Abstract: Disclosed is a simple two channel monopulse receiver in which .SIGMA. and .DELTA. inputs are first fed to a hybrid to generate equal amplitude signals, A and B. The A and B signals are hard limited and then phase compared to provide a direction indication valid for angles within two beamwidths. The limited A and B signals are also fed to a second hybrid to generate new .SIGMA. and .DELTA. signals at a new amplitude level. These two outputs of the second hybrid are amplitude detected and substracted by a differential amplifier to provide an output proportional to angle from boresight. The two output signals together provide unambiguous indication of the direction and angle off boresight for targets up to two antenna beamwidths off boresight.

Abstract: A method of mounting a semiconductor device and making electrical connections without the use of bond wires is disclosed. In preferred form this process also includes fabrication of an IR detector array. Mesas in the mirror image of a desired array pattern are formed on the surface of a bar of IR sensitive material by etching to a depth greater than the desired final detector array thickness. A lead pattern for the desired detector array is formed on a support member with contact pads plated to a thickness greater than the final detector thickness. The bar of detector material is turned over and the etched surface bonded to the support member by means of an adhesive which also fills the area between the lead pattern contact pads and contact areas of the detector, to form a semiconductor unit. The semiconductor unit is lapped to final detector thickness to form a coplanar surface of the lead pattern contact pads, detector contact areas, and the adhesive material.

Abstract: A thermal energy receiver is disclosed comprising a cooling means for cooling an infrared detector including a detector array for producing electrical representations of thermal energy radiating from a scene and an array of cold shields providing an individual cold shield aperture for substantially shielding each detector element of the array from energy generated outside the solid angle subtended by the optical elements, and electro-optics for converting the electrical output of the detector array to visual signals for displaying the scene.

Abstract: An improved IR detector and method of fabrication is disclosed. The improved IR detector comprises at least one detector element having a slab of bulk intrinsic semiconductor material, a pair of spaced electrodes formed on said slab, the space between the electrodes forming an interelectrode dimension of the slab, and an active region selectively formed in the interelectrode dimension of the slab between the electrodes.

Abstract: The specification discloses a radar antenna which is fabricated by forming a plurality of elongated flat ribs each having an inwardly curved forward edge. Slots extending normally from the forward or rearward edge are formed along the length of each of the ribs. A plurality of the ribs are oriented vertically and the slots therein are mated with the slots in a plurality of the ribs which are disposed horizontally. The vertical and horizontal ribs are thus interconnected in a rigid lattice network which defines a plurality of rectangular compartments. The inwardly curved forward edges of the ribs in the lattice network define a contoured shape for an antenna reflecting surface. A screen is attached over the forward edges in order to provide a reflecting surface on the radar antenna.

Abstract: Disclosed is a wire grid for tuning a radome or irdome to pass microwave frequency energy while not interfering with the passage of lower radio frequencies such as those used for communications. The wire grid is embedded in the dome material and comprises a plurality of small closely packed wire loops. The close packing of the wire loops provides capacitive coupling between adjacent loops. At microwave frequencies the capacitive coupling between loops makes the pattern equivalent to the prior art continuous wire grid pattern and enhances transmission of a band of microwave frequencies. At low radio frequencies the capacitive coupling between loops is insignificant and the low frequency signals pass through the dome with no reflection. Intermediate frequency signals are attenuated by the wire grid.

Abstract: The specification discloses a RF generator for use in a radar system. The generator includes an oscillator having a crystal for generating a predetermined VHF signal. A multiplier multiplies the VHF signal to a desired RF signal. Amplifying circuitry amplifies the RF signal and applies a signal to a first isolator. A filter is connected to the output of the first isolator and includes plural cavaties for filtering all but a selected narrow bandwidth signal from the RF signal. A power divider divides the narrow bandwidth signal to provide a stable local oscillator signal and an exciter signal. A second isolator is connected to receive the exciter signal and a high pass filter is connected to the output of the isolator. A coherent oscillator generates a stable coherent oscillator signal and a transmit switch is provided to gate the coherent oscillator signal in response to a radar timing signal. A mixer mixes the gated coherent oscillator signal with the filtered exciter signal.

Abstract: The specification discloses a semiconductor magnetic modulator for use with a moving target indicator radar transmitter and which utilizes a plurality of charging capacitors for receiving charging current from a direct current power source and discharging in parallel. Silicon controlled rectifiers are connected to each of the charging capacitors and are operable to triggering signals to cause said capacitors to discharge at a predetermined time. A de-Q-ing circuit is connected to each of the charging capacitors in order to sense the voltage level across the capacitors and to dissipate voltage above a predetermined threshold level. The charging capacitors discharge through a hold-off inductor and through a switching transformer to a pulse forming network including a second charging capacitor. Compression occurs in the pulse charging network and a resulting high power modulator pulse is applied from the network to a klystron power tube in a moving target indicator radar transmitter.

