초록 ▼

A global positioning system (GPS) receiver includes a phase locked loop that locks to the carrier signal from the GPS satellite at an offset frequency in order to recover the GPS data. The loop includes a phase shifter driven by a system clock through a synchronous clock inversion circuit. The phase

A global positioning system (GPS) receiver includes a phase locked loop that locks to the carrier signal from the GPS satellite at an offset frequency in order to recover the GPS data. The loop includes a phase shifter driven by a system clock through a synchronous clock inversion circuit. The phase of the system clock is periodically inverted synchronously with respect to the clock in order to compensate for the offset loop frequency so that the loop does not lose lock because of the offset error.

대표청구항 ▼

Phase correction apparatus for a spread spectrum phase locked loop, said phase locked loop including a system clock source for providing a system clock and a phase shifter for effecting loop phase adjustments, comprising control means for repeatedly providing a phase inversion signal, and clock inve

Phase correction apparatus for a spread spectrum phase locked loop, said phase locked loop including a system clock source for providing a system clock and a phase shifter for effecting loop phase adjustments, comprising control means for repeatedly providing a phase inversion signal, and clock inversion means responsive to said phase inversion signal and to said system clock for inverting said system clock in response to said phase inversion signal, thereby providing a phase corrected system clock, said phase shifter being responsive to said phase corrected system clock for effecting said loop phase adjustments.