Frequency agility investigations on compact omnidirectional antennas using variable inductors

This paper investigates the possibility to introduce a variable inductor on a compact antenna structure in order to obtain a frequency agility. The structure is a compact shorted microstrip antenna characterized by omnidirectional radiation properties over a narrow frequency band which has to be broadened for telecommunication systems. For that, a variable inductor is placed on the antenna structure and tuned so as to obtain frequency reconfigurability.