Instantaneous phase detecting circuit and clock recovery signal generating circuit incorporated in differential demodulator

An instantaneous phase detecting circuit for detecting the phase of a digital phase modulation wave signal comprising:

• a first logic circuit receiving the modulation wave signal and a first carrier signal, said first logic circuit performing a logical operation using said modulation wave signal and said first carrier signal to generate a first arithmetic output;
• a second logic circuit receiving the modulation wave signal and a second carrier signal, the phase of said second carrier signal being delayed by a fixed period with respect to the phase of said first carrier signal, said second logic circuit performing a logical operation using said modulation wave signal and said second carrier signal to generate a second arithmetic output;
• a first phase detecting circuit receiving said first arithmetic output and said first carrier signal, said first phase detecting circuit detecting the phase of said first arithmetic output and generating a first detection output signal;
• a second phase detecting circuit receiving said second arithmetic output and said first carrier signal, said second phase detecting circuit detecting the phase of said second arithmetic output and generating a second detection output signal;
• and
• a third logic circuit receiving said first and second detection output signals, said third logic circuit comparing a periodic deviation of said first and second detection output signals thereby detecting the phase of the modulation wave signal.