| 摘要 |
PROBLEM TO BE SOLVED: To measure a phase difference over one cycle without directly dividing the frequencies of an object signal and a reference signal. SOLUTION: Phase differential signals are provided by respectively comparing an object signal passed through a π/4 phase delay part 2 and delayed by π/4 and an object signal passed through a π/4 phase advance part 1 and advanced for π/4 with a reference signal. These two phase differential signals are applied to an up/down discriminating part with a rotary vector as a basic principle. At the up/down discriminating part 9, a phase difference α, the increase direction and decrease direction of the phase difference a are recognized. Based on these data, the phase difference α to be arbitrarily increased/decreased is cumulatively added so that the phase difference can be measured over one cycle. |
