HISTORICAL PERSPECTIVES ON MICROWAVE AND
MILLIMETER-WAVE INTEGRATED CIRCUITS
Arthur A. Oliner
Department of Electrical Engineering
Polytechnic University
Brooklyn , NY 11201
INTRODUCTION
The principal highlights in the early history of electromagnetic guided waves are
reviewed first, in order to show when and why hollow pipes were proposed and built as
guiding structures for microwaves. The paper then develops the transition from that
elemental form to rnodern-day microwave and millimeter-wave integrated circuits, including
the competition between strip line and microstrip line, by combining the underlying physical
principles with historical developments and anecdotes . The paper concludes by propo sing
that the development of microwave integrated circuits be viewed in terms of three stages ,
corresponding simultaneously to time periods and to the types of solutions required to
characterize the circuit performance.
I. MAJOR DEVELOPMENTS LEADING TO THE USE OF HOLLOW PIPES
AS WAVEGUIDES
A. The Early History (Before About 1910)
Although many individuals made important contributions to the early developments in
electromagnetic waves, we select here only four outstanding individuals and their particular
contributions to indicate the major steps in these developments. These four individuals are
Maxwell, whose theory showed that electromagnetic waves were possible, Hertz , who
verified Maxwell's theory experimentally, Rayleigh, who was the first to derive the
properties of waveguides , and Marconi, whose successful demonstration that lowfrequency waves could be propagated over long distances was a major element in
postponing any further interest in microwaves for over two decades.
1. James Clerk Maxwell: Before Maxwell developed his well-known theory , much
was already known about electromagnetics, from contributions made by many people with
famous names like Ampere and Faraday. Maxwell's elegant and beautiful theory, which he
Directions [or the Next Gene ration of MM1C Devices and Systems
Edited by N. K. Das and H. L. Bertoni, Plenum Press, New York, 1997
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perfected over a long period of time around 1860 or so, tied all these separate bits of
understanding into a unified whole, but he also introduced a new concept, the displacement
current, to make electricity and magnetism more symmetrical. With this added term, his
equations showed that electromagnetic waves were possible. When he solved for the
velocity of these waves and then compared them with the measured velocity of light, he
found excellent agreement.
His theory indeed demonstrated that light was an electromagnetic wave, but the more
general, and more important, implication was that it should be possible to produce
electromagnetic waves at any frequency. At that time, however, his theory was not weIl
understood, and many of his contemporaries were skeptical. On the other hand, it was clear
that his results would be very important, if true. Some German leamed societies offered
prizes to anyone who could prove Maxwell's theory experimentally, but there were no
takers because there were no sources or detectors; they had to be invented. It was not until
about 20 years later, some 10 years after Maxwell died, that the theory was experimentally
proved.
The famous physicist, Richard P. Feynman, has stated the truly great importance of
Maxwell's contribution in this way [I]: "From a long view of the history of
mankind...there can be litde doubt that the most significant event of the 19th Century will be
judged as Maxwell's discovery of the laws of electromagnetics."
2. Heinrich Hertz: The experimental verification of Maxwell's theory was
performed by Heinrich Hertz in aseries of brilliant experiments that he began in 1886.
Hertz created a spark generator with aresonant circuit attached, devised detectors, invented
the dipole antenna, built parabolic-cylinder reflectors, showed that waves could be
propagated in air and also along wires, and produced standing waves. He also did original
theoretical work . His contributions are described in detail in a relatively recent short book
[2].
Unfortunately, he died from an illness at an early age (36 years); he would undoubtedly
have contributed much more had he lived Ionger. His experiments not only verified
Maxwell's theory very clearly, but he showed that electromagnetic waves could be excited at
various frequencies . In his own experiments he produced electromagnetic waves with
wavelengths of 6 meters, 3 meters and 60 centimeters. After his landmark experiments, the
field of electromagnetic-wave engineering moved rapidly in various directions, and in
various countries.
For his important fundamental contributions, the unit of frequency, the Hertz , has been
appropriately named after hirn. In addition, the IEEE has established the Hertz Medal as one
of its major awards. Since this symposium is sponsored by the Polytechnic University, it is
appropriate to mention that a Polytechnic University professor, Nathan Marcuvitz, was the
first recipient of that award.
3. John William Strutt, Lord Rayleigh: Rayleigh, who succeeded Maxwell as
Cavendish Professor at Cambridge, was a prolific contributor to all sorts of topics in
classical physics. He seems to have been the first in nearly everything, including the
resolving power of gratings, an explanation of why the sky is blue, a host of new results on
the theory of sound, and the discovery of argon, for which he received the Nobel Prize .
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