CN204465715U - Simulated television transmitter digital-to-analogue is with the system broadcast - Google Patents
Simulated television transmitter digital-to-analogue is with the system broadcast Download PDFInfo
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- CN204465715U CN204465715U CN201520152992.XU CN201520152992U CN204465715U CN 204465715 U CN204465715 U CN 204465715U CN 201520152992 U CN201520152992 U CN 201520152992U CN 204465715 U CN204465715 U CN 204465715U
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Abstract
Simulated television transmitter digital-to-analogue is with the system broadcast, comprise signal source converting system, decoder, switch, transmitting antenna, signal source is connecting signal source converting system and decoder respectively, signal source converting system is connected with multiplexer in turn, digital modulator, amplifier, the output of decoder is connected with exciter, the output of amplifier and exciter all connects switch, the output of switch is connected with signal distribution module in turn, 16 power amplifier modules in parallel, signal syntheses filtration module and directional coupler, the test port of directional coupler connects monitor, the output of directional coupler connects transmitting antenna, being changed by the form of signal source converting system to signal source, then one of them exciter be replaced by digital modulator and increase amplifier in digital modulator rear end, achieving digital-to-analogue with broadcasting.The utility model achieves the transformation of simulated television with low cost, solves the problem that current simulated television improvement cost is high.
Description
Technical field
The utility model belongs to simulated television digital improvement field, is specifically related to a kind of simulated television transmitter digital-to-analogue with the system broadcast.
Background technology
Point out about " ground digital television broadcast nerve of a covering development plan " file content according to General Bureau of Radio, Film and Television: move forward steadily terrestrial television digitlization conversion, progressively increase terrestrial DTV coverage and number of programs, to the end of the year 2018, complete digitlization switch transition, the year two thousand twenty whole nation stops simulated television broadcasting.Meanwhile, accelerate to advance terrestrial DTV development, improve quality and the level of radio and television public service, meet the inspirit culture demand that the people is growing, tool is of great significance.Adopt digital technology that various television equipment not only can be made to obtain the performance higher than original analogue means, but also the New function that analogue technique cannot realize can be realized.
But Digital Television replaces simulated television and needs longer evolution, with reference to the transition experience of developed countries, consider the renewal of receiving terminal, " digital-to-analogue " is with broadcasting and will continuing the quite a while.
In view of, need very large fund input to comprehensive replacing of the huge simulating transmitting machine of existing use amount, the whole nation is each launches and covers unit and can not realize comprehensive digitlization with settling at one go.
Be illustrated in figure 1 in prior art, simulated television transmitter principle block diagram; This simulating transmitting machine have employed the configuration of double excitation device, the ASI signal source of the MEPG2 form sent here by front-end adapter enters decoder, after demodulating the TV programme of needs, analogue audio frequency and vision signal are sent into simultaneously in two exciters, switch well ensure that the hot-swap of double excitation, finally by 2 grades of distribution, i.e. 2 distributors and two 8 distributors, radiofrequency signal is delivered in 16 amplifier tubes and finally amplify, enter No. 2 synthesizers via 28 tunnel synthesis and enter antenna transmission system.
How to utilize existing device resource, explore covered ground digitlization and seem particularly important.
Utility model content
The utility model aims to provide a kind of with low cost, effective simulated television transmitter digital-to-analogue with the system broadcast.
For solving the problems of the technologies described above, the utility model provides following technical scheme: simulated television transmitter digital-to-analogue is with the system broadcast, comprise signal source converting system, decoder, switch, transmitting antenna, signal source is the input of connecting signal source converting system and the input of decoder respectively, the output of signal source converting system is connected with multiplexer in turn, digital modulator, amplifier, the output of decoder is connected with exciter, the output of amplifier and exciter all connects switch, the output of switch is connected with signal distribution module in turn, 16 power amplifier modules in parallel, signal syntheses filtration module and directional coupler, the test port of directional coupler connects monitor, the output of directional coupler connects transmitting antenna.
Signal source converting system comprises adapter, 4 tunnel transcoders, 2 outputs of adapter connect the input of 24 tunnel transcoders respectively, the output of each 4 tunnel transcoders is all connected with 4 road AVS+ encoders, the input of the output connection multiplexing device of 24 road AVS+ encoders.
