Tag that enhances vehicle radar visibility of objects

A tag, comprising:

• a receive antenna configured to receive a signal;
• and
• a bandpass filter configured to receive the signal from the receive antenna and to allow a portion of a frequency range of the signal from the receive antenna through;
• an amplifier configured to receive and amplify the filtered signal from the bandpass filter;
• and
• a transmit antenna configured to transmit the amplified signal, wherein
• the receive antenna, the transmit antenna, and the amplifier are configured such that antenna-to-antenna isolation between the receive antenna and the transmit antenna is greater than a gain of the amplifier.

A tag, comprising:

• a plurality of antennas, at least two of the plurality of antennas oriented in different directions;
• a bandpass filter configured to receive a signal from at least one of the plurality of antennas and to allow a portion of a frequency range of the received signal through;
• and
• an amplifier configured to receive and amplify the filtered signal from the bandpass filter such that the amplified signal is significantly more powerful than the received signal, wherein
• the plurality of antennas of the tag are oriented such that radar signals from vehicles approaching from at least two directions can be received, amplified, and retransmitted with a larger RCS.