A Compact Hybrid Fractal Antenna using Koch and Minkowski Curves

A small size multiband antenna immensely beneficial for wireless devices. Hybrid fractal technique gives an opportunity to design multiband and less weight antenna. In this article, two types of antennas are designed. Koch curved fractal antenna is superimposed on minkowski curve and minkowski curve is superimposed on Koch curve. Both proposed antennas are reciprocal to each other. FR4 material is used as a substrate and microstrip line feed is used to energized patch. The comparisons between proposed fractal antennas are conducted with single fractal geometry antenna and also analysis radiation pattern, gain, current distribution, VSWR and defected ground effects on return loss. The simulated and optimized results are observed on HFSS simulator. Thanks to KMHFA, huge impedance bandwidth is achieved and due to MKHFA, multiband behavior hybrid fractal antenna is designed. The maximum gain of MKHFA antenna is 6dB and maximum bandwidth of KMHFA is 1900MHz. Dimensions of KMHFA is 30x12mm2 and MKHFA is 28x19mm2. Thus, it is found that both proposed antennas are beneficial for different applications such as Wi-Fi (5GHz and 5.5GHz), WLAN(5.725-5.825GHz), satellite communication downlink (3.7-4.2GHz), satellite communication uplink (5.6-6.4GHz), GSMI800(1.7-1.8GHz), GSMI900(1.8-1.9GHz), 3G-WCDMA (1900MHz uplink-2100MHz downlink), Airborne and Naval Radars (8.6-9.3GHz), Amateur Radio (10.2-10.5GHz). Indian cellular SIM of Jio 4G operating at Band-3 with uplink 1.710-1.785GHz and downlink 1.805-1.880GHz frequencies which usher in revolution (provides digital voice calling, high speed internet and so on) in cellular mobile communication. In future, these types of hybrid fractal antennas are used for 5G which operates over 3000MHz.