Common Mode Choke Patents: Who Leads, Where the Gaps Are 2026
- 43.1% concentration. The top 5 of 63 ranked assignees hold 53 of 123 records in scope — filing is concentrated but not locked down by a single owner.
- Filing has cooled since 2018. Annual filings peaked at 7 in 2018 and had fallen to 2 by the 2022 midpoint, pointing to a mature, claim-dense field rather than a growing one.
- Two IPC classes carry the field. H03H (filters) and H01F (inductors/transformers) each cover roughly half of all 123 records, while H05K and H02H sit in single digits — a visible gap around board-level and protective integration.
What this dataset covers
Common mode chokes and related EMI filter components sit at the intersection of magnetics and circuit protection: a wound core suppressing common-mode noise while passing differential signal with minimal loss. This landscape draws on 123 published records filed between 2015 and mid-2026, filtered to documents that specify measurable properties such as common mode impedance, differential mode leakage, saturation under load, creepage and clearance, or insertion loss — not just components named in passing.
Because publication typically lags filing by around 18 months, the most recent filing year in any trend undercounts real activity. Read the 2025 and 2026 figures as provisional floors, not a finished picture.
Filing trend and technology composition
The filing curve and the IPC breakdown below are drawn from the same 123-record set. Together they show a field that has passed its filing peak while claim density has settled around two structural classes.
A field past its peak
Filings ran from 4 in 2017 to a peak of 7 in 2018, then eased toward 2 by the 2022 midpoint, with the partial 2026 count still to be revised upward as later publications land.
Two anchor classes, several thin branches
H03H (impedance networks and filters) and H01F (inductors and transformers) each appear in roughly half of all 123 records, confirming these as the structural core of the art. H04B, H01P, H02M and H04L each sit in the 13–16% band, while H05K (printed circuits) and H02H (protective circuits) trail at 12.2% and 8.1% respectively — thinner coverage that is worth checking before assuming it is open.
Shares are the percentage of the 123 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Common Mode Chokes and EMI Filter Components with Eureka
This page is one run against one query. Ask Eureka your own question about common mode chokes and emi filter components and every answer comes back with the patent numbers behind it.
Try EurekaThe documents setting the terms of the art
US11139096B2 — Common mode choke coil and wireless charging circuit
A common mode choke coil built around a core with a first and second wire wound around it, each wire connected to a pair of electrode parts on the core. The claimed device is specified by a self-resonance frequency of 700 MHz or more and a common mode inductance of 300 nH or less within a frequency band of 1 MHz or less.Filed by Murata Manufacturing, published 2021-10-05 — illustrates how far the art has moved toward numerically bounded electrical performance claims rather than structural description alone.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5142430A | Power line filter and surge protection circuit components and circuits | 161 |
| 2 | US5825259A | Electromagnetic interference isolator with common mode choke | 148 |
| 3 | US5568111A | Ferrite common mode choke adapted for circuit board mounting | 109 |
| 4 | US6535095B2 | Wound type common mode choke coil | 100 |
| 5 | US4342013A | Bidirectional power line filter | 94 |
| 6 | US5250923A | Laminated chip common mode choke coil | 90 |
| 7 | US5552756A | Chip-type common mode choke coil | 74 |
| 8 | WO1991015046A1 | Power line filter and surge protection circuit components and circuits | 61 |
| 9 | US20070252659A1 | Filter Circuit, Differential Transmission System Having Same, and Power Supply | 50 |
| 10 | JP2002110428A | Wire-wound common mode choke coil | 46 |
Citation counts reward older filings that have had more time to accumulate citations inside this corpus — treat them as a measure of influence on later filings, not as a ranking of current commercial relevance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Three figures matter most here: how concentrated ownership is, how the technology splits by IPC class, and where in the world these rights are actually being sought.
Ownership is concentrated but contestable
The leader holds 24 records and fifth place holds 6 — a steep drop-off rather than a plateau. That gap between first and fifth suggests room for a well-differentiated filer to enter without confronting a single dominant blocking portfolio.
US and Japan dominate the filing venues
The United States (60) and Japan (25) together account for the large majority of receiving-office activity, with Europe, WIPO/PCT, the UK and Australia trailing well behind. A portfolio built only for US and Japan protection is following the crowd, not avoiding it.
Filter and inductor classes dominate the claim space
H03H and H01F each sit near or above the halfway mark of all 123 records, meaning most claims are still contesting core filter and magnetic-structure territory rather than the surrounding integration classes.
