Design of miniaturized tri-band antenna based on differential evolution algorithm

A novel highly miniaturized triple band structure based on Z-slots-shaped antenna is presented in this letter, with only 0.0015 lambda 02 footprint, where lambda 0 is the free space wavelength at 1.3 GHz. The proposed design can generates three resonant frequency bands (1.3-1.62 GHz), (2.22-2.59 GHz), and (3.24-3.65 GHz) with -10 dB reflection coefficient, a triple band function is achieved by etching tow connected Z-shaped-slots in the radiating element and the differential evolution algorithm is then used to control the currents path, the prototype of the proposed antenna is printed on a single substrate layer and fed via coplanar waveguide CPW technology. The measured and simulated results are in good agreement, and validate the design principle, the results show that the antenna has a compact size (19.5 x 17.6 mm(2)), aside from its planar design, simple manufacturing, and low cost to fabricate, this antenna exhibits stable omnidirectional radiation patterns in E plane as well as bidirectional radiation patterns in H plane, making it an ideal device for multiband applications.