Shielding box application range:
1. Provide a highly efficient isolated test environment for wireless communication products, avoid interference from other signals, and avoid interference between different test systems, such as mobile phones, wifi modules, data cards, and other electronic products;
2, with the production line stability testing, automated robot testing, large-scale conformance testing;
3, other communication technology tests, such as GSM, WCDMA, WiMAX, LTE, GNSS, Bluetooth, WIFI and so on.
Note the following:
(1) Select the appropriate shielding effectiveness indicator. The distribution of the overall indicators before the design of electromagnetic shielding is very important. There are 30 dB and 70 dB guidelines. Generally speaking, when the difference between the disturbance level and the sensitivity threshold level is less than 30 dB in a pair of devices in the same environment, There is no need for special shield design during the design phase; if the difference between the two is more than 70 dB, it is difficult to ensure compatibility between the two alone. Even if the index is reached, the cost of the equipment will increase dramatically. The more feasible approach is to make the overall indicator or plan appropriate. Adjustment, 30~60 dB is the common expectation of shielding design.
(2) The structure of the shield must be concise, as much as possible to reduce unnecessary holes, as far as possible not to add additional gaps; Avoid opening slender holes, ventilation holes as possible using circular holes and array discharge. If there is a conflict between shielding and heat dissipation, make a small hole as much as possible, open more holes, and avoid opening large holes.
(3) Do not have conductors that pass directly through the shield. Pay attention to cable handling measures, cable handling is often more important than shielding itself. Once a cable is passed through the shield, the shielding effectiveness of the shield will be significantly degraded.
(4) The electrical continuity of the shield is the most important factor affecting the effectiveness of the shield. Relatively speaking, the influence of the shield performance of the material itself is insignificant (except for the low-frequency magnetic field).
2018-03-27