Multiband Circularly Polarized Fractal Boundary Microstrip Antennas

Dual band CP antennas with embedded 45 degrees rotated fractal slot at center are presented. Various fractal antennas using Koch, Minkowski, Half-circled and poly curves are studied for dual band CP operation. By varying the feed point position dual band CP antennas which resonate at 2.4 GHz, 5.8 GHz and 2.4 GHz, 3.4 GHz are designed. The 3-dB CP bandwidths obtained multiple bands are more 1%. These antennas are useful for systems operating at Wi-Fi, Wi-MAX and WLAN standards IEEE 802.11 and IEEE 802.16. These antennas are fabricated and performance is measured. A good comparison is obtained. Later, by optimizing the feeding point and dimensions of the slot triple band antennas are designed. Several antennas based on various fractal curves are designed. Best performed antennas are fabricated and tested. A close agreement between the simulation and measurement results is observed.