Abstract: Method and apparatus for detecting a length of a cable connecting information equipments are disclosed. A reference signal which is a repetitively occurring signal is transmitted through a cable. A phase difference between the reference signal transmitted through the cable and the reference signal directly transmitted without routing the cable is detected, and a signal representing the cable length is produced based on the detected phase difference.

Abstract: Apparatus and method for determining and imaging superconductor surface resistance. The apparatus comprises modified Gaussian confocal resonator structure with the sample remote from the radiating mirror. Surface resistance is determined by analyzing and imaging reflected microwaves; imaging reveals anomalies due to surface impurities, non-stoichiometry, and the like, in the surface of the superconductor.

Abstract: The thickness of the layers of rubber covering the steel belts within a tire can be measured by transmitting a microwave signal toward the outer surface of the tire and measuring the phase shift of the signal reflected by the tire. In the preferred embodiment, a waveguide is used to direct the microwave signal toward the tire. A standing wave is created within the waveguide by interference between the transmitted microwave signal and the microwave signal reflected from the tire. A series of crystal detectors mounted along the length of the waveguide measure the standing wave. A processor calculates the phase of the reflection coefficient, and determines the thickness of the rubber layer as a predetermined function of the phase. By proper selection of the microwave frequency and the spacing between the waveguide and the tire, the rubber layer thickness can be uniquely determined as a function of phase for any range of rubber thicknesses likely to be encountered in a tire.

Abstract: Method and apparatus for detecting a length of a cable connecting information equipments are disclosed. A reference signal which is a repetitively occurring signal is transmitted through a cable. A phase difference between the reference signal transmitted through the cable and the reference signal directly transmitted without routing the cable is detected, and a signal representing the cable length is produced based on the detected phase difference.

Abstract: A system for determining the average water film thickness on surfaces, and in particular roadways, with the reflection of microwaves on the surface of the film of water being measured. To be able to easily measure water film thicknesses of several millimeters without contact and with great accuracy, the system includes at least two partial systems which each comprise a signal source and a receiver. The individual partial systems operate at different frequencies which are selected such that the maximum accuracy measuring regions associated with the respective frequencies are contiguous and cover the predetermined water film thickness range to be determined. The partial systems are connected with a sampling and control device which activates at least that partial system which exhibits maximum measuring accuracy for the respective water film thickness being measured and utilizes only the output signal from the receiver of that partial system for the measurement.

Abstract: A non-invasive sensor system (50) for real-time in situ measurements of sheet resistance and thickness of conductive layers of a semiconductor wafer. The sensor (50) includes a microwave source (78) for generating a plurality of microwave signals. An emitter waveguide (52) receives the plurality of microwave signals from the microwave source (78) and emits the microwave signals in the direction of the semiconductor wafer (20) in fabrication chamber (18). The collector waveguide (84) detects the reflected microwave signals from the semiconductor wafer (20). A dual directional coupler (64) communicates with emitter waveguide (52) to direct the microwave signals to and from the emitter waveguide (52) and to generate a plurality of electrical signals that relate to semiconductor wafer (20), conductive layer (108), and deposition vapor physical characteristics. These physical characteristics include conductive layer thickness, resistivity, and substrate temperature.

Abstract: Location of a fault in electrical conductors from a terminal position which may be remote from the fault using at least a broad band pulse generator to generate a pulse at a terminal position. It also uses a voltage source at the terminal position capable of inducing a change of impedance at the fault and time measuring means also at the terminal position. The method involves generating a first pulse at the terminal position which is propagated down the conductor and reflected back to the terminal position from various impedance discontinuities, including the impedance discontinuity of the fault, if present. The pattern of reflections from points along the conductor up to the fault resulting from the first pulse are recorded. Then sufficient voltage is applied to the cable to induce a change in impedance at the fault.

Abstract: A method of determining the thickness of a layer of material, such as soil, wood, ice or coal, that utilizes a microstrip antenna as a thickness measuring sensor. The sensor is positioned over the layer and a value for a parameter of the antenna such as conductance or resonant frequency is measured. The value is compared to a calibration table of values and the thickness of the layer is determined by interpolation. Alternatively, the value is compared to a control value to initiate a decision process. The decision could be that a layer of ice is building up on a wing of an aircraft or that an explosive device is buried under a layer of soil.

Abstract: Especially precise and reliable measurements and evaluations are obtained by measuring one or more propagation parameters of electromagnetic waves in a wave guide or resonator at least partially filled with fuel and evaluated in an evaluating circuit as the measure for the alcohol content and/or the calorific value. According to one embodiment, the travel time or the travel time difference of an electromagnetic wave between two or more points in a wave guide filled with fuel is determined and is evaluated through computer or circuit technology as the measure for the alcohol content and/or the calorific value.

Abstract: An improved swept frequency domain reflectometry instrument has an input/output terminal coupled to one end of a cable. A radio frequency at the input/output terminal is converted to an intermediate frequency using a swept local frequency. The radio frequency is derived from the swept local frequency and a variable offset frequency. A controller controls the variable offset frequency, monitoring the amplitude of the intermediate frequency. A period counter counts the intermediate frequency at a first maximum response of the intermediate frequency and further counts the offset frequency at a second maximum response of the intermediate frequency. The location of a discontinuity in the cable is calculated from the counted frequencies.

Abstract: A method of for manufacturing a coated optical fiber includes depositing a conductive coating on the optical fiber and measuring a value of conductance of that coating. Featured within the manufacturing method is a method for measuring the thickness of the conductive coating on an insulator, e.g., carbon on an optical fiber, including the following steps. An electromagnetic field is established by an input signal. The conductively coated insulator is moved through the energized electromagnetic field. The conductive coating on the insulator is oriented with respect to the electric field so that their interaction increases transmission loss from input to output. An output signal is extracted from the electromagnetic field. From changes in the output signal with respect to a predetermined standard, or reference, the conductance and the thickness of the conductive coating are determined.

Abstract: The linear position of an elongated element (1) is measured using a transmission medium (2). The transmission medium comprises an emitter (3) of microwaves and a receiver (4) of microwaves and has at its one end the elongated element (1) and at its other end an electrical short-circuit (23). An asymmetrical sawtooth standing wave with substantially linear flanks is generated by reflection of the microwaves on the short-circuit (23) and on the elongated element (1). The position of the elongated element is determined by measuring the amplitude of the longer flank of the standing wave with the receiver. The method may be used in difficult circumstances and is suitable to measure mechanical vibrations of high-frequency.

Abstract: An electrohydraulic control system includes an actuator having a cylinder and a piston variably positionable therewithin. An electrohydaulic valve is responsive to valve control signals for coupling the actuator to a source of hydraulic fluid. A coaxial transmission line extends through the actuator, and includes an outer conductor formed by the actuator cylinder and a center conductor operatively coupled to the piston, such that length of the coaxial transmission line is effectively directly determined by position of the piston within the cylinder. An rf generator is coupled to the coaxial transmission line for launching rf energy therewithin, and valve control electronics is responsive to rf energy reflected by the coaxial transmission line for indicating position of the piston within the cylinder and generating electronic control signals to the valve. A second coaxial transmission line of fixed length is connected the valve and actuator so that the hydraulic fluid flows therethrough.