Reduced size harmonic suppressed fractal dipole antenna with reconfigurable feature

The presence of harmonics are undesirable in many applications. Embedding fractal technology into an antenna makes it possible to reduce the physical size, increase its operating bandwidth and directivity. However, the technique can cause significant undesired harmonics problems associated with higher order modes of the antenna. This paper presents an experimental work of a reduced size Koch fractal meander dipole antenna that has tunable capability of a reconfigurable operation within the observed range of 400 MHz to 3.5 GHz. Each undesired harmonic is removed using one or two stubs. A microwave switchable dipole antenna concept using Koch curve integrated with open circuit stubs is presented. The structure employed fractal technology that can eliminate higher order modes. With the utilization of Koch curves, the antenna size is reduced, but the number of higher order modes has proportionally increased. The size of the proposed antenna is small with regards to the operating frequency. The stub has improved the antenna performance.