H03F 3/217
Class d power amplifiers
Official title: Class D power amplifiers; Switching amplifiers
H03F3/217 (Class d power amplifiers) appears on 3,361 US grants and 3,154 published applications in this corpus.
Search patents in H03F- Granted patents
- 3,361
- Published applications
- 3,154
- Assignees
- 1,015
- Inventors
- 4,346
- Latest grant
- 29 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 5 | 0 |
| 1977 | 13 | 0 |
| 1978 | 8 | 0 |
| 1979 | 8 | 0 |
| 1980 | 4 | 0 |
| 1981 | 3 | 0 |
| 1982 | 7 | 0 |
| 1983 | 7 | 0 |
| 1984 | 13 | 0 |
| 1985 | 13 | 0 |
| 1986 | 7 | 0 |
| 1987 | 13 | 0 |
| 1988 | 11 | 0 |
| 1989 | 8 | 0 |
| 1990 | 12 | 0 |
| 1991 | 14 | 0 |
| 1992 | 15 | 0 |
| 1993 | 12 | 0 |
| 1994 | 11 | 0 |
| 1995 | 24 | 0 |
| 1996 | 15 | 0 |
| 1997 | 17 | 0 |
| 1998 | 19 | 0 |
| 1999 | 28 | 0 |
| 2000 | 32 | 0 |
| 2001 | 44 | 17 |
| 2002 | 58 | 57 |
| 2003 | 57 | 49 |
| 2004 | 72 | 87 |
| 2005 | 65 | 127 |
| 2006 | 104 | 125 |
| 2007 | 115 | 156 |
| 2008 | 110 | 145 |
| 2009 | 105 | 144 |
| 2010 | 153 | 128 |
| 2011 | 137 | 131 |
| 2012 | 138 | 103 |
| 2013 | 122 | 127 |
| 2014 | 122 | 150 |
| 2015 | 151 | 144 |
| 2016 | 158 | 150 |
| 2017 | 185 | 162 |
| 2018 | 166 | 163 |
| 2019 | 176 | 154 |
| 2020 | 183 | 170 |
| 2021 | 135 | 128 |
| 2022 | 122 | 122 |
| 2023 | 116 | 118 |
| 2024 | 92 | 108 |
| 2025 | 82 | 89 |
| 2026 | 74 | 100 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Class-D audio amplifier29 Sep 2026US 12,750,017 B2Elite Semiconductor Microelectronics Technology Inc.
- Class d amplifier and related chip and electronic apparatus29 Sep 2026US 12,750,018 B2Shenzhen Goodix Technology Co., Ltd.
- Combined class D amplifier and buck regulator29 Sep 2026US 12,750,019 B2SiliconIntervention Inc.
- Transition smoothing apparatus for reducing spurious input to a system under feedback control29 Sep 2026US 12,750,063 B2Skyworks Solutions, Inc.
- De-icing systems22 Sep 2026US 12,741,745 B2De-Ice Technologies, Inc.
- High-frequency power supply device8 Oct 2026US 2026/0312541 A1Kyosan Electric Mfg. Co., Ltd.
- Multichannel drivers1 Oct 2026US 2026/0303078 A1Cirrus Logic International Semiconductor Ltd.
- Zero-common-mode modulation with digital feedback to damp common-mode resonance and suppress cross-over distortion24 Sep 2026US 2026/0291447 A1Monolithic Power Systems, Inc.
- Modulator circuits24 Sep 2026US 2026/0291451 A1Cirrus Logic International Semiconductor Ltd.
- Switching amplifiers24 Sep 2026US 2026/0291452 A1Cirrus Logic International Semiconductor Ltd.
Most cited
By later US patents
- Power waveform synthesis using bilateral devices243US 5,930,128 AEricsson Inc. · 1999
- Integrated tunable high efficiency power amplifier216US 6,232,841 B1Rockwell Science Center, Inc. · 2001
- High power battery powered RF amplifier topology200US 10,159,524 B2Ethicon, Inc. · 2018
- Hybrid switched mode/linear power amplifier power supply for use in polar transmitter179US 7,058,373 B2Nokia Corporation · 2006
- Amplitude modulation using digitally selected carrier amplifiers178US 4,580,111 AHarris Corporation · 1986