| 摘要 |
PURPOSE:To obtain an LR filter whose cutoff frequency is set electrically by varying the equivalent inductance of Josephson junction with a pulse current and a control current. CONSTITUTION:A figure A shows that this device is used as a high-pass filter, and a signal 3 with an optional frequency component is applied to an input terminal 1 and a proper DC current suitable for a Josephson junction element J1 is applied to a bias input terminal 2 as a bias current Ig, thereby leading out an output signal 4 with a frequency component of higher than a specific cutoff frequency (fc) to a load resistance R3. In this case, the cutoff frequency (fc) is determined according to the time constant of a differential inductance L of the Josephson junction element J1 and the load resistance R3 and the differential inductance L is varied properly with the bias current, so the cutoff frequency is set adequately. Further, the load resistance R3 in front of the Josephson junction element J1, i.e. at the side of the input terminal 1 as shown in a figure B and then this device functions as a low-pass filter. |
