CONTROL OF AMPLIFICATION

Description

H03G covers circuits and techniques for regulating the gain or output level of amplifiers in response to varying input signals or operating conditions. This includes automatic gain control (AGC), automatic level control (ALC), and amplitude limiting systems used in radio receivers, audio equipment, and communication devices. The classification encompasses both analog and digital control methods, feedback mechanisms, and devices that maintain relatively constant output despite input variations. Related dynamic range compression, noise gating, and signal normalization techniques fall within this scope, while the design of basic amplifier stages themselves are classified elsewhere (H03F).

Filing statistics

CPC subclass H03G recorded 16,166 patent applications worldwide between 2013 and 2023. Annual filings declined from 1,561 in 2013 to 1,051 in 2023 (-33%), peaking at 1,737 applications in 2014. The most active applicants in class H03 are SAMSUNG ELECTRONICS COMPANY (7,293 applications), QUALCOMM (7,085 applications) and MURATA MANUFACTURING COMPANY (5,982 applications).

Source: EPO PATSTAT, worldwide filings