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Electrical Engineering Dictionary - part 4

Denise M. Wolf
Lawrence Berkeley National Laboratory
Berkeley, CA

E. Yaz
University of Arkansas
Fayetteville, Arkansas

Pochi Yeh
University of California
Santa Barbara, CA

Jeffrey Young
University of Idaho
Moscow, ID

Stanislaw H. Zak
Purdue University
West Lafayette, IN

Qing Zhao
University of Western Ontario
London, Ontario, Canada

Jizhong Zhu
National University of Singapore
Singapore

Omar Zia
Marietta, GA

Special

Symbols

α-level set

a crisp set of elements belong-

ing to a fuzzy set

A at least to a degree α

= {x ∈ X | µ

(x) ≥ α}

See also

crisp set

fuzzy set

common symbol for bandwidth, in

hertz.

rGaAs

common symbol for gallium ar-

senide relative dielectric constant.

rGaAs

.8.

rSi

common symbol for silicon relative

dielectric constant.

rSi

= 11.8.

symbol for permitivity of free space.

= 8.849 × 10

−12

farad/meter.

common symbol for relative dielectric

constant.

common symbol for DC to RF con-

version efficiency. Expressed as a percent-
age.

common symbol for power added ef-

ficiency. Expressed as a percentage.

common symbol for total or true effi-

ciency. Expressed as a percentage.

opt

common symbol for source reflec-

tion coefficient for optimum noise perfor-
mance.

common symbol for permeability of

free space constant.

= 1.257 × 10

−16

henrys/meter.

common symbol for relative perme-

ability.

common symbol for radian frequency

in radians/second.

ω = 2 · π · frequency.

common symbol for positive transition

angle in degrees.

−

common symbol for negative transi-

tion angle in degrees.

cond

common symbol for conduction an-

gle in degrees.

sat

common symbol for saturation angle

in degrees.

common symbol for FET channel-

to-case thermal resistance in

◦

C/watt.

J C

common symbol for bipolar junction-

to-case thermal resistance in

◦

C/watt.

∗

common symbol for Richardson’s

constant.

∗

= 8.7 amperes · cm/

◦

See

gate-to-drain breakdown

voltage

See

gate-to-source breakdown

voltage

dv/dt

rate of change of voltage with-

stand capability without spurious turn-on of
the device.

See

intrinsic coercive force

common symbol for excess noise in

watts.

common symbol for shot noise in

watts.

2000 by CRC Press LLC

common symbol for thermal noise in

watts.

10base2

a type of coaxial cable used to

connect nodes on an Ethernet network. The
10 refers to the transfer rate used on standard
Ethernet, 10 megabits per second. The base
means that the network uses baseband com-
munication rather than broadband communi-
cations, and the 2 stands for the maximum
length of cable segment, 185 meters (almost
200). This type of cable is also called “thin”
Ethernet, because it is a smaller diameter ca-
ble than the 10base5 cables.

10base5

a type of coaxial cable used to

connect nodes on an Ethernet network. The
10 refers to the transfer rate used on stan-
dard Ethernet, 10 megabits per second. The
base means that the network uses baseband
communication rather than broadband com-
munications, and the 5 stands for the max-
imum length of cable segment of approxi-
mately 500 meters. This type of cable is also
called “thick” Ethernet, because it is a larger
diameter cable than the 10base2 cables.

10baseT

a type of coaxial cable used to

2-D Attasi model

a 2-D model described

by the equations

i+1,j+1

= −A

i,j

+ A

i+1,j

+ A

i,j+1

+ Bu

= Cx

+ Du

i, j ∈ Z

(the set of nonnegative integers).

Here

∈ R

is the local state vector,

∈ R

is the input vector,

∈ R

the output vector, and

B, C, D are

real matrices. The model was introduced by
Attasi in “Systemes lineaires homogenes a

deux indices,” IRIA Rapport Laboria, No.
31, Sept. 1973.

