An Improved Koch Snowflake Fractal Broadband Antenna for Wireless Applications

This study proposes a compact improved Koch snowflake fractal broadband planar antenna for the second generation (2G) to the fourth generation (4G), WLAN and navigation wireless applications. The device is based on the principles and structural features of conventional Koch fractal monopole antenna elements, combined with the advantages of trapezoid CPW-fed structure. The proposed antenna adapted two iterations Koch snowflake fractal structure radiator with one iteration Koch snowflake fractal slot inside, which covers more than ten mobile applications with a bandwidth of 106.25% (1.5-4.9GHz) for GPS, BDS, GLONSS, GALILEO, DCS1800, TD-SCDMA, WCDMA, CDMA2000, LTE33-41/42/43, Bluetooth, WLAN and WiMAX frequency bands. The proposed antenna was fabricated on a G10/FR4 substrate with a dielectric constant of 4.4 and a size of 72*42*1.6 mm(3). The measurement results reveal that the omni-directional radiation patterns achieve a gain of -1.7-2.35dBi and an efficiency of 31-64%. The good agreement between the measurement results and simulation validates the proposed design approach and satisfies the requirements for various wireless applications.