CONTROLLED MULTISECTION TWO-PORT Russian patent published in 1999 - IPC

FIELD: miscellaneous radio receivers. SUBSTANCE: two-port is built up of two or more series-connected L-shaped sections of similar structure isolated at input and output by means of emitter followers, each having resistor in series branch and diode in parallel branch. Common point of emitter follower output and series branch resistor is connected through isolating resistor to high-voltage supply; resistor is inserted in parallel branch between diode and resistor of series branch; diode is connected through capacitor to common bus; collector of transistor, whose emitter is connected to common bus and base, to low-voltage supply and to output of two series- connected switches through isolating resistor; controlled inputs of first switch are connected to control-voltage terminal of TTL level. EFFECT: improved accuracy of digital attenuation of amplified signals. 1 dwg