Abstract: A voltage controlled oscillator (VCO) is described which comprises a plurality of inverter stages of odd number connected in a ring with the output of each stage connected to the input of the next stage via a voltage controlled impedance provided by the transconductance of pass transistors. In one embodiment, this VCO is incorporated into a Phase-Lock Loop circuit, in which the gates of the pass transistors are connected to a control circuit which provides a variable biasing voltage to the gates inresponse to speed-up or slow-down signals provided by a phase detector. The bias on the gates adjusts the frequency of the voltage controlled oscillator, in accordance with the speed-up or slow-down signal. The phase detector is coupled to a stream of input data pulses and to a reference train of clock pulses provided by the voltage controlled oscillator.

Abstract: Device for correcting deviations upon focussing a laser beam, which comprises electronic means, among which a quadrant detector, for forming with the output signals of said quadrant detector a correction signal -K.sub.1 V.sub.c H.sub.c /.SIGMA. (18), which is added (19) to the focussing signal (A+C)-(B+D) formed in circuit 14, A, B, C and D being the output signals of the quadrant detector (9a, 9b, 9c, 9d),V.sub.c =(A+B)-(C+D)formed in circuit 15;H.sub.c =(A+D)-(B+C)formed in circuit 17;.SIGMA.=A+B+C+Dformed in circuit 16 and K.sub.1 being a constant.

Abstract: A tuned oscillator is disclosed which comprises an active element, a resonator electrically connected to the active element and made of a magnetic material using ferro-magnetic resonance phenomenon, and a magnetic circuit for applying a magnetic field to the resonator. The resonator is made of an YIG (yttrium, iron and garnet) thin film magnetic resonance element formed by a thin film forming technique and utilizes an uniform mode ferro-magnetic resonance in the YIG thin film, and operating under the application of magnetic field of the magnetic circuit.

Abstract: A holographic method for determining rotational effects upon either gear of gears (1, 2) of a gear set having respective mutually orthogonal rotational axis (C.sub.1, C.sub.2). Particularly, a holographic recording medium or element 12 is secured to gear (1) so that is rotates in synchronization therewith about axis (C.sub.1). Gear (2) is illuminated by a pulsed collimated light beam (L) emitted from a source (14) such as a laser. Beam (L) is reflected from gear (2) as object beam (0) substantially parallel to axis C.sub.2 and means such as a semi-reflective mirror 16 having a slit (18) is provided for directing a reference beam (R) and object beam (0) towards element (12). Development of element (12) after exposing it to beams (R and 0) at two different rotational conditions provides interference lines (f.sub.1, f.sub.2) enabling a viewer of the holographic image of gear 2 to determine the effect of rotation thereupon.

Abstract: A voltage controlled oscillator (VCO) for a television tuner for tuning a large number of television channels, including signals in the microwave frequency range, the VCO comprising a printed circuit (PC) board having a dielectric substrate, a patterned metal layer on one side of the substrate, and a substantially continuous metal layer forming a ground plane on the other side of the substrate, a transistor mounted on the ground plane side of the PC board, and having emitter, base and collector leads projecting laterally from the transistor, the base of the transistor being connected to the ground plane, a d-c supply circuit connected to the transistor, a tuned circuit connected across the collector and emitter of the transistor, the tuned circuit including at least one ground connection to the ground plane of the PC board, the d-c supply circuit, the tuned circuit, and the transistor having values which produce an oscillating output at a frequency of at least one GHz, and the ground connections being interco

Abstract: A spectral analyzer and direction indicator system (10) is disclosed and includes first and second optical channels (20,30) for providing detected optical information indicative of incidence direction and spectral content of incident radiation. The first optical channel includes a reflector element (11) having a non-ruled section (11a) and a spectrally dispersing ruled section (11b); an analytical optical system (13); and a detector array (15). In the reflector element of the first optical channel the non-ruled section is tilted relative to the ruled section. The second optical channel includes a non-dispersing reflector element (17), an analytical optical system (19), and a detector array (21).

