Double split labyrinth resonator-based CPW-fed hybrid fractal antennas for PCS/UMTS/WLAN/Wi-MAX applications

摘要

In this manuscript, the design of double split labyrinth resonator (DSLR)-based Coplanar waveguide (CPW)-fed hybrid fractal antennas has been presented for distinct wireless applications. The proposed hybrid antennas are designed by fusing the Hilbert and Koch fractal geometries together and the resulted structure is named Hilbert Koch-Koch Hybrid Fractal Antenna (HKKHFA). The proposed antennas differ from each other in the feed line locations only. The CPW feed line is applied to excite the antennas at two different locations as Left and Right CPW-fed, and the proposed antennas are also named HKKHFA with Left CPW-fed and HKKHFA with Right CPW-fed. The ground plane of the proposed antennas is being modified to attain the better results. The proposed HKKHFA with Left and Right CPW-fed are also being loaded with DSLR on the reverse side of substrate for attaining wideband characteristics, better impedance matching and enhanced gain. The overall size of the proposed HKKHFAs is 30 x 30 x 1.6 mm(3) and is being designed on low-cost FR4 glass epoxy substrate with a relative permittivity of 4.4 and a thickness of 1.6. The results of unloaded and loaded proposed antennas (HKKHFA with Left and Right CPW-fed) are juxtaposed with each other and revealed that the loaded HKKHFA exhibits wider bandwidth and better impedance matching. Prototypes of HKKHFAs loaded with DSLR for both the feed locations are fabricated and tested for their results, and found good agreement between simulated and experimental results. The proposed HKKHFA loaded with DSLR for both CPW-feds exhibits the peak gain of 4.40/4.95 dB and a maximum bandwidth of 7.69/7.36 GHz, and it is useful for different wireless standards.