| 摘要 |
<P>PROBLEM TO BE SOLVED: To extend characteristics of a balun to be wideband. <P>SOLUTION: A positive signal path 44 has a circuit trace 48 and a first order phase shaping circuit 50 and provides phase shift of 360 degrees at Port 1 (0 degree input) of a 90-degree hybrid 52. A negative signal path 46 has a circuit trace 56 and a second order phase shaping circuit 58 and provides a phase shift of 270 degrees to a negative signal having a 180-degree phase difference with respect to the positive signal, thereby obtaining a 450-degree phase-shifted signal with respect to the positive signal at Port 3 (90 degree input) of the hybrid 52. Port 1 is coupled to Port 2 of the hybrid 52 which functions as an output port. The first order phase shaping circuit 50 and the second order phase shaping circuit 58 compensate for signal loss caused by a signal cable coupled to the output port and provide broad frequency band to reduce pre-shoot in a transient response. <P>COPYRIGHT: (C)2013,JPO&INPIT |
