Maximum Power Transfer:  Electromagnetic Wave Propagation
Electromagnetic Waves    Antenna Systems    Reflection    References


Maximum power transfer is an important condition in many mechanical, electrical, and electronic systems.  Although maximum power transfer is not always expected in a particular system, in the case of electromagnetic wave propagation, maxmimum power transfer is necessary because it prevents damage to transmission components and provides maximum energy to the transmitted wave.

Principles of maximum power transfer:
  1. System components and important properties:
    • Load:  System within which energy supplied by a source is converted from one form to another to perform some function.
    • Source:  System from which energy is produced, collected, or relayed.  The source provides energy to a load.
    • Impedance:  Opposition to flow of electric current.
  2. When the impedance in a load is equal to the impedance of an energy source, maximum power will be transferred from the source to the load.  In effect, the rate at which work is done within the source is the same as the rate at which work is done within the load.  This means that the source-load system is balanced, that is, no energy produced in the source is lost or reflected back to the source.
Electromagnetic wave propagation is the transfer of electrical energy in a transmitter to electromagnetic energy for transmission through the atmosphere or space.

The source is the transmitter and the load is the combination of antenna system and the atmosphere.

The transmitter energy is relayed via an antenna.  The antenna is essentially a transfer point for energy exchange between the transmitter and the atmosphere (or space).

Electromagnetic Waves    Antenna Systems    Reflection    References