| 摘要 |
PURPOSE:To reduce impedance required by a branch by reducing reactance when a diode connected in series to the branch is turned off, by adding a capacitor in parallel to the diode. CONSTITUTION:As a branch 5 connected to both sides of a main line, a series circuit of a transmission line 7 and a diode 9 capable of on-off control is provided, and a capacitor 17 is connected in parallel to the diode 9. As a result, reactance when the diode is turned off is the value of a parallel circuit of the reactance of the diode itself and reactance by the capacity C of the capacitor 17. Further, when the diode 9 is turned on, the reactance is nearly equal to that when the diode 9 is turned on substantially. Consequently, reactance X2'' when the diode 9 is biased reversely decreases greatly and is realized easily by a microstrip line. |
