Abstract: A microwave bridge circuit for measuring frequency modulation noise signals arising in low power, high frequency sources having a highly non-constant FM noise versus baseband frequency characteristic includes amplifying and filtering means for excluding signals in frequency ranges beyond the field of interest and frequency response compensator means of attenuating signals outside the primary range of interest.

Abstract: A method of forming a microwave integrated circuit is disclosed. A hole is bored in an alumina substrate and a plug having a diameter substantially equal to the hole is provided. The hole and the perimeter of the plug are coated with a thermally fusable dielectric composition and the plug is embedded in the hole. Heating the substrate fuses the plug is place and crystalizes the composition into a glass with compatible thermal expansion. At least one face of the substrate and plug are then polished to provide a planar surface. The metalized circuit is then formed on this assembly, which minimizes conductive tracking on the substrate and facilitates alignment of the circuit with the plug.

Abstract: A linearally polarized multiport multimode feed for a reflector type antenna generates a plurality of beams, each in a different pointing direction, from a single radiating aperture. Each beam possesses a distinct phase center determined by the waveguide modes establishing the aperture distribution for that beam. The feed is linear and bilateral, therefore may be utilized in a receiving or transmitting antenna.

Abstract: A microwave integrated circuit is comprised of a ferrite plug in an alumina substrate, fused therein by a glass composition thermally compatible with both plug and substrate, thereby filling any voids at the interface with dielectic material to minimize circuit losses. The method of assembly permits metalizing the substrate after insertion of the plug, minimizing conductive tracking on the substrate, and facilitating alignment of the metalized circuit with the plug.

Abstract: A reflection coefficient phase angle measurement apparatus includes a voltage controlled phase shifter coupled to phase shift a sample of one of the signals incident to and reflected from a waveguide termination. The phase shifted signal sample and a sample of the non-phase shifted signal are phase compared in a phase detector and the sign of the signal resulting from the phase comparison is noted. This sign is compared with the sign of the previous phase comparison to determine a zero crossing. When a zero crossing has not occurred an incrementing signal is added to the phase control signal applied to the voltage controlled phase shifter to alter the phase of the the phase shifted signal sample, and the procedure is repeated until a zero crossing is obtained. The control voltage applied at the zero crossing is established by interpolation and utilized to determine the reflection coefficient phase angle.

Abstract: Signals to control the signal processor in the linearizer of a frequency modulated continuous wave radar transmitter are generated by sampling the signal being transmitted, modulating and delaying this signal, mixing the modulated delayed signal with a second sample of the signal being transmitted to obtain an intermediate frequency signal, filtering the intermediate frequency signal to isolate the upper and lower sidebands of this signal and mixing the two sidebands to obtain a control signal having a frequency that varies directly with the beat frequency between the sampled and delayed signals.

Abstract: A process for preparation of polyfunctional isocyanates having an NCO functionality of at least 4 is provided. The process is conducted at temperatures below 50.degree. C. Polyols having a hydroxyl functionality of at least 4 are reacted with diisocyanates to produce the polyfunctional isocyanates. The ratio of isocyanate groups to hydroxyl groups of the polyol must be at least 4/l. The new polyfunctional isocyanates are particularly useful as crosslinking agents for propellant compositions having a binder containing pendant hydroxyl groups.

Abstract: Cross-linked double base propellants having improved low temperature mechanical properties are provided. The improved properties are achieved by using a mixture of polyglycoladipate and polycaprolactone as the binder prepolymer and employing a lacquer grade nitrocellulose containing 12.1% N to 12.6% N as the source of nitrocellulose.

Abstract: An improved process is provided for rapidly dissolving water-soluble polymer gels in which the gels are subjected to the steps of extrusion, cutting of the extruded gels, forming a slurry of gel particles, subjecting the slurry to high shear forces, and finally mixing the resulting slurry and water to form a dilute aqueous solution of polymer. The improvement comprises cutting of the water-soluble polymer gel, prior to extrusion, into pieces of gel of a size which are small enough to fit into space defined between adjacent flights of the extruder at the feed inlet of the extruder. The process enables dilute aqueous solutions to be prepared on a batch or continuous basis with good reproducibility of polymer concentration in the solution being prepared.

