spiralling up to control

Researchers at the Dresden University of Technology in Germany have proposed the first broadband amplifier using vertical inductors. All circuits are built from passive components, and improved chip design requires passive component miniaturisation and efficient structure. Vertical inductors, such as those considered here, are passive inductors with the spiral plane oriented perpendicularly to the chip substrate, as in the lower figure. The main goal of vertical inductors is to save chip area, and thanks to their vertical structures, vertical inductors occupy chip area prevalently in one dimension and not in a square manner like conventional spiral inductors, which are placed in parallel to the substrate.