公开(公告)号：US4981358A

公开(公告)日：1991-01-01

申请号：US242937

申请日：1988-09-09

申请人： Gregory J. McBrien ,  David M. Cramp ,  Winthrop H. McClure

发明人： Gregory J. McBrien ,  David M. Cramp ,  Winthrop H. McClure

IPC分类号： G01C19/72

CPC分类号： G01C19/721

摘要： A sawtooth voltage is applied to an integrated optic phase modulator by means of a high impedance variable current source in response to a charge rate control signal. The phase modulator's capacitance accumulates the charge which manifests a voltage comprising the sawtooth signal. The sawtooth signal is also provided to a comparator which in turn provides a discharge signal upon detecting the sawtooth voltage as being greater than a selected reference signal magnitude. The discharge signal is provided to a means for discharging the accumulated charge from the capacitance of the integrated optic phase modulator. A compensating resistor may be connected between the current source and the phase modulator to automatically correct for sawtooth overshoot. Various data extraction techniques are disclosed, without limiting the invention since others may be used, including counting sawtooth resets, among others, and using a current splitter to store charge separately from the serrodyne modulation circuit and relating separately stored charge to angle or rate.