Other

Weatherford/lamb, Inc.

Telecommunications Research Laboratories

James William Haslett

Frederick N Trofimenkoff

Marvin L Holbert

Robert E Smallwood

John Godfrey McRory

Faramarz Sabouri

Robert James Davies

Curtis R Leifso

Graham A Jullien

Bogdan Alexandru Georgescu

Holly Pekau

Abdel-Fattah S Yousif

Ivars Finvers

Christopher D Holdenried

A Time-to-Digital Converter (TDC) is constructed using simple digital delay circuits. The design uses a clock compensation scheme to modify and adjust the TDC's operation under integrated circuit fabrication process variations. The TDC design is based on a novel digital processing algorithm that produces one conversion every clock cycle. Therefore, this TDC is the 'first' single cycle latency TDC targeted at high speed circuit applications such as (but not limited to) time-based Analog to Digital Converters (ADCs) for direct analog to digital conversion of radio frequency signals in wireless communication systems and high speed signal measurement applications. Due to its hierarchical design approach, the TDC design uses an optimized number of delay circuits and therefore requires very little power consumption and silicon area.

Time-to-digital converter

A bandage incorporates sensor arrays. The sensor arrays may measure temperature and are fixed to a person's temple in use, or other suitable body part. An estimate of core body temperature may be made using the arrays. The bandage may carry processing electronics and a transmitter. Processing may be done on the bandage or remotely from the bandage. Other physiological parameters may be measured depending on the type of sensor used.

Bandage with sensors

An insulator for a subsurface signal transmitting apparatus. The insulator includes a housing, a mandrel axially disposed inside the housing, a first insulating material disposed between the housing and the mandrel, a first sleeve formed of a second insulating material disposed between the housing and a first tubular member and the first tubular member coupled to the mandrel.

Subsurface signal transmitting apparatus

A monolithic transformer compensated circuit with enhanced quality factor without significantly increasing noise levels is presented in this disclosure. The technique uses a monolithic transformer and a current source driving current into the transformer secondary winding to achieve loss compensation in the transformer primary. An ac current which is proportional to, and in phase with the voltage applied to the primary winding can be used to achieve theoretically perfect loss compensation at a given frequency in the RF (GHz) frequency range. Examples of circuit applications that are particularly suited to the technique include Voltage Controlled Oscillators (VCO's), Low Noise Amplifiers (LNA's) and Filters. The technique has the added advantage of reducing power consumption in some applications.

Monolithic transformer compensated circuit

A parallel-summation logarithmic amplifier is described that uses a novel topology of cascaded and parallel amplifiers to achieve extremely high bandwidth. Included in the topology is a unique delay matching scheme for logarithmic amplifiers that is amenable to fabrication in integrated circuit form. The result is flat group delay over broad frequency ranges and different power levels. The resulting log amplifier is suitable for radar applications and for use in high data rate fiber-optic networks. Also described is a unique design process that yields a set of amplifier gains that closely approximate a logarithm. Also described is the novel idea of using a parallel feedback amplifier (PFA) in piecewise-approximate logarithmic amplifiers. This innovation allows for the design of broadband amplifiers with significantly different gains and similar phase characteristics, which is extremely useful when designing high-frequency logarithmic amplifiers.

Logarithmic amplifier

A subsurface signal transmitting apparatus including an insulation coupler, a carrier device for mounting the telemetry instrumentation, and a by-pass system for avoiding pressure build-up either above or below the apparatus. The insulation coupler includes a housing member having a central opening defined by an interior surface extending in the longitudinal direction and a mandrel member having an exterior surface spaced from the interior surface of the housing member to provide a gap or clearance with an insulating bonding material occupying the clearance. The surfaces are oriented so that when the coupling is in tension at least a portion of the two surfaces experience interacting forces towards each other in the longitudinal direction of the coupling and in event of failure of the bonding material, the mandrel member is unable to withdraw from the housing member. The by-pass system includes a by-pass tube which extends through central openings of the insulation coupler and carrier device and provides for electrically insulating one end of the assembly from the other but allows for pressure equalization via a fluid passageway. The carrier device has a cylindrical body forming external channels for concealing instruments about is circumference.

