# Power Losses and Attenuation in Waveguides

In earlier discussions, we assumed a lossless waveguide  for which the attenuation constant was  and the propagation constant was . However, in general, the guide walls are not perfectly conducting and the dielectric is lossy  and there is a continuous loss of power as a wave propagates through the waveguide.

Consequently, for waveguides with conducting walls, the power (transmission) losses are primarily due to the following two causes:
1. Dielectric losses in the medium filling the space between the conductors in which the fields propagate
2. Ohmic losses or conduction losses due to conducting walls