Reflectarray for MMID and Imaging Applications
Reflectarray operating at 120 GHz is being developed. The 150-mm reflectarray is suitable for use in, e.g., millimeter-wave identification (MMID) or imaging application. The reflectarray consists of approximately 3700 patch antennas coupled to micro-electro-mechanical-system (MEMS) -based phase shifters, which are individually computer controlled.
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Figure 1. Reconfigurable millimetre-wave reflectarray (on the left). Reflectarray element with an open-ended transmission line stub as a phase shifter (on the right).
As a preliminary study perceiving the actively controlled system, static reflectarrays are designed and manufactured. Different test schemes will cover focusing the beam to a certain distance and to certain offset from boresight. The static reflectarray elements are based on grounded coplanar waveguide (GCPW) patch antennas coupled to a stub with length according to the desired phase shift.
Figure 2. Simulated beams of reflectarrays focused at a distance of 3 m; beam is directed towards the boresight (blue) and beam is directed 0.5 m offset from the boresight (red) at 3 m distance.
Contact persons: Juha Ala-Laurinaho