Characterisation of high-speed multiconductor interconnections

The paper presents a method for the determination of the capacitance matrix needed in modelling and simulation of signal transmission in multiple coupled interconnecting lines. The method utilises capacitance measurements and thus one of its useful application areas is in the validation of numerous previously published algorithms based on various approximations to field equations, originally developed for the computation of capacitance matrices. The technique described is based on the active separation of the capacitance network, achieved through the use of a unity-gain amplifier. Thanks to the circuit configurations introduced with a unity-gain amplifier it is possible to make direct capacitance measurements in the multiconductor interconnecting structures. Measurement procedures are described and analysis of errors in measured quantities caused by the imperfections of measuring equipment is discussed. A sample of results obtained in measuring manufactured test structures is included for illustration of the method and measuring procedures