Intensification of microwave radiation by hybridized plasmon effect

Abstract

In recent years, an innovative technology based on modulation and enhancement effects of subwavelength plasma on RF electromagnetic radiation has been proposed, in which the microwave radiation from an electrically small antenna can be significantly enhanced when the antenna is tightly enclosed by a subwavelength overdense plasma shell. But the exact mechanism is still not entirely clear. In this paper, we first use the theory of hybridized Local Surface Plasmon Resonance (LSPR) for visible light in nanometal to explain this cross-domain work of microwave radiation enhancement modulated by a subwavelength overdense plasma layer, and the results show that the LSPR frequency is in good accordance with the frequency of enhanced radiation signals. Furthermore, the relationship between LSPR and antenna impedance as well as their effects on the impedance matching condition between antenna and power supply are investigated. It is indicated that LSPR on the plasma layer changes the impedance of the antenna, which produces circuit resonance (differing from plasmon resonance) between the antenna and power supply, and thus more power is radiated from the power supply to free space.

A harmonic oscillator model to study the intensification of microwave radiation by a subwavelength uniform plasma discharge

“…Low-temperature plasmas are of particular interest for the design of new microwave antennas. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] From the electromagnetic point of view, such plasmas are generally described by the Drude model of the relative permittivity ε p . For a nonmagnetized low-temperature cold plasma it is given by 17…”

“…Other studies have pointed out another interesting use of low-temperature plasmas for the design of electrically small antennas. [8][9][10][11][12][13][14][15][16] In this case, the plasma behaves neither as a good electrical conductor, nor as a dielectric, but rather as a poor electrical conductor. Several explanations have therefore been proposed to explain the intensification of the microwave radiation due to the plasma.…”

“…Finally, several studies have considered this microwave radiation enhancement as directly due to the resonance of the plasma itself. 11,15,16 This resonance, also known as the localized surface plasmon resonance (LSPR) in plasmonics, may thus be excited by the dipole located within it, and it is the combination of the plasma resonator with this dipole excitation that leads to an efficient electrically small antenna. It appears that the main mechanism that stand behind the intensification of microwave radiation remains misunderstood.…”