Abstract: Apparatus which is utilized with a liquid crystal display for applying alternating current driving signals thereto, derived from applied direct current analog signals. The apparatus includes circuitry which samples and stores the applied analog signal. The apparatus also includes circuitry which level shifts the sampled signals so as to have voltage levels which are symmetrically disposed above and below a reference level associated with the liquid crystal display during alternating field times. The symmetrically disposed signals constitute applied alternating current signals to the display, with respect to the reference level.

Abstract: A microstrip linear array of dipoles is disclosed wherein the dipoles are phased in alternate directions thereby enabling them to be spaced at approximately one-half wavelength intervals along or across a microstrip line instead of the typical one wavelength interval. An additional embodiment includes two linear arrays of oppositely polarized dipoles fed by tributary lines located at either side of a main microstrip line. Alternatively, first and second linear arrays of dipoles are disposed on opposite sides of a circuit board and the dipoles fed by microstrip line that evolves into a balanced two wire line. The ground plane on one side of the circuit board is made to gradually taper to a width equal to the microstrip line on the opposite side at which point the latter is called a two-wire line.

Abstract: Laser excitation is generally initiated by "dumping" energy from a stored supply into a flashlamp. The flashlamp produces light which is a mixture of both black-body type radiation and atomic line spectra. That portion of the flashlamp output energy spectrum which overlaps the pump bands of Nd.sup.3.sup.+ causes the inversion population necessary for laser action. It has been determined that the sequence in which energy is initially supplied to the flashlamp is an important parameter. More particularly, light output in the pump bands, and hence laser efficiency, is increased by slightly turning on the flashlamp at a predetermined interval of time prior to the main energy dump. Theory indicates that this method of triggering results in a larger ionic path diameter at the time of main energy release to the flashlamp.

Abstract: The use of electronically variable phase shifters is required in phased array radar systems. Diode phase shifters are particularly well suited for use in phased array radar systems because they have size and weight advantage over other types of phase shifting components such as ferrite devices and traveling wave tubes and, in addition, offer the potential of cost reductions through the application of batch processing techniques. In accordance with the present invention, a phase bit is provided by the appropriate forward or reverse biasing of one series and one shunt diode to switch between a .pi. circuit and a loop transmission line circuit shunting the equivalent capacitance of the series diode when reverse biased.

Abstract: A planar constrained lens (bootlace lens) antenna is disclosed capable of providing a large one or two dimensional field of view with either a scanning feed or with multiple feeds. This planar constrained lens antenna is of the type which can replace both narrow field of view and wide field of view lenses in multiple beam communications satellite and in limited scan radars using focal plane scanning or with a two element lens system and a scanning phased array feed.

Abstract: The use of electronically variable phase shifters is required in phased array radar systems. Diode phase shifters are particularly well suited for use in phased array radar systems because they have size and weight advantage over other types of phase shifting components such as ferrite devices and traveling wave tubes and, in addition, offer the potential of cost reductions through the application of batch processing techniques. In accordance with the present invention, a 180.degree. phase bit is provided by two series diodes with three transmission line segments shunting each junction to ground through a common shunt diode. Operation is effected by the simultaneous forward or reverse biasing of the series and shunt diodes, thereby introducing a 180.degree. phase difference in a signal transmittal therethrough.

Abstract: A digital detection criteria control device for use in a radar tracking system incorporating a memory that is electronically synchronized to a surveillance radar in a manner to perform video mapping and control functions. This memory is organized so that each small quantum area of the radar's surveillance area has code bits which are controlled primarily by inputs from valid and invalid video return detectors. These detectors examine quantized video returns from the radar for certain bit densities and bit patterns to determine whether the video returns are valid or invalid targets. The code bits provide a history of the type of video return for each quantum area thereby making a more accurate indication of the nature of the video return possible.

Abstract: A dual frequency band horn-type antenna feed is described which has primary application to optimally illuminate a parabolic cylindrical reflector operating simultaneously at high power in both of the two bands. The principle of the invention is applicable to any two frequency bands regardless of their frequency separation including coincidence as a limiting case. The basic requirement of such a feed is that it must be as directive as possible within constraint of the feed aperture size in the plane of the cylinder axis because the cylindrical reflector does not collimate the beam in this plane and it must be relatively nondirective in the plane of the parabola for efficient illumination of the reflector. This requirement requires the phase front in the directive plane to be controlled within a small fraction of a wavelength at both frequencies.