Research On Active Electromagnetic Structure For Antenna Scattering And Radiation Characteristics Control

Since the discovery of plasma,it has been increasingly valued by researchers because of its good reconfigurability.However,since the penetration depth of plasma is a large depth,the transmission of the plasma is always at a high level.Higher transmission,to some extent,means "transparent" to electromagnetic waves.In most applications of plasma in the electromagnetic field,high transmission has a negative impact.In this paper,the relationship between the penetration depth of plasma and the characteristic scale of plasma is taken as the point.The plasma generation method commonly used in basic research and engineering practice is analyzed.There is a general problem between the penetration depth of plasma and its thickness.In order to solve this problem,it is proposed to combine the plasma photonic crystal with the frequency selective surface to improve its cut-off characteristics.Compared with the plasma of enough thickness and number of layers to meet the penetration depth,the composite electromagnetic structure is thick.We designed the periodic structure of the plasma and its array elements,as well as the periodic elements of the frequency selective surface,for the regulation of the transmission characteristics of the periodic composite electromagnetic structure.The effects of periodic composite electromagnetic structures on electromagnetic wave propagation are characterized by experiments.At different frequencies,resonance enhancement,broadband absorption and dispersion are observed.It is verified that the combination of the plasma photonic crystal and the frequency selective surface can solve the problem that the plasma transmittance is too high to some extent.This paper also addresses the problem that the working state of low-pressure gas discharge power supply is generally less.It is proposed to improve the reconfigurability of periodic composite electromagnetic structure combined with plasma photonic crystal and frequency selective surface through four-way linkage excitation power supply.