Question

Draw the time domain and frequency domain representation of sine wave and trangular wave ​

Answer 1

Answer:

Time/Frequency Domain Representation of Signals

Electrical signals have both time and frequency domain representations. In the time domain, voltage or current is expressed as a function of time as illustrated in Figure 1. Most people are relatively comfortable with time domain representations of signals. Signals measured on an oscilloscope are displayed in the time domain and digital information is often conveyed by a voltage as a function of time.

time domain digital signal with ringing

Figure 1. Time domain representation of an electrical signal.

Signals can also be represented by a magnitude and phase as a function of frequency. Signals that repeat periodically in time are represented by a power spectrum as illustrated in Figure 2. Signals that are time limited (i.e. are only non-zero for a finite time) are represented by an energy spectrum as illustrated in Figure 3.

frequency domain representation of signal

Figure 2. Power spectrum of a periodic signal.

Energy spectrum

Figure 3. Energy spectrum of a time-limited (transient) signal.

Frequency domain representations are particularly useful when analyzing linear systems. EMC and signal integrity engineers must be able to work with signals represented in both the time and frequency domains. Signal sources and interference are often defined in the time domain. However, system behavior and signal transformations are more convenient and intuitive when working in the frequency domain