A tapered feed UWB-MIMO antenna with high characteristics based on fractal method

Abstract

A miniaturized antenna based on fractal method and Tapered-feeder technique for ultra-wideband (UWB) applications is developed in this research. The structure of the component cell monopole antenna is designed by using a half circle-shaped fractal method and merging material implementation with the L-stub shape. These techniques provide a wide impedance bandwidth for the innovative wireless antenna with high characteristics, which operates from 2.73 to 12.21 GHz. The planned module cell dimensions are 20 by 16 square millimetres ( 0.181 λ L × 0.145 λ L ), where the wavelength ( λ L ) is 110 mm. This low-profile antenna has then been employed to design an array of 1 × 2 Multi Input Multi Output (MIMO) antennas with an overall size of 20 ×34 mm 2 . Two symmetric geometries are arranged in the designed miniaturized MIMO system with an inverted T-shaped decoupling copper between them. Measurement results show that the dual antenna with multiple diversity metrics has great characteristics for MIMO applications due to providing low mutual coupling value, lower than 0.33 bits per s./Hz of channel capacity loss, minor envelope correlation coefficient of fewer than 0.005, lower −11 dB of total active reflection coefficient, greater than 9.93 dB of diversity gain and proper mean effective gain (MEG ratio≈1, MEG ≤ 0.5). A high peak gain magnitude of 5.42 dBi is provided at an operating frequency of 10.5 GHz for the recommended single antenna.