JC Bose patents radio wave detector, September 30, 1901
He developed the use of galena (lead sulfide) crystals contacted by a metal point for detecting millimeter electromagnetic waves, and filed patent 755840, for a "Detector for electrical disturbances" in 1901. It was the first device to use a semiconductor junction to detect radio waves.
Bose created a portable device to study the optical properties of short waves, which incorporated the earliest waveguide and horn antenna. It would be more than 30 years before more research and analysis was done with the now widely-used horn antennas. His use of dielectric lenses, polarizers, prisms, and semiconductors at frequencies as high as 60 GHz, were also well ahead of his time.
Source: Wikipedia user Gangulybiswarup
In a 1895 demonstration, he used electromagnetic waves to ignite gunpowder and ring a bell from a distance, reported to be nearly a mile. In 1897 Bose presented his microwave experiments at the Royal Institution in London (see the photo and diagram below).
He founded the Bose Institute in 1917 in Calcutta where some of his original instruments and devices are displayed. Bose spent much of his later career studying the effects of electromagnetic radiation on plants.
Much of Bose's component technology would eventually be used to develop microwave radio transmission. For his pioneering work in quasi-optic millimeter wave research, IEEE has called him the father of radio science. According to a 1997 Microwave Symposium Digest publication, "He developed an elegant millimeter wave spark transmitter, self recovering coherer detector, wire grid polarizer, cylindrical diffraction grating, dielectric lens and prism, rectangular waveguide, horn antenna and microwave absorber, for the studies of reflection, refraction, absorption and polarization of millimeter waves and its application to wireless remote control for firing a gun."
- The work of Jagadis Chandra Bose: 100 years of mm-wave research
- Semiconductor Rectifiers Patented as "Cat's Whisker" Detectors, Computer History Museum
- Popov demonstrates radio receiver, May 7, 1895
- Tesla gives 1st public demonstration of radio, March 1, 1893
- Teardown: Maxwell's equations
For more moments in tech history, see this blog. EDN strives to be historically accurate with these postings. Should you see an error, please notify us.
Editor's note: This article was originally posted on September 30, 2013 and edited on September 30, 2016.