| 摘要 |
Using several amplifier boards for parallel and simultaneous amplification of several parts of the received signals it is possible to couple them together so that an in-coming signal on one amplifier board after amplification can be coupled over to one or more parallel boards. Each amplifier board incorporates a preamplifier stage (2), an operational amplifier (4) an isolating amplifying stage (5) and an intermediate change-over switch unit (3). The preamplifier consists of a differential input stage formed around a double monolithic PNP transistor with matched transistors and a subsequent operation low effect amplifier. The operational amplifier stage incorporates a high pass filter for AC feed and a by-pass coupling path for DC feed. The switch unit can couple signals from the preamplifier to the further amplifying stages or to the other amplifier board change-over part for continued processing. |
