Can anyone give me some examples of one port network, explaining its significance? Actually I just want to know whether or not such one port network exists? If they do,what are they used for.
Anything that connects to your circuit by only one pair of wires might be modeled as a one-port. For example,
- An antenna
- A strain gauge
- A termination circuit, when modeling a transmission line
what are they used for?
They're used for whatever they're useful for. Antennas deliver energy into free space. Strain gauges change their behavior in response to mechanical factors. Terminations determine how signal energy is delivered to a load.
One of the very well known one-port circuits (also called two-pole circuit) is a group of harmonic oscillators. Example: A grounded LC tank circuit is a typical one-port that can be transferred to an oscillator if a suitable negative resistance (actively realized with an opamp) is connected in parallel. It is the task of this negative resistance to compensate the losses (positive resistances) of the LC resonant circuit. Thus, we have an oscillatory one-port (LC tank in parallel with a negative resistance).