Also known as: Jagadish Chandra Bose, J. C. Bose, Jagadish Bose, Acharya Bose

Jagadish Chandra Bose (1858–1937) was an Indian physicist and polymath who demonstrated millimetre-wave radio transmission in the 1890s and built one of the first semiconductor crystal detectors for receiving radio waves.¹ Working at very short wavelengths that mainstream wireless would not revisit for decades, he anticipated modern microwave engineering and solid-state detection.

Bose generated and detected radio waves only millimetres long, using a horn to direct the beam and a semiconductor crystal to rectify it.

Life and work

Bose was educated in Calcutta and at the University of Cambridge, then became a professor at Presidency College in Calcutta. In an 1895 public demonstration — around the same time as Guglielmo Marconi’s early work — he used radio waves to ring a bell and set off a small explosion in an adjacent room, showing the waves passing through walls. Uniquely, Bose worked at wavelengths as short as about 5 millimetres, deep into what we now call the microwave and millimetre-wave part of the electromagnetic spectrum, extending the earlier laboratory work of Heinrich Hertz.¹

Later in life Bose turned to biophysics, building extremely sensitive instruments to measure the responses of plants to stimuli, and he was a founder of modern experimental science in India.

Contribution

Two of Bose’s radio contributions stand out:

• Millimetre-wave apparatus. He devised horn antennas, waveguides, polarizers, and dielectric lenses to generate, focus, and analyze very short waves — components that are recognizably the ancestors of today’s microwave hardware.
• The crystal detector. Bose experimented with the point-contact coherer and, crucially, with galena (lead sulphide) and other crystals whose junctions rectify radio-frequency energy. This is an early semiconductor device, foreshadowing the crystal-set detectors that dominated early broadcast reception and, ultimately, the diode.

Bose largely declined to patent his inventions, publishing openly instead, which is one reason his priority in these areas was long underappreciated in the West.

Legacy

Bose’s insistence on the millimetre-wave regime looks prophetic: the same band now carries 5G NR, automotive radar, and satellite links. His crystal detector prefigured semiconductor rectification, the basis of all later diode and transistor technology. In 1998 the IEEE recognized him among the pioneers of radio science, and a lunar crater and a research institute bear his name.

Sources

1. Jagadish Chandra Bose — Wikipedia, for his biography, the millimetre-wave demonstrations, and the crystal detector. ↩ ↩²

See also

• Radio wave
• Heinrich Hertz
• Guglielmo Marconi
• Electromagnetic spectrum
• Semiconductor