leading edge EDN, Dan Strassberg [excerpts only]
50-GHz-bandwidth, sequential-sampling DSOs test 10-Gbps networks
Of ALL DIGITAL SCOPES, only sequential equivalent-time-sampling instruments offer bandwidths as high as 50 GHz. This capability makes such scopes the instruments of choice in applications of rapidly growing importance---electro-optics, for example.
Yet, because these scopes work only with repetitive waveforms and take just one sample during each input-signal iteration, they lack the quick response of lower bandwidth, real-time -and random-sampling instruments. This characteristic limits Sequential-sampling scopes largely to applications that need extraordinary bandwidth. To address the requirements of engineers, who develop components for networks that transmit data at speeds as high as10Gbps, Tektronix has introduced a family of sequential-sampling scopes. (TDS8000 and CDS8000) -- Each scope accommodates four sampling modules.... The TDS-8000 cost $19,000. Prices for electrical-sampling modules (15GHz) begin at $10,500 each; prices for optical-sampling modules begin at $17,000 each. - Tektronix Inc, 1-800-426-2200,

ECONOMICAL leading edge --- EE-Logos.org, Harry Winter
At a $40,000 starting price (two Sampling modules), the above might be the "bleeding edge" instead, but here is a PC-Card size DSO, with nearly identical performance, but costs only $250 in a 6-GHz, and $400 in a 50 GHz version. This Card-Scope also uses sequential-sampling, but a new DS²O method (two-dimensional Sampling) takes a multitude of samples per repetition, making the DS²O a general-purpose scope for all frequency ranges. LeCroy calls a similar method NRS, “Near Real-time Sampling” and uses it in their latest line of DSOs. --- The present 6-GHz design uses only readily available (commodity) ICs, but with the new Indium Phosphide (InP) chips bandwidth can easily go beyond 50-GHz, while the power consumption still remains within the constrains of the USB link. The cost of only one of the Tektronix TDS8000 would buy about a 100 of the USB-Card DSOs, but there needs to be a standard PC each; for the display and post-acquisition processing. -- Only one "small" problem exists; the Card DSO is a “disruptive technology” and no T&M Company will market it, because it would “cannibalize” their high-end scope market. (In other words, the company looses $40,000 every time they sell a card-scope and the CEO will be fired in a short time.) This Card-scope is one of the best examples for a “disruptive technology” which is a concept discovered by Prof. Clayton M. Christensen, The Innovator's Dilemma; Harvard Business school. HWinter (740) 587-0226 hwinter2@windstream.net