Abstract: A broadband radio frequency signal are in the range between about 5 and 400 MHz and a single phase 60 Hz AC power signal are transmitted through a cable transmission line of a cable television system. Amplifiers are powered by the 60 Hz AC signal. The amplifiers are operable as repeater stations that transmit the radio frequency (RF) signal. An RF choke connected to the transmission line separates the 60 Hz AC signal from the broadband 5 to 400 MHz signal. The RF choke includes a conductor of a preselected gauge formed in a coil having a preselected number of turns wound around a ferrite coil form. A ferrite bead is in series with the coil on a selected turn of the coil. The ferrite bead displays an RF series resistance or impedance to the inductance of the coil and reduces the series resonance of the coil. A resistor is connected in parallel to a selected turn of the coil at the opposite end of the coil and functions as a shunt.

Abstract: An audio device comprises an equalizer circuit, a control circuit for controlling characteristics of volume, balance, bass and treble, control signals producing circuit which produces signals for controlling said characteristics and a reference voltage producing circuit which produces reference voltage for carrying out the characteristics controls, in which the control circuit is forcedly provided with bass and treble control signals having half values of the reference voltage upon operation of the equalizer circuit.

Abstract: A multi-port microwave device, such as an isolator or circulator, for transmission of electromagnetic energy in TEM and higher order modes non-reciprocally between parts. The device exhibits low insertion loss, high return loss (low VSWR) and high isolation and is operable over a 100 percent or more bandwidth. The microwave device includes a composite ferrite body between a circuit conductor and a ground plane. The composite ferrite body includes ferrite material having a saturation magnetization gradient for providing different frequency characteristics over the frequency pass band of the device.

Abstract: An automatic equalizer comprises a transversal filter connected to receive an input signal such as a television signal in which a predetermined periodic reference signal is present and having variable tap gains, and a correlator for forming the correlation between the input and output signals of the transversal filter and correcting the tap gains of the transversal filter to cancel out distortion components such as ghost component contained in the input signal. For the purpose of preventing the slow convergence and fluctuation of tap gains of the transversal filter due to non-periodic noise components contained in the input signal, a circuit is further provided to integrate a predetermined portion of the waveform of the reference signal contained in the input signal. An output signal of the waveform integrator circuit is correlated with the output signal of the transversal filter by the correlator.

Abstract: Fiber optic device for controlling the state of polarization of light. In one embodiment, a strand of fiber optic material is bent into a generally planar coil of relatively tight radius to stress the material and form a birefringent medium having principal axes which are rotated to control the polarization of light passing through the strand. In a second embodiment, one portion of a fiber optic strand is twisted about its axis to change the polarization, and a second portion of the strand is formed into a coil which is free to change in radius without additional twisting as the first portion is twisted.

Abstract: A method and an apparatus is disclosed for making an evanescent wave coupler. Two optical waveguides have a portion of the cladding material removed until the core is exposed. The two optical waveguides are placed in juxtaposition with an interleaf film between them. The interleaf film insures an accurate and constant spatial relation between the two optical waveguides to have reliable evanescent coupling therebetween.

Abstract: A connector for optical fibres, said connector including two groups of th cylindrical support rods, 13A, 13B, 13C, 14A, 14B, 14C, all of same diameter and guide means to keep these two groups of three rods side by side and in contact with each other so as to provide a central passage to house the optical fibres. The guide means include a group of three or four bearings held coaxially with one or two central bearings 20A, 20B, surrounding the two groups of rods on either side of their plane of contact 17 with very little play and with one end bearing 18, 19 surrounding each group of three rods with the same or a slightly greater play at a point distant from the plane of contact. Application to optical fibre transmission lines.

Abstract: Coupling devices for SAW's, which permit switching of SAW power between cnels. Channel waveguides are laid down on or in the surface of a substrate. The waveguides have a coupling region in which they are close to each other. The input waveguide is formed from a material whose acoustic wave velocity characteristic can be changed by an external means. Various means for altering the velocity of the SAW, such as electric or optical fields, are employed by applying them to the coupling region of the input waveguide.

Abstract: An optical apparatus for the deflection of a stationary beam of light to move the beam over two mutually perpendicular directions for projection onto a viewing screen. By suitably modulating the beam of light, images may be produced on the screen, as in the manner of TV images. The apparatus is defined by a piezoelectric bimorph of a known type which has been modified according to this invention so as to make each bimorph layer totally internally reflecting. The light deflection apparatus, also according to this invention, is made from a single bimorph provided with an extension of lesser mass and hence of lesser inertia. The main bimorph portion is electrically stimulated to oscillate it in a vertical (Y-axis) direction, and the extension is electrically stimulated to move it in a horizontal (X-axis) direction. The stationary beam of light is projected through the bimorph and onto the screen.

Abstract: A laser beam emitted from a laser is divided into a plurality of beams and the divided beams are introduced into respective fiberoptics. Each beam is transmitted through the corresponding fiberoptic and projected from the exit face of the fiberoptic, where the beams are synthesized to form a light spot. The affected part of a patient to be treated is exposed to the light spot.

Abstract: A scope for viewing the internal surface of a bore or similar cavity for use in combination with a light source. The scope includes a rod having an image transmitting end and an image viewing end. Diffusing and reflecting means are located at the rod viewing end and are surrounded by a housing. External light is directed onto the diffusing and reflecting means which in turn directs the light along the length of the rod to its image transmitting end and onto the cavity surface when the scope is inserted into the cavity. The image transmitting end of the rod allows the cavity surface to be viewed.

