| 摘要 |
PURPOSE:To prevent increase in branch circuit loss by switching selectively a corresponding antenna among plural antennas in synchronization with the assigned period of a burst signal of each slave station and executing span equalization at each slave station with simple constitution. CONSTITUTION:A master station 1 and plural slave stations 2a-2c constitute a time division multi-direction communication device and the communication is attained in time division between the master station 1 and the slave stations 2a-2c by using a radio burst signal having the same frequency. An antenna switching control section 8 connected to a transmission/reception section 6 and an antenna switching device 7 of the master station 1 controls the switching device in synchronization with the assigned period of the burst signal to change over antennas 3a-3c of the master station. This switching device consists of an antenna changeover switch 9a operated in interlocking with an output of the control section 8, a transmission fixed attenuator changeover switch 9b and a reception fixed attenuator changeover switch 9c, and an output of the switches 9b, 9c is connected to a circulator 12 via transmission and reception fixed attenuators 10, 11. Further, the circulator 12 is connected to the antennas 3a-3c via the switch 9a to simplify the constitution of the communication device. |
