BROADBAND SUBSTRATE TO SUBSTRATE INTERCONNECTION

A broadband substrate to substrate microwave circuit interconnection is proposed using bond wires and defected ground structure (DGS). The proposed square-shaped DGS etched under compensated microstrip open stubs not only expands its operating bandwidth, but also increases the characteristic impedance of microstrip line without narrowing its width, which breaks the PCB fabrication limitation of narrow stubs. The proposed structure can make the impedance of the microstrip line much larger than that without DGS. A 250 Ω characteristic impedance is easily achieved using 0.6 mm microstrip line with the proposed DGS. Measured S21 and S11 of the proposed interconnection are better than −0. 3a nd−15 dB from DC to 38 GHz, respectively. A bandwidth increment of more than 1200% is achieved compared with the conventional one.