Ch 2 theory

Vocabulary flashcards related to the concepts of signal transmission and filter characteristics discussed in ENEL 471.

2 criteria for distortion-less signal transmission

transfer function has constant amplitude and linear phase

Passband

The range of frequencies that are transmitted with little or no distortion.

Stopband

The range of frequencies that are strongly attenuated or rejected by the filter.

Low-pass filter

Allows frequencies below a certain cutoff frequency to pass through.

High-pass filter

Allows frequencies above a certain cutoff frequency to pass through.

Band-pass filter

Allows frequencies between a lower limit and an upper limit to pass through.

Band-stop filter

Rejects frequencies between a lower limit and an upper limit.

Why can’t ideal filters be implemented in practice?

Filters require an impulse response that extends infinitely in time and exists for negative time, making the system non-causal.

Real systems must be casual and physically realizable

Limitation of practical filters

Practical filters can have issues like large delay, amplitude distortion due to ripples in the pass-band, and group delay distortion.

Give 3 uses of filters in communication systems

Frequency selective devices, shaping devices, cleaning devices

Frequency Selective Device

Allows only certain frequencies of an input signal to pass through while attenuating others.

Shaping Device

Modifies the shape of an input signal to create a different shape optimal for transmission.

Cleaning Device

Removes unwanted signals or interference from an input to produce a clean output.