Test USB 3, USB-C and 10G Ethernet without throttling your data.
A USB 3.0 stream at 5 Gbps is an RF signal at 5 GHz — right where WiFi, Bluetooth and cellular live. JRE's mode-selective signal-phasing filters separate the two by signal mode, not frequency, so SuperSpeed data passes clean while common-mode RF is shielded out.
Conceptual — ambient RF picked up by cables vs. inside the enclosure with common-mode RF shielded out.
- 5 Gbps → USB 3.0 passes clean — total equivalent cable under ~3 m
- 40 Gbps → Thunderbolt / USB4 with an active cable on the external side
- >60 dB → Patented high-speed filter isolation at 1 GHz
When the data and the interference are at the same frequency.
The enclosure exists to block RF; your test signal is RF.
- USB 3, USB-C, 10GBASE-T and HDMI signal frequencies lie inside the 2.4–6 GHz band
- There is no frequency gap left to filter
- Capacitive and low-pass filtering both fail here
- High-speed interfaces send balanced differential data
- ambient RF picked up by cables arrives as common mode
- it is not low-pass filtering at all
High-speed interfaces send balanced differential data; ambient RF picked up by cables arrives as common mode. The signal-phasing filters built on John Ramsey's patents pass the differential signal and attenuate the common-mode RF — there is no upper frequency limit, because it is not low-pass filtering at all.
When the data and the interference are at the same frequency.
Getting data across a shielded wall is a contradiction.
Getting data across a shielded wall is a contradiction. The enclosure exists to block RF; your test signal is RF. At low speeds it is easy — a 9600-baud RS-232 line sits at ~19 kHz, far below 2.4 GHz WiFi, so a feedthrough capacitor passes the data and shorts the interference. USB 2.0 (480 Mbps) and Ethernet 10/100/1000 (up to 1 Gbps) still leave a usable gap, so a low-pass filter that rolls off above 700 MHz–1 GHz works.
But USB 3.0 SuperSpeed (5 Gbps), USB-C and Thunderbolt (5–40 Gbps), 10GBASE-T Ethernet and HDMI 1.4+ all signal squarely inside the WiFi/cellular bands. There is no frequency gap left to filter. A low-pass that blocks 2.4 GHz blocks your data too. Capacitive and low-pass filtering both fail here — a fundamentally different approach is needed.
Filter that band with a low-pass and you kill the interference and the data.
Filter that band with a low-pass and you kill the interference and the data.
How JRE solves it: discriminate by mode, not frequency.
USB 3, USB-C, 10GBASE-T and HDMI signal frequencies lie inside the 2.4–6 GHz band — the same band you are trying to shield out. A low-pass filter cannot tell the data from the interference.
High-speed interfaces send balanced differential data; ambient RF picked up by cables arrives as common mode. The signal-phasing filters built on John Ramsey's patents pass the differential signal and attenuate the common-mode RF — there is no upper frequency limit, because it is not low-pass filtering at all.
Fiber gives total isolation but breaks the conductive path, so USB enumeration, handshaking and power delivery stop working.
The JRE filters are fully passive copper-through interfaces. The link enumerates, handshakes and delivers power normally — you keep a real, compliant connection across the wall.
The filter looks like roughly 1 to 1.5 meters of cable, and it discriminates by signal mode — so it does not care whether you run 5 Gbps or 40 Gbps.
- 5 Gbps → USB 3.0 passes clean — total equivalent cable under ~3 m
- 40 Gbps → Thunderbolt / USB4 with an active cable on the external side
- >60 dB → Patented high-speed filter isolation at 1 GHz
The filter looks like roughly 1 to 1.5 meters of cable, and it discriminates by signal mode — so it does not care whether you run 5 Gbps or 40 Gbps.
Source: Understanding data signals through filtered I/O. Keep cables short and well-shielded; the mode-selective filters reach maximum isolation when the differential pair is well balanced. For lower-speed gear, the LAN-1 low-pass can outperform the 10G filter because it does not depend on balance.
The interfaces for your protocol
Every price is published. Add the filters you need to a single combined inquiry — no cart, no checkout.
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I/O Interfaces
JRE USB3-1
Isolation
80 dB isolation in test system configuration
patented mode-selective
USB 3.0 SuperSpeed (5 Gbps), single
$480.00
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I/O Interfaces
JRE USB C-1
Isolation
80 dB in test system configuration
patented mode-selective
USB-C / Thunderbolt (5–40 Gbps)
$569.00
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I/O Interfaces
JRE LAN-10G-1
Isolation
80 dB isolation in test system configuration; ~80 dB conducted attenuation, 50 MHz to over 6 GHz
patented mode-selective
10GBASE-T Ethernet, single
$545.00
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I/O Interfaces
JRE HDMI-1
Isolation
80 dB conducted attenuation, 50 MHz to over 6 GHz
patented mode-selective
HDMI 1.4 and higher, single
$480.00
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I/O Interfaces
JRE USB2-1
Isolation
Over 80 dB attenuation > 1 GHz; Data lines: > 80dB from 1 GHz through 6 GHz; Power lines: > 80dB from 400 MHz through 6 GHz
low-pass
USB 2.0 (480 Mbps), low-pass
$369.00
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I/O Interfaces
JRE UFI-1
Isolation
> 70 dB above 700 MHz; > 80 dB from 800 MHz to 6 GHz
low-pass
8 universal filtered lines
$445.00
Go deeper — engineering guides
- Understanding data signals through filtered I/O The three filtering approaches — capacitive, low-pass, signal-phasing — and when each one applies.
- USB-3 and USB-C special considerations Cable length vs. speed, active cables, and why the passive filter looks like ~1–1.5 m of cable.
- The effect of adding multiple I/O filters The weakest-link principle and the 3 dB-per-doubling rule for your system isolation budget.
- Interface & connector guide Match every connector and capacitance value to your signal type on the removable I/O plate.
- Why filtered I/O? What one unfiltered cable does A conductor has no cutoff frequency. One unfiltered cable drags a −100 dB enclosure to −40, with a live simulation of the leak.
Tell us the interfaces you need to test.
Spec your enclosure and filtered I/O — or call about a high-speed configuration that doesn't fit a stock part. We'll quote it.