Nickel films of 4–250 nm thickness were produced by DC magnetron sputtering onto glass and silicon substrates. The electrical properties of the films were investigated by the four-probe method and the surface morphology of the films was studied by atomic force microscopy. To measure the shielding effectiveness, a portable closed stand based on horn antennas was used. A theoretical assessment of the shielding effectiveness of nickel films of various thickness under electromagnetic radiation of a range of frequencies was carried out using two different approximations. The results demonstrate the shielding effectiveness of up to 35 dB of the nickel thin films in the frequency range of 2–18 GHz.

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The stadium environment represents one of the tougher environments for cellular systems given the extreme density of users and the potential for a large amount of uplink traffic. This paper presents the design and evaluation of 2D antenna arrays employed with azimuth and elevation sectorization in the stadium environment to improve the 3GPP LTE mobile network performance. A typical stadium model is introduced and different deployment options for a 2D antenna array with multiple sector beams are considered. It is found that only 2 to 4 antenna sites are sufficient to provide effective stadium coverage with up to 44 parallel spatially multiplexed sectors by using the antenna arrays consisting of 10×16 (elevation × azimuth) cross-polarized antenna element pairs. For more efficient performance the beams of each antenna array should be oriented towards the nearest stadium stands under the antenna suspension point. Using the results of system-level simulations it is estimated that the spectral efficiency of the stadium deployment can be up to 1.5-1.8 bit/s/Hz/sec resulting in the overall throughput of up to 1.5 Gbit/s which should be sufficient to provide the connectivity for tens of thousands people attending the stadium events.

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