Abstract: A suspended microstrip circuit having a dielectric substrate arranged in parallel between two parallel metal planes. First and second strip conductors are provided on the substrate, the second strip conductor being in parallel with the first strip conductor and coupled thereto. A wave phenomenon can propagate through the conductor pair in an odd mode. The metal box accommodating the microwave circuit may now be much greater so that in most cases one box is sufficient. Microwave components such as Magic-T, series-T, shunt-T, circulators, filters, attenuators, can be implemented with the suspended microstrip line.

Abstract: This device provides for a substantially orthogonal transition or connection point between a strip transmission line configuration (one conductor, or two conductors sandwiched around a dielectric support, positioned in air between two ground planes such as might be used in a microwave antenna feed network) and a coaxial line section. The particular construction of the "side-launch transition" suppresses spurious parallel plate modes, and, in the case of two conductors surrounding a dielectric, trapped modes which occur between the two conductors. A U-shaped upper "dam" and corresponding lower "dam," electrically interconnected at several points, surround the termination of the stripline conductor(s) and provide suppression of parallel plate moding at the transition. In the case of two conductors surrounding a dielectric, electrical interconnection at the terminal point of the stripline conductors suppresses the trapped modes before they can be launched.

Abstract: An electric cable comprising a plurality of separate screenings (3, 8), immunized against external parasites, particularly of high amplitude (common mode current, EMP etc.), wherein the screenings are separated by one or more insulating or slightly conducting magnetic layers (7), formed from magnetic compositions and applied by extrusion.

Abstract: An active filter provides precision filtering of an output signal over a wide range of signal input frequencies. Overall the active filter comprises a simulated L/C resonating loop which includes: a first operational amplifier in a loop with an operational transconductance amplifier simulating a capacitance; and a second operational amplifier in a second loop with a second operational transconductance amplifier simulating an inductance. The apparent capacitance of the first loop and the apparent inductance of the second loop can be regulated by applying a control current to each of the operational transconductance amplifiers. In a preferred embodiment the control current is derived as an antilogarithm of a linear voltage where the linear voltage corresponds to the logarithm of the filter resonant frequency. The filter output provides a constant percentage band width signal independent of the tuned frequency. The amplitude gain at resonance similarly is independent of the tuned frequency.

Abstract: An improved system is described for cooling high power waveguides by the use of cooling ducts extending along the waveguide, which minimizes hot spots at the flanges where waveguide sections are connected together. The cooling duct (24) extends along substantially the full length of the waveguide section, and each flange (18, 20) at the end of the section has a through hole (36) with an inner end connected to the duct and an opposite end that can be aligned with a flange hole in another waveguide section. Each flange (20) is formed with a drainage groove (60) in its face, between the through hole (36) and the waveguide conduit (16) to prevent leakage of cooling fluid into the waveguide. The ducts have narrowed sections (32, 34) immediately adjacent to the flanges to provide room for the installation of fasteners closely around the waveguide channel.

Abstract: A flux drive gyromagnetic system such as a gyromagnetic waveguide phase shifter is temperature compensated by measuring the flux change in the gyromagnetic material during a reverse in saturation magnetization, comparing that change to the change under reference conditions and modifying the drive used to set the gyromagnetic material to a non-saturated condition in accordance with the results of the comparison.

Abstract: A new strip line cable is provided comprising a dielectric in tape form made of a porous, crystalline polymer and one or more pairs of electrical conductors, each pair of conductors having one conductor located on one side of said tape and the other conductor located on the opposite side of said tape and in substantially parallel relationship to the first conductor of the pair, the pairs of conductors being arranged in substantially parallel transverse relationship across said tape, and insulating layers made of a suitable non-porous plastic material placed over the conductors to affix them to said dielectric tape and encapsulate the cable assembly. The preferred tape dielectric is expanded, porous polytetrafluoroethylene.

Abstract: To provide for response of audio reproduction equipment with the full dynamic level range, for example of music, intended by a composer, although radio signals transmitted have been compressed to reduce the signal-noise level, an expander circuit (20a, 20b, 20c) is activated based on ambient noise level conditions as sensed, for example, by a microphone (12) which determines the ambient noise level. If the ambient noise level, for example within certain frequency bands, as selected by filters (32a, 32b, 32c) is low, so that the full dynamic range (difference between low volume and high volume passages) can be reproduced, a range expander (20a, 20b, 20c) is controlled, for example within selected frequency bands, to reproduce the respective frequencies, or the overall signal, with a dynamic range greater than that of the received compressed signal and, preferably, corresponding to the dynamic range of the original signal which was then compressed for transmission.

Abstract: In order to facilitate its construction as in integrated circuit, the inductive elements of two resonant circuits in a band-pass filter are each constituted by a first port of a respective gyrator circuit (22, 23 and 24, 25 respectively) the second port of which is loaded by a capacitor (3 and 6 respectively). The first ports, across which are connected capacitors (1 and 3 respectively), are connected by a signal path one to the other, as are the second ports, in such manner that a loop is formed comprising the two gyrator circuits and the two signal paths, enabling bilateral coupling of the two gyrator circuits to be obtained by coupling otherwise unused outputs (24+ and 22+) to otherwise unused inputs (22- and 24- respectively) of two-input two-output voltage-controlled current sources (22, 24) which form part of each gyrator circuit.