| 摘要 |
PURPOSE:To secure an coincidence of the propagation phase speed between the even and odd modes, by distributing an earth conductor between the main and the secondary lines and along these lines. CONSTITUTION:A strip line type directional coupler consists of the main line 2 and the secondary line 3, and the earth conductor 10 is put between these two lines. In such way, an almost equal ratio is obtained between the number of electric lines of force distributed in an insulated substrate and that distributed in the air and in terms of the even and odd modes. Thus nearly an identical value is obtained for the phase speed of propagation between these two modes. As a result, the directional property can be improved for a directional coupler. |
