Feed Lines Must Be Transmission Lines

The first guideline is to ensure that your feedlines are true TEM or quasi-TEM transmission lines. This means the following:

1.  Feedlines must be of uniform width across the entire distance which the reference plane covers.

2.  Feedlines must not over-mode.

3.  The feedline(s) must not have an unusually high amount of loss. The metal must be conductive enough        to allow power to reach the other side of the line. In addition, the dielectric must be resistive enough so       the power is not shorted to ground before it reaches the other side.