Abstract: A digital polarimeteric system employs a signal time stretching technique and digital signal processing of the time-stretched signal to accurately measure the polarization of a received RF signal with commercially available digital hardware. A superheterodyne receiver down converts received RF signal components to IF, and analog-to-digital converters sample the signal components at much lower sampling rates than would normally be required to accurately measure the signal polarization. Each signal sample is “time stretched” by storing each sample in M locations in a memory, such that N samples occupy M×N memory locations. A digital signal processor applies incremental phase shifts to the digital samples until a phase-shifted combination of the digital samples yields a minimum null output. The phase shifts producing the minimum null identify the polarization of the received signal.

Abstract: An electronic warfare (EW) cross-eye system comprises two antennas separated a distance, d, a part, where d is much greater than the wavelength, ?, of a tracking signal emitted by a fire control radar (i.e., d>>?). The EW cross-eye system further comprises a receive polarimeter for measuring the tracking signal and a second polarimeter for synthesizing the measured tracking signal to produce, for transmission, a jamming signal comprising a pair of inverted amplitude signals that are 180 degrees out of phase with each other.

Abstract: A solid state active aperture high power polarization agile transmitter, either single or dual polarization, employing nonreciprocal antenna elements, designed such that it can be used in an Electronic Warfare (EW) system that is more efficient and less expensive. Antenna beam steering is accomplished with variable phase shifters that are used to set the RF signal phase of each element. The beam steering function is implemented with a hardware architecture where the phase shifters are built-in ahead of the power amplifiers such that these low power phase shifters impart phase delays to low power signals without wasting RF signal power and hence improving efficiency. These power transmitter devices are also more reliable, lighter in weight and smaller in size.

Abstract: A solid state active aperture high power polarization agile transmitter, either single or dual polarization, employing nonreciprocal antenna elements, designed such that it can be used in an Electronic Warfare system that is more efficient and less expensive. Antenna beam steering is accomplished with variable phase shifters that are used to set the RF signal phase of each element. The beam steering function is implemented with a hardware architecture where the phase shifters are built-in ahead of the power amplifiers such that these low power phase shifters impart phase delays to low power signals without wasting RF signal power and hence improving efficiency. These power transmitter devices are also more reliable, lighter in weight and smaller in size.

Abstract: Electronic Warfare (EW) systems aboard aircrafts are used to protect them from guided missile by denying threat radar systems the ability to track the aircrafts. In a typical operation, a threat radar system transmits RF signals aimed at the target aircraft. The surface of the target reflects a portion of the incident signal back towards the threat radar antenna where the reflected signal is detected, allowing the threat radar system to determine the target's range, angle and velocity. The present invention relates to EW systems that are dependent on measuring the RF phase of a signal transmitted by a target tracking threat radar. The use of the invented technique will make it possible to implement a robust Electronic Counter-Measures (ECM) technique, known as Cross-Eye, using two airborne platforms. The technique is very effective in preventing a threat radar from tracking a target aircraft and guiding a launched missile to the target aircraft.