H01F 21/12
Discontinuously variable
Official title: discontinuously variable, e.g. tapped
H01F21/12 (Discontinuously variable) appears on 350 US grants and 366 published applications in this corpus.
Search patents in H01F- Granted patents
- 350
- Published applications
- 366
- Assignees
- 171
- Inventors
- 662
- Latest grant
- 9 Jun 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1981 | 2 | 0 |
| 1982 | 0 | 0 |
| 1983 | 0 | 0 |
| 1984 | 1 | 0 |
| 1985 | 2 | 0 |
| 1986 | 0 | 0 |
| 1987 | 0 | 0 |
| 1988 | 0 | 0 |
| 1989 | 1 | 0 |
| 1990 | 0 | 0 |
| 1991 | 1 | 0 |
| 1992 | 1 | 0 |
| 1993 | 0 | 0 |
| 1994 | 0 | 0 |
| 1995 | 2 | 0 |
| 1996 | 1 | 0 |
| 1997 | 2 | 0 |
| 1998 | 2 | 0 |
| 1999 | 3 | 0 |
| 2000 | 4 | 0 |
| 2001 | 1 | 6 |
| 2002 | 9 | 11 |
| 2003 | 13 | 15 |
| 2004 | 9 | 21 |
| 2005 | 10 | 17 |
| 2006 | 16 | 15 |
| 2007 | 16 | 18 |
| 2008 | 18 | 20 |
| 2009 | 13 | 19 |
| 2010 | 18 | 14 |
| 2011 | 18 | 14 |
| 2012 | 15 | 10 |
| 2013 | 11 | 9 |
| 2014 | 16 | 14 |
| 2015 | 9 | 8 |
| 2016 | 9 | 16 |
| 2017 | 10 | 14 |
| 2018 | 16 | 11 |
| 2019 | 18 | 17 |
| 2020 | 9 | 16 |
| 2021 | 15 | 11 |
| 2022 | 12 | 20 |
| 2023 | 12 | 17 |
| 2024 | 15 | 10 |
| 2025 | 11 | 9 |
| 2026 | 9 | 14 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- 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.
- Composite electronic component24 Mar 2026US 12,586,712 B2TDK Corporation
- Inductor, oscillator, and terminal device3 Mar 2026US 12,567,527 B2Huawei Technologies Co., Ltd.
- 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
- Isolation transformer for medical equipment185US 5,615,091 ABiochem International Inc. · 1997
- Balanced planar transformers138US 4,816,784 ANorthern Telecom Limited · 1989
- Tunable embedded inductor devices133US 7,884,697 B2Industrial Technology Research Institute · 2011
- System and method for providing a low power receiver design114US 6,377,315 B1Broadcom Corporation · 2002
- Inductively tunable antenna for a radio frequency identification tag112US 6,480,110 B2Microchip Technology Incorporated · 2002