Patent ID: 7227412
Filing Date: 2007-06-05
Classification: H03G

Abstract:
1. An attenuation cell having an attenuation factor control device with first and second input electrodes and first and second output electrodes, the attenuation cell comprising: a first differential pair having a first bipolar transistor and a second bipolar transistor, said first and second transistors each having a transmitter electrode connected to a first power source and to said first input electrode, said first transistor having a collector connected to said first output electrode; a second differential pair having a third bipolar transistor and a fourth bipolar transistor, said third and fourth bipolar transistors each having a transmitter electrode connected to a second power source and to said second input electrode, said fourth transistor having a collector connected to said second output electrode; said first and fourth bipolar transistors having a base that is connected to a same voltage VA and said second and third bipolar transistors having a base connected to a same voltage VB; and an attenuation factor control circuit for setting voltages VA and VB respectively, including: