HF directional coupler using coupled inductances - has split ferrite core and coil windings applied to thin substrate

摘要

The coupler uses a ferrite core (11) with two parallel openings through it, through which electrical conductors, forming the inductance coils, extend. The ferrite core (11) is in two halves (12,13) with the openings defined on three sides by U-shaped channels in one half (12) and on the fourth side by the mating planar surface of the other half (13). The electrical conductors are provided by conductive layers applied to a substrate with a thickness of no more than 0.1 mm. Pref. the product of the substrate thickness multiplied by its electrical constant is about 200 micrometres. It may be attached to a support (20) with an opening (21) in the region of the coils.