Signals and Systems

1.5 CLASSIFICATION OF CONTINUOUS TIME SYSTEMS

The term system has already been introduced in section 1.1. A system is classified as follows:

• Static/Dynamic
• Causal/Non-causal
• Time invariant/Time variant
• Linear/Non-linear
• Invertible/Non-invertible

Let us introduce the above terms one by one.

1.5.1 Static and Dynamic Systems

If the output of a continuous time system depends only on the present input and not on the past or future input, the system is known as a static system. There cannot be any energy storage elements like a capacitor and an inductor are static systems. Therefore, we can say that a static system is a system without a memory.

On the other hand, if the output of a system depends on the present as on the well as past values of inputs, ...