摘要 |
Two crystal oscillators are configured as a "plug-and-play" precision transmit-receive clock system that requires no calibration during manufacture. A first crystal oscillator generates a transmit clock and a second crystal oscillator generates a receive clock that operates at a small offset frequency DELTA from the transmit clock. A frequency locked loop regulates DELTA by regulating the frequency of the detected receive pulses from a radio, radar, laser, ultrasonic, or TDR system. The clock system further includes a wrong sideband reset circuit and a phase lock injection port. Applications include a timing system for automotive backup and collision warning radars, precision radar and laser rangefinders for fluid level sensing and robotics, precision radiolocation systems, and universal object/obstacle detection and ranging.
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