We are embarking on a new family of systems. Can you help us build a test vehicle?

Yes, we can help you. We recommend 2 options, both of which WRT can help you with. Build a Test Vehicle (TV) suited to your technology roadmap that addresses issues of Fabrication validation (impedance, etch variation, etc.) 3D EM optimization of key connectors, ability to directly measure with high integrity de-embedding Use TV to validate a concerted measurement process, including S-parameter quality metrics (causality, passivity, etc.) Cross sectional analysis to determine actual “as-fabricated technology”, versus “as-designed”. Material identification fitting for EDA, including X-Y and Z-axis Dk, Df for glass/resin laminates Testing and validation of via designs and crux breakout regions. The CMP-50 is a VERY good modeling and validation platform for activity focused on the 10G to 56G PAM4 space. With purchase we conduct a 45-minute overview of Channel Modeling methods. Please contact us for more info or to set up a time.

When should/shouldn't I use forward couplers for injecting crosstalk?

We don't recommend using forward couplers for injecting crosstalk into serial link systems. There are no forward couplers in backplane or general serial link systems. Generally, they are wideband systems with channel characteristics unlike PCB t-lines. True power spectral density of the crosstalk is impacted by dielectric, and metal losses in actual PCB transmission systems, and those systems represent models that are used for COM and general serial link analysis. You can’t do any of this with forward couplers. You should seriously think about using PCB system generated crosstalk, like our XTALK-56 platform. It includes basic crosstalk coupling, via coupling, backplane/connector emulators that include the ability to add crosstalk. Finally, by having crosstalk structures that have the same loss as our PCB platforms (ISI and XTALK) you can directly determine, easily, how crosstalk impacts transmission reach penalty. By including return loss degradation structures in the XTALK platform you can perform SERDES design of experiments with variables loss, crosstalk, return loss floor through the Nyquist region. Sorry, you can't do that with forward couplers. Pluou can add both clock and data to crosstalk in the XTALK platform. Adding noise to RX input isn’t crosstalk, it is simply noise. Finally, forward couplers add strange deterministic jitter profiles, while PCB transmission does not. PCB transmission adds DJ exactly like normal transmission PCB.

When should/shouldn't I use phase shifters for skew?

First of all, PCB skew is not phase shifter skew, which often has bandwidth issues. Phase shifters work well for simple narrow band carrier based signaling systems, but not broad-band digital systems. PCB skew, such as provided by our SKEW-112 platform, has following advantages over phase shifters: The skew is calibrated using NIST traceable methodology and recorded to <100femtoseconds or 0.1psec accuracy, there is no calibration. Skew calibration is really challenging, we do all that work for you, and provide program table. We are creating skew matched calibrated cables every day, so we have special measurement techniques using both VNA and TDR. SKEW-112 is easy to use, WRT team provides apps support. The SKEW-112 has channel performance like breakout regions or common transmission paths for Serial Link systems, which means SCD21 is reasonable (diff to common mode), and relates to the skew. Backplanes do not have simple skew, the have coupled systems, and they do not have phase shifters. Simple phase shifters offer no coupling, so it only mimics TX skew, not channel skew. Signal integrity is exact same for all lengths, so doing Design of Experiments works well since channel performance does not change like it does with phase shifters. 1.5 VSWR is 14dB, SKEW-112 maintains over -20dB return loss through 2X Nyquist. For PAM4 systems return loss or S/N ratio through 1X Nyquist is very important. How is customer going to calibrate skew between set ups? SKEW-112 will work in multiple locations using simple Excel spreadsheet. WRT applications staff will also calibrate skew of your cables (WRT will do this complimentary right now, later this will be optional) and have our own 2psec, 1psec, or 0.375psec max skew matched cables for purchase. We also provide the measured S-parameters of cables.

What should we first do before engaging with WRT for services?

Our experience dramatically helps customers accelerate their signal integrity prowess, but it takes a bit of systematic effort. First, we need a mutual NDA to have a substantive first meeting. Otherwise, we can speak in general terms, which mostly doesn’t work. Next, it is a good idea to start a document outlining prioritized signal integrity issues existing presently, also future proofed for next generation activity. Common signal integrity issues include: Material ID Via design TDR impedance of transmission lines using both EDA, time domain S-parameters, and direct TDR impedance analysis Differential analysis and differential via design methodology Benchmarking EDA tools like Clarity and HFSS Signal Integrity training for either measurements or EDA simulation tools Measurement analysis using either TDR or S-parameters Elements of stack-up design Advancing simulation to measurement methodology. We initially help our customers with an option to add consulting packages for specific objectives. It would be good to have team consensus on max frequency, data rates, coding, etc. The Wild River engineering team looks forward to working with you folks.

