Abstract
A Koch fractal slot multiband antenna designed on polyimide-based flexible substrate is proposed in this paper. By cutting a Koch snowflake slot in the circular monopole, multiband characteristics are achieved. The impedance bandwidths of the proposed antenna are 55.39 % for first band (0.77 - 1.36 GHz), 29.50 % for second band (1.85 - 2.49 GHz) and 35.3 % for third band (2.80 - 4.00 GHz) with maximum gains of 1.25 dBi, 1.54 dBi and 2.23 dBi respectively. The antenna size is 115 × 90 mm 2 . This design is suitable for flexible mobile devices having relatively omnidirectional coverage of GSM 850/900/1900, UMTS, 2.4 GHz WLAN, ISM & Bluetooth, LTE 2300 and WiMAX bands.