EMC Testing Patents: Leaders, Trends & White Space 2026
- 46.6% of all 131 records sit with just five assignees, so most of the claim space that matters for freedom-to-operate checks is already staked by a small group.
- Filing growth is flat, not falling 2021 and 2024 both sit at 6 records — read the 2025-2026 dip as publication lag, not a cooling field.
- G01R measurement claims dominate at 69.5% of records, while vehicle-integrated EMC testing (B60P, 2.3%) remains a thin, largely open branch.
Filing growth compares 2021 (6 records) with 2024 (6) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 131 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
EMC testing and precompliance measurement covers the instruments, chambers and signal-processing methods used to check whether an electronic device meets radiated and conducted emission limits before it goes to formal certification. The 131 records in scope span anechoic chamber construction, line impedance stabilization networks, emission probes and test-receiver detector methods, plus the measurement-uncertainty and margin calculations that turn a raw reading into a pass/fail decision. Filings run from 2015 through the 2026-07-31 cut-off, with a peak year already visible in the trend.
Because publication lags filing by roughly 18 months, the most recent one to two years in any chart will always look thinner than they eventually turn out to be. Read the 2025 and 2026 figures as provisional, not as a genuine slowdown.
Filing trends and technology composition
The dataset covers 131 published records across receiving offices led by the United States, with meaningful activity at the EPO, in India, China and via WIPO's PCT route.
A peak in 2019, then a flat plateau
Filings ran from 6 records in 2017 to a peak of 36 in 2019, then settled into a lower band. The 2021-to-2024 comparison — 6 records each year, 0% change — is the cleanest complete-year read available; treat 2025 and 2026 as still filling in rather than as decline.
Measurement claims dominate; vehicle and wireless-network overlaps are thin
G01R (electric and magnetic measurement) appears in 69.5% of the 131 records, far ahead of H04B transmission methods (22.9%) and H05K printed-circuit assemblies (16.0%). Antenna-performance testing (H01Q, 10.7%) is a secondary cluster; testing-machine structures (G01M), motor/generator EMC (H02K), wireless network testing (H04W) and load-handling vehicle integration (B60P) each sit under 4% and mark the thinner edges of the field.
Shares are the percentage of the 131 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on EMC Testing and Precompliance Measurement with Eureka
This page is one run against one query. Ask Eureka your own question about emc testing and precompliance measurement and every answer comes back with the patent numbers behind it.
Try EurekaKey patents shaping the field
US5134405A — Electromagnetically anechoic chamber and shield structures therefor
The present invention relates to an electromagnetically anechoic chamber for EMC tests of electronic devices. The floor, ceiling and side wall of the anechoic chamber have panels of electromagnetic wave absorber having many ferrite tiles, and shield members comprising double layered shield members of copper sheets and iron sheets for absorbing and reflecting the foreign electromagnetic wave.Filed by Matsushita Electric Industrial Co., Ltd.; cited 97 times, the highest count in this dataset.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5134405A | Electromagnetically anechoic chamber and shield structures therefor | 97 |
| 2 | US6011504A | Method for building a low cost, large scale, portable EMI shielded enclosure | 54 |
| 3 | US20140141727A1 | Method and apparatus for measuring the performance of antennas, mobile phones and other wireless terminals | 50 |
| 4 | WO2017178878A1 | A full time-domain method for analyzing two or more signals for assessing them as electromagnetic interferenc… | 46 |
| 5 | WO2012171562A1 | Improved method and apparatus for measuring the performance of antennas, mobile phones and other wireless ter… | 38 |
| 6 | US5825331A | Radiated emission measuring method using GTEM cell | 35 |
| 7 | US20080305754A1 | Systems and methods for over-the-air testing of wireless systems | 34 |
| 8 | WO2007080368A1 | absorber | 21 |
| 9 | US20090295405A1 | Resonance scanning system and method for testing equipment for electromagnetic resonances | 18 |
| 10 | US6943286B1 | Electromagnetic wave absorber molding material, electromagnetic wave absorber molded element and method of ma… | 18 |
Ranked by citation count within the searched corpus; older filings accumulate citations simply by being available longer, so treat this as a signal of influence rather than of current commercial weight.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Three patterns stand out once the ranking, the trend and the IPC split are read together.
The top of the field is settled, the rest is a long tail
The leading assignee holds 22 records outright, and the top five combined account for 46.6% of all 131 records in scope. Past tenth place the field thins quickly — tenth place sits at just 3 records — which points to a long tail of single- or few-filing entrants working narrow niches around chamber design, probe geometry or specific test-receiver methods.
Flat, not falling
The only complete year-over-year comparison the data supports — 2021 versus 2024, both at 6 records — shows no change. Several leading assignees show 0 filings in the latest tracked year, but given the 18-month publication lag that is expected rather than a signal that any of them have stepped back from the space.
Measurement method claims crowd the core
Electric and magnetic measurement (G01R) touches roughly seven in ten records, meaning most filers are claiming some variant of a measurement or detection method rather than a chamber, enclosure or antenna structure. That leaves structural and integration claims — H05K assemblies, H01Q antenna test setups — comparatively less contested.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to emc testing and precompliance measurement, with the prior art for and against each one.
| Assignee | Co-assignee | Shared families |
|---|---|---|
| Toda Racing Co., Ltd. | Ohtama Co., Ltd. | 5 |
| Bluetest AB | ORLENIUS CHARLIE | 1 |
| Bluetest AB | KILDAL PER SIMON | 1 |
Only 3 co-assignee pairs appear across the dataset, the strongest linking a racing-parts specialist and a test-equipment maker on 5 shared records — most EMC testing patents here are filed by a single assignee working alone rather than through joint ventures.
Who is filing, and where the field is still open
Filing activity concentrates around established test-equipment and measurement-instrument makers, with automotive and standards-body entrants appearing further down the ranking.
One filer well ahead of the pack
The leading assignee's 22 records is more than three times the fifth-place total of 7, marking a clear gap between the single dominant filer and everyone else in the ranked list.
A fast taper after the top five
Record counts halve between fifth and tenth place, and the top 10 combined reach 64.9% of all 131 records — meaning roughly a third of the field is spread across more than 50 remaining assignees.
US-centred, with real EPO and Asia-Pacific activity
The United States receives the largest share of filings (52), followed by the EPO (20), India (9), China (8), WIPO's PCT route (8) and Germany (7) — a spread that suggests EMC precompliance filers are pursuing multi-jurisdiction protection rather than concentrating on one home market.
| Assignee | Recent year | YoY |
|---|---|---|
| Rohde & Schwarz GmbH & Co KG | 0 | — |
| DARE BV | 0 | — |
| GPT Limited | 0 | — |
| Zhuhai Enpower Electric Co., Ltd. | 0 | — |
| ETS-Lindgren Inc. | 0 | — |
| Electronics and Telecommunications Research Institute (ETRI) | 0 | -100% |
| Toda Racing Co., Ltd. | 0 | — |
| Ohtama Co., Ltd. | 0 | — |
Where to take this analysis
The ranking and composition data point to specific next questions for an R&D or IP team working in this space.
Check freedom-to-operate against the top five
With 46.6% of all 131 records held by five assignees, any new filing on core measurement methods should be checked against their claim scope first, not just against the field average.
Run a claim comparison in Eureka →Watch the thin branches for a filing window
B60P, H02K and H04W overlaps each sit under 4% of records, which is a narrower prior-art field for a first-mover claim than the crowded G01R core.
Explore white space in Eureka →Common questions about EMC testing patents
One assignee leads the ranked list with 22 records, well ahead of the fifth-place holder at 7. The top five assignees combined account for 46.6% of all 131 records in scope, so a small group controls a large share of the documented claim space. Beyond tenth place, which sits at just 3 records, the field spreads thinly across more than fifty additional assignees, most holding only one or two filings.
The clearest complete-year comparison available is 2021 to 2024, where filings held flat at 6 records each year — 0% change. Filing activity actually peaked earlier, in 2019, at 36 records, then settled to a lower plateau. The apparent drop in 2025 and 2026 is largely a publication-lag artefact, since publication typically trails filing by around 18 months, so those years should not be read as a genuine decline yet.
Electric and magnetic measurement methods, classified under G01R, appear in 69.5% of the 131 records in scope, making it by far the largest single category. Transmission-related claims (H04B) follow at 22.9% and printed-circuit assembly claims (H05K) at 16.0%. Because a single patent can carry multiple IPC classes, these shares overlap rather than sum to 100%.
US5134405A claims an electromagnetically anechoic chamber design using ferrite-tile absorber panels and double-layered copper-and-iron shield members, filed by Matsushita Electric Industrial. It is the most-cited record in this dataset at 97 citations, which signals strong influence on later chamber-design filings rather than an active block on every EMC patent — its claims are specific to chamber and shield construction, not to measurement methods generally. Anyone filing on chamber or shielding structure should review its claim scope directly rather than assume it covers unrelated measurement or probe techniques.
The thinnest documented branches are vehicle-integrated test rigs (B60P, 2.3% of records), motor and generator emission profiling (H02K, 3.1%), and wireless-network conducted emission methods (H04W, 3.1%). These sit far below the 69.5% share held by core G01R measurement claims, meaning there is comparatively little prior art to design around if a new filing targets one of these overlaps directly rather than restating a general measurement method.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.