Microhollow Cathode Plasma Studies and Effect of Array Structure on Electromagnetic Wave Propagation

Microhollow cathode discharges can produce stable and dense plasmas at high or even atmospheric pressures and at low voltages. In this paper, a microhollow cathode discharge is realised in helium gas using a sandwich-like laminated structure with four layers of metal alternating with three layers of dielectric, through which tiny-diameter vents are connected. For the disadvantage of its discharge volume limitation, the parallel microhollow cathode discharge extension structure can be used to increase the radiation area and improve the total intensity of radiation, and many microplasmas can be installed in a limited space to form a plasma array with a periodic structure type. As the microscopic periodic structure of the solid itself can show the properties of metamaterials, and the addition of plasma can change or enhance these properties, so the plasma and metal elements composed of composite arrays can also be used as a new medium to absorb electromagnetic waves, which can be used as an electromagnetic wave control device and processing tools, and its application in the metamaterials is a very different and promising research goal. In this paper, a novel composite structure is designed by combining plasma with a designed metasurface. Firstly, the discharge voltammetric characterisation of a micro-discharge unit is carried out, and the experimental results show the existence of an anomalous glow-discharge region with positive differential resistance characteristics for the micro-hollow cathode discharge, which permits large-area arrays of stabilised glow discharges operated in parallel at high or even barometric pressures, followed by simulation simulation calculations of the array structure and confirmation of the wave-absorption mechanism, and the results show that the microhollow plasma arrays act as a lossy medium for the 12.3 GHz, 13.8 GHz and 14.5 GHz electromagnetic waves.