A novel shaped antenna for designing UWB-MIMO system in microwave communications

Abstract

This paper designed and fabricated a UWB-MIMO antenna based on novel inverted comma-shaped antenna and a CPW-feeder structure. The proposed single monopole antenna is designed by combing an elliptical geometry with merging several circular shapes. The novel structure provides a wide impedance bandwidth from 2.469 to 14.203 GHz. The dimensions of the designed unit cell are 21 mm × 16 mm (0.172λL×0.131λL) and the overall size of dual symmetric antennas is 21 × 34 × 1 mm3. This compact antenna is then used to design 2 × 2 Multiple Input Multiple Output (MIMO) antennas. The proposed low-profile MIMO antenna contains two similar geometries placed with a T-shaped decoupling structure. Measurement results show multiple diversity metrics of the MIMO antenna such as low-value mutual coupling characteristics, better channel capacity losses of less than 0.29 bits/s/Hz, envelope correlation coefficient smaller than 0.004 by far-field radiation, total active reflection coefficient below − 10 dB, diversity gain of less than 9.98 dB and acceptable mean effective gain (MEG ≤ 0.5, MEG ratio = 1). The proposed antenna offers a maximum peak gain value of 6.18 dBi at operating frequency of 13.4 GHz.