Amplifier circuit with filter for digital and analog signals

摘要

The circuit includes separate surface wave filters (HS1,HS2) for analogue and digital signal reception. An emitter follower acts as a decoupling stage (EF) between the filters. The selection of one or the other filter is effected via a switch (S) which is controlled by a signal processing stage (IC). The filter for digital reception is switched to the analogue filter when receiving analogue signals. When digital signals are received the analogue filter are not switched to the digital filter. Preferably, the system processes signals other than digital and analogue signals with similar characteristics.