Abstract: A flux position sensor for magnetic bearings applications is provided by creating a secondary, or shunt, flux path in parallel with a main flux path of a magnetic bearing. The secondary flux path is formed such that a small amount of bearing magnetic flux is shunted from the main path into the secondary path. The amount of shunted flux varies in a known relationship with the flux density and/or the position of the element being supported by the bearing. By quantifying the amount of shunted flux, using any number of conventional methods, the position of the supported element can be determined. Therefore, the flux position sensor forms an integral part of a closed loop control system for an active magnetic bearing. The same sensor can be used simply for measuring flux density in a magnetic bearing or other device.

Abstract: A signal processing system for use with a radar ranging system which transmits a radio frequency beam of finite angle to a sloping target of not greater than some known slope and creates from the return signal a beat frequency signal comprising various frequencies corresponding to the various distances from the ranging system to the target. The processing system includes a first tracking bandpass filter which is caused to seek and lock onto the lowest frequency F.sub.L in the beat frequency signal. Given frequency F.sub.L, the angle of the beam and the maximum slope of the target, a theoretical maximum frequency F.sub.X is computed. A second tracking bandpass filter tracks down from frequency F.sub.X to and locks onto frequency F.sub.H, the frequency component in the beat frequency signal associated with the maximum range to the target. From frequencies F.sub.L and F.sub.H and the beam angle, the average range to and/or slope of the target can be computed.

Abstract: A frequency-modulated continuous-wave (FM-CW) ranging system produces a first signal of frequency corresponding to the measured range of a target which signal is sometimes below a given quality and produces a second signal of frequency corresponding to the measured range of a simulated target of known range. A threshold detector determines when the target signal is above the given quality at which time the period of the first signal is determined from a given cycle thereof while concurrently the period of the second signal is determined from which the range to the target can be computed.

Abstract: A tracking filter system including a phase locked loop and a tracking filter is receptive of an input signal of frequency A and undesired frequency X from a signal source such as a frequency modulated/continuous wave radar range measuring system. The phase locked loop circuit receives the input signal and produces a control signal corresponding to a frequency intermediate frequencies A and X. The tracking filter is set by the control signal to pass frequencies above or below the intermediate frequency and thus to pass frequency A and to reject frequency X.

Abstract: A frequency synthesizer of the phase-locked loop type, having an output circuit circuit which produces an output signal at any of a plurality of alternating frequency values depending on the value of a command signal applied to the output circuit. The synthesizer includes a storage apparatus for storing, for each frequency value, an indication of the precise command signal value which causes the frequency to be produced.

Abstract: The performance of a frequency-tracking filter comprising a phase-locked loop synchronized by square-wave output signal from a limiter amplifier is improved during interruptions in that signal by interposing a level discriminator between the limiter amplifier and the phase comparator element of the phase-locked loop.

Abstract: An adjustable alternating signal having a desired period, P, is applied to a cycle counter arranged to count n cycles and applied to a timer arranged to time out n.multidot.P after a first cycle is applied to the counter and timer. A comparator is coupled to the counter and timer to determine whether the counter reaches its count of n cycles first or whether the timer times out first indicating that the period of the alternating signal is shorter or longer, respectively, than desired. An integrator is responsive to the signal from the comparator for changing the alternating signal which achieves the desired period.

Abstract: A frequency-modulated continuous wave (FM-CW) ranging system for determining the range of a target includes apparatus which utilizes a target simulating delay line and target illuminating antenna, alternately switched to a difference frequency determining circuit and a scaling device to compensate for undesired changes of the FM modulation waveform.