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IPC Subgroup
H04B 3/02

Details

Introduced: September 1968

Last revised: January 2006

Full Title

Line transmission systems > Details

Classification Context

Section:
ELECTRICITY
Class:
ELECTRIC COMMUNICATION TECHNIQUE
Subclass:
TRANSMISSION

12 direct subcodes

Child Classifications

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  • H04B 3/03 Hybrid circuits
  • H04B 3/26 Improving frequency characteristic by the use of loading coils
  • H04B 3/28 Reducing interference caused by currents induced in cable sheathing or armouring
  • H04B 3/3 Reducing interference caused by unbalanced currents in a normally balanced line
  • H04B 3/4 Artificial lines; Networks simulating a line of certain length
  • H04B 3/42 Circuits for by-passing of ringing signals
  • H04B 3/44 Arrangements for feeding power to a repeater along the transmission line

Top Applicants

Top 10 applicants by patent filingsfor class H04, 2013–2023, worldwide · Source: EPO PATSTAT

  1. QUALCOMM US 97,396
  2. HUAWEI TECHNOLOGIES COMPANY CN 96,502
  3. SAMSUNG ELECTRONICS COMPANY KR 86,981
  4. TELEFONAKTIEBOLAGET LM ERICSSON (PUBL) SE 55,869
  5. HUAWEI TECHNOLOGIES COMPANY 55,349
  6. LG ELECTRONICS KR 53,649
  7. CANON 33,341
  8. SONY CORPORATION JP 32,761
  9. ZTE CORPORATION CN 32,274
  10. GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORPORATION 28,327