| 摘要 |
PURPOSE:To attain accurate control even when the phase of a reception signal is inverted by selecting a phase difference DELTAtheta or pi-DELTAtheta and controlling an endless phase shifter while revising and holding phase information. CONSTITUTION:A 2nd phase comparator 9 and a voltage comparator generate a switching signal inverted when a phase difference is + or -pi/2, an output voltage from a 1st phase comparator 8 is applied to a ROM 11, which converts the voltage into a signal representing a phase difference DELTAtheta. Then a phase difference computing element 12 calculates the value of pi-DELTAtheta,and selects a signal representing a phase difference DELTAtheta or a signal representing a phase difference pi-DELTAtheta in response to the switching signal, and controls an endless phase shifter 1 while revising and holding phase information. Thus, even when the phase of reception signals S1 and S2 is inverted, it is identified and controlled accurately for a prescribed time independently of the phase difference of the reception signals S1 and S2. |
