Radio and Wireless
Patent and Invention Milestones
Ward, Dolbear, Edison, Lodge, Baviera, Stone, Bose, Shoemaker, Murgas, Hulsmeyer, Fleming
Collins,Pickard, De Forest, Stubblefield, Alexanderson, Armstrong, Koch, Tesla, Marconi

Home Projects Experiments Warning!
Year Inventor Description Patent No.
1872 William H. Ward This patent hasn't any practical or scientific meaning. An electrical layer in the atmosphere that could carry signals like a telegraph wire between grounded towers that must be in constant contact with this layer that surrounds the earth (similar to Mahlon Loomis patent No. 129971). US126356
1886 Amos Emerson Dolbear This device relied on conduction in the ground. Phones were grounded by metal rods poked into the earth. Transmission range was half a mile. The Dolbear patent prevented the Marconi Company from operating in the United States primarily because it was similar to the 1896 model of Guglielmo Marconi. In the end, Marconi had to purchase Dolbear's patent. US350299
1886 Thomas Alva Edison An electromagnetic induction system Edison called "grasshopper telegraphy", which allowed telegraphic signals to jump the short distance between a running train and telegraph wires running parallel to the tracks. This system was successful technically but not economically, as there turned out to be little interest by train travelers in an on-board telegraph service. US465971
1890 Nikola Tesla An alternator that produced radio high-frequency current of around 10,000 hertz. Tesla suppressed the disagreeable sound of power-frequency harmonics produced by arc lamps operating on frequencies within the range of human hearing. The produced pulsations were in the longwave broadcasting range (LF) and very low frequency band (VLF). US447920
1891 Nikola Tesla A high-frequency coupled oscillator circuit with an air-cored transformer (early disruptive "Tesla" coil) which converts low-frequency currents into "current of very high frequency and very high potential", which then supplies single-terminal lamps. US454622
1896 Guglielmo Marconi This Marconi patent is the first description in print of a wireless telegraphy device. A primitive spark gap transmitter and receiving station with no tuning at all, would operate only over very short distances. The transmitter used a Ruhmkorff coil, Morse key, rotary spark gap; receivers used a coherer detector. It used various earlier techniques and instruments of various other experimenters, primarily Tesla and also Popov. Later claimed by Oliver Lodge to contain his own ideas which he failed to patent. Invalidated by the Court of Claims decision from 1935. (US586193; RE11913). GB12039
1897 Nikola Tesla An early Tesla coil, developed currents of high potential and was composed of a primary and secondary coil where the secondary being inside of, and surrounded by, the convolutions of the primary coil. The apparatus was also connected to ground when the coil was in use. US593138
1897 Nikola Tesla An early Tesla transmitter consisting of a flat-spiral quarter-wave resonator and an elevated terminal. It was upheld in the 1943 Supreme Court decision. US645576
1897 Nikola Tesla Fundamental means for transmitting and receiving radio waves and energy. Build from a signal generator, primary and secondary coils at the transmitting and receiving stations. US649621
1898 Oliver Joseph Lodge By the making of the antenna coil or inductance variable, Lodge introduced the important concept of tuning in order to select a desired station (the "syntonic" tuning concept). In 1912 Lodge sold the patent to Marconi, and it was upheld in the 1943 Supreme Court decision. US609154
1898 Nikola Tesla Wireless remote control of boats. Employed the first logic gate and rotating coherers, allowed secure communication between transmitter and receiver. US613809
1899 Julio Cervera Baviera Basic wireless system. Some see him as the true inventor of radio. GB20084
1900 Guglielmo Marconi A four-circuit design, which featured two tuned-circuits at both the transmitting and receiving antennas in order to prevent the restriction of the number of spark-gap radio transmitters which could operate simultaneously in a geographical area without causing mutually disruptive interference. Found to be invalid in the 1943 Supreme Court decision. (US patent No. 763,772). GB7777
1900 John Stone Stone An adjustable tuneable antenna circuit design (LC) for removing parasitic oscillations in the transmitter. Upheld in the 1943 Supreme Court decision against Marconi's patent 763772. US714756
1901 Guglielmo Marconi This system was more advanced than Marconi's previous works by enabling tuning capabilities by the inclusion in the aerial circuits, at both the transmission and receiving stations, variable induction coils. US676332
1901 Jagadis Chunder Bose Coherer detector and the earliest photovoltaic cell. The first patent awarded for a semiconductor device even if “semiconductor” wasn’t termed yet. Basically a pair of point contacts of galena connected in series with a voltage source. US755840
1902 Harry Shoemaker Wireless remote control of boats and other moving objects US711743
1902 Harry Shoemaker A wireless telegraph repeater which object is to make it possible to signal between stations more widely separated that before by inserting between such stations a repeating station which receives radiant energy from the transmitting station, and providing means for entirely insulating the wave responsive device at the repeating station before the transmitted energy is produced. US718535
1903 Joseph Murgas Telegraph tone system which diminished the time needed to deliver a signal - the use of two signals of different frequencies for the "dot" and the "comma" of the Morse code. US759826
1903 John Stone Stone Transmission of signals by electromagnetic waves from an elevated conductor (antenna). US767973
1903 Harry Shoemaker To reduce false signals received by employing a few distinct receiving devices working in parallel. US824676
1904 Christian Hulsmeyer Wireless remote control system that prevents disturbances from other electromagnetic resources. US810150
1905 John Ambrose Fleming Rectifying vacuum tube diode (GB24,805). US803684
1905 Archie Frederick Collins A system of wireless telephony using an electric arc light that enables high voltage and amperage without to damage the transmitter. US814942
1906 Greenleaf Whittier Pickard A silicon crystal point-contact radio detector - a fine pointed wire (cat's whisker) in delicate contact with the silicon crystal. US836531
1907 Lee De Forest Vacuum tube (valve) triode. US879532
1907 Nathan B. Stubblefield Means for electrically transmitting signals for securing telephonic communication between moving vehicles and way stations. US887357
1909 Ernst F. W. Alexanderson The Alexanderson mechanical alternator: a high-frequency generator, up to 100 kHz, for longwave transmissions, which made modulated (voice) radio broadcasts practical. US1008577
1913 Edwin H. Armstrong The regenerative circuit. US1113149
1913 Ernst F. W. Alexanderson Tunning and frequency selection by a push-pull configuration. US1173079
1919 Edwin H. Armstrong Superheterodyne receiver US1342885
1930 Edwin H. Armstrong Frequency Modulation (FM) receiver. US1941066
1955 Richard C. Koch Transistor Radio US2892931

Scientists & Inventors
Ampère André-Marie
Baird John
Bell Alexander
Carver George
Cavendish Henry
Darwin Charles
Eastman George
Edison Thomas 1
Edison Thomas 2
Einstein Albert
Electric Motor
Faraday Michael
Fitzroy Robert
Foucault Léon
Franklin Benjamin
Fuel Cell
Galileo Galilei 1
Galileo Galilei 2
Gutenberg Johannes
Hertz Heinrich
Joule, James Prescott
Leonardo da Vinci
Leeuwenhoek Antonie
Marconi Guglielmo
Mendel Gregor
Miller-Urey Experiment
Millikan Robert
Morse Samuel
Newton Isaac
Ohm Georg
Pavlov & Skinner
Pitch Drop Experiment
Radio Inventions
Spectrum of Light
Tesla Nikola
Torricelli Evangelista
Tycho Brahe
Volta Alessandro
Whitney Eli
Wright Brothers
Young Thomas
Zuse Konrad
Ampère André-Marie

Home Fair Projects Experiments
Scientists & Inventors Science Jokes Warning!

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Last updated: February 2018
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