Intermodulation Radar for RF Receiver Detections

Nonlinear radars are often used to detect the presence of RF electronics. In the state-of-art most of researchers has chosen to exploit the second-harmonic response of target. But its antenna is usually not impedance-matched at these harmonics, requiring that the useful signal is radiated by unintentional antennas formed by traces on the circuit board. A strong incident power is therefore required to guarantee a detection with an acceptable range. In this paper we propose an intermodulation radar whose incident and reflected signals are both captured and emitted by the antenna of the target.