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An ultra-miniaturized transparent electromagnetic shield based on hollow hexagonal grid with the grid line less than 5 microns is proposed. The proposed structure contains two layers of metallic grid and two layers of transparent substrate. Each unit cell is only about λ 0 /68 (λ 0 is the wavelength of the center frequency of shielding band in free space). The surface metal occupancy of the structure is only 6.6%, therefor, a high transparency of more than 90% can be realized theoretically. Simulation results show that shielding effectiveness above 45dB can be achieved throughout the band of 5-30GHz. Additionally, the proposed structure is insensitive to the polarization and the incidence angle of the illumination due to its small unit size. In this paper, multiple parameters have been studied to explore the influence they have on the shielding effectiveness.

An intelligent sliding mode controller has been developed for the tracking control of weapon pointing systems with uncertain external disturbances and system parameters perturbation. In this control scheme, nonsingular terminal sliding mode and Radial Basis Function neural network have been merged to compensate the uncertainties automatically. The control signal, therefore, has also been soften to reduce the chattering of the control system. The effectiveness of the control scheme has been verified by a unmaned turret pointing system simulation tests. This approach can also be utilized for the design and implementation of a large class of modern weapon pointing and platform systems with superior performance capabilities.