Recent-year activity has gone quiet across known leaders
None of the tracked assignees — leaders and long-tail filers alike — show a filing in the most recent tracked year, consistent with the broader decline from the 2018 peak and the usual publication lag rather than a sudden exit.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to common mode chokes and emi filter components, with the prior art for and against each one.
Who is filing, and where the claim space is still open
Sixty-three assignees appear in the ranking Patsnap Eureka returns for this search — the full set, not a top-50 cut. The leader's 24 records against a fifth-place figure of 6 shows a real gap between the front-runner and the rest, with a long tail of single- and few-filing entrants behind tenth place's 4.
One filer well ahead of the pack
The leading assignee's count is four times fifth place's 6, a bigger gap than the smoother top-10 curve suggests. That distance is where a competitor's freedom-to-operate analysis should start.
A tighter cluster from third to tenth
Between fifth and tenth place the counts compress toward single digits, with tenth place at 4 — a cluster of comparably sized portfolios rather than a second dominant player.
Most of the field files rarely
More than 50 of the 63 ranked assignees sit outside the top 10, each holding a small handful of records. That long tail is typical of a mature passive-component art where incremental design patents outnumber platform claims.
| Assignee | Recent year | YoY |
|---|---|---|
| Murata Manufacturing Co., Ltd. | 0 | — |
| Panasonic Corporation (Japan) | 0 | — |
| Andrew Corporation | 0 | — |
| Mitsubishi Materials Corporation | 0 | — |
| MADGE NETWORKS | 0 | — |
| ANTHONY A ANTHONY | 0 | — |
| Telefonaktiebolaget LM Ericsson (Sweden) | 0 | — |
| NEC Corporation | 0 | — |
Where to take this next
The dataset points to a field with settled core claims and a few thinner branches. The next step is usually narrower than another landscape scan.
Map freedom-to-operate against the leader's portfolio
With the top filer holding 24 of 123 records and a clear drop to fifth place, a claim chart against that specific portfolio will tell you more than the aggregate concentration figure.
Explore assignee portfolios in EurekaCheck the under-claimed branches before filing
H05K and H02H overlaps sit well below the H03H/H01F core in record share — worth a targeted search before assuming a board-integration or protection-circuit angle is open.
Run a white-space search in EurekaRevisit the trend once 2025–2026 publications land
The apparent decline from the 2018 peak is partly a publication-lag artefact; re-pull the trend in a year to see how much of the recent slide reverses.
Track filing trends in EurekaCommon questions about common mode choke and EMI filter patents
Across the 123 records in scope, filing is led by one assignee holding 24 records, well ahead of fifth place at 6. The top 5 assignees together hold 53 records, or 43.1% of all 123 in scope, and the top 10 hold 62.6%. That leaves more than 50 of the 63 ranked assignees filing only a handful of records each, so the field has a clear leader but no single company controlling the whole space.
Filing activity peaked at 7 records in 2018 and had fallen to 2 by the 2022 midpoint, indicating a decline rather than growth over that period. Because publication lags filing by roughly 18 months, the most recent years understate real activity, so the true 2025–2026 count will likely revise upward. Even accounting for that lag, the multi-year slide from the 2018 peak points to a maturing rather than an expanding field.
H03H (impedance networks and filters) and H01F (magnets, inductors and transformers) are the two anchor classes, each covering roughly half of the 123 records in scope. Secondary classes — H04B, H01P, H02M and H04L — each sit in the 13–16% range, reflecting overlap with transmission, microwave and power-conversion applications. H05K (printed circuits) and H02H (protective circuits) trail at 12.2% and 8.1%, marking thinner but not empty coverage.
The United States receiving office accounts for 60 of the filings tracked here, with Japan second at 25. Europe (EPO), the PCT/WIPO route, the UK and Australia make up the remainder in much smaller numbers. A portfolio strategy aimed only at the US and Japan would be following the dominant pattern rather than finding underprotected territory.
US11139096B2, assigned to Murata Manufacturing and published in 2021, claims a common mode choke coil with two wound wires connected to paired electrode parts on a shared core, defined by numeric bounds: a self-resonance frequency of 700 MHz or more and a common mode inductance of 300 nH or less within a 1 MHz or lower frequency band. It blocks designs that fall inside those specific electrode-arrangement and performance-parameter bounds, particularly in wireless-charging contexts. Designs using different winding topologies, different electrode counts, or performance parameters outside that numeric window sit outside its literal claim scope, though a full freedom-to-operate check should compare dependent claims too.
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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.