Design of a PZT-based MEMS Rotman lens

The design of a MEMS Rotman lens that uses a high dielectric constant PZT (Lead Zirconium Titanate) thick film to fill the lens cavity has been presented. The 56 mum thick Rotman lens has a footprint area of 5.5x7.1 mm², incorporates 3 beam ports, 5 array ports, and operates at 77 GHz. The small size of the Rotman lens beamformer enables to fabricate both the transmit and receive beamformers on the opposite sides of the same wafer to realize a compact MEMS based radar when integrated with necessary microelectronic circuits and microstrip antennas. Analytical simulation results show that the developed beamformer can resolve an angular resolution of up to four degrees. A fabrication procedure for the MEMS Rotman lens has been developed and verified by simulating in IntelliSuitetrade. This microscale implementation enables the Rotman lens to be used as an integral part of a radar unit for automotive collision avoidance applications.