| 摘要 |
PURPOSE:To achive the simplicity of adjustment of matching between the device and line, reduction in the number of filters used, and effective use of line frequency, by using a transmission band filter and an unbalanced hybrid. CONSTITUTION:An unbalanced type hybrid in which a bridge taking a balanced connection network 7, transformer T1 connected to a line 4, and impedance elements Z1, Z2 as sides is formed, is used and a coupler is constituted by connecting a transmission band filter 2 and a transformer T2 to obtain reception signals between opposing points of the bridge circuit. In this case, each impedance is determined to obtain the relation of ZB>(ZLXZ2)<1/2>>Z1 as the condition of the bridge. Thus, a transmission signal is avoided from turning around to a reception output terminal by using only one band filter, and the unmatching due to line variance can be compensated with the adjustment of a balanced connection network. |