2-D Fornasini–Marchesini model

a 2-D

model described by the equations

i+1,j+1

= A

i,j

+ A

i+1,j

+ A

i,j+1

+ Bu

(1a)

= Cx

+ Du

(1b)

i, j ∈ Z

(the set of nonnegative integers)

here

∈ R

is the local state vector,

∈ R

is the input vector,

∈ R

the output vector

(k = 0, 1, 2), B, C, D

are real matrices. A 2-D model described by
the equations

i+1,j+1

= A

i+1,j

+ A

i,j+1

+ B

i+1,j

+ B

i,j+1

(2)

i, j ∈ Z

and (1b) is called the second 2-D

Fornasini–Marchesini model, where

and

are defined in the same way as for (1),

(k = 0, 1, 2) are real matrices. The

model (1) is a particular case of (2).

2-D general model

a 2-D model de-

scribed by the equations

i+1,j+1

= A

i,j

+ A

i+1,j

+ A

i,j+1

+ B

i+1,j

+ B

i,j+1

= Cx

+ Du

i, j ∈ Z

(the set of nonnegative integers)

here

∈ R

is the local state vector,

∈

is the input vector,

∈ R

is the output

vector and

(k = 0, 1, 2), C, D are real

matrices. In particular case for

= B

= 0

we obtain the first 2-D Fornasini–Marchesini
model and for

= 0 and B

= 0 we obtain

the second 2-D Fornasini–Marchesini model.

2-D polynomial matrix equation

a 2-D

equation of the form

AX + BY = C

(1)

where

A ∈ R

k×p

[

s], B ∈ R

k×q

[

s], C ∈

k×m

[

s] are given, by a solution to (1) we

2000 by CRC Press LLC

mean any pair

X ∈ R

p×m

[

s], Y ∈ R

q×m

[

satisfying the equation.

The equation (1)

has a solution if and only if the matrices
[

A, B, C] and [A, B, 0] are column equiva-

lent or the greatest common left divisor of

and

B is a left divisor of C. The 2-D equation

AX + Y B = C

(2)

A ∈ R

k×p

[

s], B ∈ R

q×m

[

s], C ∈ R

k×m

[

are given, is called the bilateral 2-D polyno-
mial matrix equation. By a solution to (2) we
mean any pair

X ∈ R

p×m

[

s], Y ∈ R

k×q

[

satisfying the equation. The equation has a
solution if and only if the matrices

A 0

and

A C

are equivalent.

2-D Roesser model

a 2-D model de-

scribed by the equations

i+1,j

i,j+1

i, j ∈ Z

(the set of nonnegative integers),

= C

+ Du

Here

∈ R

and

∈ R

are the hori-

zontal and vertical local state vectors, respec-
tively,

∈ R

is the input vector,

∈ R

is the output vector and

C, D are real matrices. The model was

introduced by R.P. Roesser in “A discrete
state-space model for linear image process-
ing,” IEEE Trans. Autom. Contr., AC-20,
No. 1, 1975, pp. 1-10.

2-D shuffle algorithm

an extension of the

Luenberger shuffle algorithm for 1-D case.
The 2-D shuffle algorithm can be used for
checking the regularity condition

det [

− A

]

6= 0

for some

, z

) ∈ C×C of the singular gen-

eral model ( See

singular 2-D general model

The algorithm is based on the row compres-
sion of suitable matrices.

2-D Z-transform

F (z

, z

) of a dis-

crete 2-D function

satisfying the condi-

tion

= 0 for i < 0 or/and j < 0 is

defined by

F (z

, z

) =

∞

i=0

∞

j=0

−i

−j
2

An 2-D discrete

has the 2-D Z-transform

if the sum

∞

i=0

∞

j=0

−i

−j
2

exists.

2DEGFET

See

high electron mobility

transistor

(HEMT).

2LG

See

double phase ground fault

3-dB bandwidth

for a causal low-pass

or bandpass filter with a frequency function
H(jω) the frequency at which | H(jω) |

is less than 3 dB down from the peak value
| H (ω

) |.

3-level laser

a laser in which the most

important transitions involve only three en-
ergy states; usually refers to a laser in which
the lower level of the laser transition is sepa-
rated from the ground state by much less than
the thermal energy

kT. Contrast with

4-level

laser

3-level system

a quantum mechanical

system whose interaction with one or more
electromagnetic fields can be described by
considering primarily three energy levels.
For example, the cascade, vee, and lambda
systems are 3-level systems.

4-level laser

a laser in which the most

important transitions involve only four en-
ergy states; usually refers to a laser in which
the lower level of the laser transition is sep-
arated from the ground state by much more

2000 by CRC Press LLC

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