The interconnection structure to reduce crosstalk in reentrant off-chip RF selectivity uses differential circuits (402,415), transmission lines (423,424) and off-chip filters (422) in a structure that balances the parasitic capacitances associated with all of the differential elements. The structure includes a substrate (409) with a differential generating circuit and a receiving circuit (415). Two differential transmission lines, each with constant characteristic impedance, and each with balanced capacitance to ground, are closely spaced for some distance and couple the circuits to closely spaced terminating pads (403). A ground plane (412) is shared under both transmission lines. A second substrate (408) has a reentrant RF path (406) with the first substrate and contains an RF function such as a filter or a delay line.
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