Abstract: An adaptive cross polarization electronic countermeasures system comprising identical transmit and receive antennas. The transmit antenna is rotated 180 degrees with respect to the receive antenna. The transmit and receive antennas are mounted facing the same direction allowing for reception of an incoming RF signal from a monopulse radar and transmission of the signal back to the monopulse once ECM jamming is applied. The incoming RF signal is separated into vertical and horizontal components by coupling to vertical and horizontal feeds within the receive antenna. Each component is then amplified sequentially through the system and transmitted back to the monopulse radar. At the transmit antenna, the vertical component is transmitted out of the horizontal feed of the transmit antenna 180 degrees out of phase with respect to the feed. The horizontal component is transmitted out of the vertical feed of the transmit antenna with no phase shift.

Abstract: An improved tamper-resistant seal for use with generally U-shaped flexible closure devices, such as tabs and wire wraps, comprising an annular band dimensioned to encircle a flexible closure device and heat-shrinking the band to closely fit about the closure device to prevent removal of the closure device without prior destruction of the annular band.