  A three-dimensional model of a novel plasma based electrically small antenna
is developed for investigating the gas properties and antenna parameters under
a low pressure, low plasma temperature environment. The antenna exhibits dipole
antenna-like behavior with wide-band impedance matching from $213-700$ MHz.
Plasma is sustained by $0.9$ W of RF input power at $100$ MHz and the gas
pressure is strategically controlled at $500$ mili-Torr. The simulated $S_{11}$
is verified against the available experimental data and further antenna
parameters are extracted. The proposed ESA shows dipole-like radiation pattern
with a radiation efficiency of $16\%$ at $700$ MHz. The performance metric for
ESAs, the Chu-limit, is exceeded by this antenna with the $Bandwidth\times
Efficiency$ reaching $0.168$ with a $ka$ of $0.5571$.The findings from this
letter demonstrate the practicability of using COMSOL Multiphysics as a tool
for predicting plasma behavior and antenna performance while the boundary
conditions for all the coupled physics are respected.
