Abstract: A borehole logging tool includes a housing oriented along a longitudinal axis, and a centralizer assembly that positions the housing substantially at the center of the borehole. In one example, the centralizer assembly includes a plurality of centralizer arms radially extendable outward from the longitudinal axis. The borehole logging tool further includes a scanning head that rotates a plurality of scanning sensors axially within the borehole about the longitudinal axis. The scanning head further includes a plurality of linkage arms coupled to the plurality of scanning sensors such that the scanning sensors are radially extendable outward from the longitudinal axis. The borehole logging tool further includes an extension assembly adapted to substantially concurrently control the radial extension of the centralizer arms and the plurality of sensors.

Abstract: A borehole logging tool includes a housing oriented along a longitudinal axis, and a centralizer assembly that positions the housing substantially at the center of the borehole. In one example, the centralizer assembly includes a plurality of centralizer arms radially extendable outward from the longitudinal axis. The borehole logging tool further includes a scanning head that rotates a plurality of scanning sensors axially within the borehole about the longitudinal axis. The scanning head further includes a plurality of linkage arms coupled to the plurality of scanning sensors such that the scanning sensors are radially extendable outward from the longitudinal axis. The borehole logging tool further includes an extension assembly adapted to substantially concurrently control the radial extension of the centralizer arms and the plurality of sensors.

Abstract: A phase-locked loop includes a voltage-controlled oscillator and a charge-pump loop filter. The voltage-controlled oscillator includes a varactor having a first set of capacitor cells configured to adjust a capacitance based on a first control voltage, and a second set of capacitor cells configured to adjust a capacitance based on a second control voltage. The charge-pump loop filter receives a first and a second update signal, each having at least one state based on a phase difference between a first clock and a second clock, and comprises a first component and a second component. The first component is configured to adjust, during an update period, a voltage across an impedance from a reference level based on the states of the first and second update signals and to return the voltage across the impedance to the reference level prior to an end of the update period, wherein the voltage across the impedance comprises the first control voltage.