INVERTED KOCH FRACTAL DUAL BAND DIPOLE ANTENNA WITH HARMONIC SUPPRESSION CAPABILITY

This paper presents an inverted Koch fractal dual band dipole antenna with harmonic suppression capability. A double-sided Koch fractal dipole antenna incorporated with a tapered balun and operating at 900 MHz and 2.4 GHz was designed. Two rectangular defected ground structures were embedded on the triangular tapered balun to suppress undesired higher-order mode frequencies and enhance antenna performance. Results showed that the antenna functions at the desired frequencies (0.9 and 2.4 GHz) and eliminates higher-order harmonics (3.6 and 4.7 GHz). The antenna was simulated using the electromagnetic simulation software CST Microwave Studio. The simulated and experimental results were compared and good agreement was observed. The proposed antenna design presents a small size and low fabrication complexity.