May 22, 20266 min read

How we validated RayRF against 43 VNA measurements

Short answer

RayRF was validated against 43 structures fabricated on a physical test PCB and measured on a vector network analyzer. For many patch antennas and an interdigital bandpass filter, the resonant and pole frequencies match the measurement within about 1 percent across the band. We do not publish a single magnitude number, and the reason is explained below.

Speed is easy to claim and easy to demo. Accuracy is the part that decides whether a simulator is worth using, and the only honest way to show it is to put the simulation next to measured hardware. So that is what we did, on a physical board, with a VNA.

The method

We fabricated a set of structures on a controlled substrate, measured each one on a calibrated vector network analyzer, and then simulated the same structures in RayRF using the same nominal dimensions and material properties. The structures span the kinds of things PCB RF designers build:

Single-resonance rectangular patch antennas.
A dual-band patch with modes near 4 and 6.4 GHz.
An interdigital bandpass filter with four reflection poles.

Many of the structures use ZYF 300CA-C, a PTFE substrate with a dielectric constant near 2.94, which keeps the material properties well controlled for the comparison.

What the agreement looks like

A sample of the validation set. The full per-structure overlays and the complete report are on the validation page.
Structure	What was checked	Agreement
Interdigital bandpass filter (~2.4 GHz)	Number, spacing, and order of four S11 poles	Pole frequencies within ~1% across the band
Dual-band patch (~4 / 6.4 GHz)	Both resonant frequencies	Both within ~1%
Single patches (6 GHz band)	Resonant frequency	Tracks within ~1%

The honest caveat about magnitude

Why no single accuracy percentage

We report frequency agreement, not a single magnitude accuracy number. At a sharp resonance a small shift in frequency turns into a large change in magnitude, so a single percentage figure would look precise and be misleading. Frequency match is the headline because it is the honest one.

This is the same reason a measured trace and a simulated trace can look slightly apart at the bottom of a deep notch while still agreeing on where that notch sits. For design work, getting the resonance in the right place is usually what matters.

See it for yourself

The validation page shows the 9 most representative of these, with overlaid simulation and measurement traces per structure, with the method and substrate listed, so you can judge the agreement rather than take a claim on faith. If you want the speed side of the story, the matched-mesh benchmark covers that separately.

Frequently asked questions

How is RayRF validated?

RayRF simulations are compared against 43 structures fabricated on a physical test PCB and measured on a vector network analyzer. The comparison looks at whether the simulated S-parameter features, such as resonance and pole frequencies, line up with the measured ones across the band.

How accurate is RayRF against measurements?

For many patch antennas and for an interdigital bandpass filter, the resonant and pole frequencies track the measurement within about 1 percent across the band. RayRF does not claim a single headline magnitude number, because at sharp resonances a small frequency shift turns into a large magnitude shift, so one percentage would not be honest.

Can I see the validation data myself?

Yes. The validation page shows the overlaid simulation and measurement traces per structure, with the method and the substrate used, and links to the full report.

Run a validated design yourself

The bundled patch example is one of the validated structures. Open it, run it, and compare. 30-day free trial, no card required.

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