| |
USB 3.0: cranking up to superspeed
|
|
|
We present a novel low-loss 3-spot mode coupler to selectively address 6 spatial and polarization modes of a few-mode fiber. The coupler is used in a 66 MIMO-transmission experiment over a 154-km hybrid span consisting of 129-km depressed-cladding and 25-km graded-index few-mode fiber.
|
Low differential group delay (DGD) between the modes of a graded-index few-mode fiber is obtained by combining segments with DGD of opposite sign. Transmission of mode-multiplexed 620-GBd QPSK over a record distance of 1200 km is demonstrated.
|
We experimentally demonstrate multiple-input-multiple-output transmission of a combined 3-space-, and 2-polarization-, and 5-wavelength-division multiplex in a 3-core microstructured fiber over 4200 km. This is the record transmission distance for spatial-division multiplexing in a fiber.
|
LeCroy SPARQ Signal Integrity Network Analyzers rapidly characterize crosstalk in interconnects, backplanes and cable assemblies. Both near-end crosstalk (NEXT) and far-end crosstalk (FEXT) can be measured using either single-ended or differential port assignments. With 8 and 12 port SPARQs (model numbers SPARQ-3008E and SPARQ-3012E), signal integrity engineers can validate their crosstalk models with multi-differential lane NEXT and FEXT measurements, at a fraction of the price of a VNA.
|
Scattering or S-parameters obtained from direct measurements or through EM wave simulations may violate physical laws due to measurement or numerical errors. If used in simulations, such S-parameters lead to incorrect results and wrong conclusions. This paper focuses on three such properties of S-parameters – causality, passivity and reciprocity. Tests are provided to detect if any of the three conditions are violated. Separate algorithms are provided to make S-parameters causal, passive and reciprocal. The proposed algorithms are proven to be the best in the solution space, and are easy to implement.
|
This paper addresses a new methodology for 12 Gbps interoperability that combines a concerted family of pathological channels, internal eye monitoring, and external EQ simulation tools, providing insight into an EQ optimization strategy that addresses the specific channel’s mix of crosstalk noise, jitter, and channel loss. This also provides a backplane designer the ability to configure a high-loss, crosstalk aggressed system.
|
We explore in detail the relationship between discrete-frequency responses connected with sparameters and the implied continuous time response. This is done in both the frequency- and time-domain to develop the proper insight and explore issues with real time-domain responses, time-aliasing, causality, interpolation and re-sampling of discrete-frequency data. Using the insight gained, we identify the conditions for sufficiency of sampling and the side-effects of the invariable practical conditions when these side-effects cannot be completely dispelled. This paper is especially useful for understanding issues involved in direct application of sparameters in linear simulations, like those used in virtual probing applications in scopes.
|
A single-polarization 160-Gb/s (80-Gbaud) electronically time-division-multiplexed (ETDM) quadrature phase-shift-keyed (QPSK) signal is generated and coherently detected using two 45-GHz-bandwidth oscilloscope prototypes and offline processing.
|
|
