Circuit Packaging and Performance

The devices were research demonstration vehicles tested using wafer probing techniques and were not packaged. Given the presence of MEM varactors, however, it is clear that packaging techniques and considerations similar to those employed in the case of phase shifters would be applicable. Figure 5.16 shows the measured performance [34]. The lumped-element filter exhibited a minimum insertion loss of 4.9 dB, a return loss of ~10 dB, and a tuning range of 4.2% over a voltage range of 65V. The coupled distributed resonator filter, on the other hand, exhibited a minimum insertion loss of 3.8 dB, an average return loss of ~15 dB, and a tuning range of 2.5% over a voltage range of 50V. In comparing the observed tuning range with the simulated one, Kim et al. [34] point out that the smaller measured tuning range results from the lower capacitance change of a partially deflected beam (i.e., larger deflection at the beam tip than at the anchor), whereas the simulated change assumed uniform gap shrinking.