Antennas and Wireless Sensors
(Figure: Dual-polarized beam-steerable millimeter-wave antenna array.)
We are surrounded by wireless devices and majority of the internet traffic goes through antennas. We develop antennas that produce radiation more efficiently, can focus the energy to the receiver, and can simultaneously utilize many propagation paths (MIMO antennas). Better antennas result into lower power consumption, longer range, better reliability and increased data rates.
There are three main research areas in the field of antennas and wireless sensors:
Current antennas of mobile phones can waste up to 99 % of available RF energy for heating up the user and the device. We study adaptive antennas consisting of many, collaborative radiating elements making it possible to adapt the antennas operation to the given frequency and mitigate losses due to the user. See a 2-minute youtube video on the concept (https://youtu.be/1IcNtoTL00k). We also develop beam-steerable mm-wave antennas for mobile devices. In particular, we study how these antennas could share the same volume with LTE antennas.
Compared to microwaves, mm-waves makes it possible to focus radio waves much better with antennas of the same size. We study how to best realize mm-wave beam-steerable antennas and our research is related for instance to wide-band arrays with wide beam steering range, mitigation of active reflection, integration of active electronics with passive antenna structures, usage of novel materials in mm-wave antennas and manufacturing of the antennas with 3D printing technologies.
We study RF-powered devices that can harvest the required energy from ambient radio waves and use the same waves for communication too. We focus our research in particular in adaptive antennas, power harvesters, modulators and sensors.
Group members
Latest publications
Misalignment Compensation for Two Orthogonally Polarized Acquisitions in Planar Near-Field Scanning
Analysis of Differential Signals in a Concentric Dual-Polarized Tapered Slot Antenna
Differential Aperture-Coupled PCB-to-Waveguide Transition for Antenna-IC Integration at 100 GHz
Method for Unique Permittivity Extraction Using Transmission-Only Free-Space Measurements at THz Frequencies
Permittivity Extraction of Electrically Thin Samples by Reflection-Only Free-Space Measurements
Comparison of Pattern Synthesis Methods Using Magnitude Least-Squares Fitting
Accounting for Structural Scattering and Mutual Coupling in Characterization of Multiport Time-Modulated Scatterers
A Multifrequency System Model for Multiport Time-Modulated Scatterers
Mutual-Coupling-Aware Optimization of a Time-Floquet RIS for Harmonic Backscatter Communications
Quasioptic, Calibrated, Full 2-port Measurements of Cryogenic Devices under Vacuum in the 220- 330 GHz Band
Contact:
Associate Professor Ville Viikari
Email: ville.viikari@aalto.fi
Tel.: +358 50 4135 458
Postal address:
Department of Electronics and Nanoengineering
Aalto University School of Electrical Engineering
P.O. Box 15500, 00076 Aalto, Finland
Visiting address:
TUAS-building
Maarintie 8, 02150 Espoo