Signal distribution module comprises 1 No. 2 synthesizer and two No. 8 synthesizers, the input of described No. 2 synthesizers is connected with the output of switch, two outputs of No. 2 synthesizers connect the input of two No. 8 synthesizers respectively, the output wired power amplifier module of two No. 8 synthesizers.
First and second attenuator, prime amplifier tube, four intermediate amplifier tubes and the final stage amplifying unit be made up of four final stage amplifier tubes, the output of the first attenuator connects the input of prime amplifier tube, the output of prime amplifier tube connects the input of the second attenuator, the output of the second attenuator connects the input of four intermediate amplifier tubes, the output of four intermediate amplifier tubes connects four final stage amplifier tubes by 4 distributors, and the output of four final stage amplifier tubes connects the input all connecting No. 4 synthesizers.
Signal syntheses filtration module comprises No. 2 synthesizers and two No. 8 synthesizers, the signal output part of 16 power amplifier modules connects the input of two No. 8 synthesizers respectively, the synthesis output of each No. 8 synthesizers connects No. 2 synthesizers respectively by a digital band-pass filter, and the load outputs of No. 8 synthesizers connects load group.
The multiplication factor of amplifier is 30-33dB.
The power attenuation amount of described first attenuator is 2dB, and the power attenuation amount of described second attenuator is 3dB.
By above technical scheme, the beneficial effects of the utility model are: 1, the signal source converting system of front end, achieves the conversion of signal source, improve the quality of signal source, make it meet up-to-date international standard; 2, by one of them exciter is replaced by digital modulator, thus digital-to-analogue can be realized with the requirement broadcast; 3, digital modulator rear end increases amplifier, overcomes the power output of digital modulator own lower, cannot promote the shortcoming of simulating transmitting machine power amplifier module; 5, three grades of amplifications are set at power amplifier module, ensure that the band shoulder index of output signal; 6, increase attenuator before prime amplifier tube, its effect is to ensure impedance matching to greatest extent, improves signal stabilization; Increase attenuator before middle rank amplifier tube, its objective is that radiofrequency signal is not amplified because excessively fissioning and causes index to reduce in the process of this grade of amplification, thus avoid distorted signals; 8, the band pass filter of end setting, can carry out filtering to digital signal, avoid clutter to the interference of signal.
Accompanying drawing explanation
Fig. 1 is simulating transmitting machine structured flowchart in prior art;
Fig. 2 is system principle diagram described in the utility model;
Fig. 3 is signal source converting system theory diagram;
Fig. 4 is signal source distribution module theory diagram;
Fig. 5 is power amplifier module theory diagram;
Fig. 6 is signal syntheses filtration module.
Embodiment
Embodiment 1, simulated television transmitter digital-to-analogue is as shown in Figure 2 with the system broadcast, comprise signal source converting system, decoder, switch, transmitting antenna, signal source is the input of connecting signal source converting system and the input of decoder respectively, the output of signal source converting system is connected with multiplexer, digital modulator, amplifier in turn, amplifier is used for the power of amplifying signal, its multiplication factor is 30dB, it is lower that the amplifier arranged solves the power output of digital modulator own, cannot promote the problem of simulating transmitting machine power board.The output of decoder is connected with exciter, and the output of amplifier and exciter all connects switch, the switch of setting, by debugging exciter switched system, realizes modulus with broadcasting.The output of switch is connected with signal distribution module, 16 power amplifier modules in parallel, signal syntheses filtration module and directional coupler in turn, the test port of directional coupler connects monitor, and the output of directional coupler connects transmitting antenna.
