correcting value Fafc of said fractional frequency division than P; Correcting value Fafc is sent to logic processing circuit 309, the temperature variant unsteadiness of frequency of oscillation that correcting value Fafc can compensated crystal oscillator 101.Logic processing circuit 309 is used to receive fractional frequency division than P and correcting value Fafc, accomplishes following logical process: P+Fafc/Fxtal, and the result of logical process is sent to sigma-delta modulator 310.Sigma-delta modulator 310 is encoded to low-resolution signal to high-resolution signal with pulse density modulated through over-sampling, promptly representes the high-resolution signal of low sampling rate with the low-resolution signal of high sampling rate.Many frequency dividing ratios frequency divider 106 is used for according to frequency dividing ratio N, generates two above frequency dividing ratios, under the control of the output signal of sigma-delta modulator 310, between two above frequency dividing ratios, switches continuously, and the frequency of switching is the sample rate of sigma-delta modulator 310.
Particularly, integer frequency ratio N equals the integer part of Fchan/Fxtal, and fractional frequency division equals the fractional part of Fchan/Fxtal than P.The number of two above frequency dividing ratios that many frequency dividing ratios frequency divider 106 generates is less than or equal to 2t; T is the figure place of the output signal of sigma-delta modulator 310; These two above frequency dividing ratios comprise N and N+1, equably to the expansion of the both sides of N and N+1, are the center basically with N again.For example: many frequency dividing ratios frequency divider 106 has 4 frequency dividing ratios;
be N=4 then,
these 4 frequency dividing ratios can be respectively N=4, N+1=5, N-1=3 and N+2=6.Many frequency dividing ratios frequency divider 106 ceaselessly switches between two above frequency dividing ratios under the control of the output signal of sigma-delta modulator 310, makes the frequency dividing ratio of many frequency dividing ratios frequency divider 106 equal N+P+Fafc/Fxtal.
The course of work of present embodiment is following: local oscillator 10 generates local oscillated signal; Frequency mixer 11 carries out mixing with the radiofrequency signal and the local oscillated signal that receive; Analog to digital converter 303 carries out analog-to-digital conversion with the signal after the mixing; Signal after 12 pairs of analog-to-digital conversion of frequency-selecting filter carries out the intermediate frequency FM signal that frequency-selective filtering obtains receiving channels, and 13 couples of intermediate frequency FM of demodulator signal carries out demodulation process and obtains audio signal and export this audio signal.Present embodiment has adopted following automatic frequency correction technology: phase discriminator 103, loop filter 104, voltage controlled oscillator 105 and many frequency dividing ratios frequency divider 106 form a phase-locked loop; Correcting value estimation module 307 is obtained the correcting value Fafc of fractional frequency division than P according to the audio signal of demodulator 13 outputs; And correcting value Fafc fed back to local oscillator 10 through logic processing circuit 309 and sigma-delta modulator 310; Through after the processing of phase-locked loop; Behind real-time tranception frequency difference=0, the receive frequency of receiver is aimed at the tranmitting frequency of transmitter, and this moment, correcting value Fafc no longer changed.Present embodiment employing automatic frequency correction technology makes behind real-time tranception frequency difference=0; Frequency dividing ratio=the N+P+Fafc/Fxtal of many frequency dividing ratios frequency divider 106; And frequency=Fxtal* (the N+P+Fafc/Fxtal)=Fchan+Fafc of the local oscillated signal that local oscillator 10 generates; With respect to prior art, Fafc has compensated the temperature variant unsteadiness of frequency of oscillation of crystal oscillator 101, makes that the frequency of local oscillated signal is more accurate.
In the present embodiment, the minimum channel stepped intervals of voice receiver depends on the dynamic range of sigma-delta modulator 310, and for example: the dynamic range of sigma-delta modulator 310 is 120dB, and then the minimum channel stepped intervals of voice receiver is Fxtal * 10
-6, suppose Fxtal=20MHz, then minimum channel stepped intervals is 20Hz, well below the minimum channel stepped intervals 25KHz of Fig. 1 sound intermediate frequency receiver.Because the minimum channel stepped intervals of voice receiver is very little; Through adopting the automatic frequency correction technology; Can automatically the receive frequency of receiver be aimed at the tranmitting frequency of transmitter, reduce requirement, needn't adopt the frequency accuracy of calibrating crystal oscillator manually the frequency accuracy of crystal oscillator; Also needn't select the higher crystal oscillator of frequency accuracy, become to produce cost and to the requirement of the frequency accuracy of crystal oscillator thereby reduced.
