| 摘要 |
<p>The present invention relates to a filter circuit which is suitable for use in an integrated circuit formed of transistors or field effect transistors, and controls the frequency band of the amplifying circuit used for the signal receiver, for example, within an optical communications system. The filter circuit includes a first transistor (T1) having a base or gate grounded with high-frequency component via a first resistor (R1); and a second resistor (R2) and a capacitor (C1) each having one end connected to the emitter or source of the first transistor (T1) and the other terminal grounded with high-frequency component. The filter circuit acts as a circuit in which the first transistor (T1) inputs the current (Iin) at a juncture at which the second resistor (R2) and the capacitor (C1) are connected therewith and outputs its collector or drain current (Iout).</p> |
