Complete history of microwave technology starting in 1873, including all influencial figures until the practical application in the 1940s of an application such as microwave ovens. First in six part series.

In 1873, James Clerk Maxwell laid the foundations of modern electomagnetic theory in his work, 'A Treatise on Electricity and Magnetism' in Scotland. In this treatise, Maxwell theorized that, if combined, electrical and magnetic energy would be able to travel through space in a wave. If Maxwell were here today, he would be pleased to see his four equations routinely solved many thousands of times per second by today's three-dimensional structural simulators using finite element analysis.

Several years later, German Heinrich Hertz conducted experiments that proved Maxwell's theories were correct. Hertz began testing these theories by using a high-voltage spark discharge (a source rich in high-frequency harmonics) to excite a half-wave dipole antenna. A receive antenna consisted of an adjustable loop of wire with another spark gap. When both transmit and receive antennas were adjusted for the same resonant frequency, Hertz was able to demonstrate propagation of electromagnetic waves.

In another experiment, Hertz used a coax line to show that electromagnetic waves propagated with a finite velocity, and he discovered basic transmission line effects such as the existence of nodes in a standing wave pattern a quarter wavelength from an open circuit and a half wavelength from a short circuit. He then went on to develop cylindrical parabolic reflectors for


directional antennas, as well as a number of other radio frequency (RF) and microwave devices and techniques.