Abstract:
With the development of 5G and beyond applications, there is an increased demand
for high data rate communication. High band allocations up to mm-waves ensure these high
data requirements. Among different beamforming structures, the Rotman lens (RL) is an
attractive passive microwave lens-based beamforming network due to its low cost,
reliability, design simplicity, and wide-angle scanning capabilities. Conventionally, RL is
implemented using micro strip lines (MSL) technology for which there are inherent high
atmospheric absorption and path losses which become severe for the applications operating
at these high frequency bands. To mitigate these losses, high gain and narrow pencil-like
beam radiation patterns are preferred for the applications operating at mm-Wave
frequencies. So, for 5G and beyond applications, there is an increased demand for more
efficient, directional and wideband beamforming devices. In this context, a novel fabrication
technology i.e., Substrate Integrated Coaxial Line (SICL) is used for the first time to design
the RL which provide accurate beamforming with the lowest possible radiation losses.
This thesis presents a complete design development and performance analysis of
SICL based RL beam former for the applications of 5G and beyond. By using SICL,
isolation between the ports up to 15 dB is achieved which ensure a good impedance
matching between the input beam ports. Due to the use of low-loss SICL technology, a high
gain up to 13 dBi is achieved with an excellent scanning capability of -30 to 30 degrees over
a wide frequency band of 24 to 28 GHz with 26 GHz as the central operating frequency.
Owing to the low-loss and high gain performance, the designed SICL RL is suitable to be
used for mm-Wave applications.