Signal source converting system is used for encoding to signal source, changing, the signal source of MPEG2 form is converted to the signal of AVS+ form, it is made to meet up-to-date GB, as shown in Figure 3, comprise adapter and 4 tunnel transcoders, 2 outputs of adapter connect the input of 24 tunnel transcoders respectively, the output of each 4 tunnel transcoders are all connected with 4 road AVS+ encoders, the input of the equal connection multiplexing device of output of 24 road AVS+ encoders, thus the conversion of settling signal.In the process of conversion, the signal source of MPEG2 form carries out format conversion by adapter, be converted into ASI data flow, transcoding operation is carried out and encoder carries out recompile successively through 4 tunnel transcoders, signal is converted into the signal of AVS+ form, under the effect of multiplexer, the code check of every programs is set, making often to overlap TV expression program code check is 1.5Mbit/S, signal after conversion enters digital modulator, , for reducing costs, raise the efficiency simultaneously, the transfer process of this signal source is moved to signal source machine room, this system is positioned over signal source machine room.
Signal distribution module is used for being distributed equally as multichannel to signal, as shown in Figure 4, comprise 12 distributor and 28 distributors, the output of switch connects the input of 2 distributors, two outputs of 2 distributors connect the input of 28 distributors respectively, the output wired power amplifier module of 28 distributors, 2 tunnels and two 8 distributors can export same-phase, same frequency, radiofrequency signal with level, guarantee that each road watt level is impartial, thus guarantee synthesizing stable.
Power amplifier module is used for amplifying the power of signal, and inside is provided with variable potentiometer, and by regulating variable potentiometer can the multiplication factor of regulatory work amplification module, variable potentiometer be the equipment that power amplifier module just had originally.As shown in Figure 5, power amplifier module comprises the first and second attenuator, prime amplifier tube, 4 intermediate amplifier tubes and the final stage amplifying unit be made up of 4 final stage amplifier tubes, the output of the first attenuator connects the input of prime amplifier tube, the output of prime amplifier tube connects the input of the second attenuator, the output of the second attenuator connects the input of 4 intermediate amplifier tubes, the output of 4 intermediate amplifier tubes connects 4 final stage amplifier tubes by 14 distributor, the output of 4 final stage amplifier tubes all connects the input of No. 4 synthesizers, can ensure that the band shoulder of single power amplifier module meets international standard by arranging two attenuators.
The first attenuator and the second attenuator is increased respectively before prime amplifier tube and intermediate amplifier tube, ensure that the multiplication factor of the veneer of power amplifier module is at 45dB, wherein the power attenuation amount of the first attenuator is 2dB, its effect is to ensure impedance matching to greatest extent, improves signal stabilization; The power attenuation amount of the second attenuator is 3dB, and object is that radiofrequency signal is not amplified because excessively fissioning and causes index to reduce in the process of this grade of amplification, thus avoids distorted signals; Simultaneously by the variable potentiometer of adjustment power amplifier module, adjust the electric current of power amplifier module, method of adjustment is first reduce the static working current of intermediate amplifier tube, is reduced to 0.8A; Finally adjust the static working current of final stage amplifier tube, be reduced to 0.6-0.8A.
Signal syntheses filtration module is used for synthesizing amplified Hou 16 road signal, carries out the interference that signal is avoided in filtering to it simultaneously.As shown in Figure 6, signal syntheses filtration module comprises 2 No. 8 synthesizers and 1 No. 2 synthesizer, the signal output part of 16 power amplifier modules connects the input of 2 No. 8 synthesizers respectively, the synthesis output of each No. 8 synthesizers all connects No. 2 synthesizers by a band pass filter, and the load outputs of No. 8 synthesizers connects load group.
In the process of transformation, first by signal source converting system, signal source is changed, make it meet up-to-date international standard.
Then, carry out the transformation of equipment, because there being two exciters in simulated television transmitter, for realizing modulus with broadcasting, one of them exciter grand master pattern being intended television transmitter removes, and is replaced by digital modulator, increase amplifier in digital modulator rear end simultaneously, the output signal of digital modulator is amplified, thus it is lower to overcome the power output of digital modulator own, cannot promote the shortcoming of simulating transmitting machine power amplifier module.The multiplication factor of amplifier being set to 30dB herein, is the working effect in order to ensure transmitter and multiplication factor; After the replacing carrying out equipment, also need to arrange the working frequency points of digital modulator and modulation system, output level is adjusted to minimum simultaneously, thus guarantees rear end equipment safety.
