H03F 1/22 by use of cascode coupling, i.e. earthed cathode or emitter stage followed by earthed grid or base stage respectively
Introduced: September 1968
Full Title
Full titles differ between systems:
Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements > Modifications of amplifiers to reduce detrimental influences of internal impedances of amplifying elements > by use of cascode coupling, i.e. earthed cathode or emitter stage followed by earthed grid or base stage respectively
Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements > Modifications of amplifiers to reduce detrimental influences of internal impedances of amplifying elements (wide-band amplifiers with inter-stage coupling networks incorporating these impedances H03F1/42) > by use of cascode coupling, i.e. earthed cathode or emitter stage followed by earthed grid or base stage respectively
CPC subdivides this area 3x more granularly than IPC with 2 additional codes.
2 codes are CPC-only extensions.
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