Abstract
The frequency range over which most types of directional couplers will operate is rather limited. This is especially true of wave-guide couplers, since the impedance of the guide changes with frequency. A new type of coupler is described which uses a small loop that responds to both the electric and the magnetic fields. When used in conjunction with a special section of ridge wave guide, it is possible to obtain excellent directional characteristics over a two-to-one frequency range.