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SPARQ Signal Integrity Network Analyzers

Includes the latest and most frequently asked questions regarding the SPARQ Signal Integrity Network Analyzer.

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SPARQ Series Signal Integrity Network Analyzers - Passivity, Reciprocity and Causality Enforcements


What are passivity, reciprocity and causality enforcement?


Passivity, reciprocity and causality are three physicality rules that can apply to electrical networks. Due to the nature of random and/or deterministic errors that are a part of all measurements, instruments measuring S-parameters may return S-parameters that do not obey passivity, reciprocity or causality This can lead to problems when using S-parameters in simulations.

The SPARQ includes options to enforce passivity, reciprocity and causality in the output S-parameters. Here is a brief description of each rule.

Passivity Enforcement: Ensures that the S-parameter matrix obeys passivity, which must hold for devices that do not generate power (i.e. passive devices)

Reciprocity Enforcement: Ensures that the S-parameter matrix is reciprocal, meaning that Sij = Sji. Most (but not all) passive devices are reciprocal.

Causality Enforcement:Ensures that the impulse response derived from an S-parameter does not include an inversion of cause and effect; i.e. the response should not occur before the impulse.

See the individual FAQs on each of these rule for more information.


(All support files listed here have been scanned and are virus free)

Product Group:
Signal Integrity Network Analyzers

Model Numbers:
SPARQ-4002E, SPARQ-4002M, SPARQ-4004E


Causality Enforcement, Passivity Enforcement, Reciprocity Enforcement

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