| 摘要 |
PURPOSE:To widen a frequency band characteristic, by providing inductive posts near coupling holes. CONSTITUTION:A couple of waveguides are coupled at the coupling holes 5, 7 via cavity resonators 3, 4. Thus, the waveguides serve as a directional filter for branching/combining. The inductive posts 8, 9 are provided between the coupling holes 5, 7 and short sides of the waveguides. The inductive posts change the distribution of magnetic field in a cross section of the waveguides and incease the component of waveguide axis direction of the magnetic field. Thus, the coupling holes are provided at a location apart from the wall of the waveguides. Further, the amount of coupling of a circularly polarized wave at the coupling holes is increased with the working of the inductive posts. The wave selected at the cavity resonators 3, 4 among the waves inputted to the waveguide 1 is introduced to the waveguide 2. The increase in the amount of couplig allows a wave of a broad frequency band to be branched. |
