Classified by whether total energy or average power is finite.
Energy E=∫‖x‖²dt (finite for pulses) and average power P=lim(1/2T)∫‖x‖²dt (finite for periodic signals) classify signals. A signal cannot be both energy and power type. Energy of a signal in time equals energy in frequency (Parseval).
A sinusoid of amplitude A has average power A²/2.
Energy and power classify signals by how they behave over all time, which determines the right analysis method.
Classified by whether total energy or average power is finite.
Energy and power classify signals by how they behave over all time, which determines the right analysis method.
A signal with finite total energy over all time, which usually means it dies away, such as a single pulse.
A signal with finite average power but infinite energy, such as a sustained periodic wave.
Typical applications include deciding whether a single pulse should be analysed by energy or a periodic wave by power, computing the average power of a sine wave for a load estimate and checking whether a transient signal has finite energy.
Study "Even and odd signals" first (topic 4 of 101 in Signals, Control & Comms). It covers the groundwork this topic builds on.
Energy signals have P=0. Power signals have E=∞. Units depend on the physical signal.
A sinusoid of amplitude A has average power A²/2.
The next topic is "Basic signals", which builds directly on this one.
It is classed as Beginner in Signals, Control & Comms (topic 5 of 101). It is an entry-level topic. It relies only on basic school mathematics and the ideas introduced earlier in this discipline.
Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.