The fundamental meaning of the shielding box: the shielding box is made of conductive or magnetic materials, plates, sleeves and other shielding bodies of various shapes. The electromagnetic ability is limited to a certain space range and used to suppress radiation interference. A device that stops handling conduction and radiation in order to provide a non-interference test environment for the wireless communication device under test.
Purpose of using shielded box
The first is to limit the radiated electromagnetic energy inside the equipment to go beyond a certain area;
The second is to prevent external radiated electromagnetic energy from entering a certain area.
Shielding effectiveness of shielding box:
Refers to when the imitating interference source is placed outside the shielding box, the ratio of the electric field strength, magnetic field strength or power at a certain point in the space before and after the shielding box is placed and then taking the logarithm (lgp1/p2), expressed in dB.
The test equipment includes:
Network analyzer (signal generator + spectrum analyzer), dipole antenna, horn antenna, shielding box.
Classification of shielding box:
It can form manual, electric, fully automatic and other different work forms according to different test request systems.
1. The manual shielding box is generally small in size and easy to operate. It is currently the most commonly used one on consumer lines such as small communication devices such as mobile phones. There are also some parts that are too large and inconvenient to use pneumatic operation, but also use manual door opening.
2. Pneumatic shielding box is generally larger in size, which improves the test efficiency and reduces the fatigue of the operator in the consumer test.
3. Fully automatic shielding box After the international standard RS232 interface, the test shielding box is stopped and controlled according to the communication instructions to complete the entire test process. Generally, small radio frequency modules are used in large-scale production lines to improve consumption efficiency.
The role of shielding box
As far as wireless communication product consumer manufacturers are concerned, the inability of the products to be launched in time or the rapid increase in volume has resulted in the loss of a large amount of output value and profits. Directly affect the follow-up business and market share expansion.
The radio frequency test process is usually the most complicated and most influential process in the production line of wireless communication equipment such as mobile phones, and it is usually the bottleneck of the production line. The radio frequency test station is usually composed of several parts such as test instrument, shielding box, test software, etc., and usually can be divided into calibration test, comprehensive test, antenna test and so on. Due to capacity requirements, the RF test process is usually run in parallel by multiple identical test stations. The passing rate of one or some test stations is low; lower output will lead to bottlenecks in the production line and a sharp increase in consumption costs. The reasons can be roughly divided into: product design or material reasons, test problems (errors) Test problems), radio frequency interference and other environmental factors, and the uncertain problems of the test.
Electromagnetic interference/EMI is a problem that must be faced and restrained in the entire electronic field. Common examples of wireless communication products are: mobile phones, wireless network cards, wireless routers, wireless headsets, Bluetooth headsets, wi-fi, wimax, data cards, walkie-talkies, RFID In the process of stop board test and final test, wireless communication equipment and wireless communication modules are all used to improve the test environment by using radio frequency test shield box/RF Shield Box.
Function and application range:
1. The shielding box is used for wireless communication test
2. EMI test
3. Coupling test
4. RF function test
5. The flexibility test of the receiving machine
6. Transmitter radiated power test
7. EMI and EMS testing of small UHF equipment
9. LTE test shielding box-UN-TOJOIN specification
10. Automatic test of car anti-theft device D4560 shielding box UN-TOJOIN specification