| 摘要 |
PURPOSE:To attain transmission changeover efficiently by allowing the reception side to attain switching without causing out of synchronism and hit of an output of a spare transmitter even if an output of an active transmitter is hit at the operation of a waveguide switch. CONSTITUTION:An output from a transmitter 1 and an output from a transmitter 2 lower by 20dB than the former output are transmitted simultaneously from an antenna 5 normally and since the level difference of two waves is nearly 40dB at the reception side, no same channel interference is caused. In operating the waveguide switch 3, the output of the transmitter 1 is hit at the switch 3. Since the output of the transmitter 2 is transmitted always through directional couplers 9, 8, the signal is not interrupted at the reception side. Although the reception level is decreased by nearly 40dB, the level is amplified by an AGC circuit provided to a receiver, the signal is not interrupted. When the switch 3 completes the switching, since the output of the transmitter 2 is transmitted through a coupler 9, the switch 3 and a coupler 8, the transmission level from the antenna 5 is transmitted normally. |
