H04B 3/20
Reducing echo effects or singing
Official title: Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other
H04B3/20 (Reducing echo effects or singing) appears on 1,794 US grants and 1,034 published applications in this corpus.
Search patents in H04B- Granted patents
- 1,794
- Published applications
- 1,034
- Assignees
- 544
- Inventors
- 2,486
- Latest grant
- 15 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 12 | 0 |
| 1977 | 19 | 0 |
| 1978 | 12 | 0 |
| 1979 | 10 | 0 |
| 1980 | 9 | 0 |
| 1981 | 8 | 0 |
| 1982 | 13 | 0 |
| 1983 | 9 | 0 |
| 1984 | 16 | 0 |
| 1985 | 17 | 0 |
| 1986 | 34 | 0 |
| 1987 | 24 | 0 |
| 1988 | 27 | 0 |
| 1989 | 33 | 0 |
| 1990 | 30 | 0 |
| 1991 | 22 | 0 |
| 1992 | 17 | 0 |
| 1993 | 14 | 0 |
| 1994 | 26 | 0 |
| 1995 | 34 | 0 |
| 1996 | 30 | 0 |
| 1997 | 32 | 0 |
| 1998 | 44 | 0 |
| 1999 | 35 | 0 |
| 2000 | 29 | 0 |
| 2001 | 43 | 23 |
| 2002 | 43 | 50 |
| 2003 | 55 | 73 |
| 2004 | 73 | 66 |
| 2005 | 65 | 53 |
| 2006 | 84 | 45 |
| 2007 | 50 | 50 |
| 2008 | 49 | 39 |
| 2009 | 42 | 49 |
| 2010 | 56 | 53 |
| 2011 | 38 | 41 |
| 2012 | 64 | 24 |
| 2013 | 60 | 49 |
| 2014 | 55 | 43 |
| 2015 | 55 | 52 |
| 2016 | 69 | 32 |
| 2017 | 48 | 34 |
| 2018 | 47 | 46 |
| 2019 | 51 | 46 |
| 2020 | 47 | 35 |
| 2021 | 31 | 33 |
| 2022 | 31 | 31 |
| 2023 | 29 | 22 |
| 2024 | 23 | 20 |
| 2025 | 21 | 18 |
| 2026 | 9 | 7 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Smart amplifier diagnostic systems and methods15 Sep 2026US 12,738,976 B2Avago Technologies International Sales Pte. Limited
- Transmission line diagnostics18 Aug 2026US 12,712,593 B2Analog Devices International Unlimited Company
- Full duplex DOCSIS amplifier with legacy upstream support14 Jul 2026US 12,683,754 B2ARRIS Enterprises LLC
- Robust foreground/background filtering control for acoustic echo cancellation30 Jun 2026US 12,671,767 B2Dolby Laboratories Licensing Corporation
- Double talk detection using capture up-sampling9 Jun 2026US 12,652,076 B2Dolby Laboratories Licensing Corporation
- Methods and apparatus for echo cancellation in transceivers1 Oct 2026US 2026/0303148 A1
- Full-Duplex Cable Modem Calibration17 Sep 2026US 2026/0280603 A1MaxLinear, Inc.
- Methods and apparatus to transmit a serial data stream30 Jul 2026US 2026/0222005 A1
- Internal reflection tuning and optimization for full duplex node and amplifier25 Jun 2026US 2026/0180620 A1ARRIS Enterprises LLC
- Systems and methods for covariance smoothing19 Mar 2026US 2026/0080881 A1Dolby Laboratories Licensing Corporation
Most cited
By later US patents
- Gateway with voice281US 6,765,931 B1Broadcom Corporation · 2004
- Method and system for crosstalk cancellation239US 7,050,388 B2Quellan, Inc. · 2006
- Method and apparatus for improved control and time sharing of an echo canceller210US 4,712,235 AInternational Business Machines Corporation · 1987
- Method and system for signal emulation200US 7,804,760 B2Quellan, Inc. · 2010
- Network echo canceller184US 5,307,405 AQUALCOMM Incorporated · 1994