Tunable metamaterial absorber based on resonant strontium titanate artificial atoms

This paper presents a phenomenological study about the passive intermodulation (PIM) behavior on a reconfigurable nickel-coated cell array. An artificial transmission line with reconfigurable nonlinearity is employed for demonstrating PIM generation and propagation behavior. This test fixture gets rid of metal contact distortion by using coupled power to stimulate nonlinear sources. Using the finite element analysis, the simulated magnetic field intensity is compared with the tested PIM data. A set of nonanalytic PIM models directed toward nickel-coated distributed PIM sources is demonstrated. Based on the proposed PIM fixture, a novel PIM reconfiguration method using nonlinearity array is proposed and a strength predictable PIM standard is obtained. The proposed test fixture can work as a practical PIM building-block to provide stable PIM reference. In the demo cases concerning three PIM test frequency spots, the minimal PIM of this device can reach below –112 dBm @ 2 × 43 dBm, while its maximal PIM dynamic range can reach about 20 dB. It exhibited a rudiment of PIM standard that can be applied in practical PIM test calibration field.

Reconfigurable Passive Intermodulation Behavior on Nickel-Coated Cell Array

Synthesizing amorphous Ni-P micro-/nano-composites with perfect roundness or embryo-like structures

The Ni based alloys and composites synthesized by electro-deposition techniques were investigated in this paper. The co-deposition techniques for development of Ni-Co alloys, synthesis of oxide doped nanocomposites were analyzed. The hardness, wear resistance and corrosion resistance of different coatings: Ni, Ni-Co alloys, Ni-Fe2O3, Ni-Al2O3, Ni-Fe-BN, Ni-TiN composites were studied in detail. The Ni-Fe-BN and Ni-TiN showed more than 550 percent increase in hardness of stainless steel substrate. The Hardness was found to be about 600-1180Hv for Nitride impregnated coatings. These films also showed higher corrosion resistance in comparison to other Ni based alloy and composite coatings. The microstructural investigation of these alloys showed nanostructured rods and fibres in the deposited films.

Electrodeposition of Nanostructured Ni Based Alloys/Composites – A Critical Analysis

The present study investigated the preparation and characterisation of alternative black anodic films on aluminium alloy 1050 using three different inorganic colouring processes. The colouring process was performed via the standard chemical reaction and two alternative mechanisms, i.e. electrochemical reaction or a combination of electrochemical and chemical reactions. Black anodic films with high thermo-optical properties (αs ≥ 0.90 and en ≥ 0.90) were successfully obtained using all three processes. Differences in chemical content and location of the Co-based pigments in the coatings were highlighted and explained according to the colouring reaction mechanisms.

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P. Arockiasamy

Papers

Flat Absorber Phosphorous Black Nickel Coatings for Space Applications