High frequency module board device

摘要

The present invention relates to a high frequency module board device having a high frequency transmitting and receiving circuit for modulating and demodulating a high frequency signal. The high frequency module board device comprises a base board ( 2 ) whose main surface is formed as a build-up surface ( 2 a) and a high frequency circuit part ( 3 ) formed on the build-up surface of the base board ( 2 ) and having passive elements formed. The base board ( 2 ) has an area ( 29 ) in which wiring is not formed in a lower layer from a fourth wiring layer ( 8 b). The high frequency circuit part ( 3 ) has an upper electrode part ( 36 ) and a lower electrode part ( 35 ) in positions corresponding to the area ( 29 ) in which the wiring is not formed. Thus, since a capacitance ( 18 ) is provided just above the area ( 29 ) in which the wiring is not formed, a parasitic capacity that the capacitance ( 18 ) receives from ground patterns ( 14 ) is reduced. Accordingly, the characteristics of the capacitance ( 18 ) can be improved.