The subsurface signal transmitting apparatus ( ) including an insulation coupler ( ), a carrier device ( ) for mounting the telemetry instrumentation ( ), and a by-pass system for avoiding pressure build-up either above or below the apparatus. The insulation coupler ( ) includes a housing member ( ) having a central opening ( ) defined by an interior surface ( ) extending in the longitudinal direction and a mandrel member ( ) having an exterior surface ( ) spaced from the interior surface ( ) of the housing member ( ) to provide a gap or clearance ( ) with an insulating bonding material ( ) occupying the clearance. The surfaces are oriented so that when the coupling is in tension at least a portion of the two surfaces that when the coupling is in tension at least a portion of the two surfaces experience interacting forces towards each other in he longitudinal direction of the coupling and in event of failure of the bonding material, the mandrel member is unable to withdraw from the housing member. The by-pass system includes a by-pass tube ( ) which extends through central openings ( ) of the insulation coupler ( ) and carrier device ( ) and provides for electrically insulating one end of the assembly from the other but allows for pressure equalization via a fluid passage-way ( ). The carrier device ( ) has a cylindrical body ( ) forming external channels ( ) for concealing instruments ( ) about its circumference.

A 1.1 GHz fully integrated GaAs MESFET active inductor is presented. Both the inductance and loss resistance are tunable with the inductance independent of series loss tuning. The measured loss resistance is tunable over a &minus;10 &OHgr; to &plus;15 &OHgr; range with a corresponding change in inductance of less than 10% at 100 MHz and less than 4% for frequencies above 500 MHz for capacitive tuning. The inductance is tunable from 65 nH to 90 nH. The measured loss resistance is shown to be dc bias voltage tunable over a 0 to &plus;10 &OHgr; range with an inductance tunable from 55 nH to 110 nH, with negligible interaction between loss resistance and inductance for frequencies from 100 MHz to 1.1 GHz. Several embodiments a using MESFETs and MOSFETs are described. A negative impedance converter is included to achieve increased bandwidth in all circuit realizations. Considerably larger bandwidths can be achieved depending on the fabrication technology employed and the intended application of the circuit.

Active tunable inductor

A subsurface signal transmitting apparatus including an insulation coupler, a carrier device for mounting the telemetry instrumentation, and a by-pass system for avoiding pressure build-up either above or below the apparatus. The insulation coupler includes a housing member having a central opening defined by an interior surface extending in the longitudinal direction and a mandrel member having an exterior surface spaced from the interior surface of the housing member to provide a gap or clearance with an insulating bonding material occupying the clearance. The surfaces are oriented so that when the coupling is in tension at least a portion of the two surfaces experience interacting forces towards each other in the longitudinal direction of the coupling and in event of failure of the bonding material, the mandrel member is unable to withdraw from the housing member. The by-pass system includes a by-pass tube which extends through central openings of the insulation coupler and carrier device and provides for electrically insulating one end of the assembly from the other but allows for pressure equalization via a fluid passage-way. The carrier device has a cylindrical body forming external channels for concealing instruments about its circumference.

An electrical network creates a differential voltage signal and comprises a plurality of first impedance elements of substantially equal values which are connected to form an impedance bridge. The impedance of at least one of the first impedance elements changes in response to at least one selected external condition to which the first impedance elements are exposed. The network also comprises a second impedance element which has two nodes. The second impedance element is connected at these nodes between a first pair of the first impedance elements. The differential voltages are measured between these nodes and between another node or nodes with magnitudes and signs being dependent upon the change in the impedance of the first impedance elements.

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Calgary, Canada

James William Haslett