Ultra-wideband signal amplifier for radio receiver uses tunable narrow band amplifier connected to frequency control circuit with store for sequence of chosen bands

摘要

The signal amplifier (8) is tunable so as to operate over a number of narrow channels or signal bands. It has two inputs (15- 1,15-2) connected to bandpass switching networks (16-1,16-2). The networks are connected (17-1,17-2) to NMOSTs (18.1,18.2). Frequency control signals (KW) are transmitted to the bandpass switching networks via connections (11- 1,11-2) leading from the frequency control circuit. The NMOSTs are connected to a cascode stage (23). A switch control logic circuit (34) receives control signals and is connected to groups of switches (31a- 1...31a-N) and (31b-1...31b-N), switching capacitors (30a-1...30a-N) and (30b-1...30b-N) in and out of circuit.