Frequency tuning of an electrically small antenna for HF ground wave transmission

In this paper, the methods are investigated to change the resonant frequency of our electrically small antenna using tunable lumped-element components. While the instantaneous bandwidth of the antenna cannot be improved in this manner, a tunable antenna can achieve frequency agility necessary to overcome various deployment variances and propagation effects. The location for the placement of the lumped element is evaluated via simulation using the numerical electromagnetics code (NEC). The simulation result is compared with the measured data at the optimal location. Results for the tuning range and tuning sensitivity are reported