| 摘要 |
A multilayer dielectric substrate (2) for mounting a semiconductor device (3) in a cavity (33) formed on a substrate. The multilayer dielectric substrate is provided with an opening (50) formed on a front layer grounding conductor (18) arranged on the substrate in the cavity (33), an impedance transformer (60) having a length substantially equal to a quarter of the effective wavelength of a signal wave in the substrate and coupling electrically with the cavity (33) through the opening (50), a forward end short-circuiting dielectric transmission line (80) having a length substantially equal to a quarter of the effective wavelength of the signal wave in the substrate, a coupling opening (65) formed in an inner layer grounding conductor at the joint of the impedance transformer (60) and the dielectric transmission line (80), and a resistor (70) formed in the coupling opening (65). The semiconductor device and the transmission line are operated stably by enhancing electromagnetic wave absorption efficiency thereby suppressing cavity resonance surely. |