Secondly, transform power amplifier module, set up three grades of amplifications of prime amplifier tube, intermediate amplifier tube and final stage amplifier tube, the I/O impedance that every one-level is amplified is 50 Ω; Every one-level amplifies unitary strip shoulder index at more than 50dB, thus realizes the amplification to signal, and sets up the first attenuator and the second attenuator respectively before prime amplifier tube and intermediate amplifier tube, ensures the stability of signal.
Again, testing of equipment: whether use frequency spectrograph test switch, distributor and synthesizer working properly, determination methods is: frequency spectrograph and needs are surveyed the equipment connection established, and then indication equipment is normal when display showing straight line; In the middle of appearance, open circuit or other fault, then display can demonstrate transkit attenuation, thus prevent equipment fault, affect the normal use of transmitter, thus avoid because unit exception causes jitter;
Again, belt replacement bandpass filter: as shown in Figure 5 for signal syntheses filtration module, because before transformation, band pass filter needs to carry out filtering to analog signal, need to change it herein, it is made to be suitable for the Frequency point of work at present, for selecting of new band pass filter, can be determined by the frequency of testing current signal, thus reduce the distortion of signal;
Finally, transmission signal parameters adjusts: take on index by the monitor monitors complete machine band be connected with the test port of directional coupler, and by adjustment digital modulator and pusher operation level, find out the best operating point of band shoulder and power, need to be undertaken by observation band shoulder indicatrix, band shoulder index ensures as 32dB herein.
Simulated television transmitter is transformed into through part replacement, local directed complete set the system being adapted to digital signal transmission by the utility model, take full advantage of the resource of existing simulated television transmitter, compare overall for changing digital type, this system has greatly saved input cost, stable digital-to-analogue also can meet transmitting station to digitized smooth transition with broadcasting pattern, solves the problem that current simulated television improvement cost is high.
Embodiment 2, as different from Example 1: the multiplication factor of the amplifier increased after digital modulator is 32dB; Before prime amplifier tube and intermediate amplifier tube, increase the first attenuator and the second attenuator respectively, ensure that the single multiplication factor of power amplifier module is at 47dB; In transmission signal parameters adjustment process, index is takeed on by the monitor monitors complete machine band be connected with the test port of directional coupler, and by adjustment digital modulator and pusher operation level, find out the best operating point of band shoulder and power, need to be undertaken by observation band shoulder indicatrix, band shoulder index ensures as 34dB herein.
Embodiment 3, as different from Example 1: the multiplication factor of the amplifier increased after digital modulator is 33dB; Before prime amplifier tube and intermediate amplifier tube, increase the first attenuator and the second attenuator respectively, ensure that the single multiplication factor of power amplifier module is at 50dB; In transmission signal parameters adjustment process, index is takeed on by the monitor monitors complete machine band be connected with the test port of directional coupler, and by adjustment digital modulator and pusher operation level, find out the best operating point of band shoulder and power, need to be undertaken by observation band shoulder indicatrix, band shoulder index ensures as 36dB herein.
Claims (7)
1. simulated television transmitter digital-to-analogue is with the system broadcast, it is characterized in that: comprise signal source converting system, decoder, switch, transmitting antenna, signal source is the input of connecting signal source converting system and the input of decoder respectively, the output of signal source converting system is connected with multiplexer in turn, digital modulator, amplifier, the output of decoder is connected with exciter, the output of amplifier and exciter all connects switch, the output of switch is connected with signal distribution module in turn, 16 power amplifier modules in parallel, signal syntheses filtration module and directional coupler, the test port of directional coupler connects monitor, the output of directional coupler connects transmitting antenna.
2. simulated television transmitter digital-to-analogue as claimed in claim 1 is with the system broadcast, it is characterized in that: signal source converting system comprises adapter, 4 tunnel transcoders, 2 outputs of adapter connect the input of 24 tunnel transcoders respectively, the output of each 4 tunnel transcoders is all connected with 4 road AVS+ encoders, the input of the output connection multiplexing device of 24 road AVS+ encoders.
3. simulated television transmitter digital-to-analogue as claimed in claim 2 is with the system broadcast, it is characterized in that: signal distribution module comprises 1 No. 2 synthesizer and two No. 8 synthesizers, the input of described No. 2 synthesizers is connected with the output of switch, two outputs of No. 2 synthesizers connect the input of two No. 8 synthesizers respectively, the output wired power amplifier module of two No. 8 synthesizers.
