On the miniaturization of microstrip line-fed slot antenna using various slots

With the advancement in microelectronic technology, there is a growing tendency in the hardware of the wireless communication systems to be smaller in size with much more functionalities. Along with this miniaturized RF systems and components, the size of the antenna becomes one of the largest and cumbersome system components. As a result, small size, light weight, low profile and power efficient antennas are in great demand. In this paper the study of the effect of various geometrical slots in the ground plane of a 50Ω microstrip transmission line fed slot antenna for compact operation is presented. The study includes four different types of ground plane slots: (a) conventional rectangular slot, (b) square dumbbell slot, (c) circular dumbbell slot and (d) double cross slot. It was found that using the square dumbbell slot resulted in 31% reduction in the antenna size compared to the conventional slot antenna. Numerical simulations are carried out using CST microwave studio based on the finite integration time-domain technique. Additional simulations were carried out using EMPIRE XCcel™ finite-difference time-domain (FDTD) software.