Further; In the present embodiment, phase discriminator 103, loop filter 104, voltage controlled oscillator 105, many frequency dividing ratios frequency divider 106, frequency mixer 11, analog to digital converter 303, frequency-selecting filter 12, demodulator 13, correcting value estimation module 307, channel allocation logic module 308, logic processing circuit 309, sigma-delta modulator 310 can be integrated on the integrated circuit.
In addition, again referring to structural representation shown in Figure 3, correcting value estimation module 307 can comprise direct current extraction unit 3071, frequency map unit 3072 and integrator 3073.Wherein, direct current extraction unit 3071 is connected with demodulator 13, and direct current extraction unit 3072 is connected with direct current extraction unit 3071, and integrator is connected with frequency map unit 3072.Direct current extraction unit 3071 is used to extract the direct current component of the signal of demodulator output; Frequency map unit 3072 is used for this direct current component is mapped as the real-time tranception frequency difference, and 3073 pairs of real-time tranception frequency differences of integrator are carried out integration and obtained the correcting value of fractional frequency division than P.
Further; Referring to structural representation shown in Figure 3, present embodiment can also comprise deaccentuator 312, expander 311 and digital to analog converter 306 again, and deaccentuator 312 is connected with demodulator 13; Expander 311 is connected with deaccentuator 312, and digital to analog converter 306 is connected with expander 311.Expander 311 is used for the dynamic range of spread signal.Alternatively, present embodiment can comprise one or two circuit in deaccentuator 312, expander 311 and the digital to analog converter 306.In addition, deaccentuator 312, expander 311 and digital to analog converter 306 can be integrated in the aforementioned integrated circuit.
As shown in Figure 4; Structural representation for the portable equipment embodiment that the utlity model has voice receiver; Can comprise channel option interface 41, voice receiver 42 and audio signal output interface 43; Wherein, channel option interface 41 is connected with voice receiver 42, and audio signal output interface 43 is connected with voice receiver 42.Voice receiver 42 can be the voice receiver among the aforementioned voice receiver embodiment.Audio signal output interface 43 can export simulated audio signal, digital audio and video signals or above both.
The utility model also provides a kind of audio communication system embodiment; Comprise audio transmitter and voice receiver; Audio transmitter becomes radiofrequency signal with Audio Signal Processing and sends; Voice receiver will be handled radiofrequency signal and obtain audio signal, and this voice receiver can be the voice receiver among the aforementioned voice receiver embodiment.
What should explain at last is: above embodiment is only unrestricted in order to the technical scheme of explanation the utility model; Although the utility model is specified with reference to preferred embodiment; Those of ordinary skill in the art is to be understood that; Can make amendment or be equal to replacement the technical scheme of the utility model, and not break away from the spirit and the scope of the utility model technical scheme.
Claims (8)
1. a voice receiver is characterized in that, said voice receiver is applied to wireless microphone system, and said voice receiver comprises:
Local oscillator; Comprise crystal oscillator, phase discriminator, loop filter, voltage controlled oscillator and many frequency dividing ratios frequency divider, said phase discriminator is connected with said crystal oscillator, and said loop filter is connected with said phase discriminator; Said voltage controlled oscillator is connected with said loop filter; Said many frequency dividing ratios frequency divider is connected between said voltage controlled oscillator and the said phase discriminator, and wherein, said many frequency dividing ratios frequency divider has two above frequency dividing ratios;
Frequency mixer is connected with said voltage controlled oscillator;
Analog to digital converter is connected with said frequency mixer;
Frequency-selecting filter is connected with said analog to digital converter;
Demodulator is connected with said frequency-selecting filter;
The channel allocation logic module; Be connected with said many frequency dividing ratios frequency divider, be used for free oscillation frequency Fxtal, generate integer frequency ratio N and fractional frequency division and compare P according to receiving channels value Fchan and said crystal oscillator; Said integer frequency ratio N is sent to said many frequency dividing ratios frequency divider; Wherein, integer frequency ratio N equals the integer part of Fchan/Fxtal, and fractional frequency division equals the fractional part of Fchan/Fxtal than P;
The correcting value estimation module is connected with said demodulator, is used for the signal according to said demodulator output, estimates the correcting value Fafc of said fractional frequency division than P;
Logic processing circuit is connected with said channel allocation logic module with said correcting value estimation module, and said logical circuit receives said fractional frequency division than P and said correcting value Fafc, carries out following logical process: P+Fafc/Fxtal;
Sigma-delta modulator is connected between said logic processing circuit and the said many frequency dividing ratios frequency divider;
Said many frequency dividing ratios frequency divider is used for according to said frequency dividing ratio N, generates said two above frequency dividing ratios, under the control of the output signal of said sigma-delta modulator, between said two above frequency dividing ratios, switches.
