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Topic: Frequency deviation

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	Amateur Radio application of Frequency Modulation
		Frequency Modulation (FM) is a system where the amplitude of a carrier wave is held constant while the frequency is varied in sympathy with the voltage of the modulating signal.
		Frequency is the Angular Velocity divided by 2 * pi.
		In a strict sense, an FM signal is one where the frequency deviation resulting from a constant amplitude modulating signal is the same for all modulating frequencies, whereas a PM signal is one where the frequency deviation resulting from a constant amplitude modulating signal is proportional to the modulating frequency.
	www.vk1od.net /FM/FM.htm (3127 words)

	Digital Music online course - Basic Frequency Modulation Synthesis Technique
		Sound engineers tend to refer to the carrier frequency as the fundamental frequency, but musicians often avoid this nomenclature because in music the term "fundamental frequency" is normally associated with pitch and in FM the carrier frequency does not always determine the pitch of the sound.
		The frequency ratio is a useful tool for the implementation of a phenomenon that is very common among conventional instruments, that is, achieving variations in pitch whilst maintaining the timbre virtually unchanged.
		If the frequency ratio and the modulation index of a simple FM instrument are maintained constant but the offset carrier frequency is modified then the sounds will vary in pitch, but their timbre will remain unchanged.
	x.i-dat.org /~csem/UNESCO/5/index.html (1349 words)

	Frequency Assessment
		The under frequency is the percent deviation between the nominal frequency and the actual frequency measured.
		In this example, the rms of the values gives 0.52% deviation from the nominal frequency while the rms of the deviation is 60% higher with 0.82% deviation.
		The precision of the frequency is not so important as long as the frequency is reduced or increased for adjusting the clock.
	grouper.ieee.org /groups/1159/1/frequency_assessment.htm (953 words)

	Quartz Crystals and Oscillators, Commercial Space and Industrial Applications
		The frequency vs. temperature curve is a sine with the inflection temperature at ~ +52"C. This crystal operates in the thickness shear mode.
		Nonlinear distortion characterized by the appearance, in the output of a device, of frequencies that are linear combinations of the fundamental frequencies and all harmonics present in the input signals.
		The frequency vs. temperature curve is a sine with the inflection temperature at ~ +78°C. This crystal operates in the thickness shear mode.
	www.frequencymanagement.com /glossary.html (9653 words)

	Measurement of magnitude and phase angle of voltage and current phasors and frequency deviation in power systems - ...
		The method of determining frequency deviation claimed in claim 6 wherein the three state variables of said frequency deviation estimation procedure correspond to the amplitudes in-phase and quadrature-phase and frequency deviation.
		Frequency deviations in the output on the order of.+-.0.5 hertz are within acceptable limits, but any frequency deviation greater than 0.5 hertz, even those lasting only minutes, can cause significant damage to the generator, thus shortening the useful life of an asset often costing hundreds of thousands of dollars.
		Finally, the frequency deviation of the voltage waveform is electronically calculated by linearly relating the frequency deviation to the average rate of change of the phase angle.
	www.freepatentsonline.com /4661769.html (3276 words)

	Frequency spectra of fm waves under various conditions
		Modulation index is frequency deviation divided by the frequency of the modulating signal.
		In the four examples of view (A), the modulating frequency is constant; the deviation frequency is changed to show the effects of modulation indexes of 0.5, 1.0, 5.0, and 10.0.
		In view (B) the deviation frequency is held constant and the modulating frequency is varied to give the same modulation indexes.
	www.tpub.com /neets/book12/49c.htm (839 words)

	The Calculation of Time Domain Frequency
		Frequency offset may be removed from phase data by subtracting a line determined by the average of the first differences, or by a least-squares linear fit.
		Frequency drift may be removed from the phase data by a least-squares or 3-point quadratic fit [5], or by subtracting the average of the second differences.
		Frequency drift may be removed from frequency data by subtracting a least-squares linear fit, by subtracting a line determined by the first-differences of the frequency data or by calculating the drift from the difference between the two halves of the data.
	www.ieee-uffc.org /freqcontrol/paper1ht.html (3604 words)

	Hy-Q International Australia - Glossary Of Terms (Oscillators)
		Frequency ageing: This is the ability of the oscillator to maintain its design frequency over a specified time period.
		Nominal frequency: The frequency for which the oscillator is designed and to which it is tuned.
		Overall frequency stability: The maximum permissible frequency deviation of the oscillator due to all combinations of specified operating and environmental parameters within a specified period of time and at a fixed tuned frequency.
	www.hy-q.com.au /oscillators/osc-glossary.htm (2589 words)

	Filtdeviator (Site not responding. Last check: 2007-10-12)
		The idea behind filtdeviator is to use a frequency response function to not only filter a sound (as with filter), but to create a topology of frequency deviation working in correlation with the filter.
		With the frequency shift control, a constant or function value is added to all the bin frequencies to produce a nonlinear pitch domain translation of the spectrum.
		If however changes in frequency are made, then the FFT integrity is compromised, necessitating use of the oscillator bank method in which each bin is synthesized as a sine wave changing in frequency and amplitude.
	www.waveformsoftware.com /PVCX/PVCX_Help/Filtdeviator.htm (2207 words)

	FM Deviation Meter
		A deviation monitor can be made by connecting some form of frequency modulation (FM) detector to an AC voltmeter and calibrating the meter in units of frequency deviation.
		The essential circuit blocks are a heterodyne oscillator, frequency mixer, phase locked loop and a metering circuit calibrated in frequency deviation.
		Equipped with the crystal specified, a frequency of 145.3 MHz is generated and this heterodynes with signals in the 146.05 MHz to 146.55 MHz region to provide a beat frequency for the PLL input within 750 to 1250 kHz.
	users.tpg.com.au /users/ldbutler/DeviationMeter.htm (1622 words)

	[No title]
		In order to prevent extreme modulations and resulting overflows beyond the frequency limits, amplitude and frequency deviations limiters should be connected on each voice channel in such a way that they cannot be disabled and should be used constantly.
		On the voice frequency channels, lowpass filters that achieve an attenuation level of at least 30 dB for amplitude in accordance with amplitude of 15 kHz, for frequencies between 19-100 kHz should be used.
		During this process, amounts of frequency deviation of the output and input signals should be so close to each other that the maximum difference in its amplitude should be 0,5 dB.
	www.kktcyyk.org /Statutes.doc (3251 words)

	Learning Resources: Statistics: Power from Data! Variance and standard deviation
		Standard deviation is the measure of spread most commonly used in statistical practice when the mean is used to calculate central tendency.
		Generally, the more widely spread the values are, the larger the standard deviation is. For example, imagine that we have to separate two different sets of exam results from a class of 30 students; the first exam has marks ranging from 31% to 98%, the other ranges from 82% to 93%.
		Although standard deviation is less susceptible to extreme values than the range, standard deviation is still more sensitive than the semi-quartile range.
	www.statcan.ca /english/edu/power/ch12/variance.htm (1369 words)

	RF Cafe - Frequency Modulation Equations Formulas Bessel
		Frequency modulation uses the instantaneous frequency of a modulating signal (voice, music, data, etc.) to directly vary the frequency of a carrier signal.
		, is used to describe the ratio of maximum frequency deviation of the carrier to the maximum frequency deviation of the modulating signal.
		Depending on the modulation index chosen, the carrier and certain sideband frequencies may actually be suppressed.
	www.rfcafe.com /references/electrical/frequency_modulation.htm (213 words)

	Frequency Modulation (FM)- Developer Zone - National Instruments
		Frequency Modulation (FM) is a form of modulation in which changes in the frequency of the carrier wave correspond directly with changes in the baseband signal.
		In the equation above, ∆ƒ is the frequency deviation and it represents the maximum frequency difference between the instantaneous frequency and the carrier frequency.
		Frequency Modulation (FM) is an important modulation scheme both because of its widespread commercial use, and because of its simplicity.
	zone.ni.com /devzone/cda/tut/p/id/3361 (1182 words)

	Frequency Electronics Inc. - RUBIDIUM ATOMIC FREQUENCY STANDARDS (Site not responding. Last check: 2007-10-12)
		Frequency locking of the VCXO is accomplished by operating the Rubidium Physics Package as a frequency discriminator, i.e., departures of a frequency from an input signal (50.255+ MHz from the VCXO) from a defined center frequency (Rubidium atomic resonance) produce a DC output signal (control voltage).
		When the applied microwave frequency is equal to 6.8+ GHz, the Rubidium atoms are resonated by the microwave field in the cavity.
		The decrease in light, when the microwave frequency is equal to the Rubidium frequency, is then converted electronically to an error signal with phase and amplitude information used to steer the VCXO via its control voltage and keep it on frequency at 50.255+ MHz.
	www.freqelec.com /FE-5650A.htm (1054 words)

	Ecliptek Corporation - Crystal Glossary of Terms (Site not responding. Last check: 2007-10-12)
		The frequency stability is dependant upon the plane or the angle of the crystal element in relation to the crystalline axes of the crystal.
		In Figure 2, the frequency stability versus operating temperature range is plotted as a function of "AT" cut angle (0).
		Derived from Equation 1 and rearranged, the capacitive ratio is a component of Equation 4.
	www.ecliptek.com /crystals/glossary.html (1357 words)

