Junkosha Inc.EMF-06 / 6 SeriesRoHS Compliant

< 1 ps Between Every Pair. Factory-Verified. Guaranteed at Shipment.

When you're measuring picosecond jitter, cable skew the same order of magnitude as your signal contaminates every result. 6 Series cables ship as precision-matched pairs — so your measurement setup starts from truth. Available in Israel through Koto Electronics.

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50 Ω — All VariantsSupplied as Matched PairsAuthorized Israeli Rep.

Junkosha 6 Series Skew-Matched Cable Pair

< 1 ps

Skew Between Pair

< 0.3°

Phase Deviation at 1 GHz

67 GHz

Maximum Frequency

4 models

26.5 – 67 GHz Range

The hidden measurement error

When Cable Skew Becomes the Signal

Generic cable pairs — even from the same reel — can carry 2–8 ps of differential skew into every measurement. At those magnitudes, you are no longer measuring your DUT. You are measuring your cables.

Jitter You Can't Explain

When cable skew exceeds your DUT's actual jitter, every anomaly you report is cable noise — not device behavior. Your compliance pass/fail result is a function of which cables you happened to grab, not the device under test.

Eye Diagrams That Lie

Even picoseconds of differential skew close the eye. Engineers spend hours chasing signal integrity problems that vanish the moment cables are swapped — because the problem was always the cables, not the DUT.

False Failures in Compliance

USB4, PCIe, and HDMI compliance suites have tightened jitter masks year over year. A cable pair with 3–5 ps of skew can push a marginal DUT from pass to fail — and ship it back to engineering for a root cause that doesn't exist.

The solution

Measured Together. Shipped Together. Guaranteed Together.

The 6 Series is not a single cable — it is a matched cable system. Pairs are manufactured from the same material lot, individually characterized, and selected so that differential skew is below 1 ps before they leave the factory.

✓
Factory Skew Verification — < 1 ps Guaranteed
Each pair is measured on a VNA across its full frequency range. The skew spec is not a nominal — it is a guaranteed value, verified for the specific two cables that ship together.
✓
< 0.3° Phase Deviation at 1 GHz Between Pair
Phase matching is tighter than skew matching alone. At 1 GHz, the two cables in a pair deviate by less than 0.3°. For high-speed differential measurements, this is the number that determines the quality of your baseline.
✓
Low-Density PTFE Insulation — Stable Electrical Length
Foam PTFE dielectric gives a high velocity of propagation and a stable, repeatable phase response. The electrical length of each cable is consistent batch-to-batch, making the matched-pair guarantee reproducible.
✓
26.5 to 67 GHz — Four Models to Match Your Instrument
MWX621 (26.5 GHz, SMA/N) through MWX661 (67 GHz, 1.85mm). Select the model that matches your test frequency and connector interface — the skew guarantee is identical across the range.
✓
Applications: USB4, HDMI, BERT, Jitter Analysis
Used for USB4 and USB 3.x compliance (eye diagram, jitter), HDMI TMDS differential pair verification, bit error rate testing, and jitter separation (random vs. deterministic) at frequencies up to 67 GHz.

The Matched-Pair Process

1
1. Manufacture
Cables are produced from the same material lot under controlled conditions to minimize inherent variation.
2
2. Characterize
Each cable's electrical length and phase response is measured across the full frequency range using a VNA.
3
3. Match
Pairs are selected so differential skew is < 1 ps and phase deviation is < 0.3° at 1 GHz — both verified before shipment.
4
4. Ship
Matched pairs leave the factory together, tagged with the same pair ID. Separate them and the guarantee no longer applies.

Primary Applications

USB4 / USB 3.x Compliance
Eye diagram and jitter testing to USB-IF specifications
HDMI Compliance Testing
TMDS differential pair skew verification
BERT & Jitter Analysis
BER testing, jitter separation, random/deterministic analysis

6 Series — Skew-Matched Pairs

Choose Your Frequency Range

All models supplied as factory-matched pairs. Skew < 1 ps guaranteed at shipment. Temp: −30 to +85 °C. Lead time: 11 business days.