4. simulated television transmitter digital-to-analogue as claimed in claim 3 is with the system broadcast, it is characterized in that: each power amplifier module comprises the first and second attenuator, prime amplifier tube, four intermediate amplifier tubes and the final stage amplifying unit be made up of four final stage amplifier tubes, the output of the first attenuator connects the input of prime amplifier tube, the output of prime amplifier tube connects the input of the second attenuator, the output of the second attenuator connects the input of four intermediate amplifier tubes, the output of four intermediate amplifier tubes connects four final stage amplifier tubes by 4 distributors, the output of four final stage amplifier tubes connects the input all connecting No. 4 synthesizers.
5. simulated television transmitter digital-to-analogue as claimed in claim 4 is with the system broadcast, it is characterized in that: signal syntheses filtration module comprises No. 2 synthesizers and two No. 8 synthesizers, the signal output part of 16 power amplifier modules connects the input of two No. 8 synthesizers respectively, the synthesis output of each No. 8 synthesizers connects No. 2 synthesizers respectively by a digital band-pass filter, and the load outputs of No. 8 synthesizers connects load group.
6. simulated television transmitter digital-to-analogue as claimed in claim 5 is with the system broadcast, and it is characterized in that: the multiplication factor of amplifier is 30-33dB.
7. simulated television transmitter digital-to-analogue as claimed in claim 6 is with the system broadcast, and it is characterized in that: the power attenuation amount of described first attenuator is 2dB, the power attenuation amount of described second attenuator is 3dB.
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| CN201520152992.XU CN204465715U (en) | 2015-03-18 | 2015-03-18 | Simulated television transmitter digital-to-analogue is with the system broadcast |
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| CN201520152992.XU CN204465715U (en) | 2015-03-18 | 2015-03-18 | Simulated television transmitter digital-to-analogue is with the system broadcast |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106231215A (en) * | 2016-07-22 | 2016-12-14 | 中仪英斯泰克进出口公司 | Simulated television transmitting station system |
| CN106878641A (en) * | 2017-02-15 | 2017-06-20 | 河南省无线发射传输管理中心 | A kind of high-power universal transmitter of Whole frequency band multichannel realizes device and method |
| CN107947884A (en) * | 2017-11-17 | 2018-04-20 | 深圳思凯微电子有限公司 | A kind of digital-to-analogue broadcast singal combining device and method |
| CN113903545A (en) * | 2021-10-14 | 2022-01-07 | 杭州诺驰生命科学有限公司 | Demagnetizing device, demagnetizing system and demagnetizing method for geomagnetic shielding room |
-
2015
- 2015-03-18 CN CN201520152992.XU patent/CN204465715U/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106231215A (en) * | 2016-07-22 | 2016-12-14 | 中仪英斯泰克进出口公司 | Simulated television transmitting station system |
| CN106231215B (en) * | 2016-07-22 | 2018-07-10 | 中仪英斯泰克进出口公司 | Analog/digital TV transmitting station system |
| CN106878641A (en) * | 2017-02-15 | 2017-06-20 | 河南省无线发射传输管理中心 | A kind of high-power universal transmitter of Whole frequency band multichannel realizes device and method |
| CN106878641B (en) * | 2017-02-15 | 2019-06-21 | 河南省无线发射传输管理中心 | A kind of high-power universal transmitter realization device of Whole frequency band multichannel and method |
| CN107947884A (en) * | 2017-11-17 | 2018-04-20 | 深圳思凯微电子有限公司 | A kind of digital-to-analogue broadcast singal combining device and method |
| CN113903545A (en) * | 2021-10-14 | 2022-01-07 | 杭州诺驰生命科学有限公司 | Demagnetizing device, demagnetizing system and demagnetizing method for geomagnetic shielding room |
| CN113903545B (en) * | 2021-10-14 | 2023-06-06 | 杭州诺驰生命科学有限公司 | Demagnetizing device, demagnetizing system and demagnetizing method for geomagnetic shielding room |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150708 Termination date: 20160318 |