Quantum radar is a speculative remote-sensing technology based on quantum-mechanical effects, such as the uncertainty principle or quantum entanglement. Broadly speaking, a quantum radar can be seen as a device working in the microwave range, which exploits quantum features, from the point of view of the radiation source and/or the output detection, and is able to outperform a classical counterpart. One approach is based on the use of input quantum correlations (in particular, quantum entanglement) combined with a suitable interferometric quantum detection at the receiver (strongly related to the protocol of quantum illumination).
Paving the way for a technologically viable prototype of a quantum radar involves the resolution of a number of experimental challenges as discussed in some review articles,[1][2][3] the latter of which pointed out "inaccurate reporting" in the media. Current experimental designs seem to be limited to very short ranges, of the order of one meter,[4][5][6] suggesting that potential applications might instead be for near-distance surveillance or biomedical scanning.
^Luong, L; Balaji, B.; Sandbo Chang, C. W.; Ananthapadmanabha Rao, V. M.; Wilson, C. (2018). "Microwave Quantum Radar: An Experimental Validation". 2018 International Carnahan Conference on Security Technology (ICCST). pp. 1–5. doi:10.1109/CCST.2018.8585630. ISBN978-1-5386-7931-9. S2CID56718191.