Abstract: A system for accurately controlling the movement of an object through a predetermined non-rectilinear path in a predetermined volume having X, Y and Z axes. The system uses three tracking laser interferometers rigidly positioned relative to the volume and a single retroreflector rigidly coupled to the object to control movement of the object non-rectilinearly through the volume along a predetermined path. Using two more tracking laser interferometers and an additional retroreflector rigidly coupled to the object, the system controls angular orientation of the object about one of the axes. Adding a sixth tracking laser interferometer and a third retroreflector to the object, the system can also control angular orientation about the other two axes. Each tracking laser interferometer comprises an interferometer and a tracking mirror which is pivoted to maintain the interferometer output beam on its associated retroreflector.

Abstract: In the horizontal drive of a raster scanned video display, a free running astable multivibrator responsive to a synchronization input signal provides a horizontal output signal to horizontal deflection circuitry for synchronizing the video display's raster scan with the video information presented thereon. The astable multivibrator includes a pair of coupled transistors which are alternately rendered conductive in accordance with the time constant of a respective RC network associated with each transistor. To compensate for the temperature-dependent operation of the transistor pair which causes the multivibrator's operating frequency to increase with increasing temperature, a pair of back-to-back coupled diodes are connected to provide the synchronization input signal to one RC network so as to increase the charge on a capacitor within the network, the time constant of which is similarly increased. The temperature-dependent change in voltage across the diodes compensates for the change in V.sub.

Abstract: In a demodulation circuit, a timing synchronizing circuit generates a timing signal representing a sampling timing of an A/D converter and has a timing signal generator, a polarity identification circuit and a logic circuit. The timing signal generator is phase-controlled by a phase control signal and generates a timing signal. The polarity identification circuit identifies a polarity of a differential coefficient of the baseband signal at a sampling point of the A/D converter and generates a polarity identification signal. Upon logic processing, the logic circuit supplies to the timing signal generator the phase control signal representing a deviation of an actual sampling point of the baseband signal from an optimal sampling point. A carrier asynchronism detection circuit detects an asynchronism state of a carrier regenerating circuit and supplies to the timing synchronizing circuit a signal which changes its loop parameter.

Abstract: A method and an apparatus for optical inspection of transparent articles. The method and apparatus use a light beam scanning field which is separated into at least two portions. The field portions are directed at the article at differing angles of incidence such that they eliminate blind spots caused by portions of the apparatus which block the passage of the light through the article. A feature of the invention is its provision of a folded optical path to increase the length the beam travels between the beam generator and the object beyond the physical distance between the beam generator and the object.

Abstract: An auto-focus system for focusing reflecting objects which are under investigation in a measuring device. The invention comprises a light source for producing an illumination beam for illuminating an object plane of an objective lens to be focused, an imaging beam and a focusing beam, both originating from the illuminated object, means for separating the focusing beam and the imaging beam, the latter producing an image of the object in an image plane which is evaluated, and an amplitude object not visible in the imaging beam. Means are provided to render visible the amplitude object in two detector planes, where resulting counter moving interference patterns are evaluated and used for focusing the objective lens.

Abstract: A improved microwave dielectric oscillator module which is provided with a removable temperature compensated dielectric resonator channel element is described. The removable temperature compensated dielectric resonator channel element cooperates with an electrically shielded housing. A substrate is mounted within the housing. Microstrip or stripline conductive patterns deposited on the substrate couple energy from the removable dielectric resonator to the remainder of the oscillator circuitry. The oscillator achieves wideband operation utilizing a GaAs FET transistor as the oscillators active element in conjunction with an intergral trombone-line phase adjuster.

