Patent ID: 7233219

Claim:
A balanced output filter comprising: a package having an input ground metal pattern and an output ground metal pattern; and a filter chip having an inphase filter and an antiphase filter, which filters are mounted on the package, at least one of the inphase and antiphase filters having an input ground terminal connected to the input ground metal pattern and an output ground terminal connected to the output ground metal pattern, the input and output ground terminals of said at least one of the inphase and antiphase filters being separate from each other on the filter chip, wherein: the input ground metal pattern comprises a first portion and a second portion separate from the first portion; and the output ground metal pattern comprises a third portion and a fourth portion separate from the third portion, the first portion being coupled to the input ground terminal of the inphase filter, the second portion being coupled to the input ground terminal of the antiphase filter, the third portion being coupled to the output ground terminal of the inphase filter, the fourth portion being coupled to the output ground terminal of the antiphase filter.