Virtual Electromagnetics Laboratory - Electrical Dept., IIT Bombay

Surface current of rectangular waveguide in TE11 mode

- Contributed by Koustav Jana


1) The surface current in all the 4 faces of the rectangular wave guide have been graphically represented

2) Assuming the 4 faces to be perfectly conducting, the surface current density J is give by n x H, where H is the magnetic field at the respective interface and n is the unit normal vector into the air medium.

3) In all the following figures, the vertical axis corresponds to z-axis and the horizontal one may be y or x-axis depending on the face chosen

Key Observations:

1) The horizontal component of the surface current density vector is always zero at the mid-axis of the face whereas the vertical component is always zero at the 2 extremes.

2) So the mid-axis of all the faces are nodes for the horizontal component and similarly all the 4 edges are nodes for the vertical component.

3) Thus one node per face for each component and it is quite obvious as the rectangular waveguide is operating in TE11 mode.

4) In the intermediate region the arrowheads representing the surface current density vector follow an elliptical path.

Choose the desired face to get its graphical representation: