Page 339 - Electrical Engineering Dictionary

group. Parameters such as device character- nonlinearities within the device or circuit act-
istics, quiescent bias point, RF load line, sig- ing on the fundamental frequency.
nificant harmonic and/or mixing frequencies,
and amplitude and waveform of the applied harmonic converter found in a mi-
signal(s) should be included with the class crowave receiver, this component uses the
definition, thus defining the major contribu- technique of harmonic mixing to convert the
tors to the physical actions taking place in RF signal to a lower IF frequency for fur-
one of these amplifiers. ther processing. Harmonic converters can be
used as part of a vector network analyzer.
harmonic analysis the branch of math-
harmonic distortion caused by the non-
ematics dealing with the decomposition of
linear transfer characteristics of a device or
signal functions as a linear combination of
circuit. When a sinusoidal signal of a single
basis functions which represent “waves” of
frequency (the fundamental frequency) is ap-
various frequencies. When the basis func-
plied at the input of a nonlinear circuit, the
tions are sines and cosines each with a fre-
output contains frequency components that
quency that is an integer multiple of the
are integer multiples of the fundamental fre-
signal’s frequency, we have trigonometric
quency (harmonics). The resulting distortion
harmonic analysis, in other words classical
is called harmonic distortion.
Fourier analysis, which provides the ampli-
tudes and phases of the constituent sinusoids.
harmonic frequency integral multiples
( See Fourier transform. ) With other basis
of fundamental frequency. For example, for
functions, for example wavelets, we have
a 60-Hz supply, the harmonic frequencies are
non-trigonometric harmonic analysis ( See
120, 180, 240, 300, ....
wavelet, wavelet transform). Abstract har-
monic analysis studies the generalization of
harmonic generation in nonlinear op-
Fourier analysis to abstract spaces.
tics, the process in which a laser beam in-
teracts with a material system to produce
harmonic balance technique one of sev- new frequency components at integer multi-
eral techniques for analyzing nonlinear cir- ples of the frequency of the incident beam.
cuits. The nonlinear circuit is divided into Under carefully controlled circumstances,
two portions of linear and nonlinear ele- the lower-order harmonics (e.g., second and
ments, and a portion of linear elements is cal- third)canbegeneratedwithhigh(> 50%)ef-
culated in a frequency domain and a portion ficiency. Under different circumstances, har-
of nonlinear elements is calculated in a time monics as high as the 30th can be generated.
domain, respectively. The calculated volt-
ages or currents at connecting nodes of these harmonic load-pull measurement a
portions are balanced by using Fourier trans- measurement method where transfer char-
forming or inverse Fourier transforming. acteristics of a device at the fundamental
frequency can be measured by electrically
harmonic component a Fourier compo- changing the load impedance at harmonic
nent of order greater than one of a periodic frequencies.
waveform.
harmonic orthogonal set the set of func-
tions e jωt . It is called harmonic because
harmonic content the internally gener-
each basis function is a harmonic of a cer-
ated, harmonically related spectral output
tain frequency and because the inner product
from a device or circuit. Harmonic energy
between any two functions is zero:
is that energy that is at exact multiples of
R +∞ jω 1 t jω 2 t
the fundamental frequency, generated by the e e dt = 0,ω 1 6= ω 2
−∞
c
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