Drawbacks and possible improvements of Short Pulse Propagation technique

Abstract

Short Pulse Propagation (SPP) technique for characterisation of PCB and packaging interconnect losses and dispersion was introduced in early 90-s and standardized by the Institute of Printed Circuits or IPC [IPC-TM-650]. It was successfully used to build broadband models for dielectrics and conductor roughness up to 30 GHz. Though, it is not widely used and multiple new material characterisation techniques were recently proposed. Is SPP useful for 30 Gbps interconnect design and manufacturing? This paper analyses advantages and drawbacks of the original SPP technique and suggests some simplifications and improvements. It is shown that the number of characterisation steps can be substantially reduced without loss of accuracy. To reduce the sensitivity to the connector and launch reflections and improve accuracy, it is also suggested to use S-parameters instead of TDT pulse responses.