Antenna designs for sub-6 GHz and millimeter-wave communications systems
Thesis event information
Date and time of the thesis defence
Place of the thesis defence
L5 Linnanmaa campus
Topic of the dissertation
Antenna designs for sub-6 GHz and millimeter-wave communications systems
Doctoral candidate
Master of Science Zeeshan Siddiqui
Faculty and unit
University of Oulu Graduate School, Faculty of Information Technology and Electrical Engineering, CWC-Radio Technologies
Subject of study
Communications engineering
Opponent
Associate Professor Tim Brown, University of Surrey
Custos
Professor Aarno Pärssinen, University of Oulu
Antenna designs for sub-6 GHz and millimeter-wave communications systems
An antenna is an essential component in every wireless system, as it converts the wired signal to a free space signal and vice versa. This thesis presents antenna solutions at sub-6 GHz and millimeter-wave (mm-Wave) frequencies with potential applications in 5G networks.
For sub-6 GHz frequencies, antenna solutions based on leaky coaxial cables (LCX) are presented to improve the indoor coverage of communications system. An LCX is among the simplest and oldest antennas with distributed radiation attributes. It is generally used in mines and tunnels as its uniform radiating nature suits the long and narrow geometry. However, the small amount of propagating energy limits communicating with distant devices. To use LCX cables in complex indoor environments like hospitals, airports and offices, ways to control and improve their radiation performance are needed. In this thesis, by introducing periodic perturbations over cable, a significant improvement and control over the radiation performance of the cable is achieved. This may pave the way for more widespread use of leaky cables in complex indoor communications environments.
For high data rate applications of 5G networks, mm-Wave communication is a key enabling technology, as it offers wide bandwidth. It is challenging to design antennas with several wide operating bands that comply with strict fabrication rules and limitations at these frequencies. In this thesis, printed antenna designs are proposed to address the recent demands of mm-Wave 5G base stations. They have the advantage of low profile, being cost effective and integrability with electronics. On the other hand, they are generally narrowband antennas. This bandwidth limitation is addressed by introducing multi-layer stacked antenna structures. The proposed solutions also demonstrate decent filtering capability in addition to wide, multi-band operations. The demonstrated antenna designs are prospective antenna solutions for 5G mm-Wave base station antenna arrays.
For sub-6 GHz frequencies, antenna solutions based on leaky coaxial cables (LCX) are presented to improve the indoor coverage of communications system. An LCX is among the simplest and oldest antennas with distributed radiation attributes. It is generally used in mines and tunnels as its uniform radiating nature suits the long and narrow geometry. However, the small amount of propagating energy limits communicating with distant devices. To use LCX cables in complex indoor environments like hospitals, airports and offices, ways to control and improve their radiation performance are needed. In this thesis, by introducing periodic perturbations over cable, a significant improvement and control over the radiation performance of the cable is achieved. This may pave the way for more widespread use of leaky cables in complex indoor communications environments.
For high data rate applications of 5G networks, mm-Wave communication is a key enabling technology, as it offers wide bandwidth. It is challenging to design antennas with several wide operating bands that comply with strict fabrication rules and limitations at these frequencies. In this thesis, printed antenna designs are proposed to address the recent demands of mm-Wave 5G base stations. They have the advantage of low profile, being cost effective and integrability with electronics. On the other hand, they are generally narrowband antennas. This bandwidth limitation is addressed by introducing multi-layer stacked antenna structures. The proposed solutions also demonstrate decent filtering capability in addition to wide, multi-band operations. The demonstrated antenna designs are prospective antenna solutions for 5G mm-Wave base station antenna arrays.
Last updated: 8.5.2024