Square loop antenna miniaturization using fractal geometry

Antenna design is a very tricky problem. Common designs are sensitive to only a narrow range of frequencies, and are not efficient if they are smaller that a quarter of the wavelength. This is a problem for small, portable antennas, such as those on cellular phones. Fractal antenna designs can overcome some of these problems. Experiments have shown that antennas built with only a small number of iterations of a fractal process can exhibit sensitivity at several frequencies. As the number of iterations increases, the lowest frequency of the antenna gets lower, and additional higher frequencies are added. Also, fractal antennas can operate efficiently at one-quarter the size of more traditional designs. Properly harnessed, these features represent real advantages. Fractals already are being used for compact, multifrequency antennas in cellular phones and military communications hardware. Fractal antennas are now used in cellular phone antenna fitting inside the body of the phone, and the multifrequency aspect of the antenna will allow GPS to be incorporated in the phone. Other applications include compact, multifrequency wireless LAN and maritime antennas. In this paper we present a miniaturization model of a square loop antenna using a non-return to zero pulse as a generator instead of the square pulse in Minkowski fractal model that allows an increase in the total electric length without occupying more space. This led to an easy matched compact loop antenna, but with a small sacrifice of the gain.