Abstract: This disclosure relates to an improved airborne monopulse radar system used for tracking ground targets. The system includes a null command generator designed to provide an error signal proportional to the angle between a preselected target azimuth and the monopulse antenna difference pattern null azimuth which error signal is unaffected by the presence of moving targets within the area under radar surveillance. The error signal is applied to the monopulse antenna drive servomechanism in order to physically reorient the antenna to have the difference pattern null and the preselected target aligned along the same azimuth.

Abstract: A diffraction grating head up display is disclosed which blocks solar radiation from impinging upon and washing out the image of display information on an optical display device. This is accomplished by means of a filter such an optical element made of photochromic material which is positioned between the display information surface and relay optics lenses, preferably at the back focal plane thereof, so that focused solar radiation darkens a localized spot in the photochromic material. The darkened spot blocks the solar energy but reversibly lightens after the focused solar energy is removed. This photochromic material allows substantially unimpeded transmittance of the image of the display information except at the darkened spot. Also included in the optical system are a folding reflector and a combiner lens element which combines and superimposes the image of the display information on the scene being viewed when an observer looks through the combiner element.

Abstract: Apparatus for processing radar video signals and applying the processed signals to a radar display. The apparatus includes video extraction circuitry which removes random pulse interference and noise from the video signals. The improvement of the present invention comprises clutter transmission circuitry and a memory which transmits and stores clutter video signals provided by the video extraction circuitry. In addition, comparison circuitry is provided which compares the applied signals (present video) provided by the video extraction circuitry to time-averaged signals computed thereby. The comparison circuitry transmits the present video signals to the radar display when the difference between the present video signals and the time-averaged signals is greater than a predetermined value. In one specific embodiment, the comparison circuitry includes scan-to-scan correlation circuitry which provides time-averaged video signals which are averaged in a predetermined manner over a plurality of azimuth scans.

Abstract: A power-radiating slotted waveguide comprises one or more rods mounted inside the waveguide adjacent a non-inclined slot. The rod causes power to be radiated and because the slot is non-inclined, undesirable cross-polarized radiation is minimized. The energy radiated from the slot can be varied by varying the area between the rod and the waveguide walls.

Abstract: A chip-level power combiner comprises plural amplifier devices, a power divider, and a power combiner. The power divider and the power combiner are disposed in mirror-image fashion. Each divider/combiner comprises a first divider/combiner section having plural branch transmission lines cascading from/to a main transmission line, and a second divider/combiner section having plural feeder transmission lines cascading from/to each branch of the transmission line. Each of the branch and feeder transmission lines has an isolation resistor interposed between adjacent lines, and the feeder transmission lines are tapered.