Design and Characterization of Reconfigurable Fractal Microstrip Antennas below 10 GHz

Fractal antennas have the capability to work in different frequency bands. Embedding PIN diodes as switching elements to the antennas enables reconfigurability of the antennas. In this work a simple reconfigurable T-form Pythagorean-tree fractal microstrip antenna was proposed. The reconfigurable fractal antenna was simulated and fabricated on a 1.4 mm thick FR4 substrate with six PIN diodes connected inside. The computer simulation showed for several on-off diode conditions, different following resonant frequencies 1.52 GHz, 3.98 GHz, 4.23 GHz, 4.96 GHz, 5.12 GHz, and 7.56 GHz to 9.1 GHz. The calculated radiation patterns showed symmetrical or tilted directional characteristics depending on symmetrical or unsymmetrical on-off cases. Measurements confirmed the calculated results.