An Ultracompact Butterworth Low-Pass Filter Based on Coaxial Through-Silicon Vias

Based on through-silicon-via technology, we propose an ultracompact Butterworth low-pass filter (LPF) with area of 0.01 mm². An equivalent circuit model of the proposed LPF is exploited, analyzed, and simplified. The comparisons of filtering characteristics among ideal 4-GHz fifth-order Butterworth LPF, equivalent circuit model, and full wave simulation of proposed LPF validate the accuracy of the equivalent circuit model. And the proposed LPF exhibits ultracompact size and superior filtering characteristics compared with the existing LPF.