| 摘要 |
A directional coupler for coupling an RF signal from a first conduit (30) to an adjacent second conduit (20), said first and second conduits having parallel conduit portions located side by side, each of said conduit portions comprising a sandwich structure with an upper conductive strip (20; 30), an intermediate layer (1) constituted by said dielectric substrate material and a lower conductive strip connected to said upper strip, so as to eliminate any electrical field in said intermediate layer. The upper and lower conductive strip (20; 30) cooperates with upper and lower ground plane layers, respectively located at a distance therefrom, the two parallel conduit portions being surrounded sideways by air gaps (40) therebetween, whereby the RF signals will propagate with the electric fields being located substantially in air gaps surrounding the upper and lower conductive strips. |
