Wideband frequency reconfigurable Koch snowflake fractal antenna

In this study, a Koch snowflake frequency reconfigurable antenna for wideband applications is presented including experimental verification. The frequency reconfigurable approach is obtained for UHF band using RF PIN diodes, lumped capacitor and inductors. Proposed antenna is compact, therefore, it can be used as an array element. It has three measured frequency bands. These bands are: case I, 3.34- 4.52 GHz (30%); case II, 2.2-3.4 GHz (43%); and case III, 1.45-4.1 GHz (95.49%). In cases I and II, two different bands are obtained and case III covers almost the frequency band of case I and case II. Thus, the impedance bandwidth of the proposed antenna provides continuous wideband frequency coverage from 1.45 to 4.52 GHz (103%). In addition, the measurements are carried out to validate the performance of the antenna. The proposed antenna has good agreement between simulated and measured results with reasonably low cross polarisation.