| 摘要 |
The circuit arrangement of a switching amplifier in which the output voltage is generated by the addition of part-voltages, a corresponding number of voltage stages, which can be bypassed by diodes, being connected in series via switches depending on the magnitude of the AF input signal to be amplified, which is sampled with a sampling frequency which is in the RF range, and in which a low-pass filter is provided for eliminating the radio-frequency components which are caused by the switching steps of the switches, has the object of effectively filtering harmonics whilst, at the same time, controlling shortcircuit currents by means of power semiconductor switches. This is achieved by the fact that each switch (21, 22, ... 2n) constructed in the form of a power semiconductor is followed by a choke coil (41, 42, ... 4n) which is in each case inserted into the output line (terminals A, B) after the junction of a power semiconductor, used as a switch, for a voltage source (11, 12, ... 1n) with the diode (31, 32, ... 3n) bypassing this voltage source, and that the total inductance of all choke coils is selected in such a manner that, together with the capacitance of a capacitor (5) in parallel with the output line, results in a low-pass filter for the radio-frequency components. <IMAGE>
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