H01F 21/00
Variable inductances or transformers of the signal type
Official title: Variable inductances or transformers of the signal type (H01F36/00 takes precedence)
H01F21/00 (Variable inductances or transformers of the signal type) appears on 699 US grants and 665 published applications in this corpus.
Search patents in H01F- Granted patents
- 699
- Published applications
- 665
- Assignees
- 404
- Inventors
- 1,391
- Latest grant
- 6 Oct 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 4 | 0 |
| 1977 | 8 | 0 |
| 1978 | 4 | 0 |
| 1979 | 4 | 0 |
| 1980 | 4 | 0 |
| 1981 | 8 | 0 |
| 1982 | 4 | 0 |
| 1983 | 7 | 0 |
| 1984 | 7 | 0 |
| 1985 | 11 | 0 |
| 1986 | 4 | 0 |
| 1987 | 4 | 0 |
| 1988 | 4 | 0 |
| 1989 | 2 | 0 |
| 1990 | 1 | 0 |
| 1991 | 3 | 0 |
| 1992 | 5 | 0 |
| 1993 | 1 | 0 |
| 1994 | 4 | 0 |
| 1995 | 6 | 0 |
| 1996 | 5 | 0 |
| 1997 | 4 | 0 |
| 1998 | 4 | 0 |
| 1999 | 5 | 0 |
| 2000 | 6 | 0 |
| 2001 | 4 | 7 |
| 2002 | 13 | 18 |
| 2003 | 19 | 19 |
| 2004 | 14 | 35 |
| 2005 | 17 | 26 |
| 2006 | 23 | 31 |
| 2007 | 25 | 30 |
| 2008 | 26 | 29 |
| 2009 | 22 | 32 |
| 2010 | 25 | 24 |
| 2011 | 29 | 27 |
| 2012 | 24 | 17 |
| 2013 | 21 | 16 |
| 2014 | 22 | 34 |
| 2015 | 19 | 22 |
| 2016 | 23 | 32 |
| 2017 | 28 | 37 |
| 2018 | 31 | 19 |
| 2019 | 33 | 32 |
| 2020 | 20 | 31 |
| 2021 | 32 | 23 |
| 2022 | 21 | 33 |
| 2023 | 26 | 36 |
| 2024 | 30 | 19 |
| 2025 | 22 | 19 |
| 2026 | 11 | 17 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Thin film inductor element and thin film variable inductor element6 Oct 2026US 12,755,882 B2Japan Atomic Energy Agency
- Tunable integrated voltage regulator25 Aug 2026US 12,719,362 B2APPLIED Materials.Inc.
- Stabilization and tuning of persistent currents using variable inductance9 Jun 2026US 12,651,685 B2The Regents of the University of California
- Coil former, inductive component and method for adjusting an inductance5 May 2026US 12,621,909 B2Philip Morris Products S. A.
- Inductor device28 Apr 2026US 12,614,656 B2Realtek Semiconductor Corp.
- Device Having a Multimode Antenna With Variable Width of Conductive Wire17 Sep 2026US 2026/0279661 A1NuCurrent, Inc.
- Digital phase shift circuit23 Jul 2026US 2026/0213723 A1Fujikura Ltd.
- Digital phase shifter23 Jul 2026US 2026/0213734 A1Fujikura Ltd.
- Digital phase shift circuit16 Jul 2026US 2026/0205088 A1Fujikura Ltd.
- Wideband inductive component18 Jun 2026US 2026/0171294 A1QUALCOMM Incorporated
Most cited
By later US patents
- Intravascular pressure and flow sensor523US 5,873,835 ASciMed Life Systems, Inc. · 1999
- Inductive structures for semiconductor integrated circuits217US 5,095,357 AMitsubishi Denki Kabushiki Kaisha · 1992
- Isolation transformer for medical equipment185US 5,615,091 ABiochem International Inc. · 1997
- Resonant converter with controlled inductor145US 5,684,678 ADelco Electronics Corporation · 1997
- Balanced planar transformers138US 4,816,784 ANorthern Telecom Limited · 1989