Why do forward couplers fall short for aggressor injection in SERDES Testing?

Forward couplers are often proposed for aggressor signal injection in SERDES testing—but they introduce fundamental limitations that make them unsuitable for accurate crosstalk modeling. In real-world backplane and serial link systems, forward couplers are not present. These systems are inherently wideband, and their transmission characteristics—defined by PCB traces, vias, and dielectric loss—are vastly different from what a directional coupler can emulate. Crosstalk behavior in practical PCB systems is shaped by dielectric and conductor losses, along with layout-specific factors like via structures and connector transitions. These are critical variables for accurate Channel Operating Margin (COM) and serial link analysis, and none of them are captured using forward couplers. Instead, consider using a purpose-built PCB crosstalk platform like XTALK-56. It’s designed to replicate realistic inter-symbol interference (ISI) and crosstalk characteristics across a range of channel types. XTALK-56 includes: True PCB-based crosstalk coupling Via and backplane/connector emulation Return loss degradation structures Support for simultaneous clock and data interference By modeling loss and crosstalk together, XTALK-56 allows engineers to quantify how these impairments affect transmission reach and perform SERDES design of experiments (DoE) with precision. Crucially, adding noise to the RX input is not crosstalk—it’s just noise. Forward couplers inject deterministic jitter profiles that don’t match the stochastic nature of real PCB crosstalk. XTALK-56, by contrast, introduces jitter in a way that reflects actual high-speed PCB transmission paths. If your goal is to evaluate the true impact of crosstalk on SERDES performance, I strongly recommend exploring XTALK-56 over any forward coupler-based approach.

Are your test platforms available for evaluation?

Wild River Technology does not typically offer test platforms for general evaluation. However, in select cases, we may provide access to a test platform based on the specific needs and qualifications of the project. Evaluation opportunities are reviewed individually and may depend on factors such as technical alignment, timeline, and intended use. If you're interested in evaluating one of our platforms, please reach out to Wild River Technology Sales to discuss your requirements. We’re happy to explore whether a tailored evaluation arrangement makes sense for your situation.

How much does XXX cost?

We have set up an auto-quote feature on the website for just this purpose. Simply go to the product(s) you are interested in, select from the options if there are any, and press the "Request a Quote" button. We will email you an instant quote.

FAQs Archive - Wild River Technology

Q: What should we first do before engaging with WRT for services?

Our experience dramatically helps customers accelerate their signal integrity prowess, but it takes a bit of systematic effort. First, we need a mutual NDA to have a substantive first meeting. Otherwise, we can speak in general terms, which mostly doesn’t work. Next, it is a good idea to start a document outlining prioritized signal integrity issues existing presently, also future proofed for next generation activity. Common signal integrity issues include: Material ID Via design TDR impedance of transmission lines using both EDA, time domain S-parameters, and direct TDR impedance analysis Differential analysis and differential via design methodology Benchmarking EDA tools like Clarity and HFSS Signal Integrity training for either measurements or EDA simulation tools Measurement analysis using either TDR or S-parameters Elements of stack-up design Advancing simulation to measurement methodology. We initially help our customers with an option to add consulting packages for specific objectives. It would be good to have team consensus on max frequency, data rates, coding, etc. The Wild River engineering team looks forward to working with you folks.

Q: Why do forward couplers fall short for aggressor injection in SERDES Testing?