Abstract: An infrared detection module is disclosed for interfacing a plurality of detector elements to external electronics. The module is formed of a plurality of multi-channel integrated circuits stacked in substantially overlapping registry with adjacent integrated circuits separated by an insulating layer. Each integrated circuit is formed to have exposed conductive areas along first and second edge portions thereof. Each detector array segment is disposed transverse to the plane of the integrated circuits and connected to conductive areas on each integrated circuit along first edge portions thereof. A module header interface is disposed transverse to the plane of the integrated circuits and is electrically connected to the conductive areas along the integrated circuit second edge portions.

Abstract: Disclosed is a stroboscopic method of determining the quality of meshing between respective teeth of two or more gears. By way of example, a method is disclosed by which a standard is established by directing an adjustable pulse rate light beam (L) from a stroboscopic light source (18) towards a region (R) generally encompassing the location of meshed engagement between respective teeth (6; 8) of a pair of gears (2, 4) rotating at a predetermined rpm that are selected on the basis that they possess degree of mesh engagement quality desired for such gear pairs.

Abstract: A directly modulated microwave source for use in communications equipment is disclosed. The arrangement, fabricated in an open ended waveguide comprises an oscillator section operating in the TE.sub.101 mode and an impedance matching section providing adjustable coupling to a load. A suitable active element is a Gunn diode, post mounted in proximity to the closed end of the waveguide for H field coupling. Modulation in frequency or phase is achieved by a varactor diode, also post mounted, positioned approximately 2/3 of the length of the waveguide from the closed end. A vertically adjusted post for the load coupling adjustment, is placed adjacent the varactor post, but nearer the opening. The two adjacent posts define the boundary between sections and provide H field coupling to the varactor diode. Temperature stabilization means and frequency tuning means are located respectively on the upper and lower surfaces of the waveguide at anti-nodial portions of the oscillator section.

Abstract: A circuit for generating a noise signal for use in a jet engine noise simtor which utilizes two component pseudo-random noise (PSN) generators and a combination field effect transistor (FET) and resistor circuit to which the outputs of the PSN generators are connected such that the signal from one PSN generator is modulated by the signal from the other PSN generator.

Abstract: An improved method and apparatus for reducing the amount of memory required to implement a digital echo modulator. A single permanent memory stores digital representations of a series of samples of a signal element for several phases of the signal element. A temporary memory is provided to store the digital representations from a plurality of signal elements to be overlapped. The signal element values are clocked out of the permanent memory and into the temporary memory at a rate, during each sampling interval, equal to the number of overlapping signal elements. The contents of the temporary memory are then provided to a summation circuit for producing a digital representation of the composite signal during that sampling interval. Phases of the signal element which are 180.degree. out of phase with the stored phases are generated using two's complement circuitry.

Abstract: A phase locking circuit for effecting pull-in of a phase locked loop to a desired frequency component even in the presence of spurious signals includes a phase locked loop, a scanning circuit and a control circuit. The scanning circuit generates a scanning current to the phase locked loop which activates a voltage controlled oscillator (VCO) therein, the VCO output being phase locked to an input signal by operation of the phase locked loop. The control circuit produces a periodic scanning restart signal causing the scanning circuit to periodically generate a second scanning current independent of the phase lock status of the phase locked loop until a phase lock to the desired frequency component is realized. The second scanning current functions to unlock a VCO output locked to a spurious signal.

Abstract: An oscillator circuit including an odd number of inverters connected in cascade to form a loop; a delay element inserted between adjacent inverters; and a pulling circuit. The pulling circuit pulls up and/or pulls down the potential of the output terminal of the delay element during a predetermined period in response to the inversion operation of one of the inverters.

Abstract: A demodulator circuit comprises an integrator (A1) having its input connected through a first switch (S1) to a summing point (P). A modulated carrier signal to be demodulated is applied to the summing point through an input resistor (R1). A sample-and-hold circuit comprises a second switch (S2) operable at the carrier signal frequency in antiphase with the first switch (S1) to connect the output of the integrator (A1) to a holding capacitor (C2) and an operational amplifier (A2) having 100% negative feedback. A feedback connection including a feedback resistor (R2) is connected between the output of the amplifier (A2) and the summing point (P).