Abstract: A radio frequency (RF) obstacle detection system of a vehicle includes an RF radar module that transmits an initial RF signal having a first signal strength and to receive at least one reflected RF signal having a second signal strength based on the initial RF signal. A radar reflector module is coupled to the vehicle and disposed at a first distance remotely located from the RF radar module. The radar reflector module receives the RF signal generated by the RF radar module and efficiently retroreflects the RF signal to generate a reflected signal having a second signal strength back to the RF radar module. A control module determines a second distance between the radar reflector module and at least one obstacle remotely located from the vehicle based on the reflected signal provided by the radar reflector module and a received signal induced by the at least one obstacle.

Abstract: A radio frequency (RF) obstacle detection system of a vehicle includes an RF radar module that transmits an initial RF signal having a first signal strength and to receive at least one reflected RF signal having a second signal strength based on the initial RF signal. A radar reflector module is coupled to the vehicle and disposed at a first distance remotely located from the RF radar module. The radar reflector module receives the RF signal generated by the RF radar module and efficiently retroreflects the RF signal to generate a reflected signal having a second signal strength back to the RF radar module. A control module determines a second distance between the radar reflector module and at least one obstacle remotely located from the vehicle based on the reflected signal provided by the radar reflector module and a received signal induced by the at least one obstacle.

Abstract: A macroscopic mirror for wide angle scanning applications comprises: a silicon substrate section of a predetermined shape and macroscopic size cut from a silicon wafer comprising a flat, polished surface side and an etched, rough surface side; and a plurality of layers, including a layer of reflective medium, disposed on the flat, polished surface of the substrate section in such a manner to minimize flexural distortion of the flat surface. The macroscopic mirror is made by a method comprising the steps of: preparing the silicon wafer by polishing one side to a predetermined flatness and etching the other side to a predetermined roughness; cutting the substrate section from the prepared silicon wafer to a predetermined shape and macroscopic size; and applying the plurality of layers on the flat, polished surface.