Forward couplers are often proposed for aggressor signal injection in SERDES testing—but they introduce fundamental limitations that make them unsuitable for accurate crosstalk modeling. In real-world backplane and serial link systems, forward couplers are not present. These systems are inherently wideband, and their transmission characteristics—defined by PCB traces, vias, and dielectric loss—are vastly different from what a directional coupler can emulate. Crosstalk behavior in practical PCB systems is shaped by dielectric and conductor losses, along with layout-specific factors like via structures and connector transitions. These are critical variables for accurate Channel Operating Margin (COM) and serial link analysis, and none of them are captured using forward couplers. Instead, consider using a purpose-built PCB crosstalk platform like XTALK-56. It’s designed to replicate realistic inter-symbol interference (ISI) and crosstalk characteristics across a range of channel types. XTALK-56 includes: True PCB-based crosstalk coupling Via and backplane/connector emulation Return loss degradation structures Support for simultaneous clock and data interference By modeling loss and crosstalk together, XTALK-56 allows engineers to quantify how these impairments affect transmission reach and perform SERDES design of experiments (DoE) with precision. Crucially, adding noise to the RX input is not crosstalk—it’s just noise. Forward couplers inject deterministic jitter profiles that don’t match the stochastic nature of real PCB crosstalk. XTALK-56, by contrast, introduces jitter in a way that reflects actual high-speed PCB transmission paths. If your goal is to evaluate the true impact of crosstalk on SERDES performance, I strongly recommend exploring XTALK-56 over any forward coupler-based approach.

Q: Are your test platforms available for evaluation?

Wild River Technology does not typically offer test platforms for general evaluation. However, in select cases, we may provide access to a test platform based on the specific needs and qualifications of the project. Evaluation opportunities are reviewed individually and may depend on factors such as technical alignment, timeline, and intended use. If you're interested in evaluating one of our platforms, please reach out to Wild River Technology Sales to discuss your requirements. We’re happy to explore whether a tailored evaluation arrangement makes sense for your situation.

Q: How much does XXX cost?

We have set up an auto-quote feature on the website for just this purpose. Simply go to the product(s) you are interested in, select from the options if there are any, and press the "Request a Quote" button. We will email you an instant quote.

Frequently Asked Questions

At Wild River Technology, we know that high-speed design and signal integrity challenges can raise a lot of questions. This FAQ section addresses the most common inquiries about our services, technologies, and processes—from test fixture design and VNA measurement to 3D modeling and simulation workflows. Whether you’re an engineer, program manager, or system architect, you’ll find helpful insights here.

We are embarking on a new family of systems. Can you help us build a test vehicle?
Yes, we can help you. We recommend 2 options, both of which WRT can help you with. Build a Test Vehicle (TV) suited to your technology roadmap that addresses issues of Fabrication validation (impedance, etch variation, etc.) 3D EM optimization of key connectors, ability to directly measure with high integrity de-embedding Use TV to validate [...]
When should/shouldn’t I use forward couplers for injecting crosstalk?
We don't recommend using forward couplers for injecting crosstalk into serial link systems. There are no forward couplers in backplane or general serial link systems. Generally, they are wideband systems with channel characteristics unlike PCB t-lines. True power spectral density of the crosstalk is impacted by dielectric, and metal losses in actual PCB transmission systems, [...]
When should/shouldn’t I use phase shifters for skew?
First of all, PCB skew is not phase shifter skew, which often has bandwidth issues. Phase shifters work well for simple narrow band carrier based signaling systems, but not broad-band digital systems. PCB skew, such as provided by our SKEW-112 platform, has following advantages over phase shifters: The skew is calibrated using NIST traceable methodology [...]
What should we first do before engaging with WRT for services?
Wild River Technology helps teams accelerate their signal integrity capabilities through structured collaboration. We begin with an NDA and a prioritized review of current and next-gen SI challenges, offering consulting support tailored to your design and measurement needs.
Why do forward couplers fall short for aggressor injection in SERDES Testing?
Forward couplers fall short in SERDES testing, failing to replicate real PCB crosstalk. XTALK-56 offers a more accurate, loss-aware platform for evaluating true transmission impairments and jitter behavior.
Are your test platforms available for evaluation?
Test platforms are not typically available for evaluation, but in select cases, Wild River Technology may consider it based on project needs. Contact Sales to inquire.
How much does XXX cost?
Use our website’s auto-quote feature. This eliminates the need for back-and-forth communication and lets you get pricing details quickly and efficiently. If you have further questions or need a formal proposal, our sales team is always available to help.

FAQs

Frequently Asked Questions

We are embarking on a new family of systems. Can you help us build a test vehicle?

When should/shouldn’t I use forward couplers for injecting crosstalk?

When should/shouldn’t I use phase shifters for skew?

What should we first do before engaging with WRT for services?

Why do forward couplers fall short for aggressor injection in SERDES Testing?

Are your test platforms available for evaluation?

How much does XXX cost?

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