IPC Subgroup
H03B 5/22 active element in amplifier being vacuum tube
Introduced: September 1968
Last revised: January 2006
Full Title
Generation of oscillations using amplifier with regenerative feedback from output to input > with frequency-determining element comprising resistance and either capacitance or inductance, e.g. phase-shift oscillator > active element in amplifier being vacuum tube
Classification Context
- Section:
- ELECTRICITY
- Class:
- ELECTRONIC CIRCUITRY
- Subclass:
- GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
Additional Content
Frequency-determining elements being part of bridge circuit in closed loop around which signal is transmitted; frequency-determining elements being connected via a bridge circuit to such a closed loop
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