Disclosed is a radar detection assistant apparatus for increasing detection accuracy when detecting an object using a radar detection device. The radar detection assistant apparatus includes a radar signal receiver for adjusting a radar candidate signal received through a reception antenna to a predetermined magnitude and filtering out a signal other than the radar candidate signal, a radar signal analyzer for receiving the radar candidate signal from the radar signal receiver and determining whether or not the radar candidate signal is a preset radar signal, a radar signal production controller for generating a control signal for an assistant apparatus production signal or an assistant apparatus reproduction signal on the basis of at least one of pieces of information on a type, a bandwidth, and a period of the radar candidate signal received from the radar signal analyzer, and a radar signal producer.

Techniques for characterizing a vocal tract by using radar measurements. A radar marker that is arranged in or on the vocal tract is used.

A system for communication can include a frequency selective surface having a tunable radar cross section configured to receive an electromagnetic signal. The frequency selective surface can include an isolation layer, a plurality of conductive elements disposed on a first side of the isolation layer, and a plurality of tunable components, each coupled with a respective conductive element. A control system can be configured to adjust a bias voltage applied to the tunable components to modulate the radar cross section of the frequency selective surface and encode binary data in a reflected electromagnetic signal. A radar system can be configured to transmit the electromagnetic signal and receive the reflected electromagnetic signal. The frequency selective surface can operate within a frequency band corresponding to an operational frequency of the radar system to enable adaptive, reflected-signal communication.