The market is rapidly adopting high speed multi-lane serial data signaling, creating new technical challenges for design engineers. All SPARQ models utilize a built-in OSLT calibration kit to allow users to rapidly calibrate the analyzer and measure the device under test, without using error-prone calibration standards that are external to the instrument. This means that a user can complete a full 12-port S-parameter measurement in approximately 30 minutes with much of that time being unattended acquisition and calculation time.
Cloud computing, mobile computing, smartphones and streaming video applications are pushing the marketplace to deliver greater and greater network bandwidth. Communication standards utilize multi-lane differential signalling to carry traffic at ever-increasing bitrates. Multi-lane differential signalling has become pervasive, and is used in standards such as PCIe Gen3, Serial Rapid IO, InfiniBand, and 40/100 GBASE Ethernet. More than ever, signal integrity issues due to crosstalk and channel effects such as intersymbol interference lead to closed eyes and jitter. Signal integrity engineers find that they must attempt to both predict and understand these issues when designing multi-lane differential circuits and interconnects to avoid design modifications and costly re-spins.
When using a network analyzer with only 4 ports, signal integrity engineers can measure the S-parameters of only a single differential lane. These measurements only provide a partial understanding of circuit behaviour, and do not characterize the crosstalk between lanes. With the SPARQ-3012E, users can measure the complete 12-port S-parameter matrix in both single-ended and mixed-mode representations, at the click of a button. The resulting S-parameters characterize the near-end (NEXT) and far-end (FEXT) crosstalk between up to three differential lanes, and which can then be used in aggressor-victim-aggressor modelling in order both to predict circuit performance and to study transmitter and receiver equalization schemes that may be required to open closed eyes. The new SPARQ models are rated to 30GHz end frequency, and can return S-parameter results out to 40 GHz. This makes the SPARQ suitable for crosstalk measurements on a wide variety of commonly deployed high speed multi-lane serial data standards.
The 8 and 12-port SPARQ units are extensions to the SPARQ series of Signal Integrity Network Analyzers launched in September, 2010. SPARQ is designed specifically for signal integrity applications, and uses state-of-the-art TDR/TDT techniques to measure the S-parameters of passive devices. SPARQ users connect the SPARQ to their DUT and to their PC, which runs the SPARQ application. After configuring the measurement by setting the number of ports, points and end frequency, the measurement is started by simply clicking “Go”.
The SPARQ automatically calibrates in only about 1 minute using the built-in OSLT calibration kit, and then measures the DUT without any need to disconnect/reconnect between the calibration and DUT measurement steps. By performing the calibration automatically, users avoid the tedious and error-prone steps involved with calibrating a VNA. With a 12-port SPARQ, a complete measurement, including calibration, can be made in about 30 minutes. “Preview mode” 12-port results can be obtained in less than 10 minutes. Results can be saved to a standard Touchstone 1.0 file, which can be imported into other simulators or instruments like LeCroy oscilloscopes, such as WaveMaster and LabMaster oscilloscopes with bandwidths up to 60 GHz with up to 20 input channels. Users can emulate channel effects or de-embed structures using measured or modeled S-parameters, and measure eye diagrams, jitter and crosstalk on multiple serial data lanes.