Bandwidth enhancement and further size reduction of a class of miniaturized slot antennas

In this paper, new methods for further reducing the size and/or increasing the bandwidth (BW) of a class of miniaturized slot antennas are presented. This paper examines techniques such as parasitic coupling and inductive loading to achieve higher BW and further size reduction for this class of miniaturized slot antennas. The overall BW of a proposed double resonant antenna is shown to be increased by more than 94% compared with a single resonant antenna occupying the same area. The behavior of miniaturized slot antennas, loaded with series inductive elements along the radiating section is also examined. The inductive loads are constructed by two balanced short circuited slot lines placed on opposite sides of the radiating slot. These inductive loads can considerably reduce the antenna size at its resonance. Prototypes of a double resonant antenna at 850 MHz and inductively loaded miniaturized antennas at around 1 GHz are designed and tested. Finally the application of both methods in a dual band miniaturized antenna is presented. In all cases measured and simulated results show excellent agreement.