De-embedding interconnects boosts high-speed signal measurement accuracy

January 19, 2016 // By Graham Prophet
SignalCorrect is software by Tektronix designed to simplify the process of characterising and de-embedding the effects of cables, fixtures and other interconnects for more accurate and repeatable measurement results.

The solution consists of SignalCorrect software and the TSC70902 calibration source and works with Tektronix’ DPO/MSO70000 real-time oscilloscope. Various types of interconnects such as cables, fixtures, adapters or RF switches are used to connect the signals on a device under test (DUT) to an oscilloscope. As signal speeds increase, interconnects impact signal characteristics and can lead to distorted eye shapes due to ISI, parasitics, delay, impedance mismatch, losses and variability. Until now, characterising and de-embedding interconnects has required specialist expertise and the use of expensive specialised equipment. With this solution, Tek asserts that even novice engineers can quickly and easily perform these tasks using a standard high-speed real-time oscilloscope.

To simplify the interconnect characterisation process, SignalCorrect provides step-by-step guidance from initial set-up through to measuring insertion loss and creating and applying filters. The software is designed for intuitive operation with a GUI and detailed information that guides the user through the process using both text and graphical content. This powerful software supports creation of multiple filters from a single measurement and enables comparison of raw waveforms with different filter designs.

The standalone TCS70902 calibration source uses a compact form factor for placement closer to the interconnect under test (IUT) for more accurate measurements. Two 9 psec fast-edge outputs enable dual input measurements and full de-embed of single-ended, differential and common mode signals. This fast rise time enables users to characterise at speeds beyond 50 GHz with an suitable performance oscilloscope. The unit can also be used as a source for other applications.