Lecture
The course in circuit engineering continues and builds upon the academic discipline
“Technical Electronics.” The task of circuit engineering is to create instruments
and equipment for converting electromagnetic energy, and for transmitting,
processing, and storing information. Thanks to advances in circuit engineering,
industry produces radio-electronic equipment (REE) for communications,
automation, television, radar, navigation, computing technology,
process control systems, lighting engineering, infrared technology, X-ray technology, etc.
The entire period of development of circuit engineering can be divided into four
successive generations:
– circuit engineering based on electron tubes;
– circuit engineering based on semiconductor devices;
– circuit engineering based on integrated circuits;
– circuit engineering based on functional blocks.
The first generation of communications circuit engineering begins in 1896, i.e., from
the time the Russian scientist A.S. Popov invented the radio. In connection with this,
the task of detecting high-frequency oscillations arose. For this purpose
the English scientist J.A. Fleming proposed using the phenomenon of
thermionic emission, which was discovered in 1884 by the American scientist
T.A. Edison. On this basis, in 1906 J.A. Fleming invented the first electronic
device with one-way conductivity – a two-electrode tube with
a hot cathode (diode). To increase the power of the diode, in 1905 A. Hull in the USA
invented the gas-filled diode (gas tube rectifier).
At the same time the task of amplifying oscillations arose, without which a radio receiver could not be realized. For this purpose, in 1907 the American engineer Lee de Forest
introduced a third electrode – a control grid – into the diode between the cathode and anode,
thereby creating an amplifying three-electrode tube – the triode. Amplifiers
based on this device became the most widespread among devices using
electron tubes, and the control grid for amplification remained forever
not only in the triode but also in other multi-electrode tubes.
In 1907, a professor at the St. Petersburg Institute of Technology,
B.L. Rosing, proposed using a cathode-ray tube to receive
images, thereby laying the foundation for television.
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The development of triode amplifier circuitry and the advance
of amplifiers into the higher-frequency range put forward new requirements for
the improvement of electron tubes.
To raise the upper frequency limit of amplification, in 1915 the German
physicist W. Schottky invented a four-electrode tube (tetrode) with a screen grid. Although amplifiers using tetrodes conquered higher frequencies, they did not
provide good amplification quality because of distortions caused by the so-called
dynatron effect. Therefore A. Hull in the USA began improving screened tubes and in 1930 proposed a five-electrode tube (pentode), amplifiers based on which became the most widespread.
Alongside the development of electronic amplifying technology, the task
of light reception arose. For this purpose, in 1930 L.A. Kubetsky in the USSR invented
the photoelectron multiplier (PMT). This device was for some time
the image receiver in television. At the same time, the development
of television required the creation not only of image-receiving technology but
also of transmitting technology. Therefore the real impetus for the development of television was
the proposal of O.P. Konstantinov and S.I. Kataev (USSR) for the creation
of special transmitting television tubes (iconoscopes). Similar
tubes were created in the USA by the Russian émigré V.K. Zworykin. In 1933 P.V. Shmakov
and P.V. Timofeev (USSR) proposed transmitting television tubes with
increased sensitivity – supericonoscopes, and in 1939 G.V. Braude
(USSR) put forward the idea of creating the superorthicon – an ultra-sensitive
transmitting television tube.
Alongside the development of low-frequency electronic technology, there began
mastery of ultra-high-frequency (UHF) circuit design. Thus in 1932 Soviet
scientist D.A. Rozhansky proposed dynamic control of the electron
beam in order to use the transit time of electrons between electrodes as a
useful phenomenon for raising the upper frequency limit. On the
basis of this proposal, A.N. Arsenyeva and O. Heil (USSR) created in 1939
devices for generating and amplifying UHF oscillations. In 1940,
V.F. Kovalenko (USSR) invented the reflex klystron – a UHF generator
that is still used today.
Despite the rapid development of vacuum tube technology, the search began for more
reliable, economical, durable and compact devices and equipment.
Thus in 1922, engineer A.V. Losev of the Nizhny Novgorod laboratory discovered the possibility of generating and amplifying electrical oscillations using a
crystal (semiconductor) detector. He also discovered the phenomenon of glow at a "metal-semiconductor" contact, i.e., A.V. Losev was the first to create a light-emitting diode. To great regret, A.V. Losev's work was not recognized in the USSR.
The birth of second-generation circuit design falls in 1948, when
American researchers J. Bardeen, W. Brattain and W. Shockley invented the
semiconductor triode (transistor). From that moment, the rapid
development of semiconductor circuit design began. Today semiconductor
circuit design has completely displaced vacuum tubes from receiving-amplifying equipment, information-measuring technology, devices
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for computing, etc. It became possible to implement complex
functions that were unavailable to vacuum-tube circuit design because of high
power consumption, bulkiness and low reliability.
However, even in second-generation circuit design, miniaturization, power consumption and reliability quickly reached the limits of their possibilities.
Let us illustrate this with an example.
Suppose it is necessary to create a compact electronic device that
contains 106
components with an average power consumption of 15 mW, average
mass of 0.5 g, average volume of 1 cm3 and a failure probability of 10-5 (hour)-1
.
The result would be as follows:
– the power dissipated inside the device would be 15 kW;
– the volume would reach 1 m
3
;
– the mass would be equal to 500 kg;
– the average failure rate would reach 10 (hour)-1, i.e. 10 times per hour.
As we can see, the device would turn out to be far from compact, with an unacceptable
dissipated power and, most importantly, inoperable, since
it fails every 12 minutes.
Given that modern electronic devices are many orders of magnitude
more complex, it becomes clear that they cannot be created by means of discrete
transistor technology.
The third generation of circuit design, which arose in the late 1950s
of the last century, aims to solve such problems using qualitatively new
methods that provide a reduction of several orders of magnitude
in size, power consumption, cost and failure rate. It was precisely such
elements that integrated circuits (ICs) became. Their manufacturing
technology makes it possible to create, within microscopic volumes of solid material,
electronic devices that contain a far greater number
of components (transistors, diodes, resistors, etc.). Then the electronic equipment designer
obtains an IC, which is a ready-made functional unit in the form of a
structurally complete electronic device, for example, an amplifier,
a pulse counter, an encoder, a decoder, or even a computer.
It is precisely thanks to the existence of ICs that we have, in particular, a modern
communications system, in which computer technology is not a "big adding machine" but a genuine technical tool.
The appearance of a micro-computer within an IC should also be singled out as
one of the generations, for circuit design based on a micro-computer provides fundamentally
new possibilities unknown before. For example, amplification can
can be accomplished by multiplying the digital copy of the signal by a constant number, but
unlike an amplifier, this does not introduce nonlinear, frequency, or
phase distortions, there is no risk of self-excitation at arbitrarily
high gain, no noise is introduced, and so on.
The development of circuit design based on microcomputers and computers in general has not
yet exhausted itself and remains a rewarding task.
The fourth generation consists of functional microcircuits, devices
and assemblies in which it is difficult or impossible to distinguish traditional components
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(transistors, diodes, resistors, capacitors, etc.). Here,
the integration of various volumetric and surface phenomena is carried out. The consequence
may be overcoming the complexity barrier. This generation is at
an embryonic stage of development and has not yet gone beyond the laboratory.
Today the fifth generation is approaching, associated with the creation
of quantum computing devices. Reports have appeared in the periodical press about
the creation of the first quantum computing device prototypes,
whose speed is increasing by several orders of magnitude
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