M.Sc Thesis

M.Sc StudentVilner Pavel
SubjectDesign of Dense Antenna Array in 60-80GHz Range with
Emphasis on Utilizing Decoupling and Optimal
Feeding Techniques
DepartmentDepartment of Electrical and Computer Engineering
Supervisor ASSOCIATE PROF. Emmanuel Cohen
Full Thesis textFull thesis text - English Version


This thesis presents a research in the performance optimization of a generic multiport antenna. The investigation encompasses transmission, reception, and simultaneous transmission and reception operations. The last situation is viewed as a particularly significant, because it enables a full-duplex communication by independent electronically steerable subarrays on board of a small mobile device in the next generation of wireless networks.

Two distinct approaches, finding vectors of optimal beamforming coefficients for the transmitting and the receiving subarrays and finding a matrix representation of an optimal matching network, are presented. For each of the antenna operation directions, its specific performance characteristics, namely far-field radiation parameters for the transmission, signal-to-noise ratio for the reception and transmitter-to-receiver power leakage for the simultaneous operation, are addressed. Wider system concerns, such as an ease of the matching network hardware realization and designing the transmitter excitations to account for the power amplifiers efficiency characteristics are also reviewed.  

The proposed approaches are evaluated by a numerical simulation. Models of the antenna arrays are created and solved using a commercial full-wave 3D electromagnetic simulator (Ansys HFSS), whereas the investigated optimization algorithms are applied in the post-processing stage using a mathematical software (MATLAB). The simulations indicate that the suggested methods successfully improve the performance of the antennas under test over the classical uniform beamforming. The most notable results include bringing the transmitting realized gain of linear dipole arrays to its theoretical maximum over the entire scanning arc, reducing the power coupling between the transmitting and the receiving subarrays by the factor of 1e-4 without harming the transmitter performance and utilizing the receiver beamforming to reject both the far-field aggressors and the transmitter-induced noises. Together, these advances demonstrate that it is possible to achieve a full duplex operation with independent receiving and transmitting scans with a small, dense 2.7cm x 0.7cm linear array of 16 dipoles at the 73GHz central frequency.