| 摘要 |
PURPOSE:To perform amplitude modulation where the balance precision is high and phase modulation of zero and pi is possible, by connecting controllable variable attenuating devices to the second and the third terminals of a four-terminal hybrid transformer. CONSTITUTION:The high frequency signal inputted to an input terminal 1 of a hybrid transformer 11 is branched into two by a hybrid circuit and is outputted to terminals 2 and 3. The output of the terminal 2 is applied to a pin diode 12 through a path capacitor 14 and is attenuated in accordance with the impedance of the diode 12, and the reflected wave is outputted to a terminal 4. Meanwhile, the output of the terminal 3 is applied to a diode 13 through a path capacitor 15. If the impedance of the diode 13 is equal to the characteristics impedance R0 of the system, the output is terminated by the diode 13 and is not reflected. Thus, diodes 12 and 13 are controlled in the same mode for phase zero as wel as pi, and the unbalance of the output is out generated. |
