Frequency selective surface with tunable radar cross section

A system for communication, comprising:

• a frequency selective surface having a tunable radar cross section configured to receive an electromagnetic signal, the frequency selective surface comprising:
• an isolation layer;
• a plurality of conductive elements disposed on a first side of the isolation layer;
• and
• a plurality of tunable components, each tunable element coupled with a respective conductive element of the plurality of conductive elements;
• a control system configured to adjust a bias voltage applied to each tunable component of the plurality of tunable components to modulate a radar cross section of the frequency selective surface to encode binary data in a reflected electromagnetic signal following receipt of the electromagnetic signal by the frequency selective surface;
• a radar system configured to transmit the electromagnetic signal and receive the reflected electromagnetic signal;
• and
• the frequency selective surface is configured to operate within a frequency band corresponding to an operational frequency of the radar system;
• wherein:
• the frequency selective surface includes a ground layer disposed on a second side of the isolation layer opposite the plurality of conductive elements,
• the frequency selective surface includes a substrate layer disposed on the first side of the isolation layer,
• each tunable component of the plurality of tunable components includes a PIN diode,
• the control system is configured to adjust the bias voltage applied to each PIN diode to modulate the frequency selective surface between a high radar cross section state and a low radar cross section state,
• an increase to the bias voltage modulates the frequency selective surface to the low radar cross section state,
• a decrease to the bias voltage modulates the frequency selective surface to the high radar cross section state,
• the high radar cross section state represents a binary of 1,
• the low radar cross section state represents a binary of 0, and
• the radar system comprises a signal processor configured to decode a variation in the reflected electromagnetic signal corresponding to the encoded binary data.

A method for communication, comprising:

• providing a system for communication, comprising:
• a frequency selective surface having a tunable radar cross section configured to receive an electromagnetic signal, the frequency selective surface comprising:
• an isolation layer;
• a plurality of conductive elements disposed on a first side of the isolation layer;
• and
• a plurality of tunable components, each tunable component coupled with a respective conductive element of the plurality of conductive elements;
• a control system configured to adjust a bias voltage applied to each tunable component of the plurality of tunable components to modulate a radar cross section of the frequency selective surface to encode binary data in a reflected electromagnetic signal following receipt of the electromagnetic signal by the frequency selective surface;
• a radar system configured to transmit the electromagnetic signal and receive the reflected electromagnetic signal;
• and
• the frequency selective surface is configured to operate within a frequency band corresponding to an operational frequency of the radar system
• transmitting an electromagnetic signal toward the frequency selective surface;
• adjusting the bias voltage applied to the plurality of tunable components of the frequency selective surface to modulate the radar cross section to encode binary data in the reflected electromagnetic signal;
• and
• decoding the binary data from the reflected electromagnetic signal.