Allpassstrukturen

Allpassstrukturen, also known as all-pass filters, are electronic or digital filters that modify the phase of a signal while leaving its amplitude unchanged. This unique characteristic makes them invaluable in various signal processing applications. Unlike low-pass or high-pass filters that attenuate certain frequencies, all-pass structures aim to manipulate the timing or delay of different frequency components within a signal.

The core principle behind an all-pass structure is to create a frequency-dependent delay. This means that higher frequencies might be delayed more or less than lower frequencies, altering the signal's waveform without affecting its overall strength. In the frequency domain, their magnitude response is flat at all frequencies, meaning no signal is amplified or attenuated. However, their phase response varies with frequency, exhibiting a non-linear curve.

All-pass structures are commonly implemented using either analog circuits, typically involving resistors, capacitors, and operational amplifiers, or digital algorithms that operate on sampled data. Their applications are diverse. In audio processing, they are used for equalization, reverberation, and creating phasing effects. In telecommunications, they are employed to correct phase distortion in transmission channels, ensuring that different frequency components arrive at the receiver at the correct relative times. They also find use in control systems and in the design of more complex filter structures.