Inventor · Reigate, GB

Christopher B. Marshall

43Patents
13h-index
36Co-inventors
81Inventor score

Filing activity: Feb 4, 1982 → May 24, 2019

Most-cited inventions

PatentTitleAreaCited byStatus
US4768187A Signal transmission system and a transmitter and a receiver for use in the system Electricity 138 Expired
US4488119A FM Demodulator Electricity 90 Expired
US6618671B2 Method of determining the position of a mobile unit Physics 77 Expired
US7010267B2 Arrangement with beacon for providing information service Electricity 52 Expired
US4723318A Active polyphase filters Electricity 46 Expired
US4696055A RF tuning circuit which provides image frequency rejection Electricity 46 Expired
US4864643A Radio transmission system providing adjacent channel and image frequency rejection Electricity 32 Expired
US4523324A Direct modulation FM data receiver Electricity 32 Expired
US4713563A d.c. Block capacitor circuit for rejection of d.c. offset Electricity 26 Expired
US5678199A Transceiver with controlled transmit/receive impedance switching device Electricity 16 Expired
US5502744A Data coding system Electricity 16 Expired
US7183925B2 Interactive system using tags Physics 14 Expired
US4672636A AFC circuit for direct modulation FM data receivers Electricity 13 Expired
US5832374A Radio transceiver including transmitter power control circuit Electricity 11 Expired
US5852634A Data coding system Electricity 7 Expired
US4994994A Apparatus performing modulo p addition, where operands are expressed as powers of a generator, using a reduced size zech look-up table Physics 7 Expired
US8804551B2 Location estimation by observing wireless signals Electricity 6 Active
US5991607A Telecommunication device with switching arrangement constructed as a ring circuit Electricity 6 Expired
US5008849A Apparatus adding values represented as residues in modulo arithmetic Physics 5 Expired
US7103340B2 Antenna diversity arrangement Electricity 4 Expired
US7233282B2 GPS receiver with encrypted data transmission Physics 3 Expired
US7089112B2 Method of determining the position of a mobile unit Physics 3 Expired
US9681408B2 Determining clock-drift using signals of opportunity Physics 3 Active
US9035827B2 Positioning using a local wave-propagation model Physics 2 Active
US8779980B2 Position validation Physics 2 Active

Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.