发明名称 |
Variable gain amplifier stage |
摘要 |
A variable gain amplifier stage has first and second input terminals for receiving a differential input signal and first and second emitter follower transistors having their base electrodes coupled to the input terminals and their emitter electrodes coupled to a pair of matched voltage controlled current sources. A differential pair of transistors has their base electrodes coupled to the emitter electrodes of the first and second emitter follower transistors and their emitter electrodes coupled together and to a third voltage controlled current source. The voltage controlled current sources are controlled by the same voltage source so that a decrease in the differential pair tail current increases the bandwidth and decreases the gain of the stage, but a decrease in the current through the emitter follower transistors decreases the bandwidth of the stage so that by carefully controlling the relationship between these currents, a constant bandwidth can be maintained.
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申请公布号 |
US2002171489(A1) |
申请公布日期 |
2002.11.21 |
申请号 |
US20020102971 |
申请日期 |
2002.03.22 |
申请人 |
AGILENT TECHNOLOGIES, INC. |
发明人 |
RITCHIE CHARLES GRAEME |
分类号 |
H03G1/00;(IPC1-7):H03F3/45 |
主分类号 |
H03G1/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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