| 摘要 |
PURPOSE:To improve sample and hold characteristics and, at the same time, to prevent the occurrence of an error, by supplying control signals through a line whose characteristic impedance is constant and providing an impedance matching element on the drive side of a diode switch. CONSTITUTION:When the characteristic impedance of coaxial cables 10 and 11 is designated as Z0, the impedance viewed from a control signal generator 6 becomes a fixed value of Z0/2 unless reflection takes place on the opposite sides of the coaxial cables 10 and 11 and control signals Q and Q' are injected without distortion. Moreover, when the resistance values of resistances 12 and 13 and the dynamic resistance at the rising time viewed from the drive sides C and D of a diode switch 2 are respectively designated as R and Rx, the impedance Z when the diode switch 2 is viewed from the coaxial cable 10 or 11 can be expressed by a formula I. When the formula I is changed to a formula II by selecting the resistance value R so that the impedance Z can become Z0, impedance matching is established and reflection is prevented.
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