| 摘要 |
PURPOSE:To obtain a filter for optical and milimeter waves which has structure to be simply produced by photomasking technique by connecting one of two output openings of a plane type directionla coupler to a plane type wave absorbing element to take out waves having frequency appearing from the other output opening. CONSTITUTION:When an input wave Si is applied to an input opening #1 of the directional coupler DC, output waves S03, S04 appear from output openings #3, #4 in accordance with characteristics shown in the figure. When the input wave Si is in level ''1'' at all frequency, the output wave S03 has the peak of level ''1'' at frequency f0 and the level is reduced in accordance with the difference from the frequency f0 in both high and low frequencies. Quite contrary to the output wave S03, the other output wave S04 becomes level ''0'' at the frequency f0 and the level is increased up to the level ''1'' in accordance with the difference from the frequency f0. Thus, the filter for optical and milimeter waves can be obtained by using the photomasking technique to be used for the manufacture of a semiconductor integrated circuit. |
