| 摘要 |
PURPOSE:To obtain an inexpensive LPF having a compact and light-wight structure by using conical and V-shaped amplitude compensating circuits. CONSTITUTION:A signal generator and a level meter are connected to an input terminal 17 and an output terminal 18 respectively. Then coils 21 and 22 are set at prescribed attenuation polar frequencies respectively, and a fine adjustment is given to the variable coils and variable resistances of series resonance circuits 12 and 14 as well as to the variable resistance of a frequency compensating circuit 13. Therefore the frequency characteristics of a desired transmission function are secured for a frequency range including from a direct current to a frequency containing the minimum power energy by 99%. Then a random pattern generator having a bit rate equal to a prescribed Nyquist space is connected to the terminal 17, and a synchroscope is connected to the terminal 18 respectively. Then the external clock of the pattern generator is triggered to perform a fine adjustment again to obtain the best degree of convergence of an eye pattern. In such a way, a desired roll-off filter is obtained with inexpensive coil, capacitor and resistance. |
