I. OVERVIEW
The rapid development of mobile communications brought great convenience to people's life, but the wider use of mobile phones, there are some problems that can not be ignored, the main ones being :
Become the new insecurity, bring hidden dangers to production safety in enterprises.
At petrol filling stations, oil depots and other places using cellular phones, will lead to a fire or explosion. Its very serious consequences.
Leaking into new channels, posing a threat to the security of confidential information.
The development of science and technology, mobile phone positioning, tracking and surveillance, the rest of the world has become the most important means of reconnaissance and intelligence sources. Therefore, as long as the locations associated with carrying mobile phones, regardless of whether or not to use, as long as the designated state, most likely caused by leaking secrets to the unit or individual. Even seriously harm the party and the state.
As a new source of the noise that interferes with the normal working order.
The increasing popularity of mobile phones, conference rooms, courts, libraries and other places in the gradual deterioration of the environment, noise and mobile phones have destroyed these places quiet and solemn atmosphere, affecting people's normal work.
Become a new crime, the impact on social stability.
Some opportunistic people use mobile phones cheating on exams, a number of terrorists and hostile elements, but also the use of mobile phone detonated a bomb : : Facts have shown that mobile phone on a number of occasions, has become a tool for criminals to commit a crime, had a negative impact on social stability.
Centralized management is not conducive to the lowering of production and operational efficiency.
Centralized management of the enterprises, employees frequently use cell phones during the phone calls and are unable to master the work of the staff association, reduced the efficiency of the production and operation of enterprises, the enterprises weakened supervision of the staff.

My company recently developed a series of DZ mobile phone shielding devices to produce and downlink station with the frequency jamming signals cell phone reception reach cut off communications, DZ series of products and market other manufacturers of mobile phone shielding Comparison With significantly improved by adopting effective section, the removal of unwanted interference so useful frequency improved greatly interfere with larger, more important is not to interfere with the base station. Effective shielding at the mobile phone service area cellular phones could not be shown to enter the mobile phone service is not (or not access). DZ complete series of products applicable to a variety of occasions, different screening area, and thereby eliminate the negative impact of mobile phones, has played the role of security and protection. Police have passed on security products and electronic product quality inspection center, and the PLA Information Security Testing Evaluation and Certification Center, the State Quality Supervision and Inspection and explosion-proof electrical equipment rigorous certification testing centers.

Second, uses and characteristics : Return to the top
(1) purposes :
Mobile phone shielding NG mobile phone telephony alone have an effect on other electronic equipment without interference, and is harmless to the human body, which can be widely used in the meeting rooms, a hall, the courts, interrogation rooms, prisons, libraries, scorers, gasoline stations, oil depots, military, command centers, and all other places ban on the use of mobile phones.
(2) features :
DZ series by the latest mobile phone shielding NG patch and integrated circuits, it has good performance, and the manual switch with remote control, install and easy to use. Sub-effective only downlink interference, the base station will not interfere.
Strict compliance with the ISO 9001 Quality System production process, reliability and stability is to strengthen information security guarantee safety and protection of the environment, a good, reliable security products.

Third, the major functional and technical indicators : Return to the top
(A) The main functions :
Channel 4 models effective shielding CDMA, GSM, DCS, PHS mobile signal.
Shielding only cell phone signal, and this will not affect the normal operation of other electronic equipment.
Power can be connected to prolonged stability.
Relief to start the circuit design can avoid mechanical shape Sparking.
(B) technical specifications
Effective shielding radius = 20 m (indoor)
Frequency shielding :
CDMA:870-880MHZ GSM:930-960MHZ
DCS:1805-1850 PHS:1895-1918MHZ
PCS:1975-1980MHZ
Output Power :
CDMA terminal
-- Average Power 35dbm
-- Channel Power 5dbm/100khz (lowest)
GSM terminal
-- Average Power 35dbm
-- Channel Power 5dbm/100khz (lowest)
DCS terminal
-- Average Power 33dbm
-- Channel Power -2dbm/100khz (lowest)
Telephone links end
-- Average Power 33dbm
-- Channel Power -2dbm/100khz (lowest)
Power AC220V+10% 45-55MHZ
Host blooming size of 175mm x 50mm x (长×宽×高)
2 kg weight
Security Regulations UL (E190582), the CSA (LR112971LEVE13)

Fourth, install and use : Return to the top
(1) installation procedures and methods
1.1 Development Institute shielding removed from the packet;
120 antennas were put into their own spin antenna;
NG 1.3 peg to put shielding wall, the best installation height of 180 cm;
Power exchange to import 1.4 inserted electricity socket, remote control or manually switch opened, the light should turn next to the antenna that has been shielding NG normal;
(B) Note :
1, must first be installed antenna, and power supply connected to the mainframe.
2, the effective shielding NG NG Shield coverage is a circular area for the center, using the correct choice of the location of shielding NG to avoid shielding corner.
3, shielding NG should be rotating in ventilated areas to avoid large objects sight and out of heat and electromagnetic sources, and to ensure shielding effect of prolonged stability.
4, shielding NG work, or in other articles on storage to avoid damage to machines and shielding effects.
5, outdoor use shielding NG, it is waterproof attention.
6, at the shield when not in use, should be promptly 7659, in order to avoid affecting the normal use of mobile phones.
7, when an area larger than the effective shielding of reference, the proposed multi-shielding device, placed in different positions, to ensure shielding effectiveness.

5, maintenance : Return to the top
1, MF equipment belonging to the shielding NG without maintenance.
2, cleans the surface, to avoid the use of chemical solvents, and avoid flooded inside.
3, shielding NG is not in use, should be stored in dry ventilated place to avoid prolonged exposure to salt spray and harmful gases.
4, the shielding NG warranty period is one year, instead of three, free repairs, the only charge the cost of materials, as appropriate.

6 : Questions and answers Return to the top
1, in shielding device for mobile phones, mobile phone signal indicator still signaled Why?
Answer : This is just like a fake, in fact, here's a cell phone communication has been impossible. When you can dial a crucial meet? Found, the signal indicator and have no instructions on this point signal.
2, and mobile phones will not interfere with other electronic equipment shielding NG normal?
A : No, it's not. This is because the mobile phone signal shielding of Electromagnetic NG entirely in the mobile phone working band will have a shield to mobile telephone communications, and this signals remained in a relatively static state, will not have an impact on any electronic equipment.
3, and mobile phones, and mobile phones are harmful to human shield NG?
Answer : Please rest assured users that mobile phone electromagnetic shielding NG fired the signal intensity is very weak, the test data show that the signal intensity far not cause harm to humans. Meanwhile, mobile phone shielding NG only to the cell phone signal shielding, cell phones establish contact with the base station, it will not do any harm to the cell phone itself.
4, and mobile phones, at the indoor and outdoor use of shielding distance difference?
A : There are. Normally, the signal outdoors than indoors, outdoors shielding effectiveness poor. Strictly speaking : either indoors or outdoors and effective instrument distance and shielding electromagnetic environment and the surrounding environment to a certain extent, such as the proximity from the base stations used, and so on.
5, mobile phone shielding device for a certain period of time after the shell will break and there will be no damage to machines?
A : Thank you for the careful and red shell will be a normal phenomenon. In design, we took advantage of the thermal conductivity of metal shell to auxiliary heat, and thus be able to assure prolonged stability, it will not be damaged by hot shell machines.