IPC Subgroup
H03F 3/38 DC amplifiers with modulator at input and demodulator at output; Modulators or demodulators specially adapted for use in such amplifiers
Introduced: September 1968
Last revised: January 2006
Full Title
Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements > DC amplifiers with modulator at input and demodulator at output; Modulators or demodulators specially adapted for use in such amplifiers
Classification Context
- Section:
- ELECTRICITY
- Class:
- ELECTRONIC CIRCUITRY
- Subclass:
- AMPLIFIERS
Related Keywords
CHOPPER(S) in D. C. amplifiers
2 direct subcodes
Child Classifications
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- H03F 3/387 with semiconductor devices only
- H03F 3/4 with tubes only
Top Applicants
Top 10 applicants by patent filingsfor class H03, 2013–2023, worldwide · Source: EPO PATSTAT
- QUALCOMM US 5,625
- SAMSUNG ELECTRONICS COMPANY KR 5,496
- MURATA MANUFACTURING COMPANY JP 5,478
- HUAWEI TECHNOLOGIES COMPANY CN 3,383
- INTEL CORPORATION US 3,091
- TEXAS INSTRUMENTS US 3,070
- MURATA MANUFACTURING COMPANY 2,722
- SKYWORKS SOLUTIONS US 2,290
- SEIKO EPSON CORPORATION 2,177
- IBM (INTERNATIONAL BUSINESS MACHINES CORPORATION) US 2,158