| 摘要 |
PURPOSE:To facilitate the manufacture and to make the operation stable by forming a high frequency transmission line by a multi-layer board and forming a throughhole around the transmission line. CONSTITUTION:A hybrid IC 1 is provided on the multi-layer board 3. a high frequency transmission line 4 is formed in the inside of the multi-layer board 3, a case foil 7, a DC bias pattern 9 and a throughhole 2 are formed to the outside. Then the throughhole 2 is so constituted that it surrounds the high frequency transmission line 4 in the inside of the multi-layer board 3. Thus, the isolation characteristic of an input/output high frequency transmission pin 5 of the hybrid IC 1 is improved and the leakage of a high frequency signal to the external device is reduced. |
