H03F 1/28
In discharge-tube amplifiers
Official title: in discharge-tube amplifiers {(constructional modifications H01J23/11)}
H03F1/28 (In discharge-tube amplifiers) appears on 6 US grants and 3 published applications in this corpus.
Search patents in H03F- Granted patents
- 6
- Published applications
- 3
- Assignees
- 4
- Inventors
- 5
- Latest grant
- 21 Sep 2021
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1989 | 1 | 0 |
| 1990 | 0 | 0 |
| 1991 | 0 | 0 |
| 1992 | 0 | 0 |
| 1993 | 0 | 0 |
| 1994 | 0 | 0 |
| 1995 | 0 | 0 |
| 1996 | 0 | 0 |
| 1997 | 0 | 0 |
| 1998 | 0 | 0 |
| 1999 | 0 | 0 |
| 2000 | 0 | 0 |
| 2001 | 0 | 0 |
| 2002 | 0 | 0 |
| 2003 | 0 | 0 |
| 2004 | 0 | 0 |
| 2005 | 0 | 0 |
| 2006 | 0 | 0 |
| 2007 | 0 | 0 |
| 2008 | 0 | 0 |
| 2009 | 0 | 0 |
| 2010 | 0 | 0 |
| 2011 | 0 | 0 |
| 2012 | 0 | 0 |
| 2013 | 0 | 0 |
| 2014 | 0 | 0 |
| 2015 | 0 | 0 |
| 2016 | 0 | 0 |
| 2017 | 0 | 1 |
| 2018 | 2 | 0 |
| 2019 | 0 | 2 |
| 2020 | 1 | 0 |
| 2021 | 2 | 0 |
By publication year. Applications have been published since 2001.
Recent patents
- Low voltage tube circuits21 Sep 2021US 11,128,262 B2
- Vacuum tube amplification system capable of reducing residual noise and a grounding method thereof14 Sep 2021US 11,121,678 B1Echowell Electronic Co., Ltd.
- Vacuum tube rear device25 Aug 2020US 10,755,885 B2Echowell Electronic Co., Ltd.
- Grounding structure and grounding method of vacuum tube audio amplifier20 Nov 2018US 10,135,402 B1Echowell Electronics Co., Ltd.
- Noise cancellation in amplifier systems10 Jul 2018US 10,020,781 B2
Most cited
By later US patents
- Noise cancellation in amplifier systems1US 10,020,781 B22018
- Grounding structure and grounding method of vacuum tube audio amplifier1US 10,135,402 B1Echowell Electronics Co., Ltd. · 2018
- Low voltage tube circuits1US 11,128,262 B22021
- Noise reducer for microwave amplifier1US 4,837,522 AThomson-CSF · 1989