2. voice receiver according to claim 1; It is characterized in that said phase discriminator, loop filter, voltage controlled oscillator, many frequency dividing ratios frequency divider, frequency mixer, analog to digital converter, frequency-selecting filter, demodulator, correcting value estimation module, channel allocation logic module, adder, sigma-delta modulator are integrated on the integrated circuit.
3. voice receiver according to claim 1 and 2 is characterized in that, also comprises:
Digital to analog converter is connected with said demodulator.
4. voice receiver according to claim 1 and 2 is characterized in that, said correcting value estimation module comprises:
The direct current extraction unit is connected with said demodulator, is used to extract the direct current component of the signal of said demodulator output;
The frequency map unit is connected with said direct current extraction unit, is used for said direct current component is mapped as the real-time tranception frequency difference;
Integrator is connected with said frequency map unit, is used for that said real-time tranception frequency difference is carried out integration and obtains the correcting value Fafc of said fractional frequency division than P.
5. voice receiver according to claim 1 and 2 is characterized in that, also comprises:
Expander is connected between said demodulator and the said digital to analog converter, is used to expand the dynamic range of the signal of said demodulator output.
6. voice receiver according to claim 1 and 2 is characterized in that, also comprises:
Deaccentuator is connected between said demodulator and the said digital to analog converter.
7. the portable equipment with voice receiver is characterized in that, comprising:
The channel option interface;
Voice receiver;
The audio signal output interface;
Wherein, said voice receiver comprises the arbitrary described voice receiver of claim 1-6.
8. an audio communication system comprises audio transmitter and voice receiver, it is characterized in that, said voice receiver comprises the arbitrary described voice receiver of claim 1-6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012200604332U CN202475405U (en) | 2012-02-22 | 2012-02-22 | Audio receiver, portable equipment with same, and audio communication system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012200604332U CN202475405U (en) | 2012-02-22 | 2012-02-22 | Audio receiver, portable equipment with same, and audio communication system |
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| CN202475405U true CN202475405U (en) | 2012-10-03 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2012200604332U Expired - Lifetime CN202475405U (en) | 2012-02-22 | 2012-02-22 | Audio receiver, portable equipment with same, and audio communication system |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102970030A (en) * | 2012-11-01 | 2013-03-13 | 南京国睿安泰信科技股份有限公司 | System for achieving spectrum analyzer down-conversion by using broadband local oscillator and high frequency phase discrimination |
| CN103346812A (en) * | 2013-07-01 | 2013-10-09 | 北京昆腾微电子有限公司 | Channel switching method and device of audio receiving chip and audio receiving machine |
| CN105897298A (en) * | 2016-06-03 | 2016-08-24 | 北京航空航天大学 | Multi-stage modular wireless transceiver experimental platform |
-
2012
- 2012-02-22 CN CN2012200604332U patent/CN202475405U/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102970030A (en) * | 2012-11-01 | 2013-03-13 | 南京国睿安泰信科技股份有限公司 | System for achieving spectrum analyzer down-conversion by using broadband local oscillator and high frequency phase discrimination |
| CN103346812A (en) * | 2013-07-01 | 2013-10-09 | 北京昆腾微电子有限公司 | Channel switching method and device of audio receiving chip and audio receiving machine |
| CN103346812B (en) * | 2013-07-01 | 2015-11-25 | 昆腾微电子股份有限公司 | The tune platform method and apparatus of audio frequency receiving chip and voice receiver |
| CN105897298A (en) * | 2016-06-03 | 2016-08-24 | 北京航空航天大学 | Multi-stage modular wireless transceiver experimental platform |
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Owner name: BEIJING KUNTENG MICRO-ELECTRONICS INC. Free format text: FORMER NAME: KT MICRO, INC. Owner name: KUNTENG MICROELECTRONIC CO., LTD. Free format text: FORMER NAME: BEIJING KUNTENG MICRO-ELECTRONICS INC. |
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Address after: 100195 Beijing, Yuquan, No. 23 Haidian District Road, building No. 4 Patentee after: KT MICRO, Inc. Address before: 100195 Beijing, Yuquan, No. 23 Haidian District Road, building No. 4 Patentee before: Beijing Kunteng electronic Limited by Share Ltd. |
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Address after: 100195 Beijing, Yuquan, No. 23 Haidian District Road, building No. 4 Patentee after: Beijing Kunteng electronic Limited by Share Ltd. Address before: 100097 Beijing city Haidian District landianchang Road No. 2 Jin Yuan Business Center Building 2, block B, 8 A, B Patentee before: KT MICRO Inc. (BEIJING) |
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Granted publication date: 20121003 |