During implementation of the filter on microstrip substrate
, once again the value of the reconfigured capacitor [C.sub.r] needs to be adjusted.
Figure 20 shows two different varieties--a uniform and non-uniform circular-patterned planar PBG on microstrip substrates
. As can be seen in the figure, the uniform and the non-uniform circular patterns are etched with a period a on the ground plane of standard microstrip transmission lines to form a PBG engineered microstrip transmission line.
The tab of the sliding contact can be made small to accommodate thin microstrip substrates
. On the negative side, the sliding contacts are difficult to push into position because they are small and delicate.
The 10 mil thickness provides the maximum heat conductivity to the baseplate and the minimum discontinuity in ground plane when interfaced with thin microstrip substrates
. The 10 mil substrate is also thick enough to maintain sufficient yields during fabrication.