DIFF Subgroup
H03F 3/387 with semiconductor devices only
Introduced: July 1974
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 > with semiconductor devices only
IPC and CPC are identically structured here. All 1 subcodes exist in both systems.
IPC defines codes here since 1974.
Child Classifications
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Top Applicants
Top Applicants (IPC)
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
Top Applicants (CPC)
Class H03,2013–2023, worldwide · Source: EPO PATSTAT
- SAMSUNG ELECTRONICS COMPANY KR 7,293
- QUALCOMM US 7,085
- MURATA MANUFACTURING COMPANY JP 5,982
- HUAWEI TECHNOLOGIES COMPANY CN 4,641
- INTEL CORPORATION US 3,863
- TEXAS INSTRUMENTS US 3,409
- MURATA MANUFACTURING COMPANY 2,874
- SK HYNIX KR 2,644
- SKYWORKS SOLUTIONS US 2,545
- IBM (INTERNATIONAL BUSINESS MACHINES CORPORATION) US 2,437