Rate locked loop radar timing system
AssigneeMcEwan Technologies, LLC
InventorThomas McEwan
Life of this patent
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Abstract
A rate locked loop (RLL) regulates phase slip between two clock signals to provide precision timing for radar, TDR and laser ranging systems. Two clocks having a small mutual frequency offset exhibit a slowing changing relative phase, or phase slip, that produces a stroboscopic time expansion effect in a ranging system. A phase detector converts clock phase to voltage and the voltage is differentiated to provide a rate-of-change signal to a loop controller that precisely regulates the rate-of-phase change. The RLL controls a VCO to produce a constant, linear phase slip having phase errors below the time equivalent of 1-picosecond.
Claims13
A rate locked loop, comprising:
- a frequency source for providing a first and second dock signal and further comprising a phase control, wherein the phase control adjusts the phase between the clock signals,
- a phase detector responsive to the phase between the first and second clock signals for producing a phase detector output proportional to phase,
- a differentiator having an output proportional to the derivative of the phase detector output to produce a derivative signal;
- and
- a controller responsive to the derivative signal for producing a feedback signal to the phase control, wherein the first and second clock signals provide timing for a pulse-echo rangefinder.
A method for generating clock signals having a relative phase slip, comprising:
- generating a first clock frequency,
- generating a second clock frequency,
- detecting the phase between the first and second clock frequencies to produce a phase signal,
- differentiating the phase signal to produce a derivative signal;
- and
- controlling the second clock phase using the derivative signal to produce a controlled phase slip.
A radar, laser or TDR ranging system comprising:
- a transmitter triggered by a first clock signal,
- a receiver gated by a second clock signal,
- a phase detector responsive to phase between the first and second clock signals for producing a phase signal,
- a differentiator for producing a derivative signal from the phase signal,
- a phase control for adjusting the phase of the second clock signal;
- and
- a controller responsive to the derivative signal for producing a feedback control signal to the phase control.
Dependencies are inferred from the claim text.