| 摘要 |
PROBLEM TO BE SOLVED: To prevent a phase deviation of transmission output occurring in switching from an active system to a nonactive system, and an instantaneous cutoff of a transmission signal occurring in a switching operation. SOLUTION: In a hot-standby wireless apparatus, a modulated-carrier frequency oscillator 3 and a carrier local oscillation frequency oscillator 4 are used in common in both an active system 1 and a nonactive system 2 for a modulating part and a transmission part which are each provided in both systems, thereby, a phase variation of a received signal before and after the changeover can be suppressed within a range of pulling-in phase on demodulation. Further, switches 6, 7 of a system changeover part 5 are controlled by separate change-over signals for each system, the active system is cut off after the nonactive system starts a transmission, the instantaneous cut-off of a signal as a transmitting line is eliminated by overlapping the transmitting time of the two systems, thus, the line failure which involves an instantaneous cutoff in changing the hot-standby can be avoided.
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