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Kiểm tra tích hợp là tập hợp con của các bài kiểm tra thực hiện đầy đủ quy mô và chức năng được thực hiện bởi phòng thí nghiệm bảo đảm chất lượng các nhà cung cấp thiết bị, nhắm mục tiêu đối với các vấn đề khu vực được biết đến hoặc các chức năng phức tạp. | WLAN Test Environments Anechoic chambers have walls that are lined with an absorbent foam material that minimizes the reflection of RF energy within the chamber. In larger anechoic chambers this material may be formed into wedge and pyramid shapes so that any residual reflection from the surface of the foam is directed away from the DUT and eventually absorbed by some other portion of the foam. Anechoic chambers or variants thereof are used in most chambered tests such as radiated power and sensitivity measurements or antenna patterns. Anechoic chambers are commonly rectangular and intended to simulate free-space conditions by maximizing the size of the quiet zone described below . A variation is referred to as a taper chamber and uses specular reflections from a pyramidal horn to produce a plane resultant wavefront at the DUT taper chambers are used more commonly at lower frequencies. Reverberation chambers are the opposite of anechoic chambers they have no absorbent foam and are designed to maximize reflections. A stirrer or tuner is used to further break up standing waves that may form at specific frequencies within the chamber. The DUT is therefore subjected to a relatively uniform isotropic electromagnetic field with a statistically uniform and randomly polarized field within a large portion of the chamber volume. As the field is entirely confined within the chamber the field density is also much larger than in an anechoic chamber or open-air site. Reverberation chambers are hence very useful for measurements of shielding effectiveness of DUT enclosures rapid measurements of emissions or sensitivity covering all angles and polarizations and so on. A variant of an anechoic chamber is the small shielded enclosure whose main purpose is to exclude external electromagnetic interference from reaching the DUT. In this case the absorption of the walls within the chamber is of no consequence however for improved shielding and reduced self-interference due to incidental
