Towards antenna miniaturization at radio frequencies using plasma discharges

Abstract

An original electrically small antenna concept relying on plasma discharges is presented in this paper. It consists of a small coaxial probe placed above a ground plane and surrounded by a hemispherical inductively coupled plasma discharge. This plasma discharge behaves as a subwavelength epsilon-negative resonator exhibiting a localized surface plasmon resonance at microwave frequencies with significant radiation efficiency. Measurements show that the plasma allows impedance matching of the radiating element and frequency agility from 310 to 390 MHz by controlling the power delivered to the discharge. Meanwhile, significant radiation enhancement up to 20 dB at 300 MHz is measured. The existence of the localized surface plasmon resonance is finally confirmed by a Mie analysis considering the measured plasma characteristics.

Design of a Tunable Subwavelength Plasma-Based Resonator for Electrically Small Antenna

“…Such an implementation allows to separate the plasma source with the plasma discharge operating as an electrically small resonator. For antenna applications, a possible electromagnetic coupling of this resonator would be to insert a small coaxial probe through the center of the Faraday shield [12].…”

“…According to image theory, this problem is equivalent to a plasma sphere in free space. The resonant behavior of this spherical plasma is finally studied as a scattering problem using Mie theory [12], [15].…”

“…Recently, a plasma-based ESA has been demonstrated in the low UHF band [12]. It consists of a small coaxial probe placed above a ground plane and surrounded by a hemispherical glass shell that confines an inductively coupled plasma discharge.…”

Experimental and numerical studies of the plasmonic resonance of a low-pressure hemispherical plasma discharge in the upper VHF band

“…First studied in the late 1960s for the radio frequency domain [2], interest in this plasmonic resonance has been revived more recently for the development of electrically small antennas. In the VHF band, the resonance condition may be obtained using cold plasmas out of thermodynamic equilibrium [3].…”

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…”