Circuit to amplify a high-frequency signal of at least two high frequency ranges, 2 - band - receiver with the circuit, 2 - band - mobile radio device to the receiver and to use of a series connection of a capacitive element and a high frequency line in an amplifier circuit

摘要

The amplifier circuit has an amplifier (V1) with a matching circuit (C1) at its output for harmonic termination of the first HF range and/or a transformation circuit (TL1,C2) for transforming the output impedance of the amplifier for the first HF range, with at least one switched capacitance element (C3,C4) used for adapting the matching circuit and/or the transformation circuit to the second HF range. The capacitance element is connected in series with a HF line (SL1,SL2) acting as the switching line for the capacitive element and provided with an open end or a short- circuit termination.