	MODULATION
		Frequency modulation is the process of varying the frequency of a carrier wave in proportion to the instantaneous amplitude of the modulating signal without any variation in the amplitude of the carrier wave.
		Because the amplitude of the wave remains unchanged, the power associated with an FM wave is constant.
		After frequency modulation takes place, angular velocity of the carrier wave varies in proportion to the instantaneous amplitude of the modulation signal.
	www.sem.mosaic-service.com /electron2/fm.htm (352 words)

	Frequency Modulation
		In frequency modulation, the instantaneous frequency of the radio-frequency wave is varied in accordance with the modulating signal, as shown in view (A) of figure 2-5.
		The amount by which the frequency departs from the average is controlled by the amplitude of the modulating signal.
		Both the frequency and the amplitude of the modulating signal are translated into variations in the frequency of the rf carrier.
	www.tpub.com /neets/book12/49b.htm (1094 words)

	Ecliptek Corporation - ECCM5A Series Crystal (Site not responding. Last check: 2007-10-12)
		The frequency stability is determined by the following primary factors: Type of quartz cut and angle of the quartz cut.
		This frequency is dependent upon the crystal design and the amount of Load Capacitance, if any, the oscillator circuit presents to the crystal.
		Shunt Capacitance is derived from the dielectric of the quartz, the area of the crystal electrodes, and the capacitance presented by the crystal holder.
	www.ecliptek.com /crystals/eccm5a (883 words)

	OFDM synchronization demodulation circuit (US5608764)
		A carrier frequency deviation detection circuit detects a frequency deviation of the detected carrier based on a rotation of the constellation of the demodulated symbol detected by the constellation analyzing circuit.
		A carrier detection circuit responsive to the frequency deviation detected by the carrier frequency deviation detection circuit controls the detected carrier.
		A clock frequency deviation detection circuit detects a frequency deviation of the detected clock based on rotations of the constellations of at least two demodulated symbols detected by the constellation analyzing circuit.
	www.delphion.com /details?pn10=US05608764 (620 words)

	tvSigGen
		All the frequency deviation break points represent an octave deviation from the fundamental frequency.
		The first octave deviation value (together with the fundamental frequency (frqHz)) is used to determine the starting frequency of the signal.
		The last octave deviation value is used to determine the ending frequency of the signal.
	homepages.nyu.edu /~kpl2/dsts6/tvSigGen.html (1178 words)

	Method and apparatus for controlling frequency deviation of a portable transceiver (US5517491)
		A method and apparatus to control frequency deviation of a portable transceiver (PT) (122) utilizing a time-division-duplex (TDD) protocol for communicating with a base transceiver (116).
		The PT (122) generates (828) a second signal having second deviation levels (830) controlled by control signal values (323), samples (832) the second signal to derive a second received signal, and appraises (902) the second received signal to derive estimates of the second deviation levels (830).
		The PT (122) compares (906) corresponding estimates of the first and second frequency deviation levels (830) to derive adjusted control signal values (908) for controlling the second deviation levels (830) to approximate the first deviation levels (706), and thereafter controls (914) the second deviation levels (830) in accordance with the adjusted control signal values (908).
	www.delphion.com /details?pn10=US05517491 (527 words)

	Frequency Modulation
		To reduce the wavelength for efficient transmission and reception (the optimum antenna size is ½ or ¼ of a wavelength).
		Sometimes it is referred to as the "swing" in the frequency.
		is as a measure of the peak frequency deviation,
	www.fas.org /man/dod-101/navy/docs/es310/FM.htm (1801 words)

	Frequency Modulation (Site not responding. Last check: 2007-10-12)
		is called the frequency deviation of the modulation scheme.
		In general the determination of the frequency content of an FM waveform is complicated, but when
		Your FM dial goes from 88 MHz to 108 MHz (this range is in between the frequency ranges for the TV channels 1-6, and 7-12.
	robotics.eecs.berkeley.edu /~sastry/ee20/modulation/node4.html (327 words)

	Significant frequency deviation of the class I polymorphism HLA-A10 in schizophrenic patients -- Laumbacher et al. 40 ...
		Significant frequency deviation of the class I polymorphism HLA-A10 in schizophrenic patients -- Laumbacher et al.
		Significant frequency deviation of the class I polymorphism HLA-A10 in schizophrenic patients
		frequency deviation was found in patient panel 2 as compared
	jmg.bmjjournals.com /cgi/content/full/40/3/217 (1792 words)

	frequency deviation- Developer Zone - National Instruments
		Frequency deviation quantifies the amount by which a frequency differs from its specified value, as when measuring how much an oscillator frequency deviates from its nominal frequency.
		In frequency modulation, frequency deviation refers to the maximum absolute difference, during a specified period, between the instantaneous frequency of the modulated wave and the carrier frequency.
		Refer to the RF & Communications Resources page for additional information about RF terminology, fundamentals, and National Instruments RF products.
	zone.ni.com /devzone/cda/tut/p/id/692 (186 words)

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