Development and Application of a New Wideband Capacitor

Abstract

Decoupling capacitor circuits designed for use in industry must have substantially low impedance over a wide frequency range. It has become much more complicated to realize this design objective with the conventional implementation, which uses a combination of discrete capacitors. We have developed a new capacitive device which possesses an internal transmission line structure to address the needs for low-impedance decoupling circuits. The device was applied to the power circuits of notebook PC CPUs and embedded systems with FPGAs for evaluation. In the notebook PC CPU application, this capacitive device was able to substitute for 39 conventional capacitors, thus simplifying the power circuit design, with the added benefit of reducing the board space needed for components. In the FPGA application, the effects of this decoupling device were verified through simulation and actual board measurements. Results confirm that this device is an attractive solution for reducing EMI effects.