Abstract:
The use of the millimeter wave (mmWave) spectrum and further exploration of sub mmWave has led to a new era in wireless communication, as the need for higher
data rates grows. High frequencies, on one hand, incur a higher path loss, requiring
an increase in antenna gain requirements. Metasurfaces, which emerge as a promis ing technology for mitigating path loss effects by utilizing 2D arrays of engineered
meta-atoms resembling metamaterials that control the surface’s electromagnetic re sponse has been introduced. Currently, they are primarily considered as passive
reflecting devices in wireless communications, assisting conventional transceivers
in shaping propagation environments. The work herein presents an alternative ap plication of metasurfaces for wireless communications as active reconfigurable an tennas for next generation transceivers. A framework that demonstrates the design
process of a metasurface antenna structure is introduced and further used to design
a 4⇥4 array and its reconfigurable counterpart. In contrast to conventional array an tennas, a reconfigurable metasurface (RMS) antenna does not require phase-shifters
and amplifiers, hence, leading to a reduction of costs. Instead, each individual ele ment achieves reconfigurability by shifting the resonating frequency using semicon ductor devices such as PIN diodes. The proposed metasurface antenna is designed
to operate at a frequency of 28 GHz and 40 GHz. The work achieved a return loss of
-18.57 dB and -22.0 dB, which indicates good impedance match between transmis sion line and antenna. In addition, an increase in gain and directivity is observed
when diodes are added to the metasurface antenna array. However, as a result of
diode losses, the radiation efficiency of the metasurface array decreased. Future di rections have been explored that may pave way to present the full potential of active
metasurface antennas in upcoming wireless communications
Description:
Thesis (MEng of Engineering, Computer and Telecommunications) --Botswana International University of Science and Technology, 2022
