28GHz-43GHz Nadir/Near-Nadir (~70-90 degrees wrt horizontal) Low Probability of Intercept Radio Frequency Direction Finding/GeoLocation Capability

In this program, we propose a radio frequency (RF) direction finding sensor for low probability of intercept (LPI) RF radar system. This sensor consists of a dielectric lenses focusing system and an innovative focus plane detector array (FPDA) developed by Spectrum Magnetics, LLC (SM). The focusing system project the RF signal onto its focus plane. A novel FPDA based on emerging spintronic and metamaterials devices, with each element being much smaller than the EM wavelength, accurately detects the diffracted field distribution produced by the lenses. The center of the distribution is related to the direction of the incident waves. The direction can thus be extracted from the position of image of the transmitter in the focus plane and parameters of the focusing lens system.