Abstract: Disclosed is a magnetron powered selectable pulsewidth radar system having minimum receiver bandwidth for each pulsewidth and automatic centering of the intermediate frequency at the true center of the input filter pass band. A frequency discriminator adjusts the local oscillator frequency after each transmitted pulse to cause the intermediate frequency on the return of that pulse to equal an internal adjustable frequency reference. The filtered IF noise signal between received pulses is compared to the internal reference by the frequency discriminator and its output is used to adjust the reference to equal the center frequency of the actual receiver input pass band.

Abstract: Disclosed is a zero center frequency IF system having an all digital complex multiplier in which DC components in the IF signals are removed from an A/D converter output. Any DC level which reaches the input of the A/D converter or any misalignment in the A/D converter causes the digital outputs to contain unequal numbers of positive and negative words. The sign bit of the digital output is coupled to the input of an integrator which generates a DC output proportional to the DC offset in the A/D converter output. The integrator output is substracted from the IF signal coupled to the input of the A/D converter and cancels any DC components present.

Abstract: Disclosed is a solid state power source for microwave ovens which combines the power from multiple solid state oscillators or amplifiers in phase into a single port or load. Amplifiers are driven in phase and drive the load in phase through an equal phase power combiner. Oscillators are phase locked through an equal phase power combiner to drive the single load in phase. In phase operation prevents absorption of power by the amplifiers or oscillators, increasing power delivered to the load and preventing damage to the individual amplifiers or oscillators.

Abstract: Disclosed is a method particularly useful in fabricating microwave components for joining two metallic surfaces together to form an extremely strong bond, having good electrical and mechanical characteristics. One surface is primed or prepared with a suitable primer. An alloy adhesive, such as a polyamide-epoxy, is either deposited on the prepared surface or, if the adhesive is in film form on a release paper, then the film and release paper are heat tacked or ironed onto the prepared metallic surface. The paper release backing is then removed and the two metallic surfaces are mechanically assembled and positioned within a vacuum bag. The bag is evacuated and subjected to normal atmospheric pressure (14 psi) and heated to approximately 350.degree. for 1 hour whereupon the component is allowed to cool to 100.degree.F at which time the vacuum may be released and the component removed from the bag.

Abstract: A charge coupled device analog multiplexer in which a CCD shift register is characterized by an array of sets of phase electrodes. A plurality of charge packet injection input channels lead to an electrode in each of preselected sets in the array. A transfer gate common to all input channels admits charge packets to the array. A clock applies shift voltages to the array to move said charge packets to the multiplexer output where detector means responds to charge packets appearing at the output.

Abstract: Disclosed is an improved optical thin film coating system comprising all essential elements of resistive and electron beam evaporation systems, chemical vapor deposition systems and reactive plasma deposition systems. Sequences of cleaning and deposition processes which previously required moving substrates through several chambers are performed in a single vacuum chamber. The evaporative sources also efficiently vaporize solid materials to provide reactive gases for reactive plasma and chemical vapor deposition processes, which were previously difficult or impossible to perform. Substrate movement, masking, and monitoring means previously used with evaporative sources are used to control thickness and uniformity of films deposited by chemical vapor and reactive plasma processes, to provide optical quality films.

Abstract: Disclosed is a surface wave device comprising one transducer having its fundamental resonant frequency at a subharmonic of the device operating frequency and a second transducer having its fundamental resonant frequency at the device operating frequency. Both transducers respond to surface waves at the operating frequency. Only the harmonic operated transducer responds to bulk waves at the operating frequency. Thus, signal coupled from one transducer to the other at the operating frequency contains no noise generated by bulk mode coupling.

Abstract: Multilayer printed circuit board is fabricated by coating a suitable substrate, metal, plastic, paper, with a photosensitive coating, exposing the photosensitive coating to form a dielectric thereof, coating the dielectric layer with a coating of a photosensitive chemical solution, selectively imaging and developing the photosensitive coating to form a desired circuit pattern on the dielectric coating, forming a first layer of circuitry by coating the circuit pattern with a conducting material, coating the circuitry bearing layer with a second layer of photosensitive material, selectively exposing and developing the second layer of photosensitive material to form a dielectric with open windows to the first circuit layer, coating the second dielectric layer of the first circuitry with a coating of photosensitive chemical solution, selectively imaging and developing the coating of photosensitive chemical solution to form a circuit pattern and an interconnect pattern and forming a conductor layer of circuitry an

Abstract: An additive process for producing printed wiring boards is taught. In the process metal substrates having desired hole patterns are powder coated with a dielectric material electrostatically. The dielectric powder coating is then fused on the metal substrate. Next, a continuous film of pre-catalyzed adhesive is applied to all surfaces; then a plating resist is applied to all areas on which copper is not desired. The exposed catalyzed adhesive is then activated and plated in an electroless copper bath.