| 摘要 |
<p>PURPOSE:To simplify the circuit configuration of the circuit so as to reduce the area occupied by the circuit by switching the status of small attenuating amounts by changing the bias polarities of PIN diodes. CONSTITUTION:This high-frequency attenuator circuit is constituted of PIN diodes 1, impedance transformers 2, 1/4-wavelength open stubs 3, chokes 4 for impressing diode biases, a choke 5 for returning bias currents, a GND terminal 6, a bias impression terminal 7, and a main transmission line 8. In this attenuator circuit, such a circuit system that a change in the impedance of the PIN diodes 1 does give any large influence to the main transmission line 8 is adopted by utilizing a fact that series resistances to the currents of the diodes 1 nearly converge when the currents exceed a certain level. Accordingly, desired switching of small attenuating quantities can be stably performed by changing the bias polarities of the two PIN diodes 1. Therefore, circuit configuration of the this attenuator circuit can be simplified and the area occupied by the circuit can be reduced.</p> |
