| 摘要 |
PURPOSE:To obtain a simple and inexpensive circuit device by directly detecting a phase difference between intermediate frequency signals by using an intermediate frequency signals by using an intermediate frequency band phase shifting means for a phase synthesizer that detects the phase difference from a composite wave obtained by synthesizing signal waves from two antennas, and then puts both the signal waves in phase with each other. CONSTITUTION:Two signal waves are converted into intermediate frequency signals, which are applied to input terminals 21 and 22; and they are passed through switch parts 27 and 31 and supplied to a synthesis part 35 for in-phase synthesis to be outputted to an output terminal 38. Both the signal waves are applied partially from branch parts 26 and 30 to a phase difference detection part 32, which controls a phase shifting part 25 to obtain a pi/2 phase difference between both the signals, so that a pi/2 synthesizer 35 performs accurate in-phase synthesis. This circuit constitution requires none of a local oscillation part, a frequency conversion part, etc., so the generation of a spurious component is prevented and the input level of an intermediate frequency signal to a phase shifting means is invariably constant so that the circuit is made simple and inexpensive. |