Abstract: A nozzle/valve device for a ducted rocket motor is provided. The nozzle valve device employs a design in which a nozzle throat blockage element can be moved by translational motion into and out of the nozzle throat section of the device. The blockage element is designed so that in the closed position the nozzle throat has a minimum cross-sectional flow area and therefore the nozzle throat is never fully closed. The seals employed in the nozzle/valve device are isolated from contact with reaction products of the gas generator and effective use of minimum amounts of erosion resistant materials is achieved.

Abstract: Progressive burning propellant granules are prepared by a process in which the solvent-wet propellant granules are wetted with a mixture of burning rate deterrent and solvent. The burning rate deterrent penetrates the solvent-wet granules. After deterrent coating, the granules are dried to remove processing solvents initially present in the granules.

Abstract: Composite rocket propellants, in which the base component is a functionally terminated rubber, and case-bonded rocket motors containing same, are provided, wherein cross-link density at, and adjacent at least a portion of the initial propellant burning surface is lower than that throughout the remainder of the propellant to provide greater strain capability at the initial burning surface together with greater propellant strength for higher mass ratio and improved case bonding than possible utilizing a single "compromise" propellant cross-link density of the prior art.

Abstract: A castable solid propellant composition suitable for use as a fuel generator for a ducted rocket motor is provided. The binder for the composition is a crosslinked polysiloxane. The polysiloxane polymer which is crosslinked to form the binder has a viscosity measured at 77.degree. F. of from about 12 poise to about 50 poise. The metal fuel for the composition is a mixture of spherical and flake magnesium. The composition contains from about 16% to about 20% polysiloxane binder and from 55% to 63% magnesium fuel. The oxidizer is principally ammonium perchlorate.

Abstract: A dielectric system for coaxial electrical conductors is provided. The dielectric system separates an inner and outer conductor and is composed of a first layer of braided high tensile strength polymeric fluorocarbon filaments in an open weave surrounding the inner conductor. Surrounding the layer of braided filaments is a layer of cellular polyparabanic acid tape which is helically wound along the length of the cable with a negative overlap. Circumferentially surrounding these two layers along the length of the cable is a continuous layer of polymeric film which is in turn surrounded by a continuous layer of a crosslinkable polymeric lacquer.

Abstract: A process for purification of nitrocellulose containing residual acid from nitration is provided. In this process the nitrocellulose is cut in the presence of water to form an aqueous slurry of cut nitrocellulose fibers. The pH of the slurry is adjusted to a value of at least about 8 and the slurry is heated under pressure. The pH of the slurry is maintained above 8 during heating by addition of basic solution to the slurry. When the residual acid in the slurry is substantially completely neutralized, the fibers are separated from the slurry. The purified nitrocellulose is of reduced viscosity and satisfactory stability.

Abstract: A process is provided for deterrent coating of propellant compositions useful as gun propellant in which the propellant contains nitrocellulose, nitroglycerin and nitroguanidine. In the process strands of propellant containing processing solvents are coated with burning rate deterrent on the exterior surface of the strand only. The strands are cut and dried. The process reduces exposure of the propellant to heat by elimination of the preliminary drying step to remove processing solvents prior to deterrent coating. Ethyl alcohol is the preferred processing solvent.

Abstract: Smokeless crosslinked double-base propellant compositions having good mechanical properties over a wide temperature range are provided. The propellant compositions contain nitrocellulose, energetic plasticizer, a crosslinking agent which is a prepolymer of a hydroxy terminated polyester and a diisocyanate, lead salt and carbon black.

Abstract: Small charges of high energy double base propellants are prepared by solventless extrusion of propellant billets prepared by a slurry type process.

Abstract: An insulated electrical conductor is provided that exhibits excellent physical, electrical and chemical protection for wire and cable and is particularly suitable for use in aircraft applications. The electrical conductor is insulated with (A) a film selected from ethylene tetrafluoroethylene copolymer film and fluorinated ethylene-propylene (FEP) copolymer coated polyimide film and (B) a topcoat insulation system comprising (a) a first layer of polyimide, (b) a second layer of polyvinylidene fluoride, and (c) a third layer of crosslinked acrylic polymer.

Abstract: A process is provided for inhibiting the deposition of scale onto the surfaces of metals in a cooling water system. In the process a copolymer of maleic anhydride or maleic acid and certain allyl monomers is employed as the scale inhibiting composition. The copolymers are effective as scale inhibitors when employed in substoichiometric amounts.