| 摘要 |
A high-frequency input/output terminal comprises a lower dielectric substrate in which are formed a bottom face ground layer, side ground layers, a line conductor and cofacial ground layers (formed on both sides of the line conductor on one and the same face of the lower dielectric substrate); and an upper dielectric substrate joined to the lower dielectric substrate so that portions of the line conductor and cofacial ground layers are sandwiched between the lower and upper dielectric substrate. In order to suppress return and insertion losses of signal in millimeter wave range due to a difference in transmission mode to improve transmission characteristics, the upper dielectric substrate is made thicker than the lower dielectric substrate. The width of the portion of the line conductor which is sandwiched between the lower dielectric substrate and the upper dielectric substrate is smaller than that of another portion. The cofacial ground layers are projected toward the line conductor. The transmission modes for high-frequency signals are made even, so that the return and insertion losses can be reduced and excellent transmission characteristics of high-frequency signals can be attained. |
