Page 227 - Radar Technology Encyclopedia

217 INDUCTANCE integrated circuit, digital

INDUCTANCE is “the property of an electric circuit by vir- In radar applications, information measures are used for
tue of which a varying current induces an electromotive force information description of a radar channel. IAM
in that circuit or in a neighboring circuit.” Essentially it is the Ref.: DiFranco (1968), Ch. 7; Kosenko (1982), pp. 30–33.
rate of increase in magnetic “linkage” with an increase in cur-
INTEGRATED CIRCUIT. An integrated circuit is a solid-
rent in an electric circuit such as a coil, where linkage is
state circuit that is “the combination of interconnecting circuit
defined as the product of the magnetic flux through the circuit
elements inseparably associated or within a continuous sub-
(coil) and the number of turns. The inductance of a coil is
strate.” Integrated circuits can be of hybrid and monolithic
given by
types (Table I1).
X
L = --------
2p f Table I1
where X is the reactance and f the frequency of the alternating Comparison of Microwave Integrated Circuits
current. PCH
Ref.: Van Nostrand (1983), p. 1,592. Hybrid Monolithic
Characteristics integrated integrated
INFORMATION MEASURE [METRIC]. An information circuits circuits
measure describes the amount of information, determining
the unit and method of measurement of information in the Possibility of replacement and Yes No
process of its receipt. This consists of “transformation” of tuning of components
some a priori distribution, P = {p , k=1, n}, describing Possibility of producing sig- Yes No
k
n
observed objects and their assumed properties in the empiri-
nificant output power
cal Q = {q , k = 1, n} after processing of the received data.
n
k
As the information measure we use the difference Possibility of creating built-in Yes Limited
nonreciprocal devices and
I = Hp ( ) Hq ( , 1 N
) k =
,
–
k k k microwave filters
where H(x) is entropy. Depending on the type of function
Reliability Lower Higher
describing entropy, one can use Shannon, Kulbak,
Kotel’nikov, Bayes, or Fisher measures. Yield High Lower
The Bayes measure corresponds to entropy of the type
Cost Lower Higher
H(x) = 1 - x, x Î (0,1)
The amount of Bayes information is determined by the Integrated circuits make possible the microminiaturiza-
expression tion of electronic equipment (increasing the density of com-
I = q - p .
k k k ponents per unit volume by a factor of 10 to 100),
The Fisher measure corresponds to entropy of the type improvement in speed by a significant factor, increase in reli-
2
H(x) = ln x, x Î (0,1). The quantity of Fisher information is ability, and reduction in power consumption. Such circuits are
determined by the expression widely used in radar signal processors, receivers, and lower
2
2
k = ln p - ln q . power portions of radar transmitters. IAM
k
k
The Kotel’nikov measure corresponds to entropy of the Ref.: IEEE (1993), p. 662; Frey (1985); Jordan (1985), Ch. 20; Hoffman
(1987); Gassanov (1988), p. 24; Nikolaev (1992), pp. 9, 273.
type H(P ) = 1 - max {p , ... , p }, and determined by the
n 1 n
expression A bipolar integrated circuit is based on bipolar transistors
I = max {q , ... , q } - max {p , ... , P }. of the NPN or PNP type. Such circuits have a speed that is an
1
n
n
1
order of magnitude higher than integrated circuits on an MOS
The Kulbak measure corresponds to entropy of the type
structure. By a criterion such as power-to-speed ratio, a bipo-
1 – x
Hx () log= ----------- , x Î ( 01 , ) lar integrated circuit also surpasses integrated MOS circuits.
x
Joint use of bipolar and MOS instruments in integrated cir-
The amount of Kulbak information is determined by the for- cuits makes it possible to improve the characteristics of the
mula devices made on their basis. IAM
q k 1 – p k Ref.: Popov (1980), p 51; Fink (1982), p. 820; Nikolaev (1992), p. 10.
I = log ----- – log --------------
k p 1 – q
k k A digital integrated circuit is used in digital signal and data
The Shannon measure corresponds to entropy of the type processing. The quality of digital integrated circuits is evalu-
H(x) = log (1/x), x Î (0,1) ated by speed and the specific delay time of signal propaga-
tion, which is no more than 2.5 ns/logic component. In terms
The amount of Shannon information is determined by the
of technology of production, digital integrated circuits are
expression
usually classed as semiconductor integrated circuits.
I = log (q /p ).
k
k k
Digital integrated circuits are widely used in computer
If the logarithm base 2 is used, then the amount of Shannon
systems with microprogram control and high productivity
information is measured in bits.