Study on Size Reduction of Quasi-Sierpinski Carpet Microstrip Antenna

In this paper, several novel contracted antenna structures are proposed, in contrast to the conventional Sierpinski carpet microstrip antenna. The novel antenna structures have cross-shaped fractal slots, U-shaped fractal slots and Hilbert slots incorporated into, respectively. In the geometries of these antennas, the 2nd order U-shaped fractal slot, Hilbert slot and cross-shaped fractal slot are embed on the 1st order antenna patch elements, and the 1st order ones on the 2nd patch elements. The effects of slots' width and length on antenna's return loss and resonance frequencies are discussed and their appropriate values are found. These novel slot microstrip antennas can all make the resonance frequencies decrease and reduce the original antenna size effectively. Compared the results with each other, Hilbert slots can reduce the antenna size most obviously.