Tunable EMI noise suppressor based on Ni nanowire arrays

We designed, fabricated and evaluated noise suppressors based on Ni nanowire arrays embedded in Anodic Aluminum Oxide (AAO) template in microstrip waveguide geometry. The effects of the length of the nanowires and the device dimensions on the microwave properties of noise suppressor are investigated. Ni nanowires with an average diameter of 200 nm and of various lengths (from 7 µm to 30 µm) were electrodeposited in AAO templates. Scanning electron microscope showed growth of highly ordered nanowires and Energy Dispersive X-ray analysis confirmed composition of nanowires. Transmission electron microscope verified the diameter and length of the deposited nanowires. The resonance frequency of the noise suppressor can be tuned up to 23 GHz by applying an external magnetic field of 4.5 kOe. This gives a frequency tunability of 66%. Signal attenuation of the device enhances by increasing the bias magnetic field by over 60% and microstrip length by 20%. Therefore such integrated devices are good electromagnetic noise suppressors in wireless communication