| 摘要 |
PURPOSE:To equalize the absolute delay time difference of two paths automatically by providing a phase difference detection means and a delay time equalizing control means, obtaining the delay time difference between the reception signals of two paths from the output of the phase difference detection means, controlling the delay time equalizing means so as to correct the absolute delay time difference. CONSTITUTION:The absolute delay time of two different transmission lines is expressed as gamma=DELTAtheta/DELTAomega, that is the tilt of phase with respect to the frequency. Assuming the frequency is changed from f1 to f2 by DELTAf, when a delay time difference exists between two paths, the phase difference DELTAtheta is generated by the delay time difference. Thus, a synchronizing detection circuit 9 gives an output detection voltage in response to the phase difference DELTAtheta. Moreover, the output detection voltage is inputted to a microcomputer 6 from an output detection voltage output terminal (a). The microcomputer 6 analyzes the output voltage to obtain the delay time based on a specific operation formula. A control signal is sent to a delay time equalizing circuit 5 based on the delay time to equalize the absolute delay time difference of the two paths.
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