MWX62126.5 GHz

Lowest loss in series — 1.4 dB/m, largest OD, SMA or N connectors

Outer Diameter6.0 mm

Cable Mass64 g/m

VSWR (max)≤ 1.33

Insertion Loss1.4 dB/m

Assembly Length200 – 1,500 mm

Connectors: SMA-M / N-M

Supplied as matched pair · < 1 ps skew guaranteed

MWX64140.0 GHz

40 GHz matched pair — 2.92mm connectors, 4.1 mm OD

Outer Diameter4.1 mm

Cable Mass35 g/m

VSWR (max)≤ 1.43

Insertion Loss3.0 dB/m

Assembly Length200 – 1,500 mm

Connectors: SMA-M / 2.92mm-M

Supplied as matched pair · < 1 ps skew guaranteed

MWX65150.0 GHz

50 GHz matched pair — slim 3.7 mm OD, 2.4mm connectors

Outer Diameter3.7 mm

Cable Mass29 g/m

VSWR (max)≤ 1.43

Insertion Loss3.8 dB/m

Assembly Length200 – 1,500 mm

Connectors: 2.92mm-M / 2.4mm-M

Supplied as matched pair · < 1 ps skew guaranteed

MWX66167.0 GHz

Highest frequency — 67 GHz, ultra-thin 2.6 mm, 1.85mm connectors

Outer Diameter2.6 mm

Cable Mass17 g/m

VSWR (max)≤ 1.43

Insertion Loss5.6 dB/m

Assembly Length200 – 1,500 mm

Connectors: 2.92mm-M / 1.85mm-M

Supplied as matched pair · < 1 ps skew guaranteed

Full Specification Comparison

Model	Max Freq.	OD	Weight	VSWR	Ins. Loss	Skew	Phase Dev.	Lengths	Temp. Range
MWX621	26.5 GHz	6.0 mm	64 g/m	≤ 1.33	1.4 dB/m	< 1 ps	< 0.3°	200 – 1,500 mm	−30 to +85 °C
MWX641	40.0 GHz	4.1 mm	35 g/m	≤ 1.43	3.0 dB/m	< 1 ps	< 0.3°	200 – 1,500 mm	−30 to +85 °C
MWX651	50.0 GHz	3.7 mm	29 g/m	≤ 1.43	3.8 dB/m	< 1 ps	< 0.3°	200 – 1,500 mm	−30 to +85 °C
MWX661	67.0 GHz	2.6 mm	17 g/m	≤ 1.43	5.6 dB/m	< 1 ps	< 0.3°	200 – 1,500 mm	−30 to +85 °C

Skew and phase deviation guaranteed between matched pair cables as shipped. Impedance: 50 Ω. Lead time: 11 business days standard.

Frequently Asked Questions

What does '< 1 ps skew' mean in practice?

It means the two cables in a pair arrive at their connectors within one picosecond of each other. At 67 GHz, one picosecond is about 0.06° of phase — effectively invisible to your measurement system. The skew specification is verified by Junkosha at the factory before shipment.

Are the cables supplied as matched pairs or individually?

6 Series cables are always supplied as matched pairs — two cables measured together and guaranteed to meet the < 1 ps skew spec as a set. You should never use a 6 Series cable without its factory-matched partner.

How does 6 Series differ from standard phase-stable cables?

Standard phase-stable cables (like 0 Series or 3 Series) guarantee each cable's absolute phase vs. temperature or bending. 6 Series goes further: it guarantees the differential skew between a specific pair of cables. The cables are manufactured, selected, and shipped together as a matched set.

Can I use 6 Series cables for single-ended measurements?

Technically yes, but the value proposition is entirely in the matched-pair guarantee. For single-ended work, a 0 Series or 3 Series cable will give you the same or better individual cable performance at lower cost.

What temperature range is guaranteed?

Operating range is −30 to +85 °C. This is narrower than some other series; if your test environment exceeds this range, contact us to discuss options.

What lead time and length options are available?

Standard delivery is 11 business days from order. Lengths range from 200 mm to 1,500 mm. Custom lengths within that range are available — contact Koto for a quote.

The EMF Series Family

The full EMF product family covers RF and microwave cable assemblies for every test and measurement application.

0 Series

26.5 – 145 GHz

1 Series

Wide Temp. / High Durability

2 Series

Flexible / Low Repulsion

3 Series

Temp. Phase Stability

Stop Attributing Cable Skew to DUT Jitter

When the cable pair is guaranteed to < 1 ps, the only skew left to explain is the DUT's. That's the measurement setup you need for accurate compliance results — and the setup 6 Series provides.

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