Analysis of Plasma Monopole Antenna Using Numerical Method and an Equivalent Circuit

This study focuses on the effects of antenna radius and plasma frequency on the characteristics of a plasma monopole antenna in its first resonant region for reconfigurable applications. It is shown that the input impedance of a plasma monopole antenna can be modeled by a simple equivalent circuit. Variations of the equivalent lumped elements with the antenna radius and the plasma frequency are numerically approximated. The bandwidth of the plasma monopole antenna increases with increase in the antenna radius. This numerical investigation estimates the relation between the resonant length and the radius, as well as the plasma frequency of the plasma antenna. The resonant length decreases by increasing the radius of the antenna and decreasing the plasma frequency. The numerical modeling shows that there is a specific band of plasma frequency for which the rate of variations of input impedance versus plasma frequency is minimal. This frequency band is the most efficient region for the plasma frequency in the application of a plasma antenna as a reconfigurable radiating element.