| 摘要 |
<p>The attenuator has devices (11, 12) which can derive a DC signal representative of the impedance offered by the FET (1) to an applied signal. There is a DC feed-back circuit (13, 15) which controls the FET (1) so that any changes in its impedance are counteracted. The FET (1) is connected to a resistor (2) and an inductance (3) in series. A further resistor (4) is connected in series with the inductance (3). An input signal (6) passes through a capacitor (7) to the point between the first resistor (2) and